TWI888221B - Workpiece processing device, grindstone, and workpiece processing method - Google Patents

Abstract

A concave grinding portion 5b at the outer periphery of a grindstone 5 has circular arc shaped portions 5e at both end sections in the thickness direction, and a linear portion 5h therebetween. The workpiece 2 and the grindstone 5 are disposed in parallel, and both are rotated while the grindstone 5 is moved relative to the workpiece 2 in accordance with movement conditions calculated based on the curvature radius of the circular arc shaped portions 5e so that the contact portion between the concave grinding portion 5b and the workpiece 2 moves along a desired cross sectional shape of the workpiece 2. The curvature radius of the circular arc shaped portions 5e of the grindstone 5 is at least 10 times the thickness of the workpiece 2 so that the circular arc shaped portions 5e contact the workpiece 2 with no gap between the chamfered portion 2a of the desired cross sectional shape. The lower surface of the workpiece 2 is adhered by suction to a suction member 10, and the circular arc shaped portion 5e on the lower side has a length equal to or greater than the chamfered section 2a on the lower side of the workpiece 2 of the desired cross sectional shape, but less than the length that contacts the suction member 10 in a state where the tangent contacts the end section of the lower surface of the workpiece 2 at a position extending at the same angle as the tapered shape 10a of the suction member 10.

Description

Workpiece processing device, grinding stone and workpiece processing method

The present invention relates to a workpiece processing device, a grinding stone and a workpiece processing method.

In the past, in order to perform chamfering on the outer periphery of a disc-shaped workpiece (processed object) such as a semiconductor wafer, a grinding stone was pressed against the outer periphery of the workpiece and ground. In order to improve the accuracy of the shape and size of the chamfered portion of the workpiece, there is the following method: a groove (molding groove) having a shape and size corresponding to the finished shape of the workpiece is formed on the outer periphery of the grinding stone, the outer periphery of the workpiece is inserted into the groove, the workpiece is rotated, and the outer periphery of the workpiece is ground by the inner peripheral surface of the groove. However, in this method, the grinding stone must be replaced every time the shape or size of the workpiece to be manufactured changes, which is not suitable for small-scale production of various types. In addition, if the chamfering process is repeated, the inner peripheral surface of the groove on the outer periphery of the grinding stone is worn or damaged, and the shape and size of the groove change, so that the accuracy of the chamfering process of the workpiece is reduced. Therefore, if the chamfering of the workpiece is performed for a long time, it is necessary to replace the grinding stone or recondition it.

In order to replace or trim the grinding stone as needed, the methods described in Patent Documents 1 and 2 first prepare a main grinding stone having a shaped groove corresponding to the finished shape of the workpiece, and then make the outer periphery of the grinding stone material abut against the inner periphery of the groove of the main grinding stone to grind, thereby preparing a shaping grinding stone (shaper) as a shaped material. Furthermore, by making the outer periphery of the shaping grinding stone abut against the grinding stone material to form the same shaped groove as the main grinding stone, the shape of the grinding stone used for chamfering of the actual workpiece can be adjusted (trimmed). The shaping grinding stone is formed of a harder material (e.g., green silicon carbide (GC) grinding stone) than the grinding stone for chamfering (e.g., resin bonded grinding stone); and the main grinding stone is formed of a harder material (e.g., metal bonded grinding stone) than the shaping grinding stone. The process of using a truing stone to shape the grindstone in this way is called truing.

In addition to teaching a method of chamfering a disc-shaped workpiece using a groove formed on a disc-shaped grindstone arranged parallel to the disc-shaped workpiece, Patent Documents 1 and 2 also teach a method of chamfering a workpiece using a groove formed on a disc-shaped grindstone arranged obliquely in the tangential direction of the outer periphery of the disc-shaped workpiece (a spiral processing method). Patent Document 3 also describes a spiral chamfering method. In the method described in Patent Document 3, a grindstone arranged obliquely in the tangential direction of the outer periphery of the workpiece has a concave groove formed on the outer periphery and has an inclined surface facing inward. The inclined surface is brought into contact with the outer periphery of the workpiece to perform grinding. Patent document 4 discloses a processing method of "grinding a disc-shaped workpiece by placing a disc-shaped grindstone parallel to the disc-shaped workpiece, and then performing more precise grinding in a spiral manner by placing a disc-shaped grindstone inclined in the tangential direction of the outer circumference of the disc-shaped workpiece", as well as a shaping grindstone and shaping method for shaping a grindstone for spiral precision grinding.

If the chamfering of the workpiece is performed using a grindstone arranged obliquely in the tangential direction of the outer periphery of the workpiece as described in patent documents 1 to 4, grinding is performed in a state where the inner peripheral surface of the groove provided on the outer periphery of the grindstone and the contact portion of the outer periphery of the workpiece are long, and further, the workpiece is rotated and ground at a low speed, thereby reducing the surface roughness of the chamfered portion of the workpiece. Therefore, the polishing process of the subsequent finishing process becomes easy to implement.

Patent document 5 discloses a method of "using a grindstone with a groove having a thickness dimension greater than the thickness of the workpiece on the outer periphery, and making the inner peripheral surface of the groove of the grindstone abut against the outer periphery of the workpiece to perform chamfering". In addition, patent document 5 discloses a method of "using a grindstone thicker than the workpiece, without a groove on the outer periphery, and with a convex cross-sectional shape of the outer periphery, and making the inclined surface of a part of the convex part of the grindstone abut against the outer periphery of the workpiece to perform chamfering".

In the method described in Patent Document 6, a disk-shaped grinding stone is arranged to be orthogonal to a disk-shaped workpiece. The workpiece can rotate about a rotation axis located at the center of its plane shape. The grinding stone can rotate about a rotation axis orthogonal to the rotation axis of the workpiece, and can also move in a direction perpendicular to the rotation axis (a direction parallel to the disk-shaped workpiece) or in a direction parallel to the rotation axis (a direction orthogonal to the disk-shaped workpiece). While the workpiece is rotating, the grinding stone is rotated and approaches the workpiece, and the outer peripheral portion of the rotating grinding stone is brought into contact with the outer peripheral portion of the workpiece rotating in a direction orthogonal to the rotation direction of the grinding stone, and the grinding stone is moved, thereby performing chamfering processing on the workpiece. Such processing processes are called contouring.

In the method described in Patent Document 7, a cup-shaped grindstone arranged to be perpendicular to a disk-shaped workpiece is used. As in Patent Document 6, the cup-shaped grindstone is rotated and brought close to the workpiece while the workpiece is rotating. The cup-shaped front end surface of the rotating cup-shaped grindstone is brought into contact with the outer periphery of the workpiece rotating in a direction perpendicular to the rotation direction of the cup-shaped grindstone, and the cup-shaped grindstone is moved to perform chamfering of the workpiece.

Patent document 8 discloses a method of using two disc-shaped grinding stones to perform chamfering in the same manner as in Patent document 6, and a method of using two cup-shaped grinding stones to perform chamfering in the same manner as in Patent document 7.

In the method described in Patent Document 9, a large double-structured cup-shaped first grindstone and a cup-shaped second grindstone are used to process the outer periphery of a workpiece; the first grindstone has a grindstone element (cup shape) on the inner periphery and a grindstone element (cup shape) on the outer periphery for grinding more precisely than the grinding stone element on the inner periphery.

In the method described in patent document 10, in the peripheral end diameter reduction processing of the wafer, two grooveless grinding stones are respectively maintained at a certain height and contacted with the wafer to process it; in the circular grinding processing, the two grooveless grinding stones are respectively moved on each surface of the peripheral end of the wafer, and the same radial position of the peripheral end of the wafer is clamped from top and bottom to process each surface simultaneously.

In the method described in Patent Document 11, a disk-shaped grinding stone having a convex grinding portion on the outer periphery is used, the disk-shaped workpiece and the grinding stone are arranged parallel to each other, the grinding stone and the workpiece are rotated, and the grinding stone is moved relative to the workpiece according to the movement conditions calculated based on the curvature radius of the circular arc-shaped portion of the grinding stone, so that the contact portion between the convex grinding portion and the workpiece moves along the desired cross-sectional shape of the workpiece.

[Learning Technology Literature]

[Patent Literature]

Patent document 1: Japanese Patent Publication No. 2005-153085

Patent document 2: Japanese Patent Publication No. 2007-165712

Patent document 3: Japanese Patent Publication No. 5-152259

Patent document 4: Japanese Patent Publication No. 2007-044817

Patent document 5: Japanese Patent Publication No. 11-207585

Patent document 6: Japanese Patent Publication No. 2000-317789

Patent document 7: Japanese Patent Publication No. 2008-034776

Patent document 8: Japanese Patent Publication No. 2014-37014

Patent document 9: Japanese Patent Publication No. 2017-154240

Patent document 10: Japanese Patent Publication No. 2008-177348

Patent document 11: Japanese Patent No. 7093875

It is difficult to form a groove for chamfering a workpiece with good accuracy on the outer peripheral portion of a grindstone arranged obliquely in the tangential direction of the outer periphery of the workpiece as described in Patent Documents 1 to 4. In order to form a chamfered portion of a desired shape on the workpiece, the inner peripheral surface of the groove must contact the outer peripheral portion of the workpiece at an appropriate angle and an appropriate contact length. In a grindstone arranged obliquely in the tangential direction of the outer periphery of the workpiece, it is difficult to form a groove having an inner peripheral surface that accurately contacts the outer peripheral portion of the workpiece at an appropriate angle and an appropriate contact length. In particular, when the shaping grindstone is rotated by a driving unit for rotating the workpiece or a driving unit for rotating the grindstone for grinding the workpiece, it is difficult to accurately form a groove that can be well chamfered while being inclined in the tangential direction of the outer periphery of the workpiece, and a simpler shaping method is needed. In addition, if the shape or size of the chamfered portion of the workpiece to be manufactured changes, the shape of the groove of the main grindstone used to make the shaping grindstone must also be changed, making the operation complicated.

When processing a workpiece using a grindstone that is tilted in the tangential direction of the workpiece, it is difficult to make fine corrections to approach the desired processing shape because the shape or size of the inner circumference of the groove cannot be easily changed. Therefore, when manufacturing a wafer having an oriented flat portion as a workpiece, the groove mainly used to form the arc-shaped portion of the outer circumference of the workpiece using a grindstone that is tilted in the tangential direction of the workpiece cannot form the oriented flat portion with good accuracy. Therefore, the groove for forming the oriented flat portion and the groove for forming the arc-shaped portion must be formed separately, which complicates the manufacture of the grindstone and increases the processing time because the two grooves are used separately.

In the method described in Patent Document 5, the outer periphery of the workpiece is ground by contacting the inclined surface of a portion of the inner periphery of the groove of the grindstone or the inclined surface of a portion of the convex portion of the outer periphery of the grindstone. The outer periphery of the workpiece is ground by moving the workpiece relatively along the inclined surface of the grindstone, so that the shape of the outer periphery of the workpiece after grinding becomes a shape corresponding to the inclined surface of the grindstone. The angle of the inclined surface of the outer periphery of the grindstone cannot be changed arbitrarily, so it is difficult to form the chamfered portion of the workpiece into an arbitrary shape. In addition, in the chamfered portions on both sides of the workpiece, the straight portion at the front end, and the curved portion between the straight portion and the chamfered portion, the workpiece is moved back and forth (traverse) relatively along the grindstone and ground, so the processing is complicated and the processing time is long.

In the method described in Patent Document 6, the disc-shaped grinding stone is arranged to be orthogonal to the disc-shaped workpiece. Therefore, if a large grinding stone is used, there is a concern that the grinding stone interferes with the mechanism (such as an adsorption table or a rotating mechanism) used to support or drive the workpiece. Therefore, in order not to hinder the stable support or smooth driving of the workpiece, a small grinding stone is used instead of a large grinding stone. As a result, the processing efficiency deteriorates and the processing time increases. In addition, compared with a large grinding stone, when a small grinding stone is used to perform chamfering processing on the same workpiece, the same part of the workpiece is in contact with the outer periphery of the workpiece and the grinding time is longer, so the service life of the grinding stone is short. Furthermore, the workpiece moves along the trajectory of the desired cross-sectional shape at the part in contact with the grindstone, but since the workpiece is moved only after each part of the workpiece is fully polished, the workpiece must be rotated at high speed for good efficiency. In this way, the workpiece is rotated at high speed and polished, and the streaks of the grindstone rotating in a direction perpendicular to the rotation direction of the workpiece are formed on the outer surface of the workpiece in a shape extending along the thickness direction of the workpiece, so the surface roughness of the polished part is large. Even after this grinding process, if a polishing process for more precise finishing is to be performed, polishing is still difficult due to the presence of streaks in a direction perpendicular to the rotation direction of the workpiece. In particular, the inclined part of the workpiece is not easy to polish in the precision polishing process of the subsequent process, and there is a possibility that streaks will remain due to insufficient polishing.

In the method described in Patent Document 7, the manufacture of the cup-shaped grindstone is complicated, and shaping is particularly difficult. In addition, the cup-shaped grindstone is not easy to be arranged and driven in such a way that the front end surface of the cup-shaped grindstone properly contacts the outer periphery of the workpiece, and the mechanism for supporting and driving the cup-shaped grindstone is complicated.

In addition to the problems of the methods described in the aforementioned patent documents 6 and 7, the method described in patent document 8 also has the problem that "in order to drive two grinding stones at the same time, the device becomes complicated, and the size or shape difference between the two grinding stones is likely to occur, making it difficult to stably perform high-precision chamfering processing."

In the method described in Patent Document 9, the shape of the first grinding stone is very complicated, and the manufacturing of the first grinding stone is complicated. In addition, since the workpiece rotates around two rotating shafts, the mechanism for supporting and driving the workpiece is also complicated. As such, the processing device for implementing the method described in Patent Document 9 is very complicated.

In the method described in patent document 10, similarly to the method described in patent document 6, grinding is performed using a disc-shaped grindstone arranged to be orthogonal to the disc-shaped workpiece. In addition, in this method, in order to adjust the thickness direction position of the workpiece rotating at high speed, a mechanism using a piezoelectric element is required, which makes the processing device complicated and expensive, and since the thickness direction position of the workpiece is frequently adjusted and the workpiece is rotated, the forming accuracy of the desired cross-sectional shape tends to deteriorate. In particular, it is difficult to make the radius (R dimension) of the arc-shaped portion of the desired cross-sectional shape of the workpiece constant throughout the entire circumference of the disc-shaped workpiece.

In the method described in Patent Document 11, the convex grinding portion of the outer circumference of the grinding stone is brought close to the workpiece to grind the workpiece, so the load and vibration during grinding are large. In addition, since the convex grinding portion has a large volume in the radial direction, the weight of the grinding stone and the inertia moment during rotation are large. As a result, the vibration of the grinding stone during rotation tends to increase, and the manufacturing cost of the grinding stone increases. In addition, even if grinding water (coolant) is supplied to the contact portion between the grinding stone and the workpiece during grinding, the grinding water that contacts the convex grinding portion is still easy to scatter, making it difficult to perform efficient and smooth grinding.

The purpose of the present invention is to provide a workpiece processing device, a grinding stone, and a workpiece processing method, which can easily, efficiently and accurately perform chamfering of the workpiece, and the mechanism for supporting and driving the workpiece and the grinding stone is simple, and the grinding stone can be easily trimmed.

The workpiece processing device of the present invention is used to form a circular plate-shaped workpiece into a desired cross-sectional shape, and is characterized in that: it has a workpiece supporting mechanism for supporting the workpiece, a circular plate-shaped grindstone arranged parallel to the workpiece, and a grindstone supporting mechanism for supporting the grindstone; the workpiece supporting mechanism rotates the workpiece, and the grindstone supporting mechanism rotates the grindstone; the rotation axis serving as the center of rotation of the workpiece performed by the workpiece supporting mechanism and the rotation axis serving as the center of rotation of the grindstone performed by the grindstone supporting mechanism are parallel to each other; the workpiece supporting mechanism has an adsorption component for adsorbing only one side of the workpiece; the adsorption component The plane shape is a circle with a smaller radius than the radius of the workpiece; the outer peripheral portion of the circular adsorption member has a front end thinner shape with the thickness becoming thinner toward the outside; the grindstone has a concave grinding portion at the outer peripheral portion; the cross-sectional shape of the concave grinding portion along the cross-sectional shape of the rotation axis of the grindstone is a concave shape that is concave from the outer peripheral side to the inner peripheral side, and has a shape in which at least both ends in the thickness direction have arc-shaped portions, and between the arc-shaped portions at the two ends, there is a straight line portion with a thickness greater than the thickness of the workpiece, and the straight line portion is used to reduce the diameter of the workpiece or to thicken the outer peripheral portion of the workpiece. The grindstone and the workpiece are relatively moved by the grindstone supporting mechanism or the workpiece supporting mechanism in a manner that they can approach or move away from each other; the grindstone supporting mechanism or the workpiece supporting mechanism moves the grindstone relative to the workpiece in accordance with a moving condition calculated based on the radius of curvature of the circular arc portion of the grindstone, so that the contact portion between the concave grinding portion and the workpiece moves along the desired cross-sectional shape of the workpiece; the radius of curvature of the circular arc portion of the grindstone is at least 10 times the thickness of the workpiece, so that the circular arc portion of the grindstone can contact the workpiece with the concave grinding portion. The length of the arc-shaped portion located on the surface side of the workpiece adsorbed by the adsorption member in the section along the rotation axis of the grindstone is greater than the length of the chamfered portion on the surface side of the workpiece of the desired cross-sectional shape, and less than the following length: the length of the thinner front end shape of the adsorption member is in contact with the end of the surface side of the workpiece at a position where the tangent of the arc-shaped portion extends at an angle consistent with the angle of the thinner front end shape of the adsorption member.

Another workpiece processing device of the present invention is used to form a circular plate-shaped workpiece into a desired cross-sectional shape, and is characterized in that: it has a workpiece supporting mechanism for supporting the workpiece, a circular plate-shaped grindstone arranged parallel to the workpiece, and a grindstone supporting mechanism for supporting the grindstone; the workpiece supporting mechanism rotates the workpiece, and the grindstone supporting mechanism rotates the grindstone; the rotation axis serving as the center of rotation of the workpiece by the workpiece supporting mechanism and the rotation axis serving as the center of rotation of the grindstone by the grindstone supporting mechanism are parallel to each other; the workpiece supporting mechanism has an adsorption component for adsorbing only one side of the workpiece; the plane shape of the adsorption component is a circle with a radius smaller than the radius of the workpiece; the outer surface of the circular adsorption component is The grindstone has a concave grinding portion on the outer peripheral portion; the cross-sectional shape of the concave grinding portion along the rotation axis of the grindstone is a concave shape that is concave from the outer peripheral side to the inner peripheral side, and has the following shape: at least at both ends in the thickness direction, each has an arc-shaped portion and an inclined surface portion that is located further outward in the thickness direction than the arc-shaped portion and continuously connected to the arc-shaped portion, and between the arc-shaped portions at the two ends, there is a straight line portion with a thickness greater than the thickness of the workpiece, and the straight line portion is used to grind at least one of reducing the diameter of the workpiece or smoothing the middle portion in the thickness direction of the outer peripheral portion of the workpiece; the inclined surface The concave grinding portion and the workpiece are provided with a concave grinding portion, which extends along the tangent direction of the arc-shaped portion at the boundary position between the arc-shaped portion and the inclined surface portion, and the angle thereof is consistent with the angle of the chamfered portion of the single side of the workpiece of the desired cross-sectional shape; the grindstone and the workpiece are relatively moved in a manner that they can approach and move away from each other by the grindstone supporting mechanism or the workpiece supporting mechanism; the grindstone supporting mechanism or the workpiece supporting mechanism moves the grindstone relative to the workpiece in accordance with the moving conditions calculated based on the radius of curvature of the arc-shaped portion of the grindstone, so that the contact portion between the concave grinding portion and the workpiece moves along the desired cross-sectional shape of the workpiece; the radius of curvature of the arc-shaped portion of the grindstone is at least 10 times the thickness of the workpiece. The inclined surface portion located on the surface side of the workpiece adsorbed by the adsorption member has a length in the cross section along the rotation axis of the grindstone that is greater than the length of the chamfered portion of the surface side of the workpiece of the desired cross-sectional shape, and less than the following length: the angle between the inclined surface portion and the surface side of the workpiece in the direction of extension is smaller than the angle between the front end thinner shape of the adsorption member and the surface side of the workpiece, and the end of the surface side of the workpiece is in contact at a position where the tangent of the arc-shaped portion extends at an angle consistent with the angle of the front end thinner shape of the adsorption member, and the inclined surface portion abuts against the length of the front end thinner shape of the adsorption member.

The workpiece processing method of the present invention is used to form a disk-shaped workpiece into a desired cross-sectional shape using a grindstone, and is characterized in that: the grindstone is rotatable, disk-shaped, and has a concave grinding portion on the outer periphery; the cross-sectional shape of the concave grinding portion in the cross-sectional shape along the rotation axis of the grindstone is a concave shape that is concave from the outer periphery to the inner periphery, and has a shape in which each of the two end portions in the thickness direction has an arc-shaped portion, and a straight line portion having a thickness greater than the thickness of the workpiece is provided between the arc-shaped portions at the two end portions, and the straight line portion A method for processing a workpiece is provided for performing grinding for reducing the diameter of the workpiece or smoothing the middle portion of the outer peripheral portion of the workpiece in the thickness direction. The method comprises: arranging the workpiece and the grinding stone in parallel with each other; and rotating the grinding stone, rotating the workpiece around a rotation axis parallel to the rotation axis of the grinding stone, and moving the grinding stone relative to the workpiece according to a movement condition calculated based on the radius of curvature of the circular arc portion of the grinding stone, so that the concave grinding portion and the contact portion of the workpiece are smoothed. The step of moving the grinding stone relative to the workpiece along the desired cross-sectional shape of the workpiece; the step of moving the grinding stone relative to the workpiece, comprising: rotating the workpiece, which has only one side adsorbed by the adsorption component, and the grinding stone, and moving the arc-shaped portion of the concave grinding portion of the grinding stone from the outer peripheral end face of the workpiece to one side of the face, relative to the workpiece, in a curve according to the angle pre-calculated according to the moving condition, thereby grinding the outer peripheral portion of the one side of the workpiece to form a chamfered portion of the desired cross-sectional shape of the workpiece; moving the grinding stone along The outer peripheral end face of the workpiece is moved relative to the workpiece from the one side to the other side; and the workpiece and the grindstone are rotated, and the arc-shaped portion of the concave grinding portion of the grindstone is moved relative to the workpiece in a curved line from the outer peripheral end face of the workpiece to the other side of the face, following the angle pre-calculated according to the moving condition, thereby grinding the outer peripheral portion of the other side of the workpiece to form a chamfered portion of the desired cross-sectional shape of the workpiece; the plane shape of the adsorption member has a radius that is larger than the half of the workpiece. The outer peripheral portion of the circular adsorption member has a thinner shape at the front end where the thickness becomes thinner toward the outside; the radius of curvature of the arc-shaped portion of the grindstone is at least 10 times the thickness of the workpiece, so that the arc-shaped portion of the grindstone abuts against the workpiece in a manner that substantially no gap is generated between the chamfered portion of the desired cross-sectional shape of the workpiece; the arc-shaped portion located on the single side of the workpiece adsorbed by the adsorption member has a length in the cross section along the rotation axis of the grindstone, The length of the chamfered portion of the one side of the workpiece having the desired cross-sectional shape is greater than or equal to the length of the chamfered portion of the one side of the workpiece, and less than the following length: the length of the chamfered portion of the one side of the workpiece in contact with the end of the one side of the workpiece, in a position where the tangent of the arc-shaped portion extends at an angle consistent with the angle of the thinner shape of the front end of the adsorption member; when performing rough grinding of the outer peripheral portion of the one side of the workpiece or the other side of the workpiece, the workpiece and the grindstone are rotated, and the concave grinding of the grindstone is The arc-shaped portion of the concave grinding portion of the grindstone is moved from the outer peripheral end face of the workpiece to the one side face or the other side face in a manner that the rotation axis of the grindstone and the rotation axis of the workpiece are located in the same plane, and the workpiece is relatively moved in a curved line according to the angle calculated in advance according to the movement condition, and then the relative movement of the grindstone with respect to the workpiece is stopped; when performing precision grinding of the outer peripheral portion of the one side face or the other side face of the workpiece, the workpiece and the grindstone are rotated, and the arc-shaped portion of the concave grinding portion of the grindstone is moved from The outer peripheral end surface of the workpiece moves toward the one surface or the other surface in a manner that the rotation axis of the grindstone and the rotation axis of the workpiece are located in the same plane, and after the workpiece is relatively moved in a curved line by an angle pre-calculated according to the moving condition, the grindstone is relatively moved in a straight line in a plane extending in a direction perpendicular or obliquely intersecting the plane where the rotation axis of the grindstone and the rotation axis of the workpiece are located during the curved movement.

Another workpiece processing method is used to form a disk-shaped workpiece into a desired cross-sectional shape using a grindstone, wherein the grindstone is rotatable, disk-shaped, and has a concave grinding portion on the outer periphery; the cross-sectional shape of the concave grinding portion in the cross-sectional shape along the rotation axis of the grindstone is a concave shape that is concave from the outer periphery to the inner periphery, and has the following shape: at least at both ends in the thickness direction, each has an arc-shaped portion, and an inclined surface portion that is located further outward in the thickness direction than the arc-shaped portion and continuously connected to the arc-shaped portion, and between the arc-shaped portions at the two ends, there is a The workpiece processing method comprises: a step of arranging the workpiece and the grindstone in parallel with each other; and rotating the grindstone, rotating the workpiece around a rotation axis parallel to the rotation axis of the grindstone, and moving the grindstone relative to the workpiece according to a movement condition calculated based on the radius of curvature of the circular arc-shaped portion of the grindstone, so that the concave portion of the grindstone is smoothed. The step of moving the concave grinding portion and the contact portion of the workpiece along the desired cross-sectional shape of the workpiece; the step of moving the grindstone relative to the workpiece, comprising: rotating the workpiece, which has only one side adsorbed by the adsorption component, and the grindstone, and moving the arc-shaped portion of the concave grinding portion of the grindstone from the outer peripheral end face of the workpiece to one side of the face, relative to the workpiece, in a curved line according to the angle pre-calculated according to the moving condition, thereby grinding the outer peripheral portion of the one side of the workpiece to form a chamfered portion of the desired cross-sectional shape of the workpiece; moving the grindstone along The outer peripheral end face of the workpiece is moved relative to the workpiece from the one side to the other side; and the workpiece and the grindstone are rotated, and the arc-shaped portion of the concave grinding portion of the grindstone is moved relative to the workpiece from the outer peripheral end face of the workpiece to the other side of the face, following the angle pre-calculated according to the moving condition, thereby grinding the outer peripheral portion of the other side of the workpiece to form a chamfered portion of the desired cross-sectional shape of the workpiece; the plane shape of the adsorption component is a circle with a radius smaller than the radius of the workpiece; the circular adsorption component The peripheral portion of the workpiece has a shape in which the thickness becomes thinner toward the outside and the front end is thinner; the radius of curvature of the arc-shaped portion of the grindstone is at least 10 times the thickness of the workpiece; the inclined surface portion extends along the tangent direction of the arc-shaped portion at the boundary position between the arc-shaped portion and the inclined surface portion, and its angle is consistent with the angle of the chamfered portion on the surface side of the single side of the workpiece of the desired cross-sectional shape; the inclined surface portion located on the surface side of the single side of the workpiece adsorbed by the adsorption member has a length in the cross section along the rotation axis of the grindstone of the desired cross-sectional shape. The cross-sectional shape is greater than the length of the chamfered portion of the one-side surface of the workpiece, and less than the following length: when the angle between the inclined surface and the one-side surface of the workpiece in the direction of extension is smaller than the angle between the thinner shape of the front end of the adsorption member and the one-side surface of the workpiece, and the end of the one-side surface of the workpiece is in contact at a position where the tangent of the arc-shaped portion extends at an angle consistent with the angle of the thinner shape of the front end of the adsorption member, the inclined surface portion abuts against the thinner shape of the front end of the adsorption member; when the angle between the inclined surface and the one-side surface of the workpiece is smaller than the angle between the thinner shape of the front end of the adsorption member and the one-side surface of the workpiece, the inclined surface portion abuts against the thinner shape of the front end of the adsorption member; When the outer peripheral portion of the one side face or the other side face of the workpiece is roughly ground, the workpiece and the grindstone are rotated, and the arc-shaped portion of the concave grinding portion of the grindstone is moved relative to the workpiece in a curved line from the outer peripheral end face of the workpiece to the one side face or the other side face in a manner that the rotation axis of the grindstone and the rotation axis of the workpiece are located in the same plane, following the angle calculated in advance according to the movement condition, and then the relative movement of the grindstone relative to the workpiece is stopped; when the outer peripheral portion of the one side face or the other side face of the workpiece is precisely ground, During grinding, the workpiece and the grindstone are rotated, and the arc-shaped portion of the concave grinding portion of the grindstone is moved from the outer peripheral end surface of the workpiece to the one surface or the other surface, so that the rotation axis of the grindstone and the rotation axis of the workpiece are located in the same plane. After the workpiece is moved in a curved line relative to the workpiece by an angle pre-calculated according to the movement condition, the state in which the rotation axis of the grindstone and the rotation axis of the workpiece are located in the plane where the rotation axis of the grindstone and the rotation axis of the workpiece are located during the curved movement is maintained, and the grindstone is moved in a straight line relative to the workpiece.

Another workpiece processing method is used to form a disk-shaped workpiece into a desired cross-sectional shape using a grindstone, wherein the grindstone is rotatable, disk-shaped, and has a concave grinding portion on the outer periphery; the cross-sectional shape of the concave grinding portion in the cross-sectional shape along the rotation axis of the grindstone is concave from the outer periphery to the inner periphery, and is in the shape of having arc-shaped portions at at least two end portions in the thickness direction, and having a straight line portion having a thickness greater than the thickness of the workpiece between the arc-shaped portions at the two end portions, and the straight line portion is used to reduce the diameter of the workpiece or to make the middle of the outer periphery of the workpiece in the thickness direction. The method for processing a workpiece comprises: arranging the workpiece and the grinding stone in parallel with each other; rotating the grinding stone and rotating the workpiece around a rotation axis parallel to the rotation axis of the grinding stone, and moving the grinding stone relative to the workpiece according to a movement condition calculated based on the radius of curvature of the circular arc portion of the grinding stone so that the contact portion between the concave grinding portion and the workpiece moves along the desired cross-sectional shape of the workpiece; the step of moving the grinding stone relative to the workpiece comprises: rotating the workpiece with only one side surface adsorbed by an adsorption member and the grinding stone relative to the workpiece; The invention relates to a method for grinding a chamfered portion of the workpiece with a grinding wheel and a grinding wheel, wherein the grinding wheel is provided with a grinding wheel and a grinding wheel, and wherein the grinding wheel is provided ... The curved movement follows the angle calculated in advance according to the movement condition, thereby grinding the outer peripheral portion of the other side of the workpiece to form the chamfered portion of the desired cross-sectional shape of the workpiece; the plane shape of the adsorption component is a circle with a radius smaller than the radius of the workpiece; the outer peripheral portion of the circular adsorption component has a thinner shape at the front end where the thickness becomes thinner as it goes outward; the radius of curvature of the arc-shaped portion of the grindstone is at least 10 times the thickness of the workpiece, so that the arc-shaped portion of the grindstone abuts against the workpiece in a manner that substantially no gap is generated between the arc-shaped portion and the chamfered portion of the desired cross-sectional shape of the workpiece; the adsorption component is located at the workpiece. The length of the arc-shaped portion of the surface side of the workpiece adsorbed by the adsorption member in the cross section along the rotation axis of the grindstone is greater than the length of the chamfered portion of the surface side of the workpiece of the desired cross-sectional shape, and less than the following length: the length of the end of the surface side of the workpiece abutting against the thinner shape of the front end of the adsorption member in a state where the tangent of the arc-shaped portion extends at an angle consistent with the angle of the thinner shape of the front end of the adsorption member; when performing rough grinding of the outer peripheral portion of the surface side of the one side or the other side of the workpiece, the workpiece is brought into contact with the surface side of the workpiece. The grindstone is rotated, and the arc-shaped portion of the concave grinding portion of the grindstone is moved in a curve relative to the workpiece from the outer peripheral end face of the workpiece to the one side face or the other side face according to the angle pre-calculated according to the movement condition, and then the relative movement of the grindstone relative to the workpiece is stopped; when performing precision grinding of the outer peripheral portion of the one side face of the workpiece, the workpiece and the grindstone are rotated, and considering the position error in the thickness direction generated when the workpiece is rotated, the arc-shaped portion of the concave grinding portion of the grindstone is moved relative to the one side face of the workpiece according to the angle pre-calculated according to the movement condition, and the position error in the thickness direction generated when the workpiece is rotated is taken into account, and the outermost position of the one side face of the workpiece in the thickness direction is taken as the reference. , from the outer peripheral end face of the workpiece to the one side face, after the workpiece is moved relative to the curve by an angle pre-calculated according to the movement condition, the movement is stopped, and at the position where the grindstone and the inclined surface of the chamfered portion of the one side face of the workpiece contact, the position of the workpiece in the thickness direction is adjusted and the rotation speed of the workpiece is slowed down, so that the workpiece rotates at least one circle, thereby offsetting the position error of the workpiece during rotation and grinding the one side face of the workpiece; when performing precision grinding of the outer peripheral portion of the other side face of the workpiece, the workpiece and the grindstone are rotated, and the position error in the thickness direction generated during the rotation of the workpiece is taken into consideration. The workpiece rotates through the outermost position of the other side of the thickness direction as a reference, and the arc-shaped portion of the concave grinding portion of the grindstone moves from the outer peripheral end face of the workpiece to the other side of the workpiece by an angle calculated in advance according to the movement conditions, and then stops the movement. At the position where the grindstone and the chamfered portion of the other side of the workpiece contact, the position of the workpiece in the thickness direction is adjusted and the rotation speed of the workpiece is slowed down, so that the workpiece rotates at least one circle, thereby offsetting the position error of the workpiece during rotation and grinding the other side of the workpiece.

According to the present invention, a workpiece processing device, a grinding stone, and a workpiece processing method can be provided, which can easily, efficiently and accurately perform chamfering of the workpiece, and the mechanism for supporting and driving the workpiece and the grinding stone is simple, and the grinding stone can be easily trimmed.

1: Workpiece processing device

2: Workpiece

2a: Chamfered part

2b: Single-sided surface (surface that is adsorbed)

3,6,14: Rotation axis

4: Workpiece support mechanism

4a: X-direction moving stage

4b: Y-direction moving stage

4c: Z-direction moving stage

4d: Motor

5: Grindstone

5a: base disc

5b: Concave grinding part

5c: Mounting hole

5d: concave part

5e: Arc-shaped part

5f: Straight line part

5g: Rectangular grinding section

5h: Sloped part

7: Grindstone support mechanism

7a: Shell

7b: Rotating bearing part

7c: Main axis

7d: flange

7e: Bolts

10: Adsorption components

10a: Thinner front end shape

11: Shaping grinding stone (shaping stone)

12: Grinding stone with groove

12a: Groove

13: Grooved grinding stone support mechanism

15: Temperature adjustment mechanism

16: Grindstone

16a: Forming groove

FIG1 is a front view of a workpiece processing device according to the first embodiment of the present invention.

FIG2 is a cross-sectional view of the grinding stone of the workpiece processing device shown in FIG1.

FIG3A is a front view showing a process of an example of a workpiece processing method of the first embodiment of the present invention.

FIG. 3B is a front view showing a process that is a continuation of the process shown in FIG. 3A .

FIG. 3C is a front view showing a process that is a continuation of the process shown in FIG. 3B .

FIG. 3D is a front view showing a process that is a continuation of the process shown in FIG. 3C .

Figure 4 is an enlarged view of the process shown in Figure 3B.

FIG5 is an enlarged view showing a process following the process shown in FIG4.

FIG6 is an enlarged view showing a process following the process shown in FIG5.

FIG. 7A is a front view showing an example of a workpiece after processing in the first embodiment of the present invention.

FIG. 7B is an explanatory diagram for illustrating the magnitude of the positional offset in the thickness direction and the horizontal direction of the top surface side of the workpiece.

FIG. 7C is an explanatory diagram for explaining the magnitude of the positional offset in the thickness direction and the horizontal direction of the bottom side of the workpiece.

FIG8 is a front view showing another example of a workpiece after processing in the first embodiment of the present invention.

FIG9 is a cross-sectional view showing an example of a grinding stone of a known workpiece processing device.

FIG10 is a cross-sectional view showing in detail an example of a grindstone and a grindstone support mechanism of the workpiece processing device shown in FIG1 .

FIG. 11 is an explanatory diagram for explaining the appropriate size of the grinding stone of the first embodiment of the present invention.

FIG12 is a cross-sectional view showing the grinding stone of the workpiece processing device of the second embodiment of the present invention.

FIG. 13 is an explanatory diagram for explaining the appropriate size of the grinding stone of the second embodiment of the present invention.

FIG. 14 is a front view of a workpiece processing device according to the third embodiment of the present invention.

FIG. 15 is a front view showing the workpiece processing device of the fourth embodiment of the present invention.

FIG. 16 is a top view of a workpiece and a grinding stone used to illustrate an example of the workpiece processing method of the present invention.

FIG. 17 is a top view of a workpiece used to illustrate another example of the workpiece processing method of the present invention.

FIG18 is an explanatory diagram for explaining an example of a workpiece processing method using the method described in FIG17.

Hereinafter, the implementation form of the present invention will be described with reference to the drawings. FIG. 1 is a front view of a workpiece processing device 1 of the first implementation form of the present invention. FIG. 2 is a cross-sectional view showing a grindstone 5 of the workpiece processing device 1. The workpiece processing device 1 is a device for grinding a disc-shaped workpiece 2 such as a semiconductor wafer, a glass substrate, or a ceramic, and performing chamfering on the outer periphery of the workpiece 2. The workpiece processing device 1 is particularly suitable for chamfering a high-hardness workpiece 2 including silicon (Si), silicon carbide (SiC), gallium nitride (GaN), gallium arsenide (GaAs), sapphire, etc. However, the workpiece processing device 1 can also be used for processing other types of workpieces.

The workpiece processing device 1 comprises: a workpiece support mechanism 4, which supports a disk-shaped workpiece 2 and rotates it around a rotation axis 3; and a grinding stone support mechanism 7, which supports a disk-shaped grinding stone 5 and rotates it around a rotation axis 6. For example, the workpiece 2 is in the shape of a disk with a diameter of 50 to 300 mm and a thickness of less than 1 mm, and the grinding stone 5 is in the shape of a disk with a diameter of 100 to 200 mm and a thickness of 20 to 60 mm. For convenience, the thickness of the workpiece 2 is shown thicker in the figure. The workpiece support mechanism 4 and the grinding stone support mechanism 7 support the disk-shaped workpiece 2 and the disk-shaped grinding stone 5 in parallel with each other. The workpiece support mechanism 4 can rotate the workpiece 2 around a rotation axis 3 located at the center of the plane shape of the workpiece 2 and perpendicular to the workpiece 2 by adsorbing and holding the surface 2b of one side of the workpiece 2 by the adsorption member 10. Similarly, the grindstone support mechanism 7 can rotate the grindstone 5 in the form of a disc around a rotation axis 6 located at the center of the plane shape of the grindstone 5 and perpendicular to the grindstone 5. The rotation axis 3, which is the center of rotation of the workpiece 2 by the workpiece support mechanism 4, and the rotation axis 6, which is the center of rotation of the grindstone 5 by the grindstone support mechanism 7, are parallel to each other. The grindstone 5 and the workpiece 2 can move relative to each other by the grindstone support mechanism 7 or the workpiece support mechanism 4 so as to be able to approach or move away from each other. For example, the grindstone support mechanism 7 can move the grindstone 5 in a direction that approaches the workpiece 2 or moves away from the workpiece 2 in a plane parallel to the grindstone 5 and the workpiece 2 (in a plane orthogonal to the rotation axis 3 and the rotation axis 6) while the grindstone 5 is rotating, and can move the grindstone 5 in a direction that approaches the workpiece 2 or moves away from the workpiece 2 in a plane orthogonal to the grindstone 5 and the workpiece 2 (in a plane parallel to the rotation axis 3 and the rotation axis 6). Therefore, the grindstone 5 can approach the workpiece 2 from any direction and move away from the workpiece 2 in any direction at least in a plane including the rotation axes 3 and 6 by the grindstone support mechanism 7. The workpiece support mechanism 4 is provided with a temperature adjustment mechanism 15, which generates a flow of liquid or gas for maintaining the temperature of the rotating shaft 3 of the workpiece support mechanism 4 at a certain level. In addition, although not described in detail, the workpiece support mechanism 4 and the grindstone support mechanism 7 can also be composed of a known adsorption table, a rotary motor, or a movable platform. The detailed and specific configuration example of the workpiece support mechanism 4 will be described later.

As shown in FIG. 2 , the grindstone 5 of the workpiece processing device 1 comprises: a base disc portion 5a, which serves as a base; a concave grinding portion 5b, which is located at the outer periphery of the base disc portion 5a; and a cross-sectional rectangular grinding portion 5g, which is arranged side by side with the concave grinding portion 5b in the thickness direction. The base disc portion 5a is formed of an alloy such as aluminum or stainless steel, and is provided with: a straight mounting hole 5c, which extends in the thickness direction, so that the rotating shaft 6 passes through it; and a concave portion 5d, which is used for mounting to a holding portion (e.g., a flange portion) not shown in the figure of the grindstone support mechanism 7. The concave grinding portion 5b located at the outer periphery of the grindstone 5 is formed of a metal bonded grindstone or a resin bonded grindstone, etc. The cross-sectional shape of the concave grinding portion 5b in the cross-sectional shape along the rotation axis 6 of the grindstone 5 is a concave shape that is concave from the outer side (outer periphery) to the inner side (inner periphery) in the radial direction, and is in the shape of "having an arc-shaped portion 5e at each of the two ends in the thickness direction, and having a straight line portion 5f having a thickness greater than the thickness of the workpiece 2 between the arc-shaped portions 5e at the two ends". The concave grinding portion 5b does not include a convex portion protruding outward in the radial direction. The cross-sectional rectangular grinding portion 5g is located further outward than the concave grinding portion 5b in the thickness direction of the grindstone 5; the surface of the cross-sectional rectangular grinding portion 5g facing the workpiece 2 is in the form of a straight line parallel to the thickness direction of the grindstone 5 in the cross section along the rotation axis 6. In FIG. 2, the boundary between the arc-shaped portion 5e and the straight line portion 5f is shown as an imaginary line (two-point chain).

A workpiece processing method using the workpiece processing device 1 shown in FIG. 1 is described. FIG. 3A to FIG. 3D are front views of an example of the workpiece processing method, respectively. As shown in FIG. 3A to FIG. 3D, the thickness of the grindstone 5 is much greater than the thickness of the workpiece 2. First, the object to be processed, that is, the workpiece 2 (for example, a semiconductor wafer), is adsorbed and held by the adsorption member 10 of the workpiece support mechanism 4 so that it rotates around the rotation axis 3. The workpiece 2 is rotated but not moved. The grindstone 5 mounted on the grindstone support mechanism 7 is rotated around the rotation axis 6 by the grindstone support mechanism 7, and is moved so that the outer periphery of the grindstone 5 abuts against the outer periphery of the workpiece 2. As an example, as shown in FIG3A, the grindstone 5 mounted on the grindstone support mechanism 7 is arranged so that the cross-sectional rectangular grinding portion 5g faces the workpiece 2 adsorbed and held by the adsorption member 10 of the workpiece support mechanism 4. The workpiece 2 is rotated around the rotation axis 3, and the grindstone 5 is rotated around the rotation axis 6, and the cross-sectional rectangular grinding portion 5g of the grindstone 5 is brought into contact with the outer periphery of the workpiece 2 for grinding. In this way, the outer periphery of the workpiece 2 is roughly ground (rough grinding) using the cross-sectional rectangular grinding portion 5g, and the diameter of the workpiece 2 is reduced to a desired size. The outer peripheral surface of the workpiece 2 roughly ground by the cross-sectional rectangular grinding portion 5g is brought into contact with the straight line portion 5f of the concave grinding portion 5b of the grindstone 5 as shown in FIG3B, and more precise grinding (fine grinding) is performed to make the workpiece 2 become the desired size (desired diameter).

Then, the grindstone 5 is moved to one side of the workpiece 2 (the upper side of the workpiece 2 in the example shown in FIG. 3A to FIG. 3D), and the workpiece 2 and the grindstone 5 are rotated continuously, and the grindstone 5 is moved relative to the workpiece 2 in a state where the outer peripheral portion of the grindstone 5 abuts against the outer peripheral portion of one side of the workpiece 2 as shown in FIG. 3C. Specifically, the grindstone 5 is slowly moved from the vicinity of the center in the thickness direction of the workpiece 2 and the inner side in the radial direction to the other side of the workpiece 2 (the bottom side in the example shown in FIG. 3A to FIG. 3D) and the outer side in the radial direction. Thereby, the arc-shaped portion 5e of the concave grinding portion 5b on the upper side of the grindstone 5 abuts against the edge of one side of the outer peripheral portion of the workpiece 2 (the upper side) to grind, chamfer, and form the chamfered portion 2a.

After the chamfering of the edge on the upper side of the outer periphery of the workpiece 2 is completed, the grindstone 5 is moved (raised) to one side (upper side in the example shown in FIG. 3A to FIG. 3D) so that the center of the grindstone 5 in the thickness direction is opposite to the workpiece 2. Then, as shown in FIG. 3D, the arc-shaped portion 5e of the concave grinding portion 5b of the grindstone 5 is brought into contact with the outer periphery of the other side of the workpiece 2, and the grindstone 5 is raised and moved from the inner side to the outer side in the radial direction of the workpiece 2. In this way, the arc-shaped portion 5e of the concave grinding portion 5b on the lower side of the rotating grindstone 5 is brought into contact with the outer periphery of the workpiece 2, and the workpiece 2 is ground to chamfer the edge on the lower side of the outer periphery of the workpiece 2, thereby forming a chamfered portion 2a. Finally, the workpiece 2 is positioned outside the concave grinding portion 5b of the grindstone 5 and the grindstone 5 is not in contact with the workpiece 2, and the chamfering of the workpiece 2 is completed. As shown in FIG. 3A to FIG. 3D, in the thickness direction of the workpiece 2 and the grindstone 5, the grindstone 5 moves back and forth (up and down) from a position opposite to the center of the workpiece 2 to chamfer the upper edge and the lower edge of the outer peripheral portion of the workpiece 2. The chamfering of the upper edge and the chamfering of the lower edge of the outer peripheral portion of the workpiece 2 are both performed by moving the grindstone 5 in the same direction in the radial direction of the workpiece 2 (moving from the inner side to the outer side of the radial direction of the workpiece 2). In this embodiment, the chamfered portions 2a on both sides are formed by moving the grindstone 5 in a single direction from the inner side to the outer side in the radial direction of the workpiece 2. For example, as described in Patent Document 5, the grindstone and the workpiece are relatively moved back and forth (reciprocatingly) not only in the straight line portion at the front end of the workpiece, but also in the curved surface portion between the straight line portion and the chamfered portion or in the chamfered portions on both sides to grind. Compared with this method, in this embodiment, the grinding process can be easily and efficiently carried out in a short time. In addition, since the concave grinding portion 5b of the grindstone 5 of this embodiment is mainly an arc-shaped curved surface, it is easy to calculate and design the curved surface shape in accordance with the shape and size of the chamfered portion 2a to be formed. In addition, in some of the drawings, in order to easily judge the desired cross-sectional shape of the workpiece 2, there are cases where the shape of the chamfered portion 2a in a nearly completed state is illustrated even when the chamfered portion 2a is in the process of being formed or almost before being formed.

Referring to Fig. 4 to Fig. 6, this workpiece processing method is described in more detail. In the processing method of this embodiment, the moving conditions for the relative movement of the grindstone 5 and the workpiece 2 are calculated so that the concave grinding portion 5b of the grindstone 5 and the contact portion of the workpiece 2 move along the desired cross-sectional shape of the workpiece 2. The size of the grindstone 5 of this embodiment is known, so the moving conditions for the relative movement of the grindstone 5 and the workpiece 2 are calculated based on the radius of curvature of the arc-shaped portions 5e at both ends of the concave grinding portion 5b of the grindstone 5 in the thickness direction. The grindstone support mechanism 7 or the workpiece support mechanism 4 moves the grindstone 5 relative to the workpiece 2 in accordance with the moving conditions calculated in this way. For example, the desired cross-sectional shape of the workpiece 2 is expressed as two-dimensional coordinates in a plane including the rotation axis 3 of the workpiece 2 and the rotation axis 6 of the grindstone 5, and the movement conditions of the relative movement of the grindstone 5 and the workpiece 2 are set in such a way that the contact portion of the grindstone 5 and the workpiece 2 tracks the points of each coordinate. In this way, in this embodiment, the grindstone 5 and the workpiece 2 are NC-controlled (Numerical Control) to move them relative to each other, thereby grinding the workpiece 2.

Specifically, after rough grinding (rough grinding) is performed by making the cross-sectional rectangular grinding portion 5g of the grindstone 5 abut against the outer periphery of the workpiece 2, as shown in FIG. 4, the straight line portion 5f of the concave grinding portion 5b of the grindstone 5 abuts against the outer periphery of the workpiece 2 to perform more precise grinding (fine grinding) to reduce the diameter of the workpiece 2. The workpiece 2 is ground until the outer periphery of the workpiece 2 becomes almost straight and the diameter of the workpiece 2 becomes a desired size. Thereafter, as shown in FIG. 5, the grindstone 5 is relatively moved in the thickness direction relative to the workpiece 2 in a manner that the corner of one side of the face side (for example, the upper side) of the workpiece 2 slides relatively along the arc-shaped portion 5e of the concave grinding portion 5b of the grindstone 5 from a preset position P1 on one side of the face side (for example, the upper side) of the workpiece 2. According to the pre-calculated movement conditions, the grindstone 5 and the workpiece 2 are appropriately moved relative to each other in the thickness direction and the radius direction, thereby the grindstone 5 relatively tracks the desired curved trajectory with respect to the workpiece 2. Then, after reaching the position P2 where "the angle α calculated from the starting point P1 of the relative movement from the outside to the inside of the radius direction of the workpiece 2 becomes a predetermined angle set in advance", the relative movement amount of the grindstone 5 and the workpiece 2 is made constant, and the grindstone 5 is relatively moved linearly with respect to the workpiece 2. In this way, the straight line portion of the desired cross-sectional shape of the workpiece 2 (indicated by a two-point chain diagram) is formed. Angle α is an angle measured from the inner circumference of the workpiece 2 in the plane including the rotation axis 3 of the workpiece 2 and the rotation axis 6 of the grindstone 5. Then, the grinding stone 5 moves relatively to the outside of one side of the workpiece 2 in the thickness direction, and becomes non-contact with the workpiece 2, completing the grinding of one side of the workpiece 2. On the other side of the workpiece 2, as shown in FIG. 6, the action of substantially reversing the action of one side of the workpiece 2 shown in FIG. 5 is performed, thereby grinding the other side of the workpiece 2.

The difference in size between the grindstone 5 and the workpiece 2 is actually much larger than that shown in FIGS. 4 to 6 (for example, the radius of curvature of the arc-shaped portion 5e of the grindstone 5 is several tens of times the thickness of the workpiece 2), and there is a situation where the arc-shaped portion 5e of the grindstone 5 and the outer peripheral surface of the workpiece 2 are in contact with each other in a nearly straight line. For example, it is possible that the grindstone 5 is in contact with the workpiece 2 in such a way that "at the time point when the grindstone 5 moves and the moving angle α becomes a predetermined size (refer to FIGS. 5 and 6), the gap between the arc-shaped portion 5e of the grindstone 5 and the desired shape (illustrated by a two-dot chain in FIGS. 5 and 6) formed on the chamfered portion 2a of the workpiece 2 is small enough to be ignored, and the chamfered portion 2a of the workpiece 2 can be ground into the desired shape as a whole". In this case, it is also considered to omit the process of "stopping the movement of the grinding stone 5 at the time point when the movement angle α of the grinding stone 5 reaches a predetermined value, and then causing the grinding stone 5 to move linearly relative to the workpiece 2". In the case of performing more precise grinding, it is appropriate to perform the process of "moving the grinding stone 5 in a curved line until the movement angle α reaches a predetermined value, and then causing the grinding stone 5 to move linearly relative to the workpiece 2". However, in the case of performing rough grinding as a pre-precision grinding stage, the process of "moving the grinding stone 5 in a curved line until the movement angle α reaches a predetermined value, and then causing the grinding stone 5 to move linearly relative to the workpiece 2" can also be omitted to simplify the operation. In this embodiment, the radius of curvature of the arc-shaped portion 5e of the grinding stone 5 is at least 10 times the thickness of the workpiece 2, so that the arc-shaped portion 5e of the grinding stone 5 abuts against the workpiece 2 in a manner that substantially no gap is generated between the chamfered portion 2a of the desired cross-sectional shape of the workpiece 2.

Thus, in this embodiment, the grinding stone 5 and the workpiece 2 are moved relative to each other according to the pre-calculated moving conditions, so that the contact portion of the grinding stone 5 and the workpiece 2 tracks the moving trajectory calculated according to the desired cross-sectional shape of the workpiece 2. As a result, the workpiece 2 can be formed into the desired cross-sectional shape. In addition, when processing different types of workpieces 2, the moving conditions for processing the workpiece 2 are calculated in accordance with the desired cross-sectional shape of the newly processed workpiece 2. At this time, the moving conditions are calculated according to the curvature radius of the arc-shaped portion 5e of the grinding stone 5, so that workpieces 2 of various shapes can be correctly processed using the same grinding stone 5.

The effect of this embodiment is explained. In the known processing methods described in patent documents 6 and 10, it is difficult to use a grindstone that is too large (large diameter) due to the structure, so a small (small diameter) grindstone must be used for processing. As a result, the service life of the grindstone is short, and the frequency of replacement or repair of the grindstone is high. However, in this embodiment, there is little concern that the grindstone 5 and the grindstone support mechanism 7 interfere with other components (specifically, the workpiece support mechanism 4), so there are few structural restrictions, and a large (large diameter) grindstone 5 can be used to process the workpiece 2. Therefore, the service life of the grindstone 5 is long, and the frequency of replacement or repair of the grindstone 5 is low. Furthermore, in the processing methods described in Patent Documents 6 and 10, the rotation direction of the grinding stone and the relative movement direction with respect to the workpiece are substantially consistent (both are the thickness direction of the workpiece 2). Therefore, if there are large concavo-convex portions on the outer periphery of the grinding stone, linear marks along the rotation direction (the thickness direction of the workpiece) are easily generated on the outer periphery of the workpiece due to the rotation of the grinding stone. The grinding stone rotates and moves relative to the workpiece in the same direction as the rotation direction (that is, in a direction substantially parallel to the linear marks), so the linear marks do not disappear and are easily left. The portion of the grinding stone that generates the linear marks on the outer periphery of the workpiece (the large concavo-convex portion) moves relatively in the thickness direction of the workpiece, and its position in the circumferential direction of the workpiece remains unchanged. Therefore, on the workpiece, a portion that does not abut the large concavo-convex portion and is not ground deeply to the same degree as the linear marks may remain. As a result, even if the grindstone moves, the linear marks do not disappear and are easily left. In addition, although the workpiece rotates in a direction perpendicular to the rotation direction of the grindstone, the length of the circumferential movement due to the rotation of the workpiece is much longer than the length of the relative movement of the grindstone and the workpiece in the thickness direction of the workpiece. The grindstone grinds the entire circumference of the workpiece and moves relative to the thickness direction of the workpiece. Therefore, in order to shorten the processing time of the workpiece, the speed at which the grindstone moves relative to the workpiece in the thickness direction of the workpiece must not be too slow. The part of the workpiece that contacts the grindstone has a narrow circumferential width of the workpiece. In order to shorten the speed at which the grindstone moves relative to the workpiece in the thickness direction of the workpiece, the rotation speed of the workpiece (circumferential movement speed) must be increased to shorten the time required for grinding by contacting the grindstone with the entire circumference of the workpiece. Since the rotation speed of the workpiece is increased in this way, the surface roughness of the workpiece after grinding becomes rough even if the workpiece and the grindstone rotate in directions orthogonal to each other. In contrast, in the present embodiment, the rotation direction of the grindstone 5 is substantially orthogonal to the relative movement direction with respect to the workpiece 2. The rotation direction of the grindstone 5 is the circumferential direction of the workpiece 2, and the relative movement direction is the thickness direction of the workpiece 2. If there are large uneven portions on the outer periphery of the grindstone 5, linear marks along the circumferential direction are generated on the outer periphery of the workpiece 2 due to the rotation of the grindstone 5. Since the grindstone 5 rotates and moves relative to the workpiece 2 in a direction orthogonal to the rotation direction (i.e., a direction substantially orthogonal to the linear marks), the linear marks are not easily left. Since the portion of the grindstone 5 that produces the linear marks on the outer peripheral surface of the workpiece 2 (large concavo-convex portion) rotates in the circumferential direction and moves in the direction orthogonal to the linear marks, the large concavo-convex portion sequentially contacts almost the entire outer peripheral surface of the workpiece 2. Therefore, almost the entire outer peripheral surface of the workpiece 2 is deeply ground by the large concavo-convex portion to the same degree as the linear marks. In this way, since the rotation direction of the grindstone 5 is substantially orthogonal to the moving direction relative to the workpiece 2, the linear marks produced on the outer peripheral surface of the workpiece 2 are easily eliminated and become smooth. In addition, in this structure, even if the rotation speed of the workpiece 2 is fast, since the rotation direction of the grindstone 5 (the circumferential direction of the workpiece 2) is orthogonal to the relative movement direction of the grindstone 5 (the thickness direction of the workpiece 2), and the relative movement distance is short, even if the grindstone 5 moves relatively very slowly along the thickness direction of the workpiece 2, the processing time will not be so long. Therefore, the relative movement speed of the grindstone 5 in the thickness direction of the workpiece 2 is slowed down, and the entire circumference of the workpiece 2 is fully ground, thereby making the surface roughness of the ground workpiece good.

In the known processing method described in patent document 5, the workpiece is relatively moved along the outer shape of the grindstone to perform grinding, so the shape of the workpiece after processing is determined by the outer shape of the grindstone (especially the shape and angle of the curved or straight inclined surface of the grindstone). Therefore, in order to produce workpieces of different shapes, the grindstone must be replaced. In contrast, in this embodiment, the relative movement of the grindstone 5 and the workpiece 2 is not performed along the outer shape of the grindstone 5, but is performed in accordance with the movement conditions calculated by considering the curvature radius of the arc-shaped portion 5e of the concave grinding portion 5b of the grindstone 5. Therefore, when the workpiece 2 has different shapes, it is sufficient to change the movement conditions without replacing the grindstone 5. That is, it is possible to use the same grindstone 5 to form workpieces 2 of various shapes without replacing the grindstone 5. The moving condition is obtained by calculation based on the radius of curvature of the arc-shaped portion 5e of the concave grinding portion 5b of the grindstone 5, etc. Since the relative movement of the grindstone 5 and the workpiece 2 is numerically controlled based on the moving condition, the processing accuracy is good. In this way, according to this embodiment, the following excellent effects can be achieved: various shapes of workpieces 2 can be formed by the same grindstone 5 with good processing accuracy, and further, the service life of the grindstone 5 is long.

According to the processing device and processing method of this embodiment, as shown in Figure 7A, a so-called T-shaped workpiece 2 whose outer periphery is formed by a pair of arc-shaped parts and a straight line part connecting them, and as shown in Figure 8, a so-called R-shaped workpiece 2 whose outer periphery is a semicircular part, can both be formed with good precision. In the case of the T-shaped workpiece 2 shown in FIG7A, the moving conditions are obtained by calculation based on "the curvature radii R1 and R2 of each of the pair of arc-shaped portions of the outer periphery, the lengths Y1 and Y2 of the straight inclined surface portions respectively connected to each of the arc-shaped portions, the angles θ1 and θ2 of these inclined surface portions relative to the surface of the workpiece 2, the length C0 of the straight line portion between the pair of arc-shaped portions, and the curvature radius of the arc-shaped portion 5e of the concave grinding portion 5b of the grindstone 5 not shown in FIG7A", and processing is performed in accordance with the moving conditions. In the case of the R-shaped workpiece 2 shown in FIG8, the moving condition is obtained by calculation based on "the radius R of the semicircular portion of the outer circumference, the lengths Y1 and Y2 of the straight inclined surface portions connected from the semicircular portion to both sides, the angles θ1 and θ2 of these inclined surface portions relative to the surface of the workpiece 2, and the radius of curvature of the arc-shaped portion 5e of the concave grinding portion 5b of the grindstone 5 not shown in FIG8", and processing is performed in accordance with the moving condition. In this way, the T-shaped workpiece 2 shown in FIG7A and the R-shaped workpiece 2 shown in FIG8 can be processed with good accuracy by calculating the moving condition based on "the dimensions of each part of the desired cross-sectional shape shown in the figure and the radius of curvature of the arc-shaped portion 5e of the concave grinding portion 5b of the grindstone 5".

In the present embodiment, the grinding stone support mechanism 7 can adjust the size of the chamfered portion 2a by adjusting the position of the grinding stone 5 before the chamfering process starts in the radial direction of the workpiece 2 (i.e., the position where the grinding stone 5 starts to contact the workpiece 2) and the position of the grinding stone 5 at the end of the chamfering process (i.e., the position where the grinding stone 5 stops contacting the workpiece 2). In addition, after considering the size of the chamfered portion 2a adjusted in this way and the speed at which the grinding stone 5 grinds the workpiece 2, the grinding stone support mechanism 7 can adjust the speed at which the grinding stone 5 rises or falls and the speed at which the grinding stone 5 moves along the radial direction of the workpiece 2, thereby adjusting the angle, shape, etc. of the chamfered portion 2a of the workpiece 2. Furthermore, the contact angle of the grindstone 5 relative to the workpiece 2 is changed depending on which part of the curved portion of the outer circumference of the grindstone 5 contacts and grinds the workpiece, so the angle and shape of the chamfered portion 2a of the workpiece 2 can be adjusted. In this way, the desired shape or size of the chamfered portion 2a of the workpiece 2 can be achieved mainly by controlling the movement of the grindstone 5 by the grindstone support mechanism 7. Therefore, the grindstone support mechanism 7 is preferably driven by numerical control (NC control).

The grindstone 5 of this embodiment has a concave grinding portion 5b, and the chamfering of the workpiece 2 is ground by the concave grinding portion 5b, so that smooth grinding can be performed stably, and the grindstone 5 can be made low-cost and have a long service life. For example, although not shown, in the case where the grindstone is provided with a convex grinding portion as in the configuration described in patent document 11, the center (rotation axis) of the grindstone and the center (rotation axis) of the workpiece are moved relative to each other in a manner close to each other while the convex grinding portion is brought into contact with the workpiece, and grinding is performed. Since this is a relative movement in the direction in which the grindstone and the workpiece collide, the collision and vibration during grinding are large, and the loads applied to the grindstone and the workpiece are large. In addition, a grindstone having a convex grinding portion is heavy and has a large moment of inertia. In contrast, the grindstone 5 of this embodiment has a concave grinding portion 5b. When the concave grinding portion 5b is in contact with the workpiece 2, the center of the grindstone 5 (rotation axis 6) and the center of the workpiece 2 (rotation axis 3) are moved in directions away from each other to perform grinding. In this method, compared with the relative movement of the grindstone 5 and the workpiece 2 in the direction of collision, the collision and vibration during grinding are smaller, the load applied to the grindstone 5 and the workpiece 2 is smaller, and the grinding surface becomes beautiful. In addition, compared with the convex grinding portion, the concave grinding portion 5b having the same size as the portion actually used for grinding can be miniaturized and lightweight, and the moment of inertia can also be reduced. This method also helps to reduce vibration during grinding. In the structure where the concave grinding part 5b of the grindstone 5 is used to grind the chamfer of the workpiece 2, the vibration and load are small, so the deterioration is slow and the service life is extended. This method reduces the manufacturing cost of the grindstone 5.

For example, when the chamfering of the workpiece is performed by the convex grinding part of the grindstone as in the configuration described in patent document 11, the contact part between the convex grinding part and the workpiece is almost point contact. However, when the chamfering of the workpiece 2 is performed by the concave grinding part 5b of the grindstone 5 as in the present embodiment, the contact part between the concave grinding part 5b and the workpiece 2 is surface contact, and the grinding can be performed efficiently and stably, and the grinding surface becomes beautiful.

Furthermore, when the grindstone has a convex grinding portion and the workpiece is ground by the convex grinding portion, even if grinding water (coolant) is supplied to the contact portion between the grindstone and the workpiece in order to perform smooth grinding, the grinding water is not easy to be retained in the contact portion between the grindstone and the workpiece. Therefore, it is not easy to perform efficient and smooth grinding, and a large amount of grinding water is required. In contrast, in the present embodiment, the grindstone 5 has a concave grinding portion 5b, and when the workpiece 2 is ground by the concave grinding portion 5b, the grinding water supplied to the contact portion between the grindstone 5 and the workpiece 2 is retained in the contact portion between the grindstone 5 and the workpiece 2 inside the concave grinding portion 5b. Therefore, efficient and smooth grinding can be easily performed with a small amount of grinding water, and can be smoothly ground without mesh clogging, excessive friction or heat.

As such, the grindstone 5 of the present embodiment has many advantages by having a concave grinding portion 5b instead of a convex grinding portion. In the past, grindstones having a concave grinding portion have been used, but the known concave grinding portion, as shown in FIG. 9 , has a so-called formed groove 16a, that is, a groove having a shape complementary to the shape of the desired workpiece after grinding. In the case of a processing method using a known grindstone 16 having a formed groove 16a, there is a high possibility that wear or damage will occur at a specific portion of the grindstone 16, such as the portion P3 of the inner peripheral surface of the formed groove 16a where the workpiece 2 first abuts. If a plurality of workpieces 2 are processed, wear or damage will occur at the portion P3, causing the shape of the formed groove 16a to change, and thus if the workpiece 2 is processed using the grindstone 16, the processing accuracy will be reduced. In this case, the grindstone 16 must be replaced or repaired. In contrast, in the present embodiment, a concave grinding portion 5b that is much larger than the workpiece 2 is provided, so that various parts of the concave grinding portion 5b of the grindstone 5 are brought into contact with the workpiece 2 for grinding, so there is no situation where only a specific part is particularly prone to wear or damage. Therefore, the service life of the grindstone 5 is longer. Furthermore, in the present embodiment, a rectangular grinding portion 5g with a cross section different from the concave grinding portion 5b is separately provided, and this rectangular grinding portion 5g is used to perform rough grinding for making the size of the workpiece 2 close to the desired size. In this way, excessive wear or damage of the straight line portion 5f of the concave grinding portion 5b is suppressed, and the service life of the grindstone 5 is extended. However, the rectangular cross-sectional grinding portion 5g is not an essential component of the present invention, and the workpiece 2 may be ground to a desired diameter only by the straight line portion 5f of the concave grinding portion 5b.

In addition, the configuration of the above-mentioned embodiment is a configuration in which the grindstone support mechanism 7 rotates and moves the grindstone 5, and the workpiece support mechanism 4 rotates but does not move the workpiece 2, but is not limited to this configuration. That is, the grindstone support mechanism 7 may only rotate the grindstone 5 but not move it, and the workpiece support mechanism 4 may rotate the workpiece 2 and move the workpiece 2 by numerical control. In this case, the workpiece support mechanism 4 can move the workpiece 2 in a direction in which the workpiece 2 approaches the grindstone 5 or moves away from the grindstone 5 in a plane parallel to the grindstone 5 and the workpiece 2 (in a plane orthogonal to the rotation axis 3 and the rotation axis 6), and can move the workpiece 2 in a direction in which the workpiece 2 approaches the grindstone 5 or moves away from the grindstone 5 in a plane orthogonal to the grindstone 5 and the workpiece 2 (in a plane parallel to the rotation axis 3 and the rotation axis 6). Therefore, the workpiece 2 can approach the grindstone 5 from any direction and move away from it in any direction at least within the plane including the rotation axes 3 and 6 by means of the workpiece support mechanism 4. In this configuration, the workpiece 2 and the grindstone 5 can be moved relative to each other so that the workpiece 2 and the grindstone 5 are in the same positional relationship as in each process shown in FIG. 3A to FIG. 6, and the same processing as the processing method shown in FIG. 3A to FIG. 6 can be implemented.

In this embodiment, the grinding stone 5 and the workpiece 2 are rotated in the same or completely opposite directions, rather than in directions orthogonal to each other, so the rotation of the grinding stone 5 and the rotation of the workpiece 2 produce a synergistic effect, and the grinding stone 5 itself does not need to rotate too fast. Therefore, the grinding stone support mechanism 7 does not need to be a mechanism that can be driven by high-speed rotation, and the structure can be simplified and low-cost. In addition, since the workpiece 2 and the grinding stone 5 are rotated and polished in parallel, the surface roughness of the chamfered portion of the workpiece 2 can be reduced.

According to this embodiment, the grindstone 5 is arranged parallel to the workpiece 2, so the grindstone 5 can be enlarged without interfering with the workpiece support mechanism 4. Thus, the outer periphery of the workpiece 2 can be formed into an arbitrary cross-sectional shape using a large grindstone 5 without complicating the structure of the workpiece processing device 1 including the grindstone support mechanism 7. In addition, by using a large grindstone 5, processing efficiency can be improved, processing time can be shortened, and a wide range of the outer periphery of the grindstone 5 can be used for processing, so the service life of the grindstone 5 is increased. Furthermore, when the grinding stone 16 having the groove 16a (molded groove) corresponding to the shape of the finished workpiece 2 is used for processing, the inner peripheral surface of the groove 16a (especially the inclined surface P3) that contacts the edge of the workpiece 2 before chamfering is easily worn or damaged. However, in the present embodiment, only a specific part of the grinding stone 5 is continuously contacted with the edge of the workpiece 2 before chamfering, so the grinding stone 5 is not easily damaged and has a long service life.

When the workpiece 2 is inserted into the forming groove 16a provided in the grindstone 16 for processing, a chamfered portion of a specific shape and size can be formed. However, in order to form a chamfered portion of a different shape and size, the grindstone 16 having a different groove 16a must be replaced. However, according to the present embodiment, the grindstone 5 having the concave grinding portion 5b is moved relative to the workpiece 2 to perform the chamfering. Therefore, by changing the moving path of the grindstone 5 by numerical control, the shape or size of the formed chamfered portion 2a can be changed. That is, chamfered portions 2a of various shapes and sizes can be formed by a single grindstone 5.

FIG10 shows a detailed configuration example of the grindstone 5 and grindstone support mechanism 7 shown in FIG1 and FIG2. The grindstone 5 of this modified example, for example, comprises: a base disk portion 5a made of metal; a concave grinding portion 5b, located at the outer peripheral portion of the base disk portion 5a, formed by a resin-bonded grindstone; and a cross-sectional rectangular grinding portion 5g, arranged in parallel with the concave grinding portion 5b in the thickness direction. The base disk portion 5a is formed of an alloy such as aluminum or stainless steel, and is provided with a mounting hole 5c through which the rotating shaft 6 passes, and a concave portion 5d. The concave grinding portion 5b is concave from the outer peripheral side to the inner peripheral side, and comprises: an arc-shaped portion 5e, which is the two end portions in the thickness direction; and a straight portion 5f, located between the arc-shaped portions 5e, having a thickness greater than the thickness of the workpiece 2. The cross-sectional rectangular grinding portion 5g is located further outward than the concave grinding portion 5b in the thickness direction of the grindstone 5, and its surface facing the workpiece 2 is in a straight line parallel to the thickness direction of the grindstone 5.

The grindstone support mechanism 7 shown in FIG. 10 includes a housing 7a, a rotary bearing 7b, a main shaft 7c, a flange 7d, and a bolt 7e. The main shaft 7c is supported in a rotatable manner by the rotary bearing 7b disposed in the housing 7a. The flange 7d is mounted on the front end of the main shaft 7c protruding outward from the housing 7a, and the flange 7d is fixed to the main shaft 7c by the bolt 7e. Then, the housing 7a is passed through the recess 5d of the grindstone 5, and the mounting hole 5c of the grindstone 5 is fixed to the flange 7d. If the main shaft 7c is rotated by a driving means not shown in the figure, the flange 7d and the grindstone 5 rotate integrally with the main shaft 7c. That is, the main shaft 7c becomes the rotating shaft 6 of the grindstone supporting mechanism 7. The grindstone 5 is supported in such a manner that the center of gravity of the grindstone 5 is located between the flange 7d, which is the mounting position of the grindstone 5, and the rotating bearing 7b supporting the main shaft 7c. In this way, by positioning the center of gravity of the grindstone 5 between the mounting position of the grindstone 5 (the flange 7d) and the rotating bearing 7b, the support and rotation of the grindstone 5 are stabilized.

In this embodiment, a two-stage grinding process is performed: grinding for reducing the radius of the workpiece 2, and grinding for chamfering both sides of the outer periphery of the workpiece 2 in order to form the workpiece 2 into the desired cross-sectional shape. Generally speaking, the former grinding is rough grinding, and the latter grinding is precision grinding. Precision grinding and rough grinding are relative expressions. Compared with rough grinding, precision grinding is a grinding with higher shape and size accuracy and smaller surface roughness of the surface after grinding. In the grindstone 5 of this embodiment, the outer periphery of the base circular plate portion 5a is provided with: a concave grinding portion (precision grinding portion) 5b, which is mainly used for grinding to form the workpiece 2 into the desired cross-sectional shape; and a cross-sectional rectangular grinding portion (rough grinding portion) 5g, which is mainly used for grinding to reduce the radius of the workpiece 2.

In this embodiment, the unprocessed workpiece 2 is mounted on the workpiece support mechanism 4 and rotated; the grindstone 5 mounted on the grindstone support mechanism 7 is rotated around the rotation axis 6 (spindle 7c), and as shown in FIG3A, the cross-sectional rectangular grinding portion 5g is brought into contact with the outer periphery of the workpiece 2. In this way, the outer periphery of the workpiece 2 is roughly ground, so that the outer diameter of the workpiece 2 becomes the desired size. Then, as shown in FIG3B, the straight line portion 5f of the concave grinding portion 5b of the grindstone 5 is brought into contact with the outer periphery of the workpiece 2, and the outer periphery of the workpiece 2 is precisely ground, so that the middle portion of the thickness direction of the outer periphery of the workpiece 2 is smoothed. Then, as shown in FIG3C to FIG3D, the arc-shaped portion 5e of the concave grinding portion 5b of the grindstone 5 is brought into contact with the outer periphery of the workpiece 2, and the edges of both sides of the workpiece 2 are chamfered, so that the workpiece 2 is formed into the desired cross-sectional shape. The cross-sectional rectangular grinding part 5g of this embodiment is a part with a coarser grinding stone grain size; the concave grinding part 5b has a finer grinding stone grain size and is a part for performing more precise grinding than the cross-sectional rectangular grinding part 5g for reducing the radius of the workpiece 2. In addition to the above-mentioned effects, this embodiment further obtains the following effects: in the case of chamfering by a two-stage grinding process, two processes can be easily performed by a single grinding stone 5, and the process is simple and low-cost.

Generally, when chamfering a workpiece 2 such as a semiconductor wafer is performed, the outer peripheral surface of the workpiece 2 is ground by a grindstone to reduce the radius, remove unnecessary parts of the workpiece 2 and make it the desired size, adjust the shape, and perform centering. Thereafter, a chamfered portion 2a is formed on the workpiece 2 by a grindstone. Assuming that such grinding is performed by a concave grinding portion, the grinding (rough grinding) for reducing the radius of the workpiece 2 in the first stage is mainly performed by making the concave grinding portion of the grindstone near the center in the thickness direction abut against the workpiece 2. The grinding (precision grinding) for forming the chamfered portion 2a in the second stage is performed by making the arc-shaped portions at both ends of the concave grinding portion in the thickness direction abut against the workpiece 2. Generally, the grinding amount (grinding volume) for reducing the radius of the workpiece 2 is larger than that for forming the chamfered portion 2a. Therefore, the area near the center of the concave grinding portion in the thickness direction is more severely worn than the arc-shaped portions at both ends in the thickness direction, causing the entire shape of the concave grinding portion to be destroyed. As a result, there is a concern that the processing accuracy of the workpiece 2 is reduced. In contrast, in this embodiment, the grinding for reducing the radius of the workpiece 2 is mainly performed by the cross-sectional rectangular grinding portion 5g; the grinding for smoothing the outer peripheral surface of the workpiece 2 after the radius is reduced can be performed by the straight line portion 5f of the concave grinding portion 5b; and the grinding for forming the chamfered portion 2a of the workpiece 2 can be performed by the arc-shaped portion 5e of the concave grinding portion 5b. That is, grinding for reducing the radius of the workpiece 2, grinding for smoothing the outer peripheral surface of the workpiece 2, and grinding for forming the chamfered portion 2a can be performed at different locations of the grindstone 5. The shape and size of the cross-sectional rectangular grinding portion 5g and the shape and size of the straight line portion 5f and the arc-shaped portion 5e of the concave grinding portion 5b can be managed independently, and even if the wear amounts of each are different, good processing can be performed by appropriately adjusting the processing conditions. In addition, the arc-shaped portion 5e of the concave grinding portion 5b is worn more evenly, and there is no situation where "only a part (for example, a part near the center in the thickness direction) is worn significantly more than other parts when it is used for grinding mainly for forming the chamfered portion 2a." Therefore, the shape of the concave grinding portion 5b of the grindstone does not change significantly, and the reduction in the processing accuracy of the workpiece 2 can be suppressed. The cross-sectional rectangular grinding portion 5g is subject to a lot of wear, but since the surface facing the workpiece 2 is a straight line parallel to the thickness direction of the grindstone 5 and is a simple shape, even if wear occurs, the processing accuracy does not decrease too much.

In addition, although not shown, the tapered portion of the main shaft 7c constituting the rotating shaft 6 can be inserted into the tapered mounting hole 5c provided in the grindstone 5 without using the flange, and a fixing member such as a nut can be installed on the front end of the main shaft 7c protruding from the base circular plate part 5a, thereby fixing the grindstone 5 to the main shaft 7c constituting the rotating shaft 6 and supporting it together with the main shaft 7c. In this way, in the grindstone support mechanism 7 of this embodiment, the flange can be omitted and the grindstone 5 can be stably fixed to the main shaft 7c constituting the rotating shaft 6, and the eccentricity of the grindstone 5 with respect to the rotating shaft 6 (main shaft 7c) can be suppressed.

As shown in FIG. 1 and FIG. 3A to FIG. 3D, the workpiece support mechanism 4 of this embodiment has an adsorption member 10 that adsorbs only a single side surface (e.g., the bottom surface in the vertical direction) 2b of the workpiece 2. Therefore, when the chamfering of the workpiece 2 is performed by the arc-shaped portion 5e of the concave grinding portion 5b of the grindstone 5 as shown in FIG. 3B, FIG. 3C, and FIG. 3D, it is necessary to avoid that the adsorption member 10 abuts against the arc-shaped portion 5e. The plane shape of the adsorption member 10 is a circle with a smaller radius than the radius of the workpiece 2; the outer peripheral portion of the circular adsorption member 10 has a front end thinner shape 10a whose thickness becomes thinner toward the outside. The radius r1 of the suction member 10 is preferably r2-10t≦r1≦r2-5t if it is represented by the radius r2 of the desired cross-sectional shape of the workpiece 2 and the thickness t of the workpiece 2. The angle θ1 of the thinner front end 10a of the suction member 10 is preferably θ2-10≦θ1≦θ2+5 if it is represented by the angle θ2 of the chamfered portion 2a of the desired cross-sectional shape of the workpiece 2. As shown in FIG11 , the length of the arc-shaped portion 5e on the side of the surface (e.g., bottom surface in the vertical direction of lead) 2b of the workpiece 2 adsorbed by the adsorption member 10 is less than the length of the end portion on the side of the surface (e.g., bottom surface in the vertical direction of lead) 2b of the workpiece 2, in the cross section along the rotation axis 6 of the grindstone 5, which is in contact with the thinner front end portion 10a of the adsorption member 10 at a position (point A in FIG11 ) where the tangent of the arc-shaped portion 5e extends at an angle θ3 that is consistent with the angle θ3 of the thinner front end portion 10a of the adsorption member 10. In the state shown in FIG11 , the tangent of the arc-shaped portion 5e at point A is inclined by θ3 from the horizontal direction and is parallel to the bottom surface of the thinner front end portion 10a of the adsorption member 10. In this state, if the arc-shaped portion 5e extends to the point D where the bottom surface of the thinner shape 10a at the front end of the adsorption component 10 contacts the arc-shaped portion 5e, further grinding process cannot be performed. Therefore, the length of the arc-shaped portion 5e is less than the length reaching point D. Let the inclination angle of the tangent at this point D from the horizontal direction be θ4, and let the curvature radius of the arc-shaped portion 5e be r. In Figure 11, as the angles of the radii of the arc-shaped portion 5e passing through points A and D (radii orthogonal to the tangents at each point) respectively with respect to the vertical direction, angles θ3 and θ4 are shown. Here, it is known that the angle θ3 is the size of the thinner shape 10a at the front end of the adsorption component 10. Therefore, the relationship between the radius of curvature r of the arc-shaped portion 5e of the grindstone 5 and the angle θ4 representing the limit point of the length of the arc-shaped portion 5e is expressed as follows. In addition, when a straight line is drawn that is parallel to the tangent line at point A of the arc-shaped portion 5e (that is, orthogonal to the radius passing through point A) and passes through point D, the distance from the straight line along the radius passing through point A to point A is r'.

r cos( θ 3- θ 4) = r - r'

θ 3- θ 4=cos ^-1 [( r - r' )/ r ]

θ 4= θ 3-cos ^-1 [( r - r' )/ r ]

By such calculations, a condition can be set for making the arc-shaped portion 5e have a length less than the following: the length of the end portion on the bottom surface side of the workpiece 2 in contact with the thinner shape 10a at the front end of the suction member 10 when the tangent line of the arc-shaped portion 5e extends at an angle θ3 that is consistent with the angle θ3 of the thinner shape 10a at the front end of the suction member 10.

In the calculation for obtaining the angle θ4 in this way, the distance r' from the straight line that is parallel to the tangent line at point A of the arc-shaped portion 5e (orthogonal to the radius passing through point A) and passes through point D, along the radius passing through point A to the point A is used. This distance r' can be obtained as follows. Here, the difference between the radius of the workpiece 2 of the desired cross-sectional shape and the radius of the adsorption member 10 is set to L. Then, the distance L is divided into three sections, and the length on the outer side of the intersection with the radius passing through point A of the arc-shaped portion 5e is set to R2. It is consistent with the radius of curvature of the curved portion on the lower side of the desired cross-sectional shape of the workpiece 2 shown in Figures 7A and 8. In addition, the portion other than the length R2 from the distance L is divided into two sections with the intersection of the straight line parallel to the tangent line on point A of the arc-shaped portion 5e (orthogonal to the radius passing through point A) and passing through point D as the center, so that the length of the inner peripheral portion is x1 and the length of the outer peripheral portion is x2. The distance from the intersection of the dividing point of the portion of length x1 and the portion of length x2 to the bottom surface of the workpiece 2 is B2. The distance from the surface of the adsorption member 10 that contacts the bottom surface of the workpiece 2 to the thinner shape 10a at the front end below it is T. The distance from the starting point of the arc-shaped portion 5e on the bottom side to the bottom surface of the workpiece 2 of the desired cross-sectional shape shown in Figures 7A and 8 is B2.

x 1 tan θ 3 = T + B 2

x 1 = ( T + B 2) / tan θ 3

x 2= L - R 2- x 1= L - R 2-( T + B 2)/tan θ 3

' = R 2+ x 2 sin θ 3= R 2+[ L - R 2-( T + B 2)/tan θ 3]sin θ 3

Substituting the thus obtained r' into the mathematical formula for calculating the angle θ4, the angle θ4 for determining the upper limit of the length of the arc-shaped portion 5e is obtained based on the dimensions of the desired cross-sectional shape of the workpiece 2 shown in FIG. 7A and FIG. 8 (i.e., the radius of curvature R2 and the distance B2), the known dimensions of the adsorption member 10 (i.e., the distance T and the angle θ3 of the thinner shape 10a at the front end), the distance L obtained from the dimensions of the desired cross-sectional shape of the workpiece 2 and the known dimensions of the adsorption member 10, and the radius of curvature r of the arc-shaped portion 5e of the grinding stone 5.

On the other hand, as shown in Fig. 7A and Fig. 8, the length of the arc-shaped portion 5e required to form the length A2 of the projection of the chamfered portion 2a of the workpiece 2 in the horizontal direction is obtained. If the angle θ _max when the length of the arc-shaped portion 5e is the minimum necessary limit is expressed using the angle θ2 of the chamfered portion 2a of the workpiece 2 with respect to the horizontal direction and the radius of curvature R2 of the curved portion, it is as follows.

A 2= R 2-R2sin θ 2+ r tan( θ 2- θ _max )×cos θ 2= R 2(1-sin θ 2)+ r tan( θ 2- θ _max )×cos θ 2

[ A 2- R 2(1-sin θ 2)]/ r cos θ 2=tan( θ 2- θ _max )

θ 2- θ _max =tan ^-1 {[ A 2- R 2(1-sin θ 2)]/ r cos θ 2}

θ _max = θ 2-tan ^-1 {[ A 2- R 2(1-sin θ 2)]/ r cos θ2 }

By such calculations, it is possible to set a condition for making the arc-shaped portion 5e have the following length: greater than the length of the chamfered portion 2a on the bottom side of the desired cross-sectional shape of the workpiece 2. Based on the dimensions of the desired cross-sectional shape of the workpiece 2 shown in FIG. 7A and FIG. 8, namely, the radius of curvature R2, the angle θ2, and the distance A2, the angle θ _max for determining the lower limit of the length of the arc-shaped portion 5e is determined.

The arc-shaped portion 5e of the grindstone can be configured to terminate within the range between the angle _θmax and the angle θ4 calculated from the vertical direction as above, so that the workpiece 2 can be processed into a desired cross-sectional shape with good accuracy. This relationship is applicable regardless of the size relationship between the angle θ2 and the angle θ3. In addition, the above description is that in the configuration in which the bottom surface of the workpiece 2 is adsorbed by the adsorption member 10, the conditions for well grinding the bottom surface of the workpiece 2 by the grindstone 5 are obtained based on "the dimensions of each part of the lower side of the workpiece 2 of the desired cross-sectional shape, and the dimensions of each part of the arc-shaped portion 5e on the lower side of the grindstone 5". Regarding the structure of adsorbing the top surface of the workpiece 2 by the adsorption component 10, the conditions for well grinding the top surface of the workpiece 2 by the grindstone 5 can be obtained based on "the dimensions of the parts of the upper side rather than the lower side of the workpiece 2 of the desired cross-sectional shape, and the dimensions of the parts of the arc-shaped portion 5e on the upper side rather than the lower side of the grindstone 5" by a method substantially the same as the above-mentioned calculation.

Next, the second embodiment of the present invention will be described. FIG. 12 is a cross-sectional view showing a grindstone 5 of a workpiece processing device 1 of the present embodiment. The grindstone 5 of the present embodiment, like the grindstone 5 of the first embodiment, comprises: a base disc portion 5a; a concave grinding portion 5b located at the outer periphery of the base disc portion 5a; and a cross-sectional rectangular grinding portion 5g arranged side by side with the concave grinding portion 5b in the thickness direction. The base disc portion 5a and the cross-sectional rectangular grinding portion 5g are substantially the same in structure as the base disc portion 5a and the cross-sectional rectangular grinding portion 5g of the first embodiment, so the description thereof will be omitted. The cross-sectional shape of the concave grinding portion 5b in the cross section along the rotation axis 6 of the grindstone 5 is a concave shape that is concave from the outer side (outer peripheral side) to the inner side (inner peripheral side) in the radial direction, and has at least an arc-shaped portion 5e and a slope portion 5h at both ends in the thickness direction, which is located further outward in the thickness direction than the arc-shaped portion 5e and is continuously connected to the arc-shaped portion 5e. A straight line portion 5f having a thickness greater than the thickness of the workpiece 2 is provided between the arc-shaped portions 5e at both ends. At point B where the "angle of inclination of the tangent line of the arc-shaped portion 5e to the horizontal direction" coincides with the "angle θ2 of the chamfered portion 2a of the workpiece 2 of the desired cross-sectional shape to the horizontal direction", the arc-shaped portion 5e changes into the slope portion 5h. Therefore, the inclined surface portion 5h extends at an angle θ2 with respect to the horizontal direction.

In this embodiment, conditions for performing good grinding by bringing a single side surface (e.g., bottom surface in the vertical direction of lead) of the workpiece 2 into contact with the grindstone 5 are determined in a state where the surface is adsorbed by the adsorption member 10 and the surface is brought into contact with the grindstone 5. As shown in FIG13 , the length of the inclined surface portion 5h on the side of the surface (e.g., bottom surface in the vertical direction of lead) of the workpiece 2 adsorbed by the adsorption member 10 is less than the length of the inclined surface portion 5h in contact with the thinner front end portion 10a of the adsorption member 10 in a cross section along the rotation axis 6 of the grindstone 5 at the end portion on the side of the surface (e.g., bottom surface in the vertical direction of lead) 2b of the workpiece 2 at a position (point A in FIG13 ) where the tangent line of the arc-shaped portion 5e extends at an angle θ3 that coincides with the angle θ3 of the thinner front end portion 10a of the adsorption member 10. In the state shown in FIG. 13 , the tangent line at point A of the arc-shaped portion 5e is inclined from the horizontal direction by θ3 and is parallel to the bottom surface of the thinner shape 10a at the front end of the adsorption member 10. In this state, if the inclined surface portion 5h extends to the point E where the bottom surface of the thinner shape 10a at the front end of the adsorption member 10 abuts against the inclined surface portion 5h, further grinding cannot be performed. Therefore, the length of the inclined surface portion 5h is less than the length reaching point E. The angle between the straight line extending from the center of curvature of the arc-shaped portion 5e to point E and the vertical direction is θ5. When a straight line is drawn that is parallel to the tangent line at point A of the arc-shaped portion 5e (i.e., perpendicular to the radius passing through point A) and passes through point E, the distance from the straight line along the radius passing through point B to point B is x5. In addition, the distance between the radius passing through point A and the radius passing through point B along the straight line is x4.

x 5= ' - x 4 tan[( θ 3- θ 2)/2]

x 4 = ( r - ' )tan( θ 3 - θ 2)

x 3=r tan( θ 2- θ 5)= x 5/tan( θ 3- θ 2)

θ 5= θ 2-tan ^-1 [ x 5/r tan( θ 3- θ 2)]

By such calculations, it is possible to set a condition for making the inclined surface portion 5h have a length less than the following: the length of the inclined surface portion 5h abutting against the thinner shape 10a of the front end of the suction member 10 in a state where the tangent line of the arc-shaped portion 5e extends at an angle θ3 that coincides with the angle θ3 of the thinner shape 10a of the front end of the suction member 10, while the concave grinding portion 5b and the end portion of the bottom surface side of the workpiece 2 are in contact at a position where the tangent line of the arc-shaped portion 5e extends at an angle θ3 that coincides with the angle θ3 of the thinner shape 10a of the front end of the suction member 10. Therefore, by configuring the inclined surface portion 5h of the grindstone 5 to terminate within the range between the angle _θmax and the angle θ5 from the vertical direction, the workpiece 2 can be processed into a desired cross-sectional shape with good accuracy.

Next, the third embodiment of the present invention will be described. FIG. 14 is a front view of the workpiece processing device of this embodiment. The workpiece processing device of this embodiment comprises: a grindstone 5, which is similar to the grindstone 5 of the first embodiment, but has a cross-sectional rectangular grinding portion 5g only on the top surface side; and a circular plate-shaped grooved grindstone 12, which is arranged obliquely in the tangential direction of the outer periphery of the circular plate-shaped workpiece 2. The grooved grindstone 12 is supported by the grooved grindstone supporting mechanism 13 and can rotate with the rotating shaft 14 as the center. This workpiece processing device performs chamfering by a two-stage grinding process; the rough grinding process of the front stage is performed by using the cross-sectional rectangular grinding portion 5g and the concave grinding portion 5b of the grindstone 5 that are the same as those of the first embodiment to implement the above-mentioned processing method. Then, the subsequent precision grinding process is performed by using the grooved grindstone 12 arranged obliquely in the tangential direction of the outer periphery of the workpiece 2. A concave groove 12a is provided on the outer periphery of the grooved grindstone 12. By inserting the outer periphery of the workpiece 2 into the groove 12a, the inner peripheral surface of the groove 12a can be ground against the outer periphery of the workpiece 2 to form a chamfered portion. According to this embodiment, the effect of the spiral processing method such as small surface roughness can be obtained, and by performing rough grinding with the rotating and moving grindstone 5, the spiral precision grinding using the grooved grindstone 12 can be performed in a shorter time and with good efficiency.

The workpiece processing device of this embodiment has a shaping grindstone 11 for shaping the grooved grindstone 12, which can be installed on the workpiece support mechanism 4 instead of the workpiece 2 and can rotate around the rotation axis 3. The shaping grindstone 11 is formed of, for example, a green silicon carbide grindstone or the like which is harder than the grooved grindstone 12 formed of a resin bonded grindstone, and is a grindstone having a diameter and thickness substantially the same as those of the workpiece 2. The shaping grindstone 11 formed of the green silicon carbide grindstone or the like is processed by the same method as the processing of the workpiece 2 using the grindstone 5 formed of a metal bonded grindstone, so as to form a cross-sectional shape to be transferred to the inclined grooved grindstone 12 (a shape corresponding to the shape of the groove 12a set in advance). In the same method as the processing of the workpiece 2, the moving condition of "the contact portion of the concave grinding portion 5b of the grindstone 5 and the shaping grindstone 11 moves along a shape corresponding to the shape of the preset groove 12a" is calculated based on the curvature radius of the circular arc portion 5e of the grindstone 5, and the shaping grindstone 11 is moved relative to the grindstone 5 in accordance with the moving condition, thereby forming the outer shape of the shaping grindstone 11. The shape of the preset groove 12a is a shape suitable for forming the workpiece 2 that contacts the inner peripheral surface of the groove 12a into a desired cross-sectional shape. In this way, the truing grindstone 11 after the cross-sectional shape is formed is rotated around the rotation axis 3 and abuts against the outer periphery of the inclined groove-attached grindstone 12 before the groove is formed or trimmed, and the outer shape of the truing grindstone 11 is transferred to the outer periphery of the groove-attached grindstone 12 to form or trim the groove 12a. In this way, the shaping of the groove-attached grindstone 12 can be easily performed. In addition, the truing grindstone 11 is formed into a shape that includes the expected cross-sectional shape change after the slight cross-sectional shape change generated during the shaping of the inclined groove-attached grindstone 12 is assumed empirically.

In addition, the wear strength of the grinding stone is, for example, that the green silicon carbide grinding stone with a grain size of #320 is stronger than the resin bonded grinding stone with a grain size of #3000, and the metal bonded grinding stone with a grain size of #800 is stronger than the green silicon carbide grinding stone with a grain size of #320. Therefore, the green silicon carbide grinding stone with a grain size of #800 can be ground into a desired cross-sectional shape. In addition, by pressing the green silicon carbide grinding stone with a grain size of #320 against the inner peripheral surface of the groove provided in the resin bonded grinding stone with a grain size of #3000, the shape of the groove can be trimmed. In addition, each grinding stone described below basically has the above-mentioned grain size. In a known workpiece processing device that performs rough grinding using a grindstone having a formed groove formed by a metal bonded grindstone and performs precision grinding using an inclined grooved grindstone formed by a resin bonded grindstone, a shaping grindstone formed by a green silicon carbide grindstone is brought into contact with the inner peripheral surface of the formed groove of the metal bonded grindstone to transfer the shape of the formed groove. Thereafter, the shaping grindstone formed by the green silicon carbide grindstone is brought into contact with the inclined resin bonded grindstone to form or trim the groove. The workpiece (wafer) is precisely ground using the groove of the inclined grooved grindstone formed by the resin bonded grindstone. Therefore, the workpiece can only be formed into a cross-sectional shape determined by the shape of the forming groove of the metal-bonded grindstone, and cannot be formed into a different cross-sectional shape.

In contrast, in the present invention, the shaping grindstone 11 formed of green silicon carbide grindstone can be formed into an arbitrary cross-sectional shape by the concave grinding portion 5b of the grindstone 5 formed of a metal bond grindstone, so that the groove 12a of an arbitrary cross-sectional shape can be formed in the groove grindstone 12 shaped by the shaping grindstone 11. In this way, the workpiece 2 of various cross-sectional shapes can be processed without replacing the grindstone. In addition, after the groove grindstone 12 is shaped, the workpiece 2 can be processed once, and the cross-sectional shape of the workpiece 2 after processing can be actually measured and compared with the target shape for feedback. Assuming that the cross-sectional shape of the workpiece 2 after processing is different from the target shape, the cross-sectional shape of the shaping grindstone 11 trimmed by the concave grinding portion 5b of the grindstone 5 is changed (corrected), and the groove grindstone 12 is reshaped again by the shaping grindstone 11 with the changed cross-sectional shape. In this way, the cross-sectional shape of the workpiece 2 trimmed by the groove grindstone 12 can be made close to the target shape. In the aforementioned known workpiece processing device, a metal bonded grindstone with a forming groove is used, so even if the cross-sectional shape of the workpiece after processing is different from the target shape, the cross-sectional shape of the shaping grindstone 11 cannot be changed (corrected). However, according to the method of the present invention, the accuracy of the cross-sectional shape of the workpiece after processing, that is, the processing accuracy of the workpiece 2 can be significantly improved.

Next, the fourth embodiment of the present invention will be described. FIG15 is a front view of the workpiece processing device of this embodiment. The workpiece processing device of this embodiment has a grooved grindstone 12 arranged obliquely in the tangential direction of the outer periphery of the disk-shaped workpiece 2, similar to the third embodiment. The grindstone 5 similar to the third embodiment is mounted on the grindstone support mechanism 7 and can rotate around the rotation axis 6. The workpiece 2 is mounted on the workpiece support mechanism 4, and can rotate around the rotation axis 3 as the center, and can move in a direction close to the grindstone 5 or away from the grindstone 5 in a plane parallel to the workpiece 2 and the grindstone 5 (in a plane orthogonal to the rotation axis 3 and the rotation axis 6), and can move in a direction close to the grindstone 5 or away from the grindstone 5 in a plane orthogonal to the grindstone 5 and the workpiece 2 (in a plane parallel to the rotation axis 3 and the rotation axis 6). As shown in FIG15, the workpiece support mechanism 4 has an X-direction moving table 4a, a Y-direction moving table 4b, a Z-direction moving table 4c, and a motor 4d. The X-direction moving table 4a can move in a plane parallel to the grindstone 5 and the workpiece 2 along the width direction of the grindstone 5 and the workpiece 2 (a direction orthogonal to the paper surface of FIG15). The Y-direction moving table 4b is mounted on the X-direction moving table 4a and can move in the approach and separation direction of the grinding stone 5 and the workpiece 2 (the left-right direction in FIG. 15 ) in a plane parallel to the grinding stone 5 and the workpiece 2. The Z-direction moving table 4c is mounted on the Y-direction moving table 4b and can move in the height direction (the up-down direction in FIG. 15 ) in a plane orthogonal to the grinding stone 5 and the workpiece 2. Although not described in detail, the X-direction moving table 4a, the Y-direction moving table 4b, and the Z-direction moving table 4c each have a known guide means (e.g., LM guide) and a moving means (e.g., a ball screw, a nut, a rotary drive means) and can move in the aforementioned directions. The motor 4d is mounted on the Z-direction moving table 4c and is a drive means for supporting the workpiece 2 via the rotary shaft 3 and rotating the rotary shaft 3. The motor 4d is a heat-generating component; a temperature adjustment mechanism 15 is provided to cover at least one of the motor 4d and the rotating shaft 3. The temperature adjustment mechanism 15 allows liquid or gas to flow through a flow path not shown in the figure to adjust the temperature of at least one of the motor 4d and the rotating shaft 3.

According to this workpiece processing device, the effects of the first to third embodiments can be achieved. In addition, although not shown, the shaping grindstone 11 can be rotated and moved in contact with the groove grindstone 12, which can simply, efficiently and accurately shape the groove grindstone 12.

The workpiece support mechanism 4 does not rotate the workpiece 2 at high speed all the time, and there are cases where the workpiece 2 is rotated at low speed or is not rotated. Specifically, when the workpiece 2 is ground by the concave grinding portion 5b or the rectangular grinding portion 5g of the grindstone 5, the workpiece 2 rotates at high speed. When the workpiece 2 is ground by the groove grindstone 12 arranged obliquely in the tangential direction of the outer periphery of the disc-shaped workpiece 2, the workpiece 2 rotates at low speed. In addition, when the workpiece 2 is replaced, the workpiece support mechanism 4 does not need to perform rotational movement. In the past, when a plurality of workpieces 2 were processed continuously, the workpiece support mechanism 4 repeated the high-speed rotation of the workpiece 2 centered on the rotation axis 3, the low-speed rotation of the workpiece 2, and the rotational movement stop state. The workpiece support mechanism 4 generates heat and reaches a high temperature when the workpiece 2 rotates at a high speed, becomes lower when the workpiece 2 rotates at a low speed than when it rotates at a high speed, and becomes even lower when the rotation motion stops. The workpiece support mechanism 4 repeats such temperature changes, and the rotation shaft 3 is deformed, such as expansion and contraction. Once the rotation shaft 3 on which the workpiece 2 is mounted is deformed, the position of the workpiece 2 in the thickness direction changes. Even if the numerical control is performed as described above to make the workpiece 2 and the grindstone move relative to each other, the processing accuracy is still greatly reduced.

Therefore, in each embodiment of the present invention, a temperature adjustment mechanism 15 is provided attached to the workpiece support mechanism 4. The temperature adjustment mechanism 15 generates a flow of liquid or gas to reduce the temperature variation of the rotating shaft 3 of the workpiece support mechanism 4 and suppress the deformation of the rotating shaft 3. In this way, by suppressing the deformation of the rotating shaft 3 caused by heat during the processing of the workpiece 2, the processing accuracy of the workpiece 2 is prevented from being reduced.

In addition, in order to keep the temperature of the rotating shaft 3 as constant as possible, it is preferable to continue the rotational movement around the rotating shaft 3. For example, when the workpiece 2 is replaced or supplemented, or when the processing of the workpiece 2 is interrupted due to a problem in the operation process, the workpiece support mechanism 4 is still preferable to continue the rotational movement around the rotating shaft 3. In this way, by keeping the workpiece support mechanism 4 in a state of performing the rotational movement around the rotating shaft 3 (for convenience, it is called an idling state or a preparatory rotation operation) when the workpiece 2 is not installed and the processing of the workpiece 2 is not performed, the temperature change can be suppressed within a small range, and the temperature can be easily stabilized in a short time. Furthermore, in this preparatory rotation operation, not only high-speed rotation or only low-speed rotation is performed, but high-speed rotation (rotating at the same speed as the workpiece 2 being processed by the grindstone during high-speed rotation) and low-speed rotation (rotating at the same speed as the workpiece 2 being processed by the grindstone during low-speed rotation) are alternately repeated, as in the actual processing of the workpiece 2. This is preferable in terms of suppressing temperature changes within a small range. In this way, when the preparatory rotation operation is changed to the processing of the workpiece 2, the temperature of the rotating shaft 3 can be immediately stabilized, and high-precision processing can be performed. In particular, if the ratio of the duration of high-speed rotation to the duration of low-speed rotation in the preparatory rotation action is made consistent with the ratio of the duration of high-speed rotation to the duration of low-speed rotation in the actual processing of the workpiece 2, it is possible to perform temperature management according to the actual processing of the workpiece 2, which is a better state. However, if the duration of high-speed rotation and the duration of low-speed rotation in the preparatory rotation action are long, when the actual processing of the workpiece 2 is started, the waiting time for the completion of the preparatory rotation action and the transition to the appropriate timing for processing the workpiece 2 (for example, the timing for switching the rotation speed of the preparatory rotation action) is increased, and there is a possibility that the working efficiency is reduced. Therefore, as mentioned above, it is advisable to make the ratio of the duration of high-speed rotation to the duration of low-speed rotation in the preparatory rotation action consistent with the ratio of the duration of high-speed rotation to the duration of low-speed rotation in the actual processing of the workpiece 2, and make the duration of high-speed rotation and the duration of low-speed rotation in the preparatory rotation action shorter than the duration of high-speed rotation and the duration of low-speed rotation in the actual processing of the workpiece 2. In this way, by controlling the temperature during the processing of the actual workpiece 2, the temperature change of the rotating shaft 3 is suppressed to a small range, the reduction of the processing accuracy is suppressed, and further, the waiting time when the preparatory rotation action is changed to the processing of the workpiece 2 can be shortened, and the reduction of the working efficiency can be suppressed.

The grindstone 5 of the present invention is configured such that "the cross-sectional shape of the concave grinding portion 5b in the cross-sectional shape passing through the rotation axis 6 of the grindstone 5 has a cross-sectional shape in which a pair of arc-shaped portions 5e located at both ends in the thickness direction are connected by a straight line portion 5f." The arc-shaped portion 5e at one end in the thickness direction of the grindstone 5 and the arc-shaped portion 5e at the other end are preferably portions formed individually in such a manner that the average value of their respective curvature radii becomes a desired size. Thereby, compared with the case where the entire concave grinding portion 5b is processed into the same curvature radius, both the end in the thickness direction and the other end can be formed with high precision and in a good manner. In addition, it is preferable to reduce the error of the curvature radius of the arc-shaped portion 5e at one end in the thickness direction and the curvature radius of the arc-shaped portion 5e at the other end to a certain extent. For example, the difference between the maximum value and the minimum value of the radius of curvature of the arc-shaped portion 5e at one end in the thickness direction and the difference between the maximum value and the minimum value of the radius of curvature of the arc-shaped portion 5e at the other end are both within the allowable range, that is, below the preset value (first preset value). In addition, the difference between the average value of the radius of curvature of the arc-shaped portion 5e at one end in the thickness direction and the average value of the radius of curvature of the arc-shaped portion 5e at the other end are both within the allowable range, that is, below the preset value (second preset value).

In the present invention, as described above, a disk-shaped workpiece 2 is formed into a desired cross-sectional shape using a grindstone 5; the grindstone 5 has a concave grinding portion 5b on the outer periphery, and the concave grinding portion 5b is in the shape of "arc-shaped portions 5e at both ends in the thickness direction and a straight line portion 5f between the arc-shaped portions 5e at both ends". The workpiece processing method includes: a step of arranging the workpiece 2 and the grindstone 5 parallel to each other; and a step of rotating the grindstone 5, rotating the workpiece 2 around a rotation axis 3 parallel to a rotation axis 6 of the grindstone 5, and moving the grindstone 5 relative to the workpiece 2 according to a movement condition calculated based on the curvature radius of the arc-shaped portion 5e of the grindstone 5, so that the contact portion between the concave grinding portion 5b and the workpiece 2 moves along the desired cross-sectional shape of the workpiece 2. The step of moving the grinding stone 5 relative to the workpiece 2 includes: rotating the workpiece 2 and the grinding stone 5, and causing the arc-shaped portion 5e of the concave grinding portion 5b of the grinding stone 5 to move relative to the workpiece 2 from the outer peripheral end face of the workpiece 2 to one side of the workpiece 2 in a curved line according to an angle pre-calculated according to the moving condition, thereby grinding the outer peripheral portion of one side of the workpiece 2; moving the grinding stone 5 relative to the workpiece 2 from one side of the workpiece 2 to the other side of the workpiece 2 along the outer peripheral end face of the workpiece 2; and rotating the workpiece 2 and the grinding stone 5, and causing the arc-shaped portion 5e of the concave grinding portion 5b of the grinding stone 5 to move relative to the workpiece 2 from the outer peripheral end face of the workpiece 2 to the other side of the workpiece 2 in a curved line according to an angle pre-calculated according to the moving condition, thereby grinding the outer peripheral portion of the other side of the workpiece 2. When rough grinding of the outer peripheral portion of one side or the other side of the workpiece 2 is performed, the workpiece 2 and the grinding stone 5 are rotated, and the arc-shaped portion 5e of the concave grinding portion 5b of the grinding stone 5 is moved from the outer peripheral end surface of the workpiece 2 to one side or the other side, in a manner that the rotation axis 6 of the grinding stone 5 and the rotation axis 3 of the workpiece 2 are located in the same plane (along the arrow F1 in Figure 16), relative to the workpiece 2, and the relative movement of the grinding stone 5 relative to the workpiece 2 is stopped. In contrast, when performing precision grinding of the outer peripheral portion of one side or the other side of the workpiece 2, the workpiece 2 and the grindstone 5 are rotated, and the arc-shaped portion 5e of the concave grinding portion 5b of the grindstone 5 is relatively curved from the outer peripheral end surface of the workpiece 2 to one side or the other side in a manner such that the rotation axis 6 of the grindstone 5 and the rotation axis 3 of the workpiece 2 are located in the same plane (along the arrow F1 in FIG. 16). After the line moves by the angle calculated in advance according to the moving condition, the grinding stone 5 is moved linearly relative to the workpiece 2 in a plane extending in a direction perpendicular or obliquely intersecting the plane where the rotation axis 6 of the grinding stone 5 and the rotation axis 3 of the workpiece 2 are located when the grinding stone 5 moves in the curved line (for example, along any one of the arrows F2, F3, F4, F5 in Figure 16).

According to this method, the roughness of the part of the workpiece 2 after grinding becomes good (becomes smoother). If the reason is explained, it is because the surface of the grindstone 5 (the surface used for grinding) is scattered with the protruding parts of the diamond and other abrasive grains. Among the parts of the workpiece 2 that are in contact with the grindstone 5, the protruding parts of the diamond and other abrasive grains of the grindstone 5 are in contact with the part of the workpiece 2, and are cut deeper than other parts. Thereafter, by moving the grindstone 5 linearly relative to the workpiece 2, the circular arc-shaped part 5e of the concave grinding part 5b of the grindstone 5 is used to grind the entire area of the workpiece 2 including the part that is cut more deeply. In this way, the part that is cut more deeply due to the contact with the diamond and other abrasive grains in the previous process is in contact with the circular arc-shaped part 5e of the concave grinding part 5b of the grindstone 5, and is ground and becomes smooth, and no residue is left. In particular, the relative movement direction of the rotation axis 6 of the grindstone 5 and the rotation axis 3 of the workpiece in the previous process is changed, and the relative movement direction of the grindstone 5 and the workpiece 2 when moving along the curve is perpendicular or obliquely crossed, and the relative movement direction is inclined or orthogonal to the rotation direction of the workpiece 2, so that the area including the part that was cut deeply due to contact with abrasive grains such as diamonds in the previous process can be re-grinded, and the workpiece 2 can be prevented from being over-grinded by the arc-shaped part 5e of the concave grinding part 5b of the grindstone 5, resulting in the angle becoming too small.

In addition, in the present invention, there is also the following situation: a grindstone 5 is used to form a circular plate-shaped workpiece 2 into a desired cross-sectional shape; the grindstone 5 has a concave grinding portion 5b on the outer periphery, and this concave grinding portion 5b is in the shape of "having an arc-shaped portion 5e at both ends in the thickness direction, and a slope portion 5h located further outward in the thickness direction than the arc-shaped portion 5e and continuously connected to the arc-shaped portion 5e, and having a straight line portion 5f between the arc-shaped portions 5e at both ends." The workpiece processing method includes: a step of arranging a workpiece 2 and a grinding stone 5 parallel to each other; and a step of rotating the grinding stone 5, and rotating the workpiece 2 around a rotation axis 3 parallel to a rotation axis 6 of the grinding stone 5, and moving the grinding stone 5 relative to the workpiece 2 according to a movement condition calculated based on a radius of curvature of a circular arc portion 5e of the grinding stone 5, so that a contact portion between a concave grinding portion 5b and the workpiece 2 moves along a desired cross-sectional shape of the workpiece 2. The step of moving the grinding stone 5 relative to the workpiece 2 includes: rotating the workpiece 2 and the grinding stone 5, and causing the arc-shaped portion 5e of the concave grinding portion 5b of the grinding stone 5 to move relative to the workpiece 2 from the outer peripheral end face of the workpiece 2 to one side of the workpiece 2 in a curved line according to an angle pre-calculated according to the moving condition, thereby grinding the outer peripheral portion of one side of the workpiece 2; moving the grinding stone 5 relative to the workpiece 2 from one side of the workpiece 2 to the other side of the workpiece 2 along the outer peripheral end face of the workpiece 2; and rotating the workpiece 2 and the grinding stone 5, and causing the arc-shaped portion 5e of the concave grinding portion 5b of the grinding stone 5 to move relative to the workpiece 2 from the outer peripheral end face of the workpiece 2 to the other side of the workpiece 2 in a curved line according to an angle pre-calculated according to the moving condition, thereby grinding the outer peripheral portion of the other side of the workpiece 2. When rough grinding of the outer peripheral portion of one side or the other side of the workpiece 2 is performed, the workpiece 2 and the grindstone 5 are rotated, and the arc-shaped portion 5e of the concave grinding portion 5b of the grindstone 5 is moved from the outer peripheral end surface of the workpiece 2 to one side or the other side, in a manner that the rotation axis 6 of the grindstone 5 and the rotation axis 3 of the workpiece 2 are located in the same plane (along the arrow F1 in FIG. 16), relative to the workpiece 2 in a curved line according to the angle calculated in advance according to the movement condition, and then the relative movement of the grindstone 5 with respect to the workpiece 2 is stopped. In contrast, when performing precision grinding of the outer periphery of one side or the other side of the workpiece 2, the workpiece 2 and the grinding stone 5 are rotated, and the arc-shaped portion 5e of the concave grinding portion 5b of the grinding stone 5 is moved from the outer peripheral end face of the workpiece 2 to one side or the other side, so that the rotation axis 6 of the grinding stone 5 and the rotation axis 3 of the workpiece 2 are located in the same plane (along the arrow F1 in Figure 16), and the workpiece 2 is relatively moved in a curved line by an angle calculated in advance according to the movement condition. Then, the grinding stone 5 is relatively moved in a straight line relative to the workpiece 2 while maintaining the rotation axis 6 of the grinding stone 5 and the rotation axis 3 of the workpiece 2 located in the plane where the rotation axis 6 of the grinding stone 5 and the rotation axis 3 of the workpiece 2 are located during the curved movement (continuing along the arrow F1 in Figure 16).

According to this method, since the concave grinding part 5b of the grindstone 5 is provided with the bevel part 5h, the area including the part that is cut deeply due to contact with abrasive grains such as diamonds is ground again by the bevel part 5h of the grindstone 5, so the part that is cut deeply due to contact with abrasive grains such as diamonds in the previous process becomes smooth without residue. In addition, the workpiece 2 is finally ground by the bevel part 5h, so there is no concern that the angle will be reduced due to over-grinding. Therefore, there is no need to change the movement direction by the relative movement of the curve of the grindstone 5 and the workpiece 2, and the relative movement of the straight line thereafter, and the workpiece 2 can be pulled out straightly when viewed from a plane.

In addition, in the present invention, a workpiece processing method uses a grindstone 5 to form a disk-shaped workpiece 2 into a desired cross-sectional shape; the grindstone 5 has a concave grinding portion 5b on the outer periphery, and the concave grinding portion 5b is in the shape of "having arc-shaped portions 5e at both ends in the thickness direction, and a straight line portion 5f between the arc-shaped portions 5e at both ends"; the workpiece processing method includes: a step of arranging the workpiece 2 and the grindstone 5 parallel to each other; and a step of rotating the grindstone 5, and rotating the workpiece 2 around a rotation axis 3 parallel to a rotation axis 6 of the grindstone 5, and moving the grindstone 5 relative to the workpiece 2 according to a movement condition calculated based on the curvature radius of the arc-shaped portion 5e of the grindstone 5, so that the contact portion between the concave grinding portion 5b and the workpiece 2 moves along the desired cross-sectional shape of the workpiece 2. The step of moving the grinding stone 5 relative to the workpiece 2 includes: rotating the workpiece 2 and the grinding stone 5, and causing the arc-shaped portion 5e of the concave grinding portion 5b of the grinding stone 5 to move relative to the workpiece 2 from the outer peripheral end face of the workpiece 2 to one side of the workpiece 2 in a curved line according to an angle pre-calculated according to the moving condition, thereby grinding the outer peripheral portion of one side of the workpiece 2; moving the grinding stone 5 relative to the workpiece 2 from one side of the workpiece 2 to the other side of the workpiece 2 along the outer peripheral end face of the workpiece 2; and rotating the workpiece 2 and the grinding stone 5, and causing the arc-shaped portion 5e of the concave grinding portion 5b of the grinding stone 5 to move relative to the workpiece 2 from the outer peripheral end face of the workpiece 2 to the other side of the workpiece 2 in a curved line according to an angle pre-calculated according to the moving condition, thereby grinding the outer peripheral portion of the other side of the workpiece 2. When performing rough grinding of the outer periphery of one side or the other side of the workpiece 2, the workpiece 2 and the grindstone 5 are rotated, and the arc-shaped portion 5e of the concave grinding portion 5b of the grindstone 5 is moved in a curve relative to the workpiece 2 from the outer peripheral end surface of the workpiece 2 to one side or the other side according to the angle pre-calculated according to the movement condition, and then the relative movement of the grindstone 5 relative to the workpiece 2 is stopped. When performing precision grinding of the outer peripheral portion of one side of the workpiece 2, the workpiece 2 and the grindstone 5 are rotated, and taking into account the position error in the thickness direction generated when the workpiece 2 is rotated, the arc-shaped portion 5e of the concave grinding portion 5b of the grindstone 5 is moved from the outer peripheral end surface of the workpiece 2 to one side of the surface by an angle pre-calculated in accordance with the movement condition, based on the outermost position (for example, H _max in Figure 18) of the side of the workpiece 2 in the thickness direction passed by the workpiece 2 when rotating, and then the movement is stopped. At the position where the grindstone 5 and the inclined surface of the chamfered portion 2a on the side of one side of the workpiece 2 are in contact, the position of the workpiece 2 in the thickness direction is adjusted and the rotation speed of the workpiece 2 is slowed down, so that it rotates at least one circle, thereby offsetting the position error of the workpiece 2 during rotation and grinding one side of the workpiece 2. When performing precision grinding of the outer peripheral portion of the other side of the workpiece 2, the workpiece 2 and the grindstone 5 are rotated, and considering the position error in the thickness direction generated when the workpiece 2 is rotated, the arc-shaped portion 5e of the concave grinding portion 5b of the grindstone 5 is moved from the outer peripheral end surface of the workpiece 2 to the other side of the workpiece 2 by an angle calculated in advance according to the movement conditions, based on the outermost position of the other side of the thickness direction passed by the workpiece 2 when rotating. After _that , the movement is stopped, and at the position where the grindstone 5 and the inclined surface of the chamfered portion 2a of the other side of the workpiece 2 are in contact, the position of the workpiece 2 in the thickness direction is adjusted and the rotation speed of the workpiece 2 is slowed down, so that the workpiece 2 rotates at least one circle, thereby offsetting the position error of the workpiece 2 during rotation and grinding the other side of the workpiece 2.

If the technical significance of this method is explained, as in the case where the workpiece 2 and the grindstone 5 are rotated in the aforementioned embodiments, there is a possibility that the position in the direction parallel to the rotation axis (thickness direction) may wobble during rotation. Generally speaking, an error of ±1.5μm to ±3μm occurs in the position in the thickness direction. Due to such errors in the thickness direction, the planar shape of the workpiece 2 after grinding also changes greatly. In particular, when the angles θ1 and θ2 of the workpiece 2 shown in Figures 7A and 8 are small, the position offset in the thickness direction produces a huge position offset in the horizontal direction (in-plane direction). Specifically, as shown in Figure 7B, if it is assumed that the position offset O1 in the thickness direction of the upper side is the opposite side and the position offset K1 in the horizontal direction is the adjacent side of a right triangle, then tanθ1=O1/K1, that is, K1=O1/tanθ1. Similarly, as shown in FIG7C, if it is assumed that the position offset O2 in the thickness direction of the lower side is the opposite side and the position offset K2 in the horizontal direction is the adjacent side of a right triangle, then tanθ2=O2/K2, that is, K2=O2/tanθ2. For example, if the angles θ1 and θ2 are 22°, the position offsets K1 and K2 in the horizontal direction are approximately 2.5 times the position offsets O1 and O2 in the thickness direction. Therefore, when the position offsets O1 and O2 in the thickness direction are ±3μm, the position offsets K1 and K2 in the horizontal direction are approximately ±7.5μm. In the R-shaped workpiece 2 shown in FIG8, the same relationship between the position offsets K1 and K2 in the horizontal direction and the position offsets O1 and O2 in the thickness direction as in the T-shaped workpiece 2 shown in FIG7A also occurs (refer to FIG7B~7C). As mentioned above, there is a possibility that the dimensions of the top and bottom surfaces of the workpiece 2 (e.g., dimensions A1 and A2 shown in FIG. 7A and FIG. 8 ) may each have an error of up to 7.5 μm. When the angles θ1 and θ2 are smaller, the errors in the dimensions of the top and bottom surfaces of the workpiece 2 (e.g., dimensions A1 and A2) become larger. Therefore, the inventors considered investigating the tendency of the positional wobble in the thickness direction during the rotation of the workpiece 2, building a piezoelectric element (not shown) into the workpiece support mechanism 4, and causing the piezoelectric element to operate precisely at high speed during the rotation of the workpiece 2, so that the workpiece 2 moves in the thickness direction to offset the positional wobble in the thickness direction. However, in this case, the structure of the workpiece support mechanism 4 becomes very complicated, resulting in high costs and easy failure. If the workpiece 2 is moved up and down at high speed in conjunction with the high-speed rotation of the workpiece 2, the shape of the workpiece 2 after grinding becomes uneven, and the accuracy of the workpiece dimensions (such as the curvature radius R1, R2, etc. shown in Figure 7A and Figure 8) may deteriorate. If these problems are solved by slowing down the rotation speed of the workpiece 2, the work efficiency will be reduced and the processing cost will increase.

Therefore, in order not to reduce the working efficiency too much, the operation of the device for moving the workpiece 2 up and down and the movement of the workpiece 2 in the thickness direction accompanying it should be performed to the minimum extent necessary during the rotation of the workpiece 2, and should be performed only in an emergency. Specifically, before performing precision grinding of the outer periphery of one side face (top side) and the other side face (bottom side) of the workpiece 2, the positional deviation state in the thickness direction of the workpiece 2 caused by the workpiece support mechanism 4 during the rotation is investigated. That is, the workpiece 2 is actually rotated by the workpiece support mechanism 4, and the height difference of the eight points H1 to H8 shown in FIG. 17 is measured. Then, the positive value H _max (for example, about +3 μm) and the negative value H _min (for example, about -3 μm) of the maximum difference from the middle point of the heights of each point H1 to H8 are obtained. Then, the workpiece 2 and the grindstone 5 are rotated, and the arc-shaped portion 5e of the concave grinding portion _5b of the grindstone 5 is moved from the outer peripheral end surface of the workpiece 2 to the top surface by an angle calculated in advance according to the moving conditions relative to the workpiece 2, and then the movement is stopped. Then, at the position where the grindstone 5 and the chamfered portion 2a of the top surface side of the workpiece 2 are in contact, the position of the workpiece 2 in the thickness direction is adjusted and the rotation speed of the workpiece 2 is slowed down so that the workpiece 2 rotates at least one _turn to offset the position error of the workpiece 2 during rotation and grind the top surface side of the workpiece 2. Similarly, the workpiece 2 and the grindstone 5 are rotated, and the arc-shaped portion 5e of the concave grinding portion 5b of the grindstone 5 is moved relative to the workpiece 2 from the outer peripheral end surface to the bottom surface by an angle calculated in advance according to the movement conditions, and then the movement is stopped. Then, at the position where the grindstone 5 and the chamfered portion 2a of the bottom side of the workpiece 2 are in contact, the position of the workpiece 2 in the thickness direction is adjusted and the rotation speed of the workpiece 2 is slowed down so that it rotates at least one circle to offset the position error of the workpiece 2 during rotation and grind the bottom side of the workpiece 2.

According to this method, in the final stage of the grinding process, the workpiece 2 is moved in the thickness direction and ground in such a way as to offset the position error of the workpiece 2 during rotation, thereby making the ground surface smooth and forming the desired cross-sectional shape with good accuracy. In addition, the movement of the workpiece 2 in the thickness direction and the low-speed rotation of the workpiece 2 may be only one or several turns in the final stage of the grinding process, and in the previous stage, the workpiece 2 is rotated at a high speed and ground without moving the workpiece 2 in the thickness direction. Therefore, the large positional displacement in the horizontal direction (in-plane direction), which is the most important dimension in the cross-sectional shape, caused by the slight positional displacement in the thickness direction is prevented. The effect of the concave grindstone and the connection of the blunt corners can almost ignore the influence of the connection between the arc-shaped part of the cross-sectional surface and the inclined surface, so high-precision processing can be performed, and the working efficiency is not reduced too much, and the device is not prone to failure. The movement of the workpiece 2 in the thickness direction is performed when the workpiece 2 rotates at a low speed, so there is no need for expensive devices such as piezoelectric elements, and a ball screw can be used. In this way, according to this method, the processing accuracy of the workpiece 2 is good, the working efficiency is good, and the processing cost is not increased too much. In addition, this method can also be combined with the aforementioned method of performing relative movement of the grindstone 5 and the workpiece 2 in the curve and then relative movement of the straight line and performing grinding.

[Note 1]

A workpiece processing device is used to form a disk-shaped workpiece into a desired cross-sectional shape, and is characterized in that: it has a workpiece supporting mechanism for supporting the workpiece, a disk-shaped grindstone arranged parallel to the workpiece, and a grindstone supporting mechanism for supporting the grindstone; the workpiece supporting mechanism rotates the workpiece, and the grindstone supporting mechanism rotates the grindstone; the rotation axis that is the center of rotation of the workpiece by the workpiece supporting mechanism and the rotation axis that is the center of rotation of the grindstone by the grindstone supporting mechanism are parallel to each other; the workpiece supporting mechanism has a function of adsorbing only one side of the workpiece. The adsorption member is a circular adsorption member; the plane shape of the adsorption member is a circle with a smaller radius than the radius of the workpiece; the outer peripheral portion of the circular adsorption member has a thinner front end shape with a thickness that becomes thinner toward the outside; the grindstone has a concave grinding portion at the outer peripheral portion; the cross-sectional shape of the concave grinding portion along the cross-sectional surface of the rotation axis of the grindstone is a concave shape that is concave from the outer peripheral side to the inner peripheral side, and has a shape in which at least both ends in the thickness direction have arc-shaped portions, and between the arc-shaped portions at the two ends have a straight line portion with a thickness greater than the thickness of the workpiece; the grindstone and the workpiece The grinding stone supporting mechanism or the workpiece supporting mechanism moves the grinding stone relative to the workpiece in a manner that allows the grinding stone to approach or move away from each other according to the movement conditions calculated based on the radius of curvature of the circular arc portion of the grinding stone, so that the concave grinding portion and the contact portion of the workpiece move along the desired cross-sectional shape of the workpiece; the radius of curvature of the circular arc portion of the grinding stone is at least 10 times the thickness of the workpiece, so that the circular arc portion of the grinding stone moves in a manner that is inversely proportional to the desired cross-sectional shape of the workpiece. The corners are substantially free of gaps and are in contact with the workpiece; the arc-shaped portion on the side of the workpiece adsorbed by the adsorption member has a length in the cross section along the rotation axis of the grindstone that is less than the length of the end of the side of the workpiece in contact with the thinner front end of the adsorption member at a position where the tangent of the arc-shaped portion extends at an angle consistent with the angle of the thinner front end of the adsorption member; and is greater than the length of the chamfered portion on the side of the workpiece of the desired cross-sectional shape.

[Note 2]

A workpiece processing device for forming a disk-shaped workpiece into a desired cross-sectional shape, characterized in that: it has a workpiece support mechanism for supporting the workpiece, a disk-shaped grindstone arranged parallel to the workpiece, and a grindstone support mechanism for supporting the grindstone; the workpiece support mechanism rotates the workpiece, and the grindstone support mechanism rotates the grindstone; the rotation axis that is the center of rotation of the workpiece by the workpiece support mechanism and the rotation axis that is the center of rotation of the grindstone by the grindstone support mechanism are parallel to each other; the workpiece support mechanism has a function of rotating only one side of the workpiece. An adsorption member for adsorption; the plane shape of the adsorption member is a circle with a radius smaller than the radius of the workpiece; the outer peripheral portion of the circular adsorption member has a front end thinner shape with the thickness becoming thinner as it goes outward; the grindstone has a concave grinding portion on the outer peripheral portion; the cross-sectional shape of the concave grinding portion along the cross-section of the rotation axis of the grindstone is a concave shape that is concave from the outer peripheral side to the inner peripheral side, and has the following shape: at least at both ends in the thickness direction, each has an arc-shaped portion, and an inclined portion located further outward in the thickness direction than the arc-shaped portion and continuously connected to the arc-shaped portion The concave grinding portion and the workpiece are provided with a straight line portion having a thickness greater than the thickness of the workpiece between the arc-shaped portions at the two ends; the grindstone and the workpiece are moved relative to each other in a manner that allows them to approach or move away from each other by means of the grindstone supporting mechanism or the workpiece supporting mechanism; the grindstone supporting mechanism or the workpiece supporting mechanism moves the grindstone relative to the workpiece in accordance with a moving condition calculated based on the radius of curvature of the arc-shaped portion of the grindstone, so that the contact portion between the concave grinding portion and the workpiece moves along the desired cross-sectional shape of the workpiece; the radius of curvature of the arc-shaped portion of the grindstone is At least 10 times the thickness of the workpiece; the length of the inclined surface portion located on the single side of the workpiece adsorbed by the adsorption member in the cross section along the rotation axis of the grindstone is less than the following length: the inclined surface portion abuts against the thinner shape of the front end of the adsorption member when the tangent line of the arc-shaped portion is in contact with the end of the single side of the workpiece at a position extending at an angle consistent with the angle of the thinner shape of the front end of the adsorption member, and is greater than the length of the chamfered portion of the single side of the workpiece of the desired cross-sectional shape.

[Note 3]

The workpiece processing device as described in Note 1 or 2, wherein the concave grinding portion and the straight rectangular grinding portion are arranged side by side in the thickness direction on the outer periphery of the grinding stone, and the surface of the rectangular grinding portion facing the workpiece is parallel to the thickness direction of the grinding stone in the section along the rotation axis; the rectangular grinding portion of the grinding stone is abutted against the outer periphery of the workpiece before grinding by the concave grinding portion, and the grinding stone is moved from the outer side to the inner side in the radius direction of the workpiece to grind the workpiece to reduce the radius of the workpiece.

[Note 4]

A workpiece processing device as described in any one of Notes 1 to 3, wherein the radius r1 of the adsorption member, if represented by the radius r2 of the desired cross-sectional shape of the workpiece and the thickness t of the workpiece, is r2-10t≦r1≦r2-5t; the angle θ1 of the thinner front end of the adsorption member, if represented by the angle θ2 of the chamfered portion of the desired cross-sectional shape of the workpiece, is θ2-10≦θ1≦θ2+5.

[Note 5]

A workpiece processing device as described in any one of Notes 1 to 4, wherein the grinding stone supporting mechanism has a main shaft on which the grinding stone is directly or indirectly mounted, and a rotating bearing portion that supports the main shaft in a rotatable manner; the grinding stone is supported in a manner such that the center of gravity of the grinding stone is located between the mounting position of the grinding stone and the rotating bearing portion.

[Note 6]

A workpiece processing device as described in any one of Notes 1 to 5, wherein the grindstone supporting mechanism and the workpiece supporting mechanism, when grinding the outer peripheral portion of one side of the workpiece, rotate the workpiece and the grindstone, and cause the arc-shaped portion of the concave grinding portion of the grindstone to move relative to the workpiece from the outer peripheral end face of the workpiece to one side of the face at an angle pre-calculated according to the movement condition; when grinding the outer peripheral portion of the other side of the workpiece, rotate the workpiece and the grindstone, and cause the arc-shaped portion of the concave grinding portion of the grindstone to move relative to the workpiece from the outer peripheral end face of the workpiece to the other side of the face at an angle pre-calculated according to the movement condition; the grindstone supporting mechanism and the workpiece supporting mechanism, when performing grinding of the one side or the other side of the workpiece. When rough grinding the outer peripheral part of the surface side of the workpiece, the workpiece and the grindstone are rotated, and the arc-shaped part of the concave grinding part of the grindstone is moved from the outer peripheral end face of the workpiece to the one side face or the other side face in a curve relative to the workpiece according to the angle pre-calculated according to the movement condition, and then the relative movement of the grindstone relative to the workpiece is stopped; when the grindstone support mechanism and the workpiece support mechanism perform precision grinding of the outer peripheral part of the one side face or the other side face of the workpiece, the workpiece and the grindstone are rotated, and the arc-shaped part of the concave grinding part of the grindstone is moved from the outer peripheral end face of the workpiece to the one side face or the other side face in a curve relative to the workpiece according to the angle pre-calculated according to the movement condition, and then the grindstone is moved linearly relative to the workpiece.

[Note 7]

A workpiece processing device as described in any one of Notes 1 to 6, wherein, in addition to the grindstone having the concave grinding portion, it further comprises: a circular plate-shaped grooved grindstone, which is arranged obliquely in the tangential direction of the outer periphery of the workpiece and is used for grinding more precisely than the grinding performed by the concave grinding portion of the grindstone; and a grooved grindstone support mechanism, which supports the grooved grindstone; the grooved grindstone support mechanism rotates the grooved grindstone.

[Note 8]

The workpiece processing device as described in Note 7 is characterized in that: it is further provided with a shaping grinding stone that can replace the workpiece and be installed on the workpiece support mechanism; the shaping grinding stone is moved relative to the grinding stone by the grinding stone support mechanism or the workpiece support mechanism in accordance with the moving condition to form an outer shape; the groove-attaching grinding stone abuts against the shaping grinding stone to transfer the outer shape of the shaping grinding stone to form or trim the groove.

[Note 9]

A workpiece processing device as described in any one of Notes 1 to 8, wherein the workpiece support mechanism has a temperature adjustment mechanism that generates a flow of liquid or gas for maintaining the temperature of the rotating shaft of the workpiece support mechanism at a certain level.

[Note 10]

A grindstone is included in the workpiece processing device described in Note 1 or 2, and is characterized in that: the straight line portion is a portion of the grindstone with a coarser grain size than the arc-shaped portion, and the arc-shaped portion is a portion used for more precise grinding than the straight line portion.

[Note 11]

A grindstone is included in the workpiece processing device described in Note 3, and is characterized in that: the cross-sectional rectangular grinding portion is a portion of the grindstone with a coarser grain size than the concave grinding portion, and the concave grinding portion is a portion used for more precise grinding than the grinding performed by the cross-sectional rectangular grinding portion.

[Note 12]

A grindstone included in a workpiece processing device described in any one of Notes 1 to 9, characterized in that the arc-shaped portion at one end in the thickness direction and the arc-shaped portion at the other end are portions formed individually in such a way that the average value of their respective curvature radii becomes a desired size.

[Note 13]

A grindstone included in a workpiece processing device described in any one of Notes 1 to 9, characterized in that: the difference between the maximum value and the minimum value of the radius of curvature of the arc-shaped portion at one end in the thickness direction and the difference between the maximum value and the minimum value of the radius of curvature of the arc-shaped portion at the other end are both less than a first predetermined value; and the difference between the average value of the radius of curvature of the arc-shaped portion at one end in the thickness direction and the average value of the radius of curvature of the arc-shaped portion at the other end is less than a second predetermined value.

[Note 14]

A grinding stone is a grinding stone included in a workpiece processing device described in any one of Notes 1 to 9, characterized in that it has a straight or tapered mounting hole extending in the thickness direction.

[Note 15]

A workpiece processing method is used to form a disk-shaped workpiece into a desired cross-sectional shape using a grindstone, wherein the grindstone is rotatable, disk-shaped, and has a concave grinding portion on the outer periphery; the cross-sectional shape of the concave grinding portion in the cross-sectional shape along the rotation axis of the grindstone is a concave shape that is concave from the outer periphery to the inner periphery, and is in a shape in which each of the two end portions in the thickness direction has an arc-shaped portion, and a straight line portion having a thickness greater than the thickness of the workpiece is provided between the arc-shaped portions at the two end portions; the workpiece processing method comprises: a step of arranging the workpiece and the grindstone parallel to each other; and rotating the grindstone, and rotating the workpiece around a rotation axis parallel to the rotation axis of the grindstone, and following a rotation direction according to the grindstone. The step of moving the grinding stone relative to the workpiece according to the movement condition calculated by the radius of curvature of the arc-shaped portion so that the concave grinding portion and the contact portion of the workpiece move along the desired cross-sectional shape of the workpiece; the step of moving the grinding stone relative to the workpiece includes: rotating the workpiece and the grinding stone, and moving the arc-shaped portion of the concave grinding portion of the grinding stone from the outer peripheral end face of the workpiece to one side of the surface relative to the workpiece in a curve following the angle pre-calculated according to the movement condition, thereby grinding the outer peripheral portion of the one side of the workpiece; moving the grinding stone relative to the workpiece along the outer peripheral end face of the workpiece from the one side of the surface to the other side of the surface; and rotating the workpiece and the grinding stone, and The arc-shaped portion of the concave grinding portion of the grindstone is caused to move in a curve relative to the workpiece from the outer peripheral end face of the workpiece to the other face at an angle calculated in advance according to the moving condition, thereby grinding the outer peripheral portion of the other face side of the workpiece; when performing rough grinding of the outer peripheral portion of the one face side or the other face side of the workpiece, the workpiece and the grindstone are rotated, and the arc-shaped portion of the concave grinding portion of the grindstone is caused to move in a curve relative to the workpiece from the outer peripheral end face of the workpiece to the one face side or the other face side in a manner that the rotation axis of the grindstone and the rotation axis of the workpiece are located in the same plane, and the angle calculated in advance according to the moving condition is followed, and then the relative movement of the grindstone relative to the workpiece is When performing precision grinding of the outer peripheral portion of the one side or the other side of the workpiece, the workpiece and the grindstone are rotated, and the arc-shaped portion of the concave grinding portion of the grindstone is moved relative to the workpiece in a curved line by an angle pre-calculated according to the moving condition in such a manner that the rotation axis of the grindstone and the rotation axis of the workpiece are located in the same plane from the outer peripheral end face of the workpiece to the one side or the other side, and then the grindstone is moved relative to the workpiece in a straight line in such a manner that the rotation axis of the grindstone and the rotation axis of the workpiece are moved relative to each other in a plane extending in a direction perpendicular or obliquely intersecting the plane where the rotation axis of the grindstone and the rotation axis of the workpiece are located during the curved movement.

[Note 16]

A workpiece processing method for forming a disk-shaped workpiece into a desired cross-sectional shape using a grindstone, wherein the grindstone is rotatable, disk-shaped, and has a concave grinding portion on the outer periphery; the cross-sectional shape of the concave grinding portion in the cross-sectional shape along the rotation axis of the grindstone is a concave shape that is concave from the outer periphery to the inner periphery, and has the following shape: at least at both ends in the thickness direction, each has an arc-shaped portion, and an inclined surface portion that is located further outward in the thickness direction than the arc-shaped portion and continuously connected to the arc-shaped portion, and a straight line portion having a thickness greater than the thickness of the workpiece is provided between the arc-shaped portions at the two ends; the workpiece processing method comprises: the steps of arranging the workpiece and the grindstone in parallel with each other; and rotating the grindstone, and The workpiece is rotated around a rotation axis parallel to the rotation axis of the grindstone, and the grindstone is moved relative to the workpiece according to a movement condition calculated based on the radius of curvature of the circular arc portion of the grindstone, so that the concave grinding portion and the contact portion of the workpiece are moved along the desired cross-sectional shape of the workpiece; the step of moving the grindstone relative to the workpiece includes: rotating the workpiece and the grindstone, and moving the circular arc portion of the concave grinding portion of the grindstone from the outer peripheral end face of the workpiece to one side of the workpiece in a curve relative to the workpiece according to an angle calculated in advance according to the movement condition, thereby grinding the outer peripheral portion of the one side of the workpiece; and moving the grindstone from the one side of the workpiece to the other side along the outer peripheral end face of the workpiece. The workpiece and the grindstone are rotated, and the arc-shaped portion of the concave grinding portion of the grindstone is moved relative to the workpiece from the outer peripheral end face of the workpiece to the other side face, following the angle calculated in advance according to the moving condition, thereby grinding the outer peripheral portion of the other side face of the workpiece; when performing the rough grinding of the outer peripheral portion of the one side face of the workpiece or the other side face, the workpiece and the grindstone are rotated, and the arc-shaped portion of the concave grinding portion of the grindstone is moved relative to the workpiece from the outer peripheral end face of the workpiece to the one side face or the other side face, following the moving condition in a manner that the rotation axis of the grindstone and the rotation axis of the workpiece are located in the same plane. The grinding stone is stopped from moving relative to the workpiece after the angle calculated in advance according to the moving condition is reached; when performing precision grinding of the outer peripheral portion of the one side or the other side of the workpiece, the workpiece and the grinding stone are rotated, and the arc-shaped portion of the concave grinding portion of the grinding stone is moved relative to the workpiece in a curved line from the outer peripheral end face of the workpiece to the one side or the other side of the workpiece in a manner that the rotation axis of the grinding stone and the rotation axis of the workpiece are located in the same plane. After the workpiece is moved relative to the workpiece in a curved line, the rotation axis of the grinding stone and the rotation axis of the workpiece are maintained in the plane where the rotation axis of the grinding stone and the rotation axis of the workpiece are located during the curved movement, and the grinding stone is moved relative to the workpiece in a straight line.

[Note 17]

A workpiece processing method is used to form a disk-shaped workpiece into a desired cross-sectional shape using a grindstone, wherein the grindstone is rotatable, disk-shaped, and has a concave grinding portion on the outer periphery; the cross-sectional shape of the concave grinding portion in the cross-sectional shape along the rotation axis of the grindstone is a concave shape that is concave from the outer periphery to the inner periphery, and is in a shape in which at least both ends in the thickness direction each have an arc-shaped portion, and a straight line portion having a thickness greater than the thickness of the workpiece is provided between the arc-shaped portions at the two ends; A workpiece processing method, comprising: a step of arranging the workpiece and the grindstone in parallel with each other; and a step of rotating the grindstone, rotating the workpiece around a rotation axis parallel to the rotation axis of the grindstone, and moving the grindstone relative to the workpiece according to a movement condition calculated based on the radius of curvature of the circular arc portion of the grindstone, so that the concave grinding portion and the contact portion of the workpiece move along the desired cross-sectional shape of the workpiece; the step of moving the grindstone relative to the workpiece, comprising : The workpiece and the grindstone are rotated, and the arc-shaped portion of the concave grinding portion of the grindstone is moved relative to the workpiece in a curve from the outer peripheral end face of the workpiece to one side of the face, following the angle pre-calculated according to the moving condition, thereby grinding the outer peripheral portion of the one side of the workpiece; the grindstone is moved relative to the workpiece along the outer peripheral end face of the workpiece from the one side of the face to the other side of the face; and the workpiece and the grindstone are rotated, and the arc-shaped portion of the concave grinding portion of the grindstone is moved relative to the workpiece from the one side of the face to the other side of the face. The outer peripheral portion of the other side of the workpiece is ground by moving the workpiece in a relatively curved line from the outer peripheral end face of the workpiece to the other side, following the angle calculated in advance according to the moving condition; when performing the rough grinding of the outer peripheral portion of the one side of the workpiece or the other side of the workpiece, the workpiece and the grindstone are rotated, and the arc-shaped portion of the concave grinding portion of the grindstone is moved in a relatively curved line from the outer peripheral end face of the workpiece to the one side of the workpiece or the other side of the workpiece, following the angle calculated in advance according to the moving condition. The grinding stone is moved relative to the workpiece by an angle calculated in advance according to the moving condition, and then the relative movement of the grinding stone with respect to the workpiece is stopped; when performing precision grinding of the outer peripheral portion of the one side face or the other side face of the workpiece, the workpiece and the grinding stone are rotated, and the arc-shaped portion of the concave grinding portion of the grinding stone is moved from the outer peripheral end face of the workpiece to the one side face or the other side face, relative to the workpiece, by a curved line at an angle calculated in advance according to the moving condition, and then the movement is stopped; when performing precision grinding of the one side face of the workpiece, the outer peripheral portion of the one side face or the other side face is rotated, and the arc-shaped portion of the concave grinding portion of the grinding stone is moved relative to the workpiece by an angle calculated in advance according to the moving condition, and then the movement is stopped; During precision grinding of the outer periphery, the workpiece and the grindstone are rotated, and considering the position error in the thickness direction generated during the rotation of the workpiece, the arc-shaped portion of the concave grinding portion of the grindstone is moved from the outer periphery end face of the workpiece to the one side face by an angle calculated in advance according to the movement condition relative to the workpiece, based on the outermost position of the one side face in the thickness direction through which the workpiece passes during the rotation, and then the movement is stopped. The position of the bevel contacting the workpiece is adjusted in the thickness direction and the rotation speed of the workpiece is slowed down so that the workpiece rotates at least one circle to offset the position error of the workpiece during rotation and grind the one side of the workpiece; when performing precision grinding of the outer periphery of the other side of the workpiece, the workpiece and the grindstone are rotated, and the position error in the thickness direction generated when the workpiece rotates is considered, and the outermost position of the other side of the workpiece in the thickness direction is taken as the reference, The arc-shaped portion of the concave grinding portion of the grindstone is moved from the outer peripheral end surface of the workpiece to the other side surface, relative to the workpiece, by an angle calculated in advance according to the moving conditions, and then the movement is stopped. At the position where the grindstone and the chamfered portion of the other side surface of the workpiece are in contact, the position of the workpiece in the thickness direction is adjusted and the rotation speed of the workpiece is slowed down so that the workpiece rotates at least one circle, thereby offsetting the position error of the workpiece during rotation and grinding the other side surface of the workpiece.

1: Workpiece processing device

2: Workpiece

3,6: Rotation axis

4: Workpiece support mechanism

5: Grindstone

5a: base disc

5b: Concave grinding part

5g: Rectangular grinding section

7: Grindstone support mechanism

10: Adsorption components

15: Temperature adjustment mechanism

Claims (17)

A workpiece processing device for forming a disk-shaped workpiece into a desired cross-sectional shape, characterized in that: It has: a workpiece support mechanism for supporting the workpiece; a disk-shaped grindstone arranged parallel to the workpiece; and a grindstone support mechanism for supporting the grindstone; The workpiece support mechanism rotates the workpiece, and the grindstone support mechanism rotates the grindstone; the rotation axis serving as the center of rotation of the workpiece by the workpiece support mechanism and the rotation axis serving as the center of rotation of the grindstone by the grindstone support mechanism are parallel to each other; The workpiece support mechanism has an adsorption member for adsorbing only one side of the workpiece; the plane shape of the adsorption member is a circle with a radius smaller than the radius of the workpiece; the outer peripheral portion of the circular adsorption member has a thinner front end shape with the thickness becoming thinner toward the outside; The grindstone has a concave grinding portion on the outer periphery; the cross-sectional shape of the concave grinding portion along the rotation axis of the grindstone is a concave shape that is concave from the outer periphery to the inner periphery, and has a shape in which at least both ends in the thickness direction have arc-shaped portions, and between the arc-shaped portions at the two ends, there is a straight portion with a thickness greater than the thickness of the workpiece, and the straight portion is used to grind at least one of reducing the diameter of the workpiece or smoothing the middle portion of the outer periphery of the workpiece in the thickness direction; The grindstone and the workpiece are moved relative to each other by the grindstone support mechanism or the workpiece support mechanism in a manner that allows them to approach or move away from each other; The grinding stone supporting mechanism or the workpiece supporting mechanism moves the grinding stone relative to the workpiece according to the movement condition calculated based on the radius of curvature of the circular arc portion of the grinding stone, so that the contact portion between the concave grinding portion and the workpiece moves along the desired cross-sectional shape of the workpiece; The radius of curvature of the circular arc portion of the grinding stone is at least 10 times the thickness of the workpiece, so that the circular arc portion of the grinding stone abuts against the workpiece in a manner that substantially no gap is generated between the chamfered portion of the desired cross-sectional shape of the workpiece; The length of the arc-shaped portion located on the single-side surface of the workpiece adsorbed by the adsorption member in the cross section along the rotation axis of the grindstone is greater than the length of the chamfered portion of the single-side surface of the workpiece of the desired cross-sectional shape, and less than the following length: the length of the end of the single-side surface of the workpiece abutting against the thinner front end of the adsorption member in a state where the tangent of the arc-shaped portion extends at an angle consistent with the angle of the thinner front end of the adsorption member. A workpiece processing device for forming a disk-shaped workpiece into a desired cross-sectional shape, characterized in that: It has: a workpiece support mechanism for supporting the workpiece; a disk-shaped grindstone arranged parallel to the workpiece; and a grindstone support mechanism for supporting the grindstone; The workpiece support mechanism rotates the workpiece, and the grindstone support mechanism rotates the grindstone; the rotation axis serving as the center of rotation of the workpiece by the workpiece support mechanism and the rotation axis serving as the center of rotation of the grindstone by the grindstone support mechanism are parallel to each other; The workpiece support mechanism has an adsorption member for adsorbing only one side of the workpiece; the plane shape of the adsorption member is a circle with a radius smaller than the radius of the workpiece; the outer peripheral portion of the circular adsorption member has a thinner front end shape with the thickness becoming thinner toward the outside; The grindstone has a concave grinding portion on the outer periphery; the cross-sectional shape of the concave grinding portion along the rotation axis of the grindstone is a concave shape that is concave from the outer periphery to the inner periphery, and has the following shape: at least at both ends in the thickness direction, each has an arc-shaped portion, and an inclined surface portion that is located further outward in the thickness direction than the arc-shaped portion and continuously connected to the arc-shaped portion, and between the arc-shaped portions at the two ends, there is a straight line portion having a thickness greater than the thickness of the workpiece, and the straight line portion is used to grind at least one of reducing the diameter of the workpiece or smoothing the middle portion of the outer periphery of the workpiece in the thickness direction; The inclined surface portion extends along the tangent direction of the arc-shaped portion at the boundary position between the arc-shaped portion and the inclined surface portion, and its angle is consistent with the angle of the chamfered portion of the single side of the workpiece of the desired cross-sectional shape; The grindstone and the workpiece are moved relative to each other in a manner that can approach or move away from each other by the grindstone support mechanism or the workpiece support mechanism; The grindstone support mechanism or the workpiece support mechanism moves the grindstone relative to the workpiece in accordance with the moving conditions calculated based on the radius of curvature of the arc-shaped portion of the grindstone, so that the contact portion of the concave grinding portion and the workpiece moves along the desired cross-sectional shape of the workpiece; The radius of curvature of the arc-shaped portion of the grindstone is at least 10 times the thickness of the workpiece; The length of the inclined surface portion located on the single side of the workpiece adsorbed by the adsorption member in the cross section along the rotation axis of the grindstone is greater than the length of the chamfered portion on the single side of the workpiece in the desired cross-sectional shape, and less than the following length: the angle between the inclined surface portion and the single side of the workpiece in the direction of extension is smaller than the angle between the front end thinner shape of the adsorption member and the single side of the workpiece, and the end of the single side of the workpiece is in contact with the front end thinner shape of the adsorption member at a position where the tangent of the arc-shaped portion extends at an angle consistent with the angle of the front end thinner shape of the adsorption member, and the inclined surface portion abuts against the length of the front end thinner shape of the adsorption member. A workpiece processing device as claimed in claim 1 or 2, wherein, the concave grinding portion and the straight rectangular grinding portion are arranged side by side in the thickness direction on the outer periphery of the grinding stone, and the surface of the rectangular grinding portion facing the workpiece is parallel to the thickness direction of the grinding stone in the section along the rotation axis; the rectangular grinding portion of the grinding stone abuts against the outer periphery of the workpiece before grinding by the concave grinding portion, and grinds the workpiece to reduce the radius of the workpiece by moving the grinding stone from the outer side to the inner side in the radius direction of the workpiece. A workpiece processing device as claimed in claim 1 or 2, wherein: The radius r1 of the adsorption member, if represented by the radius r2 of the desired cross-sectional shape of the workpiece and the thickness t of the workpiece, is r2-10t≦r1≦r2-5t; The angle θ1 of the thinner front end of the adsorption member, if represented by the angle θ2 of the chamfered portion of the desired cross-sectional shape of the workpiece, is θ2-10≦θ1≦θ2+5. A workpiece processing device as claimed in claim 1 or 2, wherein: The grinding stone supporting mechanism has a main shaft for directly or indirectly mounting the grinding stone, and a rotating bearing portion for rotatably supporting the main shaft; the grinding stone is supported in a manner such that the center of gravity of the grinding stone is located between the mounting position of the grinding stone and the rotating bearing portion. A workpiece processing device as claimed in claim 1 or 2, wherein, the grindstone support mechanism and the workpiece support mechanism rotate the workpiece and the grindstone when grinding the outer peripheral portion of one side of the workpiece, and cause the arc-shaped portion of the concave grinding portion of the grindstone to move relative to the workpiece from the outer peripheral end face of the workpiece to one side of the workpiece in a curved line according to the angle pre-calculated according to the moving condition; when grinding the outer peripheral portion of the other side of the workpiece, cause the workpiece and the grindstone to rotate, and cause the arc-shaped portion of the concave grinding portion of the grindstone to move relative to the workpiece from the outer peripheral end face of the workpiece to the other side of the workpiece in a curved line according to the angle pre-calculated according to the moving condition; The grindstone support mechanism and the workpiece support mechanism rotate the workpiece and the grindstone when performing rough grinding of the outer peripheral portion of the one side or the other side of the workpiece, and make the arc-shaped portion of the concave grinding portion of the grindstone move relative to the workpiece from the outer peripheral end surface of the workpiece to the one side or the other side of the workpiece in a curved line according to the angle pre-calculated according to the movement condition, and then stop the relative movement of the grindstone relative to the workpiece; The grindstone support mechanism and the workpiece support mechanism rotate the workpiece and the grindstone when performing precision grinding of the outer peripheral portion of the one side face or the other side face of the workpiece, and after the arc-shaped portion of the concave grinding portion of the grindstone is moved from the outer peripheral end face of the workpiece to the one side face or the other side face, the grindstone is moved linearly relative to the workpiece after the angle calculated in advance according to the movement condition is moved relative to the workpiece. A workpiece processing device as claimed in claim 1 or 2, wherein, in addition to the grindstone having the concave grinding portion, it further comprises: a circular plate-shaped grooved grindstone arranged obliquely in the tangential direction of the outer periphery of the workpiece, used for grinding more precisely than the grinding performed by the concave grinding portion of the grindstone; and a grooved grindstone support mechanism for supporting the grooved grindstone; the grooved grindstone support mechanism allows the grooved grindstone to rotate. A workpiece processing device as claimed in claim 7, wherein, there is further provided a shaping grindstone which can replace the workpiece and be mounted on the workpiece support mechanism; the shaping grindstone is moved relative to the grindstone by the grindstone support mechanism or the workpiece support mechanism in accordance with the moving condition to form an outer shape; the groove-attached grindstone abuts against the shaping grindstone to transfer the outer shape of the shaping grindstone to form or trim the groove. A workpiece processing device as claimed in claim 1 or 2, wherein the workpiece support mechanism has a temperature adjustment mechanism that generates a flow of liquid or gas for maintaining the temperature of the rotating shaft of the workpiece support mechanism at a certain level. A grinding stone is the grinding stone included in the workpiece processing device of claim 1 or 2, and is characterized in that: The straight line portion is a portion of the grinding stone with a coarser grain size than the arc-shaped portion, and the arc-shaped portion is a portion used for more precise grinding than the straight line portion. A grindstone is the grindstone included in the workpiece processing device of claim 3, characterized in that: The cross-sectional rectangular grinding portion is a portion of the grindstone with a coarser grain size than the concave grinding portion, and the concave grinding portion is a portion used for more precise grinding than the cross-sectional rectangular grinding portion. A grinding stone is included in the workpiece processing device of claim 1 or 2, wherein: The arc-shaped portion at one end in the thickness direction and the arc-shaped portion at the other end are portions formed individually in such a way that the average value of the respective curvature radii becomes a desired size. A grindstone included in the workpiece processing device of claim 1 or 2, characterized in that: The difference between the maximum value and the minimum value of the radius of curvature of the arc-shaped portion at one end in the thickness direction and the difference between the maximum value and the minimum value of the radius of curvature of the arc-shaped portion at the other end are both less than a first predetermined value; The difference between the average value of the radius of curvature of the arc-shaped portion at one end in the thickness direction and the average value of the radius of curvature of the arc-shaped portion at the other end is less than a second predetermined value. A grinding stone, which is included in the workpiece processing device of claim 1 or 2, and is characterized in that: It has a straight or tapered mounting hole extending in the thickness direction. A workpiece processing method is used to form a disk-shaped workpiece into a desired cross-sectional shape using a grindstone, the grindstone is disk-shaped and rotatable, and has a concave grinding portion on its outer periphery; the cross-sectional shape of the concave grinding portion in the cross-section along the rotation axis of the grindstone is concave from the outer periphery to the inner periphery, and at least each of the two end portions in the thickness direction has an arc-shaped portion, and between the arc-shaped portions at the two end portions, there is a shape of a straight line portion having a thickness greater than the thickness of the workpiece, and the straight line portion is used to reduce the diameter of the workpiece or smooth the middle portion of the outer periphery of the workpiece in the thickness direction. The workpiece processing method is characterized by comprising: The step of arranging the workpiece and the grindstone parallel to each other; and The step of moving the grinding stone relative to the workpiece, rotating the grinding stone and rotating the workpiece around a rotation axis parallel to the rotation axis of the grinding stone, and following a movement condition calculated based on the radius of curvature of the arc-shaped portion of the grinding stone, moving the grinding stone relative to the workpiece so that the contact portion of the concave grinding portion and the workpiece moves along the desired cross-sectional shape of the workpiece; The step of moving the grinding stone relative to the workpiece includes: The workpiece, which has only one side adsorbed by the adsorption member, and the grindstone are rotated, and the arc-shaped portion of the concave grinding portion of the grindstone is moved relative to the workpiece in a curve from the outer peripheral end face of the workpiece to one side of the face according to the angle pre-calculated according to the movement condition, thereby grinding the outer peripheral portion of the one side of the workpiece to form the chamfered portion of the desired cross-sectional shape of the workpiece; The grindstone is moved relative to the workpiece from the one side of the face to the other side of the face along the outer peripheral end face of the workpiece; and The workpiece and the grindstone are rotated, and the arc-shaped portion of the concave grinding portion of the grindstone is moved from the outer peripheral end face of the workpiece to the other side face, relative to the workpiece, in a curve according to the angle pre-calculated according to the moving condition, thereby grinding the outer peripheral portion of the other side face of the workpiece to form the chamfered portion of the desired cross-sectional shape of the workpiece; The plane shape of the adsorption component is a circle with a radius smaller than the radius of the workpiece; the outer peripheral portion of the circular adsorption component has a thinner front end shape with the thickness becoming thinner toward the outside; the radius of curvature of the arc-shaped portion of the grindstone is at least 10 times the thickness of the workpiece, so that the arc-shaped portion of the grindstone abuts against the workpiece in a manner that substantially no gap is generated between the arc-shaped portion and the chamfered portion of the desired cross-sectional shape of the workpiece; The length of the arc-shaped portion located on the single-side surface of the workpiece adsorbed by the adsorption member in the cross section along the rotation axis of the grindstone is greater than the length of the chamfered portion of the single-side surface of the workpiece of the desired cross-sectional shape, and less than the following length: the length of the end of the single-side surface of the workpiece abutting against the thinner front end of the adsorption member in a state where the tangent of the arc-shaped portion extends at an angle consistent with the angle of the thinner front end of the adsorption member; When performing rough grinding of the outer periphery of the one side or the other side of the workpiece, the workpiece and the grindstone are rotated, and the arc-shaped portion of the concave grinding portion of the grindstone is moved from the outer peripheral end face of the workpiece to the one side or the other side, in a manner that the rotation axis of the grindstone and the rotation axis of the workpiece are located in the same plane, relative to the workpiece, in a curved line that follows the angle pre-calculated according to the movement condition, and then the relative movement of the grindstone relative to the workpiece is stopped; When performing precision grinding of the outer peripheral portion of the one side or the other side of the workpiece, the workpiece and the grindstone are rotated, and the arc-shaped portion of the concave grinding portion of the grindstone is relatively moved in a curved line relative to the workpiece by an angle pre-calculated according to the moving conditions in such a manner that the rotation axis of the grindstone and the rotation axis of the workpiece are located in the same plane from the outer peripheral end face of the workpiece to the one side or the other side, and then the grindstone is relatively moved in a straight line relative to the workpiece in such a manner that the rotation axis of the grindstone and the rotation axis of the workpiece are relatively moved in a plane extending in a direction perpendicularly or obliquely intersecting the plane where the rotation axis of the grindstone and the rotation axis of the workpiece are located during the curved movement. A workpiece processing method for forming a disk-shaped workpiece into a desired cross-sectional shape using a grindstone, wherein the grindstone is rotatable, disk-shaped, and has a concave grinding portion on the outer periphery; the cross-sectional shape of the concave grinding portion in the cross-sectional shape along the rotation axis of the grindstone is a concave shape that is concave from the outer periphery to the inner periphery, and has the following shape: at least at both ends in the thickness direction, each has an arc-shaped portion, and an inclined surface portion that is located further outward in the thickness direction than the arc-shaped portion and continuously connected to the arc-shaped portion, and between the arc-shaped portions at the two ends, there is a straight line portion having a thickness greater than the thickness of the workpiece, and the straight line portion is used for at least one of reducing the diameter of the workpiece or smoothing the middle portion of the outer periphery of the workpiece in the thickness direction; The workpiece processing method is characterized by comprising: The step of arranging the workpiece and the grinding stone parallel to each other; and The step of moving the grinding stone relative to the workpiece, rotating the grinding stone and rotating the workpiece around a rotation axis parallel to the rotation axis of the grinding stone, and following a movement condition calculated based on the radius of curvature of the circular arc portion of the grinding stone, moving the grinding stone relative to the workpiece so that the concave grinding portion and the contact portion of the workpiece move along the desired cross-sectional shape of the workpiece; The step of moving the grinding stone relative to the workpiece comprises: The workpiece, which has only one side adsorbed by the adsorption member, and the grindstone are rotated, and the arc-shaped portion of the concave grinding portion of the grindstone is moved relative to the workpiece in a curve from the outer peripheral end face of the workpiece to one side of the face according to the angle pre-calculated according to the movement condition, thereby grinding the outer peripheral portion of the one side of the workpiece to form the chamfered portion of the desired cross-sectional shape of the workpiece; The grindstone is moved relative to the workpiece from the one side of the face to the other side of the face along the outer peripheral end face of the workpiece; and The workpiece and the grindstone are rotated, and the arc-shaped portion of the concave grinding portion of the grindstone is moved from the outer peripheral end face of the workpiece to the other side face, relative to the workpiece, in a curve according to the angle pre-calculated according to the moving condition, thereby grinding the outer peripheral portion of the other side face of the workpiece to form the chamfered portion of the desired cross-sectional shape of the workpiece; The plane shape of the adsorption component is a circle with a radius smaller than the radius of the workpiece; the outer peripheral portion of the circular adsorption component has a thinner front end shape with the thickness becoming thinner toward the outside; the radius of curvature of the arc-shaped portion of the grindstone is at least 10 times the thickness of the workpiece; The inclined surface portion extends along the tangent direction of the arc-shaped portion at the boundary position between the arc-shaped portion and the inclined surface portion, and its angle is consistent with the angle of the chamfered portion of the single-side surface side of the workpiece of the desired cross-sectional shape; The length of the inclined surface portion located on the single side of the workpiece adsorbed by the adsorption member in the cross section along the rotation axis of the grindstone is greater than the length of the chamfered portion of the single side of the workpiece in the desired cross-sectional shape, and less than the following length: the angle between the inclined surface portion and the single side of the workpiece in the direction of extension is smaller than the angle between the front end thinner shape of the adsorption member and the single side of the workpiece, and the end of the single side of the workpiece is in contact with the front end thinner shape of the adsorption member at a position where the tangent of the arc-shaped portion extends at an angle consistent with the angle of the front end thinner shape of the adsorption member, and the inclined surface portion abuts against the front end thinner shape of the adsorption member; When performing rough grinding of the outer periphery of the one side or the other side of the workpiece, the workpiece and the grindstone are rotated, and the arc-shaped portion of the concave grinding portion of the grindstone is moved from the outer peripheral end face of the workpiece to the one side or the other side, in a manner that the rotation axis of the grindstone and the rotation axis of the workpiece are located in the same plane, relative to the workpiece, in a curved line that follows the angle pre-calculated according to the movement condition, and then the relative movement of the grindstone relative to the workpiece is stopped; When performing precision grinding of the outer peripheral portion of the one side or the other side of the workpiece, the workpiece and the grindstone are rotated, and the arc-shaped portion of the concave grinding portion of the grindstone is moved relative to the workpiece in a curved line by an angle pre-calculated according to the moving condition in such a way that the rotation axis of the grindstone and the rotation axis of the workpiece are located in the same plane from the outer peripheral end face of the workpiece to the one side or the other side, and then the grindstone is moved relative to the workpiece in a straight line while maintaining the state that the rotation axis of the grindstone and the rotation axis of the workpiece are located in the plane where the rotation axis of the grindstone and the rotation axis of the workpiece are located during the curved movement. A workpiece processing method for forming a disk-shaped workpiece into a desired cross-sectional shape using a grindstone, wherein: the grindstone is rotatable, disk-shaped, and has a concave grinding portion on the outer periphery; the cross-sectional shape of the concave grinding portion in the cross-section along the rotation axis of the grindstone is concave from the outer periphery to the inner periphery, and is in the shape of having arc-shaped portions at at least both ends in the thickness direction, and having a straight line portion having a thickness greater than the thickness of the workpiece between the arc-shaped portions at the two ends, and the straight line portion is used to grind at least one of reducing the diameter of the workpiece or smoothing the middle portion of the outer periphery of the workpiece in the thickness direction; The workpiece processing method is characterized by comprising: The step of arranging the workpiece and the grindstone parallel to each other; and The step of moving the grinding stone relative to the workpiece, rotating the grinding stone and rotating the workpiece around a rotation axis parallel to the rotation axis of the grinding stone, and following a movement condition calculated based on the radius of curvature of the arc-shaped portion of the grinding stone, moving the grinding stone relative to the workpiece so that the contact portion of the concave grinding portion and the workpiece moves along the desired cross-sectional shape of the workpiece; The step of moving the grinding stone relative to the workpiece includes: The workpiece, which has only one side adsorbed by the adsorption member, and the grindstone are rotated, and the arc-shaped portion of the concave grinding portion of the grindstone is moved relative to the workpiece in a curve from the outer peripheral end face of the workpiece to one side of the face according to the angle pre-calculated according to the movement condition, thereby grinding the outer peripheral portion of the one side of the workpiece to form the chamfered portion of the desired cross-sectional shape of the workpiece; The grindstone is moved relative to the workpiece from the one side of the face to the other side of the face along the outer peripheral end face of the workpiece; and The workpiece and the grindstone are rotated, and the arc-shaped portion of the concave grinding portion of the grindstone is moved from the outer peripheral end face of the workpiece to the other side face, relative to the workpiece, in a curve according to the angle pre-calculated according to the moving condition, thereby grinding the outer peripheral portion of the other side face of the workpiece to form the chamfered portion of the desired cross-sectional shape of the workpiece; The plane shape of the adsorption component is a circle with a radius smaller than the radius of the workpiece; the outer peripheral portion of the circular adsorption component has a thinner front end shape with the thickness becoming thinner toward the outside; the radius of curvature of the arc-shaped portion of the grindstone is at least 10 times the thickness of the workpiece, so that the arc-shaped portion of the grindstone abuts against the workpiece in a manner that substantially no gap is generated between the arc-shaped portion and the chamfered portion of the desired cross-sectional shape of the workpiece; The length of the arc-shaped portion located on the single-side surface of the workpiece adsorbed by the adsorption member in the cross section along the rotation axis of the grindstone is greater than the length of the chamfered portion of the single-side surface of the workpiece of the desired cross-sectional shape, and less than the following length: the length of the end of the single-side surface of the workpiece abutting against the thinner front end of the adsorption member in a state where the tangent of the arc-shaped portion extends at an angle consistent with the angle of the thinner front end of the adsorption member; When performing rough grinding of the outer periphery of the one side face or the other side face of the workpiece, the workpiece and the grindstone are rotated, and the arc-shaped portion of the concave grinding portion of the grindstone is moved from the outer peripheral end face of the workpiece to the one side face or the other side face in a curve relative to the workpiece following the angle pre-calculated according to the movement condition, and then the relative movement of the grindstone relative to the workpiece is stopped; When performing precision grinding of the outer peripheral portion of the one side of the workpiece, the workpiece and the grindstone are rotated, and considering the position error in the thickness direction generated when the workpiece rotates, the arc-shaped portion of the concave grinding portion of the grindstone is moved from the outer peripheral end face of the workpiece to the one side of the face in the thickness direction, with the position of the workpiece passing through the rotation as the reference, relative to the workpiece, by an angle calculated in advance according to the movement conditions, and then the movement is stopped. At the position where the grindstone and the chamfered portion of the one side of the workpiece contact, the position of the workpiece in the thickness direction is adjusted and the rotation speed of the workpiece is slowed down, so that the workpiece rotates at least one circle, thereby offsetting the position error of the workpiece during rotation and grinding the one side of the workpiece; When performing precision grinding of the outer peripheral portion of the other side of the workpiece, the workpiece and the grindstone are rotated, and considering the position error in the thickness direction generated when the workpiece rotates, the arc-shaped portion of the concave grinding portion of the grindstone is moved from the outer peripheral end face of the workpiece to the other side of the workpiece by an angle calculated in advance according to the movement conditions, based on the outermost position of the other side of the workpiece in the thickness direction passed by the workpiece when rotating, and then the movement is stopped. At the position where the grindstone and the chamfered portion of the other side of the workpiece contact, the position of the workpiece in the thickness direction is adjusted and the rotation speed of the workpiece is slowed down so that it rotates at least one circle, thereby offsetting the position error of the workpiece during rotation and grinding the other side of the workpiece.

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