JP2011079104A - Chuck device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance the chucking accuracy of a chuck device suitable for grasping a workpiece having a tapered surface on its tapered surface. <P>SOLUTION: A jaw holder 20 is mounted on a chuck body 10 slidably in the radial direction of a spindle 2, and a jaw 30 is mounted on each jaw holder 20 turnably on the plane including the axis of the spindle 2. A grip part 31 of each jaw can be reliably grasped along a peripheral surface of a workpiece W by advancing/retracting each jaw holder 30, and turning each jaw 30 in the forward/reverse direction. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a chuck device and a chuck method that are suitable for grasping a workpiece having a tapered surface attached to a spindle end of a machine tool by the tapered surface.

  When machining a workpiece (object to be processed) having a tapered surface on the peripheral surface, such as a tapered ring of a tapered roller bearing, with a machine tool, grasp the tapered surface with a chuck device attached to the spindle end of the machine tool. Need to do.

As a chuck device for grasping the taper surface of such a workpiece, as disclosed in Patent Document 1, there is a collet chuck device in which the inner diameter surface of the inner diameter grasping collet is a tapered surface.
As disclosed in Patent Document 2, the gap between the chuck device and the taper surface of the workpiece is filled and fixed with resin during processing, and the workpiece is removed from the chuck by melting and removing the resin when processing is completed. There is a chuck device that made it possible.

However, in the case of the collet chuck device of Patent Document 1, if the inclination angle and diameter of the tapered surface of the collet and the inclination angle and diameter of the tapered surface of the workpiece do not match due to a design error or the like, there is a gap between both tapered surfaces. As a result, sufficient gripping power cannot be obtained, and the chucking accuracy is poor.
Further, in the case of the chuck device of Patent Document 2, since it is necessary to repeat the resin filling operation and the removing operation every time it is used, there is a drawback that it takes time and effort for chucking.

JP 07-051909 A Japanese Patent Laid-Open No. 06-039601

  Therefore, the problem to be solved by the present invention is to increase the chucking accuracy and shorten the chucking time for a chuck device suitable for grasping a workpiece having a tapered surface by the tapered surface.

In order to solve the above-described problems, a chuck device according to the invention is fixed to a spindle end of a machine tool and positioned by placing an end face of a workpiece against a tip of the chuck device, and the diameter of the spindle relative to the chuck body. A plurality of jaw holders that are slidable in the direction of the main shaft and are arranged in parallel in the circumferential direction of the main shaft, and are attached to each of the jaw holders so as to be rotatable on a plane including the axis of the main shaft. A plurality of jaws having a grip portion at a location facing the surface, first drive means for moving the jaw holders forward and backward in the radial direction of the main shaft, and each jaw on a plane including the axis of the main shaft. The second drive means for forward and reverse rotation is provided.
Then, the jaws are moved by the first and second driving means so that the peripheral surface of the workpiece can be grasped by the entire surface of the grip portion.

The jaws can be moved back and forth in the radial direction of the main shaft, and can be rotated forward and backward on the plane that includes the axis of the main shaft. As a result, the workpiece can be grasped with certainty and the accuracy of chucking is increased.
Because the chucking accuracy is high and the gripping force is strong, it can be used for high-load machining such as when the workpiece is made of hardened steel.

Further, since the workpiece is grasped only by the jaws, it is not necessary to repeat the filling and removing operations of the resin each time it is used unlike the chuck device of Patent Document 2.
Furthermore, since the tilt angle can be changed by rotating the jaw, it is not necessary to replace the jaw when chucking various workpieces having different grip surface tilt angles.
Therefore, it is possible to perform chucking in a short time without trouble.

Since almost the entire grasping surface of the workpiece is grasped with almost equal force, deformation of the workpiece during chucking can be prevented.
Furthermore, since the structure is simple, mass production is possible and manufacturing costs can be reduced.

As such a chuck device, both an outer diameter chucking method for grasping the outer peripheral surface of the workpiece and an inner diameter chucking method for grasping the inner peripheral surface of the workpiece are included.
In the case of the inner diameter chuck method, the workpiece is a cylindrical workpiece having an inner peripheral surface, each jaw holder is inserted into the cylindrical workpiece, and each jaw is attached to the outer diameter side of the jaw holder. .

  When the chuck device is of an inner diameter chuck type, the first driving means urges the draw bar, which is slidable in the axial direction of the main shaft through the main shaft, and the jaw holders so as to approach each other. It is preferable that the elastic member and a tapered portion formed on the inner diameter side of the jaw holder and pressed in the radial direction of the main shaft by the draw bar contact are simple and reliable.

Further, in the case of this inner diameter chuck system, the jaw has a position where its tip end is inclined in a direction away from the axis of the main shaft with respect to the rear end, and a position parallel to the axis of the main shaft. It is possible to adopt a configuration that enables rotation between the two.
With this configuration, when the inner peripheral surface of the workpiece is a tapered surface, the workpiece can be loaded into the chuck device from the small diameter side of the tapered surface by making the jaw parallel to the axis of the main shaft, Then, it is possible to grasp the jaw by rotating the jaw in a direction in which the front end portion is farther from the axis of the main shaft than the rear end portion.
In this case, since a force acts in a direction in which the workpiece is pulled into the chuck device, the grasping force can be further increased.

  It is preferable that the second driving means is composed of a cylinder having a piston slidable in the axial direction of the main shaft and an arm that links and connects the jaw and the piston because the structure is simple and the reliability is high.

  By adopting a configuration in which the grip portion of the jaw has a plurality of seating sensors for determining whether or not the peripheral surface of the workpiece is in contact with each other in parallel in the axial direction of the main shaft, the workpiece can be moved over the entire surface of the grip portion. It is preferable because it can be confirmed with a simple configuration whether or not it has been grasped.

  As a specific chucking method, the grip portions of the plurality of jaws are opposed to the tapered surface of the workpiece, and the plurality of jaws are arranged until a part of the grip portion contacts the tapered surface of the workpiece. From the step of sliding in the radial direction of the main shaft and a state in which a part of the grip portion of the jaw is in contact with the taper surface of the work, the plurality of jaws are substantially entirely on the taper surface of the work. Preferably, the method includes a step of rotating on a plane including the axis of the main shaft until contact.

  Alternatively, on the plane including the step of causing the grip portions of the plurality of jaws to face the taper surface of the workpiece, the sub-step of sliding the plurality of jaws by a predetermined amount in the radial direction of the main shaft, and the axis of the main shaft It is preferable that the step further comprises the step of bringing the entire grip portion into contact with the taper surface of the workpiece by alternately repeating sub-steps of rotating a predetermined angle.

  Since the jaws can be moved back and forth in the radial direction of the main shaft and can be rotated forward and backward on a plane including the axis of the main shaft, the degree of freedom of movement is high and the peripheral surface of the workpiece can be reliably grasped.

1 is a longitudinal sectional view of a chuck device according to a first embodiment. 1 is a longitudinal sectional view of a chuck device according to a first embodiment. 1 is a longitudinal sectional view of a chuck device according to a first embodiment. 1 is a longitudinal sectional view of a chuck device according to a first embodiment. Longitudinal sectional view of the chuck device of the second embodiment Vertical sectional view of the chuck device of the third embodiment

  Embodiments of the present invention will be described below with reference to the drawings.

  A chuck device 1 of an inner diameter chuck system according to the first embodiment shown in FIGS. 1 to 4 is attached to a tip end portion of a spindle 2 of a spindle head of a machine tool, and has a cylindrical work whose inner peripheral surface is a tapered surface t. It is suitably used for grasping the tapered surface t of W.

Specifically, the chuck device 1 includes a chuck main body 10 fixed to an end portion (main shaft end) of the main shaft 2, a plurality of jaw holders 20 attached to the chuck main body 10 so as to be slidable in the radial direction of the main shaft 2, A plurality of jaws 30 attached to each jaw holder 20 so as to be rotatable on a plane including the axis of the main shaft 2 are provided.
Further, a draw bar 3 is inserted into the main shaft 2 of the machine tool in a nested manner. The draw bar 3 is slidable in the axial direction of the main shaft 2, and the tip thereof has a tapered taper.

  The chuck body 10 includes a donut plate-shaped base 11 fixed to the end of the main shaft 2, a sleeve 12 fixed to the peripheral edge of the front surface of the base 11, and a stopper ring 13 fixed to the tip of the sleeve 12; The drawbar 3 is inserted through the base 11 having a donut plate shape.

A plurality of block-type jaw holders 20 are arranged at equal intervals in the circumferential direction of the main shaft 2, and the rear part is surrounded by the sleeve 12 and the stopper ring 13 of the chuck body 10.
The jaw holder 20 is fitted to the front surface of the base 11 of the chuck body 10 so that the jaw holder 20 can slide in the radial direction of the main shaft 2. Furthermore, each jaw holder 20 is biased in a direction approaching the draw bar 3 by an elastic member (not shown).

Further, a taper portion 21 that is inclined in the same direction as the tip portion of the draw bar 3 is formed on the inner diameter portion of the jaw holder 20. Here, the diameter of the draw bar 3 excluding the tip portion is larger than the diameter of the virtual circle connecting the tapered portions 21 of the plurality of jaw holders 20 that are close to each other by the biasing of the elastic member.
Therefore, when the draw bar 3 moves forward, the tip portion thereof comes into contact with the tapered portion 21 of the jaw holder 20, and then the jaw holder 20 is pushed in the radial direction by the wedge action. Therefore, the jaw holder 20 slides in directions away from each other. Further, when the draw bar 3 moves backward, the jaw holder 20 is released from such radial pressing, and slides in a direction approaching each other again.
The draw bar 3, the elastic member, and the taper portion 21 constitute a first driving unit of the chuck device 1.

Further, each jaw holder 20 has a built-in cylinder 22, and its piston is slidable in the axial direction of the main shaft 2 by hydraulic oil fed from an oil passage (not shown) communicating with the cylinder 22. .
Further, the outer diameter portion of the jaw holder 20 forms a tapered portion 23.

  Each jaw 30 is pin-coupled to the tip of the jaw holder 20 with the tip thereof inclined toward the axis of the main shaft 2 rather than the rear end, and the pin joint is used as a center. It can rotate on a plane including the axis of the main shaft 2.

Further, the rear end portion of the jaw 30 and the rod portion of the piston of the cylinder 22 are linked by an arm 32. For this reason, when the piston moves forward and backward in the axial direction of the main shaft 2, the jaw 30 rotates forward and backward.
The rotation range is between a position where the jaw 30 follows the follower 23 of the jaw holder 20 and a position where the piston of the cylinder 22 has advanced to the limit. As shown in the drawing, the tip end portion of the stopper ring 13 is notched on the inner diameter side so as not to obstruct the rotation of the jaw 30.
The cylinder 22 and the arm 32 constitute a second drive unit of the chuck device 1.

  The jaw 30 has a grip portion 31 on the outer diameter side, and a plurality of seating sensors arranged in parallel in the axial direction of the main shaft 2 (not shown) are attached to the grip portion 31. The seating sensor is configured to be able to determine whether or not the peripheral surface of the workpiece W has come into contact with the grip portion 31 by a change in air pressure.

  The configuration of the chuck device 1 according to the first embodiment is as described above. Next, the operation will be described with reference to FIGS.

  First, as shown in FIGS. 1 and 2, when the jaw holder 20 of the chuck device 1 is inserted into a cylindrical workpiece W and the end surface of the workpiece W is brought into contact with the stopper ring 13 of the chuck body 10, the workpiece W is positioned. At this time, the center 4 of the tailstock is pressed from the front of the workpiece W in the axial direction to prevent the workpiece W from coming off. In this state, as shown in the figure, the inner peripheral tapered surface t of the workpiece W and the grip portion 31 of the jaw 30 are opposed to each other.

  Next, as shown in FIGS. 2 to 3, the draw bar 3 is moved forward to move the jaw holder 20 in the radial direction so that a part of the grip portion 31 of the jaw 30 abuts against the tapered surface t of the workpiece W. . Whether or not a part of the grip portion 31 is in contact with the tapered surface t of the workpiece W can be determined by a change in at least one air pressure of the seating sensor.

  Further, as shown in FIG. 3, the cylinder 22 is operated to rotate the jaw 30 until substantially the entire grip portion 31 comes into contact with the tapered surface t of the workpiece W. Whether or not the entire grip portion 31 is in contact with the tapered surface t of the workpiece W can be determined by changing all the air pressures of the seating sensor.

  When it is confirmed that the workpiece W is fixed to the spindle stock by the chuck device 1, the spindle is rotated and the workpiece W is cut by the cutting tool B attached to the tool post as shown in FIG. After processing, the workpiece W is removed from the chuck device 1 by performing the reverse operation to that described above.

As described above, the jaw 30 can be moved back and forth in the radial direction of the main shaft 2 and can be rotated forward and backward on a plane including the axis of the main shaft 2. It is possible to reliably grasp in a short time along the peripheral surface (grasping surface) of the workpiece W.
Note that the plurality of jaws 30 may be individually controlled to rotate or may be controlled to rotate in synchronization.

The chuck device 1 of the outer diameter chuck type of the second embodiment shown in FIG. 5 is also attached to the end of the spindle 2 of the machine tool, and the tapered surface t of the cylindrical workpiece W whose outer peripheral surface is a tapered surface t. It is suitably used for grasping.
Detailed description of the same configuration as that of the chuck device 1 of the first embodiment will be omitted.

In this embodiment, the jaw holder 20 is attached to the base 11 at equal intervals in the circumferential direction of the main shaft 2 so as to surround the sleeve 12 and the stopper ring 13 of the chuck body 10 and is slidable in the radial direction of the main shaft 2. It has become.
The jaw holder 20 can be changed in slide position by known means such as screw feeding.

  Each jaw 30 has a grip portion 31 on its inner diameter side, a tip portion of which is pin-coupled to a tip portion of the jaw holder 20, a rear end portion, and a rod portion of a piston of a cylinder 22 built in the jaw holder 20. Are linked by the arm 32 so that the jaw 30 can be rotated forward and backward on a plane including the axis of the main shaft 2.

The configuration of the chuck device 1 according to the second embodiment is as described above. Next, the operation thereof will be described.
When the end face of the cylindrical workpiece W is brought into contact with the stopper ring 13 of the chuck body 10, the workpiece W is positioned, and when the center 4 of the tailstock is pressed from the front side in the axial direction of the workpiece W, it is prevented from coming off.
In this state, the outer peripheral tapered surface t of the workpiece W and the grip portion 31 of the jaw 30 are opposed to each other.

Next, when the jaw holder 20 is moved by a predetermined amount in the radial direction and when the cylinder 22 is actuated to rotate the jaw 30 by a predetermined angle, substantially the entire grip portion 31 contacts the tapered surface t of the workpiece W. Repeat until touching. It can be determined whether all the air pressures of the seating sensor are changed or not.
Here, the sliding amount in the radial direction per one operation of the jaw holder 20 and the planar rotation angle can be arbitrarily set.

In the chuck device 1 of the third embodiment shown in FIG. 6, in the inner diameter chuck system, the inclination direction of the jaw 30 is opposite to that of the first embodiment, that is, the tip end portion of the jaw 30 is the axis of the main shaft 2 rather than the rear end portion. Inclined away from the heart.
In this case, the jaw 30 is rotatable until it becomes parallel to the axis of the main shaft 2.

If comprised in this way, the workpiece | work W can be loaded into the chuck | zipper apparatus 1 from the small diameter side of the taper surface t by making the jaw 30 in parallel with the axial center of the main axis | shaft 2. FIG. The jaw 30 can then be rotated for chucking. In this case, since a force acts in the direction in which the workpiece W is pulled into the chuck device 1, the grasping force can be further increased.
Further, when the chuck device 1 is loaded from the small diameter side of the taper surface t of the workpiece W, it is not necessary to remove the chuck device 1 from the main shaft 2 and time and effort are not required for chucking.
Similarly, also in the outer diameter chuck system, the inclination direction of the jaw 30 may be opposite to that in the second embodiment.

The structure of the chuck body 10 is not limited to that of the embodiment, and the main point is that the chuck body 10 may be fixed to the main shaft 2 and positioned by contacting the end face of the workpiece W.
The structure of the jaw holder 20 is not limited to that of the embodiment. In short, the jaw holder 20 may be attached to the chuck body 10 so as to be slidable in the radial direction of the main shaft 2. The number of jaw holders 20 is also arbitrary, such as three or four.
The structure and the number of the jaws 30 are not limited to those in the embodiment.
The first drive means for moving the jaw holder 20 in the radial direction and the second drive means for rotating the jaw 30 are not limited to the embodiment, and a known drive mechanism such as a motor can be used. . As the seating sensor, a known sensor other than the pneumatic sensor may be used, or may be omitted depending on circumstances.
Of course, the chuck device 1 is also used for grasping a workpiece whose peripheral surface is not a tapered surface.

1 Chuck Device 2 Spindle 3 Draw Bar 4 Center of Tailstock 10 Chuck Body 11 Base 12 Sleeve 13 Stopper Ring 20 Jaw Holder 21 Taper 22 Cylinder 23 Shaft 30 Jaw 31 Grip 32 Arm W Work t Tapered Surface B Bit

Claims (8)

A chuck body 10 which is fixed to the spindle end of the machine tool and which positions the tip of the workpiece against the end face of the workpiece;
A plurality of jaw holders 20 attached to the chuck body 10 so as to be slidable in the radial direction of the main shaft 2 and parallel to the circumferential direction of the main shaft 2;
A plurality of jaws 30 attached to the jaw holders 20 so as to be rotatable on a plane including the axis of the main shaft 2 and having grip portions 31 at locations facing the peripheral surface of the workpiece;
First driving means for moving each jaw holder 20 forward and backward in the radial direction of the main shaft;
A chuck device comprising second driving means for rotating each jaw 30 forward and backward on a plane including the axis of the main shaft 2. The workpiece is a cylindrical workpiece having an inner peripheral surface;
Each jaw holder 20 is inserted into this cylindrical workpiece,
The chuck device according to claim 1, wherein each of the jaws is attached to an outer diameter side of the jaw holder. The first driving means includes
A draw bar 3 which is inserted through the main shaft 2 and is slidable in the axial direction of the main shaft 2;
An elastic member that urges the jaw holders 20 toward each other;
The chuck device according to claim 2, comprising a taper portion 21 formed on an inner diameter side of the jaw holder 20 and pushed in a radial direction of the main shaft 2 by abutment of the draw bar 3.   The jaw 30 is capable of rotating between a position where the tip end is inclined in a direction away from the axis of the main shaft 2 and a position parallel to the axis of the main shaft 2 than the rear end. The chuck device according to claim 2 or 3. The second driving means includes
A cylinder 22 having a piston slidable in the axial direction of the main shaft 2;
The chuck device according to any one of claims 1 to 4, comprising an arm 32 for linking the jaw 30 and the piston.   6. The grip portion 31 of the jaw 30 has a plurality of seating sensors for determining whether or not the peripheral surface of the workpiece is in contact with each other in parallel in the axial direction of the main shaft 2. Chuck device. A chuck method for grasping a tapered surface of a workpiece having a tapered surface on an outer peripheral surface or an inner peripheral surface with grip portions 31 of a plurality of jaws 30 arranged in parallel in a circumferential direction on a spindle end of a machine tool,
Making the grip portions 31 of the plurality of jaws 30 face the taper surface of the workpiece;
Sliding the plurality of jaws 30 in the radial direction of the main shaft 2 until a part of the grip portion 31 comes into contact with the tapered surface of the workpiece;
From a state in which a part of the grip portion 31 of the jaw 30 is in contact with the tapered surface of the workpiece, the spindle 2 is moved until substantially the entire grip portion 31 contacts the tapered surface of the workpiece. A chucking method comprising the step of rotating on a plane including the axis of. A chuck method for grasping a tapered surface of a workpiece having a tapered surface on an outer peripheral surface or an inner peripheral surface with grip portions 31 of a plurality of jaws 30 arranged in parallel in a circumferential direction on a spindle end of a machine tool,
Making the grip portions 31 of the plurality of jaws 30 face the taper surface of the workpiece;
The grip portion 31 is obtained by alternately repeating a sub-step of sliding the plurality of jaws 30 by a predetermined amount in the radial direction of the main shaft 2 and a sub-step of rotating a predetermined angle on a plane including the axis of the main shaft 2. A chuck method comprising the step of bringing substantially the entire surface into contact with the tapered surface of the workpiece.

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