JP2018151216A - Workpiece centering device and roundness measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a work centering device and a roundness measuring device capable of measuring a place where a chuck member of a work centering device is in contact. When a stylus 38 is brought into contact with a portion d to which a diaphragm blade 54 is in contact to measure a location d, the three diaphragm blades 54 are retracted away from the center c of a chuck table 58. Return to position. After that, the stylus 38 is brought into contact with the point d to measure the point d. Since the work W is fixed to the surface of the chuck table 58 by a magnetic force, the work W is measured in a centered state without being displaced with respect to the chuck table 58. [Selection diagram] FIG. 8

Description

  The present invention relates to a workpiece centering device and a roundness measuring device, and more particularly, a workpiece centering device that aligns the center axis of a workpiece with the rotation axis of a measurement table of the roundness measuring device, and the workpiece centering device. It is related with the roundness measuring apparatus provided with.

  2. Description of the Related Art Conventionally, a roundness measuring device that measures the roundness of a circular workpiece such as a cylindrical object or a cylindrical object is known (see Patent Document 1 and the like). For example, the roundness measuring apparatus places a workpiece on a rotatable measurement table, brings the measuring element into contact with the surface of the workpiece, and measures the displacement of the measuring element accompanying the rotation of the workpiece. Measure circularity.

  In such a roundness measuring machine, it is necessary to make the center axis of the workpiece coincide with the rotation center of the measuring table prior to measuring the workpiece. For this reason, a work table in which a workpiece centering device is mounted is known. As a workpiece centering device, for example, a chuck disclosed in Patent Document 2 (hereinafter referred to as a scroll chuck) or a centering device having an aperture blade disclosed in Patent Document 3 (hereinafter referred to as an iris chuck). )It has been known. These centering devices include a plurality of chuck members. The scroll chuck has a chuck claw as a chuck member, and the iris chuck has a diaphragm blade.

  The scroll chuck (also the iris chuck) has a chuck body on which a workpiece is placed and a plurality of chuck claws (aperture blades in the case of an iris chuck) provided around the center of the chuck body. By simultaneously linking a plurality of chuck claws toward the center of the chuck body corresponding to the center of rotation of the table, the work is moved on the chuck body so that the center axis of the work matches the rotation center of the measurement table. Yes.

JP 2012-145492 A Japanese Patent No. 5585460 JP 2012-64585 A

  However, the roundness measuring device provided with the workpiece centering device can measure the roundness of the workpiece in a state where the chuck member of the workpiece centering device is in contact with the workpiece, that is, in a state where the centering is held by the chuck member. Since the measurement is to be performed, the probe cannot be brought into contact with the portion where the chuck member is in contact, and there is a problem in that measurement of the portion cannot be performed.

  The present invention has been made in view of such circumstances, and even if the chuck member of the workpiece centering device is in contact with the workpiece, the workpiece centering device capable of measuring the location, and An object is to provide a roundness measuring device.

  In order to achieve the object of the present invention, a workpiece centering device of the present invention comprises a chuck table on which a magnetic workpiece is placed and a plurality of chuck members provided around the center of the chuck table. Then, the workpiece placed on the surface of the chuck table is moved toward the center of the chuck table by interlocking from the standby position toward the center of the chuck table, and the center axis of the workpiece is aligned with the center of the chuck table. A plurality of chuck members, and magnets arranged on the back surface of the chuck table, the magnets fixing the work center axis of the chuck table to the center of the chuck table by the chuck members to the surface of the chuck table; Is provided.

  According to the workpiece centering device of the present invention, first, a plurality of chuck members are kept waiting at a position spaced from the center of the chuck table, and in this state, a magnetic workpiece is placed at an arbitrary position on the surface of the chuck table. Place. Next, when the plurality of chuck members are interlocked toward the center of the chuck table, the workpiece placed on the surface of the chuck table is pushed by the plurality of chuck members and moved toward the center of the chuck table. Go. When the workpiece is completely sandwiched between the plurality of chuck members, the interlocking of the plurality of chuck members stops, and the workpiece is centered at that time. That is, the center axis of the work coincides with the center of the chuck table.

  Next, when measuring the location where the chuck member is abutted, the plurality of chuck members are returned to the retracted position separated from the center of the chuck table, and then the location is measured. At this time, since the workpiece is fixed to the surface of the chuck table by a magnetic force, the workpiece is measured in a centered state without being displaced with respect to the chuck table. Therefore, by using the workpiece centering device of the present invention, even if the chuck member of the workpiece centering device is in contact with the workpiece, the location can be measured.

  In one embodiment of the present invention, it is preferable that a plurality of magnets are arranged along a radial direction from the center of the chuck table.

  In one embodiment of the present invention, it is preferable that a plurality of magnets be arranged along a concentric circle centering on the center of the chuck table.

  According to one aspect of the present invention, workpieces having different diameters or inner diameters can be fixed using the same chuck table.

  In one embodiment of the present invention, the magnet is preferably a permanent magnet.

  In one embodiment of the present invention, the magnet is preferably an electromagnet.

  According to one embodiment of the present invention, the configuration of a workpiece centering device can be simplified by using a permanent magnet as a magnet. Further, by using an electromagnet as the magnet, it is possible to generate a magnetic force when necessary, or to generate a magnetic force having a magnitude corresponding to the size or material of the workpiece.

  In order to achieve the object of the present invention, a roundness measuring device of the present invention includes a base, a measurement table provided on the base, a workpiece centering device of the present invention mounted on the measurement table, A detector that has a probe that comes into contact with the workpiece placed on the chuck table of the workpiece centering device and detects the displacement of the probe when the workpiece and the workpiece centering device are relatively rotated. And comprising.

  According to the roundness measuring device of the present invention, since the workpiece centering device of the present invention is provided, even when the chuck member of the workpiece centering device is in contact with the roundness measuring device, the measurement of the location is performed. It can be carried out.

  According to the present invention, even if the chuck member of the workpiece centering device is in contact with the workpiece, it is possible to measure the location.

Whole perspective view of roundness measuring apparatus of embodiment The block which showed the composition of the roundness measuring device of an embodiment Top view of centering device with aperture blades in open position Top view of the centering device with the diaphragm blades positioned at the diaphragm position Top view of the centering device where the work is centered by the centering device FIG. 3 is a longitudinal sectional view of the centering device along the line AA in FIG. A plan view of a centering device showing an example of an arrangement of magnets Explanatory drawing showing work centering procedure and roundness measurement The top view of the centering apparatus which showed the other example of the arrangement | sequence form of a magnet

  Hereinafter, a workpiece centering device and a roundness measuring device according to the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a perspective view showing an appearance of a roundness measuring device 12 provided with a workpiece centering device (hereinafter referred to as a centering device) 10 according to an embodiment. FIG. 2 is a block diagram showing the configuration of the roundness measuring device 12.

  As shown in FIGS. 1 and 2, the roundness measuring device 12 includes a measuring machine main body 14 and an arithmetic processing unit 16.

  As shown in FIG. 1, the measuring machine main body 14 includes a base 17 and a measurement table (hereinafter referred to as a table) 18 that is rotatably provided on the base 17. The centering device 10 of the embodiment is mounted on the table 18. The centering device 10 will be described later.

  The table 18 is provided with an X-direction fine movement knob 20 and a Y-direction fine movement knob 22 on its side surface. The X-direction fine adjustment knob 20 and the Y-direction fine adjustment knob 22 are respectively connected to a table moving shaft (not shown). By operating the X-direction fine adjustment knob 20 and the Y-direction fine adjustment knob 22, the table 18 is moved in the X-direction and Y-direction. Fine feed in the direction. Thereby, the horizontal position of the table 18 is finely adjusted.

  Further, the table 18 includes an X-direction tilt knob 24 and a Y-direction tilt knob 26 on its side surface. By operating the X-direction tilt knob 24 and the Y-direction tilt knob 26, the tilt angle in the X direction and the Y direction of the table 18 is finely adjusted.

  In addition, a rotation mechanism 28 is provided inside the base 17 and below the table 18. The rotating mechanism unit 28 rotates the table 18 to rotate the workpiece W centered by the centering device 10 together with the centering device 10. In the following description, when “centering” is referred to, the centering device 10 causes the center axis “a” of the workpiece W to coincide with the rotation center “b” of the table 18. The configuration and operation of the centering device 10 will be described later.

  As shown in FIG. 1, a column 30 is erected on the base 17 along the Z direction (up and down direction), and a slider 32 is mounted on the column 30 so as to be movable in the Z direction. A horizontal arm 34 is mounted on the slider 32 so as to be movable in the horizontal direction. A detector 36 is provided at the tip of the horizontal arm 34, and the detector 36 is provided with a probe 38.

  At the time of measuring the workpiece W by the roundness measuring device 12, the workpiece W is placed on the centering device 10, and after centering by the centering device 10, the probe 38 is brought into contact with the outer peripheral surface of the workpiece W. The work W is rotated by the table 18. As a result, the displacement of the probe 38 is detected by the detector 36, and the displacement signal from the detector 36 is transmitted to the arithmetic processing unit 16 of FIG. 2 and processed by the arithmetic processing unit 16.

  The roundness measuring device 12 of the embodiment is a device that rotates the table 18 with respect to the detector 36, but may be a device that rotates the detector 36 with respect to the table 18. Further, an electric micrometer using a differential transformer is used as the detector 36, and the displacement of the probe 38 is detected by this electric micrometer.

  As shown in FIG. 2, the rotation mechanism 28 of the table 18 includes a bearing 39, an encoder 40, a motor 42, and the like. The table 18 is rotatably supported by the base 17 (see FIG. 1) via a bearing 39 and is rotated by the power of the motor 42. As the bearing 39, for example, an ultra-high precision static pressure air bearing is used, whereby the table 18 is rotated with high rotational accuracy. The encoder 40 is attached to the rotating shaft 43 of the motor 42, and the encoder 40 reads the rotation angle of the rotating shaft 43 with high accuracy.

  The arithmetic processing unit 16 includes an amplifier 44, an A / D converter 46, and arithmetic / processing means 48. The arithmetic processing unit 16 includes a program 50 for controlling the arithmetic processing unit 16 and a display unit 52 for displaying the processing result.

   The arithmetic processing unit 16 amplifies the detection signal (analog voltage value) from the detector 36 by the amplifier 44 and then converts it into a digital signal by the A / D converter 46. The calculation / processing unit 48 calculates the roundness of the outer peripheral surface of the workpiece W based on the rotation angle data input from the encoder 40 and the digital signal converted by the A / D converter 46, The calculation result is displayed on the display means 52.

  Next, the centering device 10 of the embodiment will be described.

  FIG. 3 is a plan view of the centering device 10 according to the embodiment, and is a plan view of the centering device 10 in which three diaphragm blades (chuck members) 54, 54, 54 are positioned in the open position. FIG. 4 is a plan view of the centering device 10 in which the three diaphragm blades 54, 54, 54 are positioned at the diaphragm position. FIG. 5 is a plan view of the centering device 10 in which the workpiece W is centered by the centering device 10. FIG. 6 is a longitudinal sectional view of the centering device 10 taken along the line AA of FIG.

  The centering device 10 of the embodiment shown in FIGS. 3 to 6 has a structure called a so-called iris chuck, and includes three diaphragm blades 54 formed in a substantially crescent shape, a base plate 56, a chuck A table 58, a plurality of magnets 60, a holding ring 62, an operation ring 64, and a magnetic shield plate 66 are provided.

  The base plate 56 is configured in a circular shape in plan view. As shown in the cross-sectional view of FIG. 6, the base plate 56 is formed with a circular recess 68 in a plan view on the back side thereof, and the recess 68 is fitted to the upper portion of the table 18 indicated by a two-dot chain line in FIG. . Accordingly, the centering device 10 is mounted on the table 18 in a state where the center c of the base plate 56 is aligned with the rotation center b of the table 18.

  A circular pedestal portion 70 is formed in a central portion on the surface side of the base plate 56 so as to protrude from the surface 56 </ b> A of the base plate 56 in a plan view. A chuck table 58 is provided integrally with the pedestal 70 at the center of the pedestal 70. The chuck table 58 is a table on which a workpiece W (see FIG. 5) is placed, and is configured in a circular shape in plan view.

  Note that, as will be described later, the magnetic workpiece W that is a measurement object is fixed to the surface of the chuck table 58 by the magnetic force of the magnet 60. For this reason, the chuck table 58 is made of, for example, austenitic stainless steel that is a non-magnetic material, but is not limited thereto. The chuck table 58 may be made of a resin as long as the work W can be fixed to the surface of the chuck table 58 by the magnetic force of the magnet 60.

  As shown in FIG. 6, a plurality of magnets 60 configured in a columnar shape are arranged and arranged on the back surface of the chuck table 58. The magnet 60 is a permanent magnet.

  FIG. 7 is a plan view of the centering device 10 showing an example of the arrangement of the magnets 60 with respect to the chuck table 58. In FIG. 7, the three diaphragm blades 54 are omitted in order to make the arrangement form of the magnets 60 easier to understand. According to FIG. 7, a plurality of magnets 60 are arranged along the radial direction from the center c of the chuck table 58. Specifically, a plurality of magnets 60 are arranged in close contact along six radial rows extending in the radial direction from the center c of the chuck table 58.

  By arranging the magnet 60 in this way, the magnetic force of the magnet 60 can be applied to the entire surface of the chuck table 58 substantially evenly. Therefore, even if the workpiece W has a different diameter or inner diameter, the workpiece W can be fixed by the same chuck table 58.

  On the other hand, the holding ring 62 shown in FIG. 6 is fitted and fixed to the pedestal portion 70. Three pins 72 (see FIGS. 3 and 4) are provided on the surface of the holding ring 62 at equal intervals along the inner periphery of the holding ring 62. One end of the diaphragm blade 54 is rotatably connected to the pin 72.

  The three diaphragm blades 54 are provided around the center c of the chuck table 58. The three diaphragm blades 54 are arranged so as to cross each other above the chuck table 58, and a cam groove 74 is formed at the other end. A pin 76 provided on the back surface of the operation ring 64 is fitted in the cam groove 74.

  As shown in FIG. 6, the operation ring 64 is rotatably provided with its outer peripheral flange portion 64 </ b> A being in sliding contact with the outer peripheral flange portion 62 </ b> A of the holding ring 62 and using the outer peripheral flange portion 62 </ b> A of the holding ring 62 as a guide. Further, as shown in FIG. 3, a knob 78 is provided on the outer peripheral flange portion 64 </ b> A of the operation ring 64, and the operation ring 64 is rotated using this knob 78.

  When the operation ring 64 is rotated in the arrow B direction from the open position in FIG. 3, the pin 76 provided on the operation ring 64 also moves in the same direction. As a result, the aperture blade 54 connected to the pin 76 via the cam groove 74 is interlocked toward the center c of the chuck table 58 and positioned at the aperture position shown in FIG. When the operation ring 64 is rotated in the direction of arrow C from the throttle position in FIG. 4, the pin 76 provided on the operation ring 64 also moves in the same direction. As a result, the aperture blade 54 connected to the pin 76 via the cam groove 74 is interlocked in a direction away from the center c of the chuck table 58, and is located at the open position shown in FIG.

  As shown in FIG. 6, the magnetic shield plate 66 is provided on the back side of the chuck table 58 so as to hold the magnet 60 with the chuck table 58. The magnetic shield plate 66 protects the devices of the roundness measuring device 12 such as the encoder 40 from magnetic field noise caused by the magnet 60.

  Next, a method for centering the workpiece W using the centering device 10 of the embodiment will be described. FIGS. 8A, 8 </ b> B, and 8 </ b> C are explanatory diagrams showing the centering procedure of the workpiece W using the centering device 10 and the roundness measurement performed thereafter.

  First, prior to centering the workpiece W, the centering device 10 is mounted on the table 18. Thereby, the rotation center b of the table 18 and the center c of the chuck table 58 of the centering device 10 coincide.

  Next, as shown in FIGS. 3 and 8A, the three diaphragm blades 54 are kept waiting at an open position spaced from the center c of the chuck table 58, and in this state, any position on the surface of the chuck table 58 is set. The work W is placed on. Thereby, the workpiece W is fixed to the surface of the chuck table 58 by the magnetic force of the magnet 60.

  Next, the operation ring 64 is rotated from the open position in FIG. 3 in the direction of arrow B, and the three diaphragm blades 54 are interlocked toward the center c of the chuck table 58. As a result, the workpiece W fixed on the surface of the chuck table 58 is pushed by the three diaphragm blades 54 and moves toward the center c of the chuck table 58.

  Then, as shown in FIGS. 5 and 8B, when the workpiece W is completely sandwiched between the three diaphragm blades 54, the interlocking of the three diaphragm blades 54 stops, and the workpiece W is centered at this point. The That is, the center axis a of the workpiece coincides with the center c of the chuck table 58 and coincides with the rotation center b of the table 18.

  Next, when the probe 38 is brought into contact with the position d with which the diaphragm blades 54 are contacted to measure the position d, the operation ring 64 in FIG. 3 is returned to the open position of FIG. 3, that is, the position spaced from the center c of the chuck table 58 as shown in FIG. Thereafter, the measurement point 38 is brought into contact with the position d to measure the position d.

  During the measurement, since the workpiece W is fixed to the surface of the chuck table 58 by a magnetic force, the workpiece W is measured in a centered state without being displaced with respect to the chuck table 58.

  Therefore, according to the roundness measuring device 12 of the embodiment, by using the centering device 10 of the embodiment, even the portion d where the diaphragm blade 54 abuts is restricted by the diaphragm blade 54. The measurement of the location d can be performed without.

  Hereinafter, modifications of the centering device 10 will be described.

  Regarding the arrangement form of the magnets 60, in the example of FIG. 7, a plurality of magnets 60 are arranged along six radial rows along the radial direction from the center c of the chuck table 58. Instead of this arrangement, a plurality of magnets 60 are arranged along a plurality (three in FIG. 9) of concentric circles centering on the center c of the chuck table 58 as shown in the plan view of the centering device 10 in FIG. May be.

  Even when the magnet 60 is arranged as shown in FIG. 9, the magnetic force of the magnet 60 can be applied substantially uniformly to the entire surface of the chuck table 58. Therefore, even if the workpiece W has a different diameter or inner diameter, the workpiece W can be fixed by the same chuck table 58.

  Moreover, although the permanent magnet was illustrated in the embodiment as the magnet 60, it can replace with this and can use an electromagnet. Similarly, in the case of an electromagnet, a plurality of electromagnets may be arranged along the radial direction from the center c of the chuck table 58, or may be arranged along a plurality of concentric circles centering on the center c of the chuck table 58. .

  In the case of an electromagnet, since the magnetic force can be varied, the fixing strength of the workpiece W with respect to the chuck table 58 can be varied. For example, in the case of a workpiece placed on the chuck table 58 in an unstable manner (for example, a cylindrical workpiece having a small diameter and a small thickness), it is preferable to increase the magnetic force.

  In the case of electromagnets, it is possible to drive only some of the electromagnets required for centering the work without driving all the electromagnets.

  DESCRIPTION OF SYMBOLS 10 ... Work centering apparatus, 12 ... Roundness measuring apparatus, 14 ... Measuring machine main body, 16 ... Arithmetic processing part, 17 ... Base, 18 ... Table, 20 ... X direction fine adjustment knob, 22 ... Y direction fine adjustment knob, 24 ... X direction tilt knob, 26 ... Y direction tilt knob, 28 ... Rotation mechanism, 30 ... Column, 32 ... Slider, 34 ... Horizontal arm, 36 ... Detector, 38 ... Measuring element, 39 ... Bearing, 40 ... Encoder , 42 ... motor, 43 ... rotary shaft, 44 ... amplifier, 46 ... A / D converter, 48 ... calculation / processing means, 50 ... program, 52 ... display means, 54 ... diaphragm blade, 56 ... base plate, 58 ... Chuck table, 60 ... magnet, 62 ... holding ring, 64 ... operation ring, 66 ... magnetic shield plate, 68 ... recess, 70 ... pedestal, 72 ... pin, 74 ... cam groove, 76 ... pin, 78 ... knob

Claims (6)

A chuck table on which a magnetic work is placed, and
A plurality of chuck members provided around the center of the chuck table, wherein the workpiece placed on the surface of the chuck table is moved to the chuck by being interlocked from a standby position toward the center of the chuck table. A plurality of chuck members that move toward the center of the table so that the center axis of the workpiece coincides with the center of the chuck table;
A magnet disposed on a back surface of the chuck table, the magnet fixing the work to the front surface of the chuck table, wherein the plurality of chuck members align the center axis of the work with the center of the chuck table;
A workpiece centering device.   The workpiece centering device according to claim 1, wherein a plurality of the magnets are arranged along a radial direction from a center of the chuck table.   The workpiece centering device according to claim 1, wherein a plurality of the magnets are arranged along a concentric circle centering on a center of the chuck table.   The workpiece centering device according to claim 1, wherein the magnet is a permanent magnet.   The workpiece centering device according to claim 1, wherein the magnet is an electromagnet. Base and
A measurement table provided on the base;
The workpiece centering device according to any one of claims 1 to 5, which is mounted on the measurement table;
Displacement of the measuring element when the workpiece and the workpiece centering device are relatively rotated, having a measuring device that contacts the workpiece placed on the chuck table of the workpiece centering device. A detector to detect;
A roundness measuring device.

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