JP2021183980A - Roundness measuring device - Google Patents

Abstract

To provide a roundness measuring device capable of measuring even a place with which a chuck member is in contact.SOLUTION: When a probe 38 is brought into contact with a point d with which a diaphragm blade 54 is in contact and the point d is measured, three diaphragm blades 54 are returned to retracted positions separated from a center c of a chuck table 58. After that, the probe 38 is brought into contact with the point d to measure the point d. Since a workpiece W is fixed to the surface of the chuck table 58 by magnetic force, the workpiece W is measured in a centered state without being displaced with respect to the chuck table 58.SELECTED DRAWING: Figure 8

Description

The present invention relates to a work centering device and a roundness measuring device, and in particular, a work centering device and a work centering device that align the central axis of the work with the rotation axis of the measuring table of the roundness measuring device. Regarding a roundness measuring device equipped with.

Conventionally, a roundness measuring device for measuring the roundness of a circular work such as a cylindrical object or a cylindrical object is known (see Patent Document 1 and the like). In the roundness measuring device, for example, the work is placed on a rotatable measuring table, the stylus is brought into contact with the surface of the work, and the displacement of the stylus due to the rotation of the work is measured. Measure the roundness.

In such a roundness measuring machine, it is necessary to align the central axis of the work with the rotation center of the measuring table prior to the measurement of the work. For this reason, it is known that the measuring table is equipped with a work centering device. As the work centering device, for example, the chuck disclosed in Patent Document 2 (hereinafter referred to as a scroll chuck) or the centering device having a diaphragm 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 (similar to the iris chuck) is equipped with a chuck body on which the work is placed and a plurality of chuck claws (throttle blades in the case of the iris chuck) provided around the center of the chuck body, and rotates. By simultaneously interlocking multiple chuck claws toward the center of the chuck body, which corresponds to the center of rotation of the table, the work is moved on the chuck body so that the center axis of the work coincides with the center of rotation of the measurement table. There is.

Japanese Unexamined Patent Publication No. 2012-145492 Japanese Patent No. 5587460 Japanese Unexamined Patent Publication No. 2012-64585

However, the roundness measuring device provided with the work centering device measures the roundness of the work in a state where the chuck member of the work centering device is in contact with the work, that is, in a state where the centering is held by the chuck member. Since it is for measurement, there is a problem that the stylus cannot be brought into contact with the portion where the chuck member is in contact, and the measurement cannot be performed at that location.

The present invention has been made in view of such circumstances, and the work centering device and the work centering device capable of measuring a position where the chuck member of the work centering device is in contact with the chuck member. It is an object of the present invention to provide a roundness measuring device.

In order to achieve the object of the present invention, the work centering device of the present invention is a chuck table on which a magnetic work is placed on the surface, and a plurality of chuck members provided around the center of the chuck table. By interlocking from the standby position toward the center of the chuck table, the work placed on the surface of the chuck table is moved toward the center of the chuck table, and the central axis of the work coincides with the center of the chuck table. A magnet to fix the work to the surface of the chuck table, which is a magnet arranged on the back surface of the chuck table and whose central axis of the work is aligned with the center of the chuck table by the plurality of chuck members. To prepare for.

According to the work centering device of the present invention, first, a plurality of chuck members are made to stand by at positions separated from the center of the chuck table, and in this state, the magnetic work is placed at an arbitrary position on the surface of the chuck table. Place it. Next, when a plurality of chuck members are interlocked toward the center of the chuck table, the work placed on the surface of the chuck table is pushed by the plurality of chuck members and moves toward the center of the chuck table. go. Then, when the work is completely sandwiched between the plurality of chuck members, the interlocking of the plurality of chuck members is stopped, and the work is centered at that point. That is, the central axis of the work coincides with the center of the chuck table.

Next, when measuring the position where the chuck member is in contact, the plurality of chuck members are returned to the retracted positions separated from the center of the chuck table, and then the measurement is performed at that position. At this time, since the work is fixed to the surface of the chuck table by a magnetic force, the work is measured in a centered state without being displaced with respect to the chuck table. Therefore, by using the work centering device of the present invention, it is possible to measure the position even at the position where the chuck member of the work centering device is in contact.

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

In one aspect of the present invention, it is preferable that a plurality of magnets are arranged along concentric circles centered 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 by using the same chuck table.

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

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

According to one aspect of the present invention, the device configuration of the work centering device can be simplified by using a permanent magnet as the magnet. Further, by using an electromagnet as a 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 work.

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

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

According to the present invention, even if the chuck member of the work centering device is in contact with the chuck member, the measurement can be performed at that location.

Overall perspective view of the roundness measuring device of the embodiment A block showing the configuration of the roundness measuring device of the embodiment Top view of the centering device with the aperture blades located in the open position Top view of the centering device with the aperture blades located at the aperture position Top view of the centering device where the work is centered by the centering device Vertical cross-sectional view of the centering device along the AA line of FIG. Top view of the centering device showing an example of the arrangement of magnets Explanatory drawing showing work centering procedure and roundness measurement Top view of the centering device showing another example of the arrangement of magnets

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

FIG. 1 is a perspective view showing the appearance of a roundness measuring device 12 provided with a centering device (hereinafter, referred to as a centering device) 10 for a work 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 measuring table (hereinafter, referred to as a table) 18 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 movement knob 20 and the Y-direction fine movement knob 22 are connected to a table movement axis (not shown), respectively, and by operating the X-direction fine movement knob 20 and the Y-direction fine movement knob 22, the table 18 can be moved in the X direction and Y. It can be finely fed in the direction. As a result, the horizontal position of the table 18 is finely adjusted.

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

Further, a rotation mechanism portion 28 is provided inside the base 17 and below the table 18. The rotation mechanism unit 28 rotates the table 18 to rotate the work W centered by the centering device 10 together with the centering device 10. In the following description, when the term "centering" is used, it means that the center axis a of the work W is aligned with the rotation center b of the table 18 by the centering device 10. 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 (vertical 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 stylus 38.

When measuring the work W by the roundness measuring device 12, the work W is placed on the centering device 10, centered by the centering device 10, and then the stylus 38 is brought into contact with the outer peripheral surface of the work W. The work W is rotated by the table 18. As a result, the displacement of the stylus 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, as the detector 36, an electric micrometer using a differential transformer is used, and the displacement of the stylus 38 is detected by this electric micrometer.

As shown in FIG. 2, the rotation mechanism portion 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 a base 17 (see FIG. 1) via a bearing 39 and is rotated by the power of a 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 rotation shaft 43 of the motor 42, and the rotation angle of the rotation shaft 43 is read with high accuracy by the encoder 40.

The arithmetic processing unit 16 includes an amplifier 44, an A / D converter 46, and an arithmetic / processing means 48. Further, the arithmetic processing unit 16 includes a program 50 for controlling the arithmetic processing unit 16 and a display means 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. Then, the calculation / processing means 48 calculates the roundness of the outer peripheral surface of the work 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 of the embodiment, and is a plan view of the centering device 10 in which the three diaphragm blades (chuck members) 54, 54, 54 are located at open positions. Further, FIG. 4 is a plan view of the centering device 10 in which the three diaphragm blades 54, 54, 54 are located at the diaphragm positions. FIG. 5 is a plan view of the centering device 10 in which the work W is centered by the centering device 10. FIG. 6 is a vertical cross-sectional view of the centering device 10 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 has three diaphragm blades 54 formed in a substantially crescent shape, a base plate 56, and a chuck. It includes a table 58, a plurality of magnets 60, a holding ring 62, an operation ring 64, and a magnetic shield plate 66.

The base plate 56 is formed in a circular shape in a plan view. As shown in the cross-sectional view of FIG. 6, the base plate 56 has a circular recess 68 formed in a plan view on the back surface side thereof, and the recess 68 is fitted to the upper part of the table 18 shown by the alternate long and short dash line in FIG. .. As a result, the centering device 10 is mounted on the table 18 in a state where the center c of the base plate 56 coincides with the rotation center b of the table 18.

A circular pedestal 70 is formed in a central portion on the surface side of the base plate 56 so as to project from the surface 56A of the base plate 56 in a plan view. A chuck table 58 is provided integrally with the pedestal portion 70 in the central portion of the pedestal portion 70. The chuck table 58 is a table on which the work W (see FIG. 5) is placed on the surface thereof, and is formed in a circular shape in a plan view.

As will be described later, the work W of the magnetic material, which is the object to be measured, is fixed to the surface of the chuck table 58 by the magnetic force of the magnet 60. Therefore, the chuck table 58 is manufactured of, for example, austenitic stainless steel which is a non-magnetic material, but the chuck table 58 is not limited thereto. The chuck table 58 may be made of 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 formed 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 form of the magnets 60 with respect to the chuck table 58. In addition, in FIG. 7, in order to make it easy to understand the arrangement form of the magnet 60, the three diaphragm blades 54 are excluded. 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 with each other along six radial rows along the radial direction from the center c of the chuck table 58.

By arranging the magnets 60 in this way, the magnetic force of the magnets 60 can be applied substantially evenly to the entire surface of the chuck table 58. Therefore, even if the work W has a different diameter or inner diameter, the work 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. On the surface of the retaining ring 62, three pins 72 (see FIGS. 3 and 4) are provided at equidistant positions along the inner circumference of the retaining 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. Further, the three diaphragm blades 54 are arranged so as to intersect 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 outer peripheral flange portion 64A of the operation ring 64 is slidably contacted with the outer peripheral flange portion 62A of the holding ring 62, and is rotatably provided with the outer peripheral flange portion 62A 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 64A of the operation ring 64, and the operation ring 64 is rotated by using the knob 78.

When the operation ring 64 is rotated in the direction of arrow B from the open position in FIG. 3, the pin 76 provided in the operation ring 64 also moves in the same direction. As a result, the diaphragm blade 54 connected to the pin 76 via the cam groove 74 is interlocked toward the center c of the chuck table 58 and is located at the diaphragm position shown in FIG. Further, when the operation ring 64 is rotated in the direction of arrow C from the aperture position of FIG. 4, the pin 76 provided in the operation ring 64 also moves in the same direction. As a result, the diaphragm blade 54 connected to the pin 76 via the cam groove 74 is interlocked in the 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 surface side of the chuck table 58 so as to hold the magnet 60 between the chuck table 58 and the chuck table 58. The magnetic shield plate 66 protects the device of the roundness measuring device 12, for example, the device such as the encoder 40 from the magnetic field noise caused by the magnet 60.

Next, a method of centering the work W using the centering device 10 of the embodiment will be described. 8 (A), (B), and (C) are explanatory views showing the centering procedure of the work W using the centering device 10 and the roundness measurement performed thereafter.

First, prior to centering the work W, the centering device 10 is mounted on the table 18. As a result, the rotation center b of the table 18 and the center c of the chuck table 58 of the centering device 10 coincide with each other.

Next, as shown in FIGS. 3 and 8A, the three diaphragm blades 54 are kept on standby at an open position separated from the center c of the chuck table 58, and in this state, an arbitrary position on the surface of the chuck table 58 is set. Place the work W on. As a result, the work 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 in the direction of arrow B from the open position in FIG. 3, and the three diaphragm blades 54 are interlocked toward the center c of the chuck table 58. As a result, the work W fixed to 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 work W is completely sandwiched between the three diaphragm blades 54, the interlocking of the three diaphragm blades 54 is stopped, and the work W is centered at this point. NS. That is, the central axis a of the work coincides with the center c of the chuck table 58 and coincides with the rotation center b of the table 18.

Next, when the stylus 38 is brought into contact with the point d to which the diaphragm blade 54 is in contact to measure the point d, the operation ring 64 in FIG. 5 is rotated in the direction of arrow C to form three pieces. The diaphragm blade 54 is returned to the open position in FIG. 3, that is, a position separated from the center c of the chuck table 58 as shown in FIG. 8 (C). After that, the stylus 38 is brought into contact with the point d to measure the point d.

During the measurement, the work W is fixed to the surface of the chuck table 58 by a magnetic force, so that the work 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 at the position d where the diaphragm blade 54 is in contact, the diaphragm blade 54 is restricted. The measurement of the point d can be performed without any problem.

Hereinafter, a modified example of the centering device 10 will be described.

Regarding the arrangement form of the magnets 60, in one 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 form, as shown in the plan view of the centering device 10 of FIG. 9, a plurality of magnets 60 are arranged along a plurality of concentric circles (three in FIG. 9) centered on the center c of the chuck table 58. You may.

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

Further, as the magnet 60, a permanent magnet is exemplified in the embodiment, but an electromagnet can be used instead of the permanent magnet. 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 centered on the center c of the chuck table 58. ..

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

Further, in the case of an electromagnet, it is possible to drive only a part of the electromagnets required for centering the work without driving all the electromagnets.

10 ... Work centering device, 12 ... Roundness measuring device, 14 ... Measuring machine body, 16 ... Arithmetic processing unit, 17 ... Base, 18 ... Table, 20 ... X direction fine movement knob, 22 ... Y direction fine movement knob, 24 ... X-direction tilting knob, 26 ... Y-direction tilting knob, 28 ... Rotation mechanism, 30 ... Column, 32 ... Slider, 34 ... Horizontal arm, 36 ... Detector, 38 ... Stylus, 39 ... Bearing, 40 ... Encoder , 42 ... motor, 43 ... rotary shaft, 44 ... amplifier, 46 ... A / D converter, 48 ... arithmetic / processing means, 50 ... program, 52 ... display means, 54 ... throttle blades, 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 (5)

A roundness measuring device that measures the roundness of a magnetic workpiece.
A chuck table on which the work is placed on the surface and
A plurality of chuck members provided around the center of the chuck table, and the work placed on the surface of the chuck table by being interlocked from a standby position toward the center of the chuck table is chucked. A plurality of chuck members that are moved toward the center of the table so that the central axis of the work coincides with the center of the chuck table.
A magnet arranged on the back surface of the chuck table, wherein the work whose central axis of the work is aligned with the center of the chuck table by the plurality of chuck members is fixed to the surface of the chuck table.
Have,
A roundness measuring device capable of measuring a portion of the work to which the plurality of chuck members are in contact by returning the plurality of chuck members to the standby position. The roundness measuring device according to claim 1, wherein a plurality of the magnets are arranged along the radial direction from the center of the chuck table. The roundness measuring device according to claim 1, wherein a plurality of the magnets are arranged along concentric circles centered on the center of the chuck table. The roundness measuring device according to any one of claims 1 to 3, wherein the magnet is a permanent magnet. The roundness measuring device according to any one of claims 1 to 3, wherein the magnet is an electromagnet.

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