JP7114862B2 - WORK HOLDING DEVICE AND WORK MACHINING METHOD - Google Patents

Description

The present invention relates to a workpiece holding device and a workpiece machining method applied to a machining apparatus for machining an annular workpiece.

For example, the outer ring and inner ring of a rolling bearing are subjected to surface finishing during the manufacturing process in order to increase the dimensional accuracy of the inner peripheral surface, outer peripheral surface, and axial end faces. Generally, a grinding machine is used for surface finishing. As this grinding machine, one axial end face of an annular workpiece is attracted to a magnetic chuck, and the outer peripheral surface of the workpiece is supported by a plurality of shoes. (see, for example, Patent Document 1).

JP 2015-136741 A

When the outer and inner rings of a rolling bearing are finished by grinding, it is necessary to grind the outer peripheral surface, the inner peripheral surface, and the axial end surface in separate processes. You have to replace the holding device. In addition, since the workpiece may have large distortion due to the previous process such as heat treatment, it is necessary to perform multi-stage grinding in which large distortion is removed by rough grinding and then finish grinding is performed. . Therefore, the number of man-hours required for surface finishing increases, leading to an increase in manufacturing costs.

In order to reduce the manufacturing cost, the inventors of the present application have conceived of finishing the surface of the workpiece by cutting such as hard turning instead of grinding. If this can be achieved, for example, it will be possible to simultaneously process the inner or outer peripheral surface of the workpiece and the axial end face, and finish machining can be performed from the beginning without the need for rough machining, which reduces the number of man-hours required. can be reduced.

However, in order to obtain a desired machining accuracy by finishing machining by cutting, it is necessary to firmly hold the work so as to withstand the load accompanying the machining. As in the past, if the entire circumference of one end face in the axial direction of the work is attracted by a magnetic chuck, it is possible to firmly hold the work. There is a possibility that the workpiece will be deformed due to If cutting is performed with the distortion corrected, the corrected distortion returns to its original state when the workpiece is removed from the magnetic chuck after machining, and the distortion cannot be removed. Such a problem of correcting and restoring the distortion becomes more conspicuous as the distortion generated in the work in the previous process becomes larger, and becomes a big obstacle when performing finish machining from the beginning without performing rough machining.

SUMMARY OF THE INVENTION An object of the present invention is to provide a workpiece holding device and a workpiece machining method that can stably hold a workpiece without deforming it.

The work holding device of the present invention comprises a first holding portion having three suction members that are spaced apart in the circumferential direction and adhere to the axial end face of an annular work; a second holding portion having an abutting member that contacts the workpiece and restricting movement of the workpiece in the radial direction by the abutting member.

In the work holding device having the above configuration, the first holding portion holds the axial end face of the work at three points by the three suction members. Therefore, compared with the case where the entire circumference of the axial end face of the work is sucked, the work is less likely to be deformed so as to correct the distortion of the work, and the distortion can be preferably removed by processing the surface. Become. In addition, since the first holding portion holds the axial end face of the work at three points, the work can be held in a stable posture without rattling. In addition, the work holding device of the present invention is provided with the second holding portion for restricting the movement of the work in the radial direction, although the force for holding the work is lower than in the case of holding the entire circumference of the axial end face of the work. Therefore, it is possible to secure a sufficient holding force necessary to maintain the machining accuracy of the workpiece.

The second holding portion includes a support member that supports the contact member movably in a radial direction of the work, and an operating member that applies a force radially outward or inward of the work to the contact member. and preferably.
With such a configuration, the contact member can be reliably brought into contact with the inner peripheral surface or the outer peripheral surface of the work.

It is preferable that the second holding portion includes a fixing member that fixes the radial position of the contact member while the contact member is in contact with the inner peripheral surface or the outer peripheral surface of the work.
With such a configuration, it is possible to reliably restrict the movement of the workpiece in the radial direction, so that the surface of the workpiece can be machined with higher accuracy.

Preferably, the fixing member is driven by fluid pressure.
With such a configuration, an operation for fixing the contact member can be performed at a position away from the contact member.

The present invention provides a method for machining a surface of an annular workpiece using the workpiece holding device described above, comprising a step of sucking one axial end face of the workpiece to three adsorption members in a first holding portion; A step of contacting an abutting member of the second holding portion against the inner peripheral surface or the outer peripheral surface of the work to limit radial movement of the work, and a step of processing the surface of the work held by the work holding device. ,including.

According to the present invention, the work can be stably held without being deformed.

1 is a front view of a work holding device according to a first embodiment; FIG. FIG. 2 is a cross-sectional view taken along the line AA in FIG. 1; FIG. 3 is a cross-sectional view taken along the line BB in FIG. 2; It is a front view which shows the relationship between the magnetic pole of a magnetic chuck, and an adsorption member. It is a front view of a work holding device according to a second embodiment. It is a sectional view corresponding to Drawing 2 of a work holding device concerning a 3rd embodiment. FIG. 7 is a cross-sectional view taken along line DD of FIG. 6; It is a side explanatory view showing an air supply route of the work holding device.

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings.
[First Embodiment]
FIG. 1 is a front view of the work holding device according to the first embodiment. 2 is a sectional view taken along line AA in FIG. 1, and FIG. 3 is a sectional view taken along line BB in FIG.
The work holding device 10 of the first embodiment is mainly applied to a cutting device such as a hard turning processing device that cuts the surface of a work using a high-hardness cutting tool, and is attached to the spindle 50 of the cutting device. used for

A work W held by the work holding device 10 is, for example, an annular member such as an outer ring or an inner ring of a rolling bearing. 1 to 3 show an outer ring of a tapered roller bearing as an example of the work W. FIG. In the following description, the term "radial direction" simply means the radial direction of the workpiece W. As shown in FIG.
The work holding device 10 of the first embodiment is used particularly when cutting the axial end faces Wa, Wb and the outer peripheral face Wc of the work W. As shown in FIG. For cutting the inner peripheral surface Wd of the work W, a work holding device of a second embodiment, which will be described later, is used.

The work holding device 10 includes a first holding portion 11 and a second holding portion 12 .
The first holding portion 11 includes a magnetic chuck 21 and an attracting member 22 . The magnetic chuck 21 is formed in a disc shape and is connected to the tip of the main shaft 50 of the cutting device. The center C of the magnetic chuck 21 is arranged so as to coincide with the axis of the main shaft 50 . The magnetic chuck 21 rotates together with the main shaft 50 around the axis of the main shaft 50, that is, around the center C of itself. One side surface of the magnetic chuck 21 serves as an attraction surface 21a that attracts a magnetic body with a permanent magnet or an electromagnet.

The attracting member 22 is formed in a disk shape and is a ferromagnetic material that becomes magnetized by being attracted to the magnetic chuck 21 . The attracting member 22 is attached to the magnetic chuck 21 by attracting one side surface 22 a to the attracting surface of the magnetic chuck 21 . The other side surface 22b of the attracting member 22 is a workpiece attracting surface 22b for attracting the workpiece W. As shown in FIG.

Three attracting members 22 are provided around the center C of the magnetic chuck 21 at intervals in the circumferential direction. More specifically, three adsorption members 22 are provided at regular intervals in the circumferential direction, that is, at intervals with a central angle of 120°. The work W is held by the first holding portion 11 at three points by being sucked by the work suction surface 22 b of the suction member 22 . Further, the center of the work W held by the first holding portion 11 coincides with the center C of the magnetic chuck 21 .

As shown in FIG. 4, magnet members 21b and 21c having different magnetic poles, N pole and S pole, are alternately arranged in the circumferential direction on the attraction surface 21a of the magnetic chuck 21 . Each attracting member 22 has a width in the circumferential direction that can be accommodated in one magnet member 21b, 21c, and is provided within a range that can be accommodated in one magnet member 21b, 21c so as not to straddle two magnet members 21b, 21c. there is The width of the attracting member 22 in the circumferential direction is set, for example, so that the central angle θ is 60° or less.

As shown in FIGS. 1 to 3, the second holding portion 12 is arranged on the inner peripheral side of the work W attracted to the first holding portion 11, and holds the inner peripheral surface Wd of the work W from the radially inner side. . The second holding portion 12 has a contact member 31 , a support member 32 , an operating member 33 and a fixing member 34 .
The contact member 31 is a pin formed in a cylindrical shape and having a spherically curved tip. The tip of the contact member 31 restricts the movement of the work W in the radial direction by contacting the inner peripheral surface Wd of the work W. As shown in FIG. A plurality of contact members 31 are provided at intervals in the circumferential direction of the work W. As shown in FIG. In this embodiment, six contact members 31 are arranged at equal intervals in the circumferential direction.

The support member 32 supports the contact member 31 so as to be movable in the radial direction of the workpiece W. As shown in FIG. The support member 32 is formed in a hexagonal shape when viewed from the front. Therefore, the outer peripheral surface 32b of the support member 32 is composed of six flat surfaces. The center axis of the support member 32 is arranged so as to match the center C of the magnetic chuck 21 . The support member 32 rotates around the center C together with the main shaft 50 and the first holding portion 11 .

Support holes 32a for supporting the contact members 31 are formed in the six flat surfaces forming the outer peripheral surface 32b of the support member 32, respectively. Each support hole 32 a is formed perpendicular to the outer peripheral surface of the support member 32 . The abutment member 31 is slidably inserted into each support hole 32a, and the tip protrudes from the support hole 32a.

The operating member 33 applies a radially outward force to the contact member 31 . The actuating member 33 of this embodiment is a biasing member such as a coil spring, and is inserted into the support hole 32a while being fitted on the contact member 31. As shown in FIG. One end of the operating member 33 contacts the bottom of the support hole 32a, and the other end of the operating member 33 contacts a spring bearing member 31a provided at the intermediate portion of the contact member 31 in the longitudinal direction. Therefore, the contact member 31 is biased by the operating member 33 toward the direction of escape from the support hole 32a, that is, toward the outside in the radial direction of the workpiece W. As shown in FIG. Then, the contact member 31 contacts the inner peripheral surface Wd of the work W attracted to the first holding portion 11 by the biasing force of the operating member 33 . The biasing force of the operating member 33 is set to a minimum magnitude necessary to bring the contact member 31 into contact with the inner peripheral surface Wd of the workpiece W. As shown in FIG. Therefore, the workpiece W is not deformed by the biasing force of the operating member 33 .

The fixed member 34 includes a fixed block 34a provided on the outer peripheral surface 32b of the support member 32, and a pressing member 34b attached to the fixed block 34a. A support hole 34 a 1 is formed in the fixed block 34 a so as to penetrate the workpiece W in the radial direction, and the support hole 34 a 1 communicates with the support hole 32 a formed in the support member 32 . A screw hole 34a2 is formed in the fixing block 34a in a direction orthogonal to the support hole 34a1. One end of the screw hole 34a2 opens at the support hole 34a1, and the other end opens at the outer surface of the fixed block 34a.

The pressing member 34b is composed of a bolt or the like that is screwed into the screw hole 34a2. The tip of the pressing member 34b enters the support hole 34a1 through the screw hole 34a2 and presses the outer surface of the contact member 31 inserted into the support hole 34a1. As a result, the radial position of the contact member 31 is fixed, and the state in which the tip of the contact member 31 contacts the inner peripheral surface Wd of the workpiece W is maintained.

In the conventional work holding device, the magnetic chuck adsorbs the entire circumference of the axial end face of the work W. Adsorb at 3 points. An outer ring, an inner ring, and the like of a rolling bearing are subjected to a pre-process such as heat treatment before the surface is finished, and the pre-process may cause distortion. When one axial end face of a distorted work is attracted to a magnetic chuck in a conventional work holding device, the work is flattened following the attraction surface of the magnetic chuck, and in this state, the other axial end face of the work W is flattened. Even if the workpiece is machined, the corrected distortion returns to its original state when the workpiece is removed from the magnetic chuck, and the machined other end face in the axial direction is also distorted.

In the present embodiment, since the axial end surface Wa of the work W is sucked by the first holding portion 11 at three points, even if the work W is distorted in the previous process, the work W is held so as to correct the distortion. becomes difficult to deform, and the other axial end surface Wb can be machined with the strain remaining. Therefore, the distortion of the work W can be preferably removed, and the other axial end surface Wb of the work W can be cut with a desired flatness. Furthermore, since the one axial end surface Wa of the work W is sucked at three points, the posture of the work W can be stabilized without the work rattling and tilting.

The posture of the work W can also be stabilized by sucking the one end surface Wa of the work W in the axial direction at four or more points. The possibility that the workpiece W is deformed and the distortion is corrected is increased by attracting the workpiece W at the remaining one or more points. Therefore, sucking the work W at three points is extremely effective in stabilizing the posture of the work and preventing deformation of the work.

Further, when the first holding portion 11 sucks the one axial end surface Wa of the work W at three points, the force for holding the work may decrease compared to the case where the entire circumference of the one axial end surface of the work is sucked. There is Therefore, the work holding device 10 of the present embodiment includes the second holding portion 12 that holds the inner peripheral surface Wd of the work W from the radially inner side by means of the plurality of contact members 31. The second holding portion 12 compensates for a decrease in holding force, and the second holding portion 12 can receive the radial force applied to the workpiece W during cutting. Therefore, the workpiece W can be firmly held by the workpiece holding device 10 of the present embodiment, and the workpiece can be cut with desired machining accuracy.

An example of a method for processing a workpiece W using the workpiece holding device 10 of this embodiment will be described. First, one axial end surface Wa of the work W is held by the work holding device 10, and the other axial end surface Wb of the work W is cut flat by the cutting device.
After the other axial end face Wb of the work W is cut flat, the work W is removed from the work holding device 10 and the other axial end face Wb of the work W is held by the work holding device 10 . Since the other axial end face Wb of the already machined workpiece W is machined into a flat surface from which distortion is removed, the distortion is not corrected when it is attracted to the first holding portion 11 . In addition, since the other axial end surface Wb of the work W is processed to be a flat surface from which distortion is removed, the attracting surface 21a of the magnetic chuck 21 without the attracting member 22 is provided with the other axial end surface Wb of the work W. The entire circumference of Wb may be adsorbed.

After holding the other axial end surface Wb of the work W, the one axial end surface Wa of the work W and the outer peripheral surface Wc of the work W are cut. Machining of these surfaces can be performed simultaneously or sequentially without changing the cutting device and workholding device 10 . Therefore, the processing time can be shortened, and the number of working steps can be reduced. Since the other axial end surface Wb of the workpiece W is a flat surface from which distortion is removed, the one axial end surface Wa of the workpiece W can also be processed into a flat surface without distortion. It is also possible to increase the parallelism of the surfaces Wa and Wb.

As described above, the surface of the workpiece W excluding the inner peripheral surface Wd can be cut by the workpiece holding device 10 of the first embodiment. For cutting the inner peripheral surface Wd of the work W, a work holding device of a second embodiment described below is used.

[Second embodiment]
FIG. 5 is a front view showing a work holding device according to the second embodiment.
A workpiece holding device 60 of the present embodiment includes a first holding portion 11 and a second holding portion 12 as in the first embodiment. The configuration of the first holding portion 11 is substantially the same as that of the first embodiment, and includes three attracting members 22 on the attracting surface 21 a of the magnetic chuck 21 . The second holding portion 12 includes a plurality of contact members 31 that contact the outer peripheral surface Wc of the workpiece W held by the first holding portion 11, a support member 32 that supports the contact members 31, and the contact member 31. and a fixing member 34 for fixing the radial position of the contact member 31 .

The support member 32 is an annular member arranged radially outward of the workpiece W. As shown in FIG. An inner peripheral surface 32c of the support member 32 is formed in a hexagonal shape. Therefore, the inner peripheral surface 32c of the support member 32 is composed of six flat surfaces. Although not shown, the inner peripheral surface 32c of the support member 32 is formed with a support hole into which the contact member 31 is slidably inserted in the radial direction of the workpiece W. is provided. A fixing member 34 fixes the position of the contact member 31 in contact with the outer peripheral surface Wc of the workpiece W due to the biasing force of the operating member. The specific configurations of the support hole, operating member, and fixing member 34 are the same as in the first embodiment.

In the work holding device 60 of the second embodiment, the first holding portion 11 sucks the axial end surface of the work W at three points, and the second holding portion 12 holds the outer peripheral surface Wc of the work W to hold the work W radially outward. restrict movement in the direction of Therefore, the workpiece W can be held firmly, and the inner peripheral surface Wd of the workpiece W can be cut with desired machining accuracy.

In the above description, after the axial end surfaces Wa, Wb and the outer peripheral surface Wc of the work W are cut using the work holding device 10 of the first embodiment, the work holding device 60 of the second embodiment is used. is used to cut the inner peripheral surface Wd of the work W, but on the contrary, the axial end faces Wa, Wb and the inner peripheral surface of the work W are cut using the work holding device 60 of the second embodiment. After cutting Wd, the outer peripheral surface Wc of the work W may be cut using the work holding device 10 of the first embodiment.

[Third embodiment]
FIG. 6 is a sectional view corresponding to FIG. 2 of the work holding device according to the third embodiment.
The work holding device 10 of this embodiment differs from that of the first embodiment in the configuration of the second holding portion 12 . Specifically, the second holding portion 12 of the present embodiment includes the contact member 31, the operating member, and the fixing member as one holding unit 40, and the holding unit 40 is attached to the support member 32. there is

7 is a cross-sectional view taken along line DD of FIG. 6. FIG. 7 corresponds to the outer side of the workpiece W in the radial direction, and the lower side of FIG. 7 corresponds to the inner side of the workpiece W in the radial direction. A mounting hole 32d that opens radially outward is formed in the outer peripheral surface of the support member 32 along the radial direction. The holding unit 40 includes a casing 41 that houses the contact member 31, the operating member 33, and the fixing member 34. The casing 41 is attached to the support member 32 while being inserted into the attachment hole 32d.

The casing 41 is formed in a cylindrical shape and has a top wall 41a arranged radially outward, a bottom wall 41b arranged radially inward, and side walls 41c arranged between the top wall 41a and the bottom wall 41b. and The top wall 41a is formed with an opening 41a1 through which a pin as the contact member 31 protrudes. The radially outer end (tip) of the contact member 31 is curved in a spherical shape, and the radially inner side (base end) is a cylindrical portion 31b formed in a cylindrical shape.

A guide member 42 that guides the movement of the contact member 31 in the radial direction is provided inside the casing 41 in the radial direction. The guide member 42 has a guide portion 42a that is inserted into the tubular portion 31b of the contact member 31 from the radially inner side. The contact member 31 moves radially along the guide portion 42a. A coil spring or the like constituting the operating member 33 is provided inside the cylindrical portion 31b of the contact member 31 and between the radial outer end of the cylindrical portion 31b and the radial outer end of the guide portion 42a. A force member is inserted. The contact member 31 is biased radially outward by the operating member 33 .

The fixed member 34 is driven by fluid pressure. Specifically, the fixing member 34 includes an annular gripping member 35 disposed on the outer peripheral side of the contact member 31, an annular piston member 36 disposed on the outer peripheral side of the gripping member 35, and a gripping member 35 and the piston member. and a return spring 38 provided between the piston member 36 and the guide member 42 . The gripping member 35 is formed to have a substantially C-shaped cross-section with a portion notched in the circumferential direction, and is capable of expanding and contracting the inner diameter by elastic deformation.

An outer peripheral surface 35a of the gripping member 35 is formed into a tapered surface in which the outer diameter increases toward the radially inner side (lower side in FIG. 7). The inner peripheral surface 36a of the piston member 36 arranged on the outer peripheral side of the gripping member 35 is formed into a tapered surface in which the inner diameter increases toward the radially inner side (lower side in FIG. 7).

The piston member 36 is provided movably in the radial direction along the inner peripheral surface of the side wall 41 c of the casing 41 . When the piston member 36 moves radially inward, the outer peripheral surface 35a of the gripping member 35 is tightened by the inner peripheral surface 36a of the piston member 36 due to the action of the tapered surfaces 36a, 35a, and the inner diameter of the gripping member 35 is reduced. As a result, the gripping member 35 is brought into close contact with the contact member 31, and the radial position of the contact member 31 is fixed.

Between the outer peripheral surface of the piston member 36 and the inner peripheral surface of the side wall 41c of the casing 41, a flow passage 43 is formed through which air can flow. The flow passage 43 may be a gap formed between the piston member 36 and the side wall 41c, or may be one or more grooves formed in the piston member 36 or the side wall 41c. An air chamber 44 communicating with the flow passage 43 is formed between the radially outer end surface of the piston member 36 and the inner surface of the top wall 41 a of the casing 41 .

An air passage 46 is formed in the guide member 42 and the bottom wall 41 b of the casing 41 to flow compressed air to the air chamber 44 through the flow passage 43 . An air passage 47 communicating with the air passage 46 is also formed in the support member 32 . As shown in FIG. 6, the air passage 47 formed in the support member 32 extends radially inward to the center C and bends along the center C toward the magnetic chuck 21 side.

FIG. 8 is a side view showing an air supply route of the work holding device 10. FIG. An air passage 48 is formed on the axis of the main shaft 50 and the center C of the magnetic chuck 21 , and communicates with the air passage 47 formed in the support member 32 . Also, the air passage 48 is connected to a compressed air supply source 52 via a rotary joint 51 .

Since the air passage 48 formed in the main shaft 50 and the magnetic chuck 21 is arranged on the axis (center C), the rotation of the main shaft 50 does not change the position, and the compressed air passes through the rotary joint 51 . By being connected to the supply source 52 so as to be relatively rotatable, the compressed air supplied from the compressed air supply source 52 can be circulated even while the main shaft 50 is rotating.

Compressed air flowing from the compressed air supply source 52 through the air passages 48, 47, 46 is supplied to the air chamber 44 through the flow passage 43 between the side wall 41c of the casing 41 and the piston member 36 in FIG. The member 36 is pushed down radially inward. Accordingly, the radial position of the contact member 31 can be fixed by reducing the inner diameter of the gripping member 35 . Further, when the supply of compressed air is stopped, the piston member 36 is pushed back radially outward by the return spring 38 . As a result, the inner diameter of the gripping member 35 expands again and the contacting member 31 is released.

The guide member 42, the bottom wall 41b of the casing 41, and the support member 32 are provided with vent holes 49 for discharging the air in the space surrounded by the piston member 36, the contact member 31, and the guide member 42 to the outside. is formed.

In this embodiment, by controlling the operation of the compressed air supply source 52, the radial position of the contact member 31 can be automatically fixed at a position away from the contact member 31, which is the first embodiment. It is not necessary to manually operate the pressing member 34b in the vicinity of the contact member 31 as described above. Therefore, the process of holding the workpiece W can be automated, which contributes to a reduction in the number of man-hours required for work, and can be applied to mass production equipment. Further, since the contact member 31, the operating member 33, and the fixed member 34 are unitized as one holding unit 40, the work of attaching the holding unit 40 to the support member 32 is facilitated, and maintenance work such as replacement is also facilitated. can be done.

In the third embodiment, a hydraulic pressure supply source may be used instead of the compressed air supply source 52. In this case, the piston member 36 is moved radially inward by the hydraulic pressure, and the inner diameter of the gripping member 35 is increased. can be reduced. Further, the second holding portion 12 in the work holding device 10 of the third embodiment has a contact member 31 that contacts the outer peripheral surface of the work W like the second holding portion 12 in the work holding device 60 of the second embodiment. It can also be applied to those that are held in contact with each other.

The present invention is not limited to the above embodiments, and can be modified within the scope of the invention described in the claims.
For example, the center C of the first holding portion 11 may be arranged horizontally or vertically.
The adsorption member 22 is not limited to a disc shape, and can be configured by a plate material such as a rectangular shape.

The number of contact members 31 is not particularly limited, and may be 5 or less or 7 or more. However, in order to reliably restrict the movement of the workpiece W in the radial direction, the number is preferably three or more.
The three adsorption members 22 may not be arranged at regular intervals in the circumferential direction. However, in order to stably support the workpiece W, it is preferable that the center angle between the two adsorption members 22 is set within a range of at least 120°±30° (90° to 150°).

The actuating member 33 of the above-described embodiment is composed of a biasing member such as a coil spring, but it applies a radially outward or inward force to the contact member 31 by fluid pressure such as oil pressure. There may be. For example, the compressed air supply source 52 in the third embodiment or a hydraulic supply source instead of this may be used to apply a radially outward or inward force to the contact member 31 .

The work holding device of the present invention can be used not only for holding the outer ring and inner ring of a rolling bearing, but also for holding any annular work.
Moreover, the work holding device of the present invention can be used not only for cutting work but also for grinding or other processing.

10: work holding device, 11: first holding section, 12: second holding section, 21: magnetic chuck, 22: adsorption member, 31: contact member, 32: support member, 33: operating member, 34: fixed member , 60: workpiece holding device

Claims (5)

A magnetic chuck having an attraction surface, and a magnetic chuck that is arranged at equal intervals in the circumferential direction on the same circumference and attracts the axial end face of an annular workpiece at intervals in the circumferential direction, and holds the workpiece at three points. a first holding portion having three adsorption members protruding from the adsorption surface;
a second holding part having a contact member that contacts the inner peripheral surface or the outer peripheral surface of the work, and restricting radial movement of the work by the contact member ;
A workpiece holding device in which the contact members are arranged at each phase in the circumferential direction where the three adsorption members are arranged . The second holding portion includes a support member that supports the contact member movably in a radial direction of the work, and an operating member that applies a force directed outward or inward in the radial direction of the work to the contact member. The work holding device according to claim 1, comprising: 3. The method according to claim 2, wherein the second holding portion includes a fixing member that fixes the radial position of the contact member while the contact member is in contact with the inner or outer peripheral surface of the workpiece. A workpiece holding device as described. 4. The work holding device according to claim 3, wherein said fixed member is driven by fluid pressure. A method for processing the surface of an annular workpiece using the workpiece holding device according to any one of claims 1 to 4,
a step of sucking one axial end face of the work to three suction members in a first holding portion;
a step of contacting an abutting member of a second holding portion against the inner peripheral surface or the outer peripheral surface of the work to limit movement of the work in the radial direction;
A work machining method, including a step of machining a surface of a work held by a work holding device.

Images