JP4204586B2 - Work holding device and grinding device provided with the same - Google Patents

Description

  The present invention relates to a workpiece holding device and a grinding device including the workpiece holding device, and more particularly to a workpiece holding device that holds a thin workpiece and a grinding device including the workpiece holding device.

  Generally, a workpiece holding device that sandwiches the outer peripheral surface of a workpiece with a plurality of claws is used for a grinding device that grinds one main surface of the workpiece. As an example, for example, Patent Document 1 discloses a workpiece holding device that softly holds the outer peripheral surface of a workpiece with a plurality of claws and tightens a projection on the other main surface of the workpiece with a collet chuck.

  However, even with the workpiece holding device of Patent Document 1, if the workpiece is thin such as used in an armature of an automobile clutch, the workpiece may be bent by pinching the outer peripheral surface with a plurality of claws. It was. As a result, the processing accuracy of the workpiece in the grinding apparatus may be deteriorated. In addition, depending on the shape and size of the protrusion provided on the other main surface of the workpiece, this may not be clamped by the collet chuck, and the workpiece may not be held during grinding.

  Therefore, for example, a workpiece holding device 1 as shown in FIG. 9 is used to hold a thin workpiece having a projection on the other main surface. As shown in FIG. 9, the workpiece holding device 1 includes a rotating shaft 2 connected to the center portion of the workpiece from one main surface side, and a pressing portion 3 disposed to face the rotating shaft 2. The pressing portion 3 advances the main body 5 toward the work by driving the cylinder 4, and presses the central portion of the work against the rotating shaft 2 from the other main surface side by the pressing member 6 of the main body 5. That is, in the workpiece holding device 1, the workpiece is held by sandwiching the center portion of the workpiece between the rotating shaft 2 and the pressing member 6. According to such a workpiece holding device 1, it is possible to firmly hold a thin workpiece in which a protrusion is provided on the other main surface without being deformed.

In a grinding apparatus provided with such a workpiece holding device 1, one main surface of the workpiece is ground by moving the grindstone 7 in the cutting direction while rotating the grindstone 7 with the workpiece rotated by the rotating shaft 2.
JP-A-11-70433

  However, in the workpiece holding device 1 that clamps the center portion of the workpiece, even if the workpiece can be held without being deformed during standby, the peripheral portion of the workpiece is caused by the thrust (grinding resistance) applied to the workpiece from one main surface side during grinding. The vicinity is pushed and bent in the cutting direction. That is, escape occurs in the vicinity of the peripheral edge of the workpiece. For this reason, the machining accuracy of the workpiece is deteriorated.

  SUMMARY OF THE INVENTION Therefore, a main object of the present invention is to provide a workpiece holding device and a grinding device including the workpiece holding device that can hold a thin workpiece having protrusions on the other main surface without being deformed during standby and during processing. It is.

In order to achieve the above-described object, the workpiece holding device according to claim 1 is provided with a support portion that supports the central portion of the workpiece from one main surface side of the workpiece, and the other main surface side of the workpiece that is disposed to face the support portion. from a workpiece holding device Ru provided with a pressing portion for pressing the workpiece to the support portion, the pressing portion includes a body, a first pressing member for pressing a central portion of the workpiece from the other main surface provided on the main body, respectively seen including a plurality of second pressing member for pressing the vicinity of the peripheral edge portion of the workpiece from the movably other main surface side provided in the main body with respect to the workpiece, and a first driving means for advancing and retracting the body relative to the workpiece, the The workpiece holding device further includes fixing means for fixing the positions of the plurality of second pressing members with respect to the main body, and the fixing means includes a plate having a through hole and the plurality of second pressing members inserted through the through hole. A plurality of frustoconical shapes A tapered member disposed in the through hole so as to be surrounded by the second pressing member, and an inclined surface in contact with the outer peripheral surface of the tapered member, and disposed between the plurality of second pressing members and the tapered member in the through hole. A plurality of fixing members, and second driving means for moving the taper member in a direction in which the second pressing member advances and retreats.

According to a second aspect of the present invention, there is provided the work holding device according to the first aspect, further comprising biasing means for biasing the plurality of second pressing members toward the workpiece.

The work holding device according to claim 3 is the work holding device according to claim 2 , wherein the biasing means has a plurality of second pressing members so that thrust applied to the work by the plurality of second pressing members is constant. Is biased toward the workpiece side.

According to a fourth aspect of the present invention, there is provided the work holding device according to the third aspect , wherein the urging means is a cylinder that operates by a fluid pressure.

According to a fifth aspect of the present invention, there is provided the work holding device according to any one of the first to fourth aspects, wherein the work is a clutch armature.

A grinding apparatus according to a sixth aspect includes the workpiece holding apparatus according to any one of the first to fifth aspects, and a grindstone that grinds one main surface of the workpiece held by the workpiece holding apparatus.

A grinding apparatus according to a seventh aspect is the grinding apparatus according to the sixth aspect , comprising at least two workpiece holding devices, wherein the workpiece holding device is moved from a standby position capable of supplying and discharging the workpiece to a grinding position for grinding the workpiece. It further comprises moving means for moving one and moving the workpiece holding device at the grinding position to the standby position.

  In the workpiece holding device according to claim 1, the first pressing member presses the center portion of the workpiece from the other main surface side, and the plurality of second pressing members advance and retreat according to the shape of the other main surface of the workpiece, respectively. The vicinity of the peripheral edge of the work is pressed from the main surface side, and the work is sandwiched between the support part and the pressing part. As a result, even a thin workpiece provided with a protrusion on the other main surface can be held without being deformed during standby. In addition, since the thrust applied to the workpiece from the one main surface side during processing can be received by the first pressing member and the plurality of second pressing members, even if the workpiece is a thin workpiece provided with a protrusion on the other main surface, It can be held without being deformed during processing. That is, the escape of the workpiece can be prevented.

Further, the work holding device according to claim 1, a plurality of second pressing member is fixed respectively by fixing means. By fixing the plurality of second pressing members in this manner, the thrust applied to the workpiece from the one main surface side during processing can be reliably received by the plurality of second pressing members, and the escape of the workpiece can be reliably prevented. .

Furthermore, a work holding device according to claim 1, with the movement of the taper member by the second driving means, pressing a plurality of fixing members a plurality of second pressing member opens radially on the inner peripheral surface of the plate. As a result, a force for moving the tapered member is amplified and applied to each fixing member by applying the wedge driving principle, and the plurality of second pressing members can be firmly fixed.

In the work holding device according to claim 2 , the plurality of second pressing members are urged toward the work side to such an extent that the urging means does not bend the work, and the plurality of second pressing members cause the other main surface side to urge. Give thrust to the workpiece. Thus, the thrust applied to the workpiece from the one main surface side during machining can be reduced, and the escape of the workpiece can be effectively prevented.

In the workpiece holding device according to the third aspect , the urging means urges the plurality of second pressing members so that the thrust applied to the workpiece by the plurality of second pressing members is always constant. Therefore, regardless of the shape of the protrusion formed on the other main surface of the workpiece, the workpiece can be held without being deformed by the thrust applied by the plurality of second pressing members. That is, it can respond to various workpieces.

In the work holding device according to the fourth aspect , the thrust applied to the work by the plurality of second pressing members can be easily made constant by using the cylinder operating with the pressure of the fluid as the urging means.

The workpiece holding device of the present invention is suitably used for holding a workpiece used in a clutch armature of a transportation device or the like, for example, as described in claim 5 .

In the grinding apparatus according to the sixth aspect , by providing the workpiece holding device according to any one of the first to fifth aspects, the workpiece can be held without being deformed at the time of machining, so that the machining accuracy can be improved. Further, since the workpiece can be held without being deformed during processing, the rotation speed and the cutting speed of the grindstone can be increased, and the production efficiency can be improved.

The grinding apparatus according to claim 7 , wherein the workpiece is ground at the grinding position by moving at least two workpiece holding devices between the standby position and the grinding position, and the ground workpiece and the unground at the standby position. Can be exchanged with other workpieces. Therefore, production efficiency can be further improved.

  According to the present invention, it is possible to obtain a workpiece holding device and a grinding device including the workpiece holding device that can hold a thin workpiece having a protrusion on the other main surface without being deformed during standby and during processing.

Embodiments of the present invention will be described below with reference to the drawings.
Referring to FIG. 1, a grinding apparatus 10 is a single-side grinding apparatus provided with a work holding apparatus of the present invention, and is used for grinding a work 100 as shown in FIG. 2, for example. The workpiece 100 includes a disc portion 102, a cylindrical connecting portion 104 provided at the center of one main surface 102a of the disc portion 102, and an annular protrusion provided in the vicinity of the peripheral portion of the other main surface 102b of the disc portion 102. 106. The upper surface of the annular protrusion 106 is wavy, and the height of the annular protrusion 106 varies depending on the position. A product obtained by grinding the workpiece 100 is used for an armature of an automobile clutch or the like.

  As shown in FIG. 1, the grinding apparatus 10 includes a gantry 12, a grindstone unit 14 for grinding the workpiece 100, a column 16 that is erected on the gantry 12 and supports the grindstone unit 14 so as to be movable up and down, and the gantry 12. A turntable 18 provided, two work holding units 20 provided on the turntable 18 for holding the work 100, and a control unit 22 for controlling each component of the grinding apparatus 10 are included.

  The grindstone unit 14 includes a rotating shaft 24, a disc-shaped support member 26 connected to the rotating shaft 24, and an annular grindstone 28 supported by the support member 26. The grindstone unit 14 rotates the rotating shaft 24 and the grindstone 28 by driving a motor (not shown).

  Each of the two workpiece holding units 20 includes a support portion 30 for supporting the workpiece 100 and a pressing portion 32 for pressing the workpiece 100 against the support portion 30. The two support portions 30 are arranged side by side on the turntable 18, and the two pressing portions 32 are arranged opposite to the support portions 30 by columns 34 that are erected between the two support portions 30 and at the center of the turntable 18. Is done.

Here, the workpiece holding unit 20 will be described in detail with reference to FIG.
The support unit 30 of the workpiece holding unit 20 includes a rotation shaft 36 to which the workpiece 100 is coupled and a drive unit 38 for rotating the rotation shaft 36. A spline portion 36 a is provided at the tip of the rotating shaft 36. The workpiece 100 is coupled to the rotary shaft 36 by fitting a spline portion 36 a and a spline groove provided on the inner peripheral surface of the coupling portion 104. The drive part 38 rotates the rotating shaft 36 and the workpiece | work 100 by the drive of the motor 40 (refer FIG. 1) provided in an inside.

  The pressing portion 32 of the work holding unit 20 includes a holding member 42 and a main body 44 that is rotatably held by the holding member 42. The main body 44 includes a rotating shaft 46 that is rotatably held in the holding member 42 via a bearing 45, and plates 48 and 50 that are sequentially attached to the lower end portion of the rotating shaft 46.

  The rotating shaft 46 is formed in a cylindrical shape. The plate 48 is formed in a disk shape having annular protrusions on both end faces, and is attached to the rotating shaft 46 by fitting the upper annular protrusion to the lower end portion of the rotating shaft 46. The plate 50 is formed in a disc shape and is fitted to the annular protrusion on the lower side of the plate 48. The rotating shaft 46 and the plates 48 and 50 are provided with through holes 46a, 48a and 50a in the center. The through holes 46a, 48a and 50a are arranged coaxially and are provided so as to penetrate the main body 44 as a whole. The through hole 46a of the rotating shaft 46 and the through hole 50a of the plate 50 are configured by arranging a large diameter portion and a small diameter portion vertically.

  In the main body 44, a pressing member 52 for pressing the central portion of the workpiece 100 from the other main surface 102b side is attached to the small diameter portion of the through hole 50a of the plate 50. The main body 44 is provided with a plurality of pressing members 54 for pressing the vicinity of the peripheral edge of the workpiece 100 from the other main surface 102b side. Each pressing member 54 is provided so that the tip thereof is in contact with the upper surface of the annular protrusion 106 corresponding to the annular protrusion 106. Each pressing member 54 is configured by arranging a large diameter portion 54a and a small diameter portion 54b vertically. In this embodiment, the pressing member 52 corresponds to a first pressing member, and the pressing member 54 corresponds to a second pressing member.

  Each pressing member 54 is inserted through the through hole 48 a of the plate 48. Referring also to FIG. 4, the large-diameter portion 54a of each pressing member 54 is slidably disposed in a semicircular recess 48b provided in a plurality (six here) in the through hole 48a. The Further, as shown in FIG. 3, the plate 50 is provided with a plurality (six in this case) of through holes 50b corresponding to the recessed portions 48b. Each through hole 50b is configured by arranging a large diameter portion and a small diameter portion vertically. The large diameter portion 54a of the pressing member 54 is slidably disposed in the large diameter portion of each through hole 50b, and the small diameter portion 54b of the pressing member 54 is slidably disposed in the small diameter portion of each through hole 50b. . The small diameter portion 54b of each pressing member 54 protrudes from the small diameter portion of the through hole 50b. Therefore, in this embodiment, the six pressing members 54 are provided on the main body 44 so that the small diameter portions 54 b are juxtaposed in the circumferential direction from the lower end surface of the main body 44.

  Further, as shown in FIG. 3, an air cylinder 56 is provided above each pressing member 54. The air cylinder 56 that is an urging means includes a piston 56 a connected to the large-diameter portion 54 a of the pressing member 54, and a cylinder chamber 56 b in which the piston 56 a and thus the pressing member 54 are disposed so as to be able to advance and retract. The A plurality (six in this case) of cylinder chambers 56 b are provided so that the openings are aligned in the circumferential direction on the lower end surface of the rotation shaft 46 corresponding to the recess 48 b. Air is supplied to each cylinder chamber 56b from an air pump 58 (see FIG. 1) provided in the gantry 12 via a supply hole 46b provided in the rotating shaft 46. Accordingly, each piston 56a and thus each pressing member 54 is urged toward the workpiece 100 side.

  As described above, the vertical dimension of each pressing member 54 provided so as to be able to advance and retreat with respect to the workpiece 100 is such that the tip of the small diameter portion 54b is the tip of the pressing member 52 in a state where the protruding amount of the small diameter portion 54b from the main body 44 is the largest. It is set to be closer to the workpiece 100 than the tip.

  In addition, a rod-like member 60 having a screw thread (not shown) formed on the outer peripheral surface is inserted into the main body 44. A taper member 62 is provided at the lower end of the rod-shaped member 60. The rod-shaped member 60 is inserted through the through hole 46a of the rotating shaft 46, and a nut 64 is screwed on the rod-shaped member 60 from above. Below the nut 64, there are two stoppers 66 each formed in an annular shape having a diameter larger than that of the small diameter portion of the through hole 46 a and smaller than that of the large diameter portion of the through hole 46 a. A spring 68 disposed between the stoppers 66 and through which the rod-shaped member 60 is inserted is provided. The spring 68 is supported by the step portion of the large diameter portion and the small diameter portion of the through hole 46 a via the lower stopper 66, and urges the nut 64 and the rod-shaped member 60 upward via the upper stopper 66. As a result, the taper member 62 is urged upward.

  A cylinder 72 is connected to the holding member 42 via a connecting member 70. The cylinder 72 pushes back the rod-shaped member 60 against the bias of the spring 68 by the piston 72a by increasing the protruding amount of the piston 72a, in other words, by moving the piston 72a forward, and the rod-shaped member 60 and thus the taper member. 62 is moved downward.

  The taper member 62 is formed in a truncated cone shape that narrows upward, and is disposed in the through hole 48 a of the plate 48. As shown in FIG. 3, when the rod-shaped member 60 is pushed back downward by the cylinder 72, the taper member 62 enters the large diameter portion of the through hole 50 a of the plate 50 from the through hole 48 a of the plate 50.

  As shown in FIG. 4, three fixing members 74 are disposed between the tapered member 62 and the large diameter portion 54 a of the pressing member 54 in the through hole 48 a of the plate 48. As shown in FIG. 3 and FIG. 4, each fixing member 74 is formed in a substantially fan-shaped cross section and a trapezoidal cross-sectional shape, has a slope contacting the outer peripheral surface of the taper member 62, and surrounds the taper member 62. Be placed. As shown in FIG. 4, each fixing member 74 is pressed against the outer peripheral surface of the taper member 62 by a spring 76 provided between the through hole 48a. In a state where the rod-like member 60 is pushed back downward by the cylinder 72, a gap is formed between the fixing member 74 and the large-diameter portion 54a of the pressing member 54.

  In this embodiment, the plate 48, the rod-shaped member 60, the taper member 62, the nut 64, the stopper 66, the spring 68, the cylinder 72, and the fixing member 74 constitute fixing means. The second driving means of the fixing means is constituted by a rod-shaped member 60, a nut 64, a stopper 66, a spring 68, and a cylinder 72.

  The holding member 42 is connected to a piston 78a of a cylinder 78 fixed in the column 34 (see FIG. 1). The cylinder 78 moves the pressing portion 32 forward and backward with respect to the workpiece 100 by moving the piston 78 forward and backward, in other words, by changing the protruding amount of the piston 78 a. As a result, the locked state in which the workpiece 100 is pressed against the support portion 30 by the pressing member 52 and each pressing member 54 and the unlocked state in which the workpiece 100 is released (the state shown in FIG. 3) are switched. In this embodiment, the cylinder 78 corresponds to the first drive means.

  A gear 80 is provided on the outer peripheral surface of the plate 50, and the gear 80 engages with a gear 82 disposed in the column 34 (see FIG. 1). The gear 82 is connected to a rotating shaft 84 that is rotated by a motor (not shown), and the pressing portion 32 rotates in synchronization with the rotating shaft 36 and, in turn, the workpiece 100 as the rotating shaft 84 and the gear 82 rotate.

  Returning to FIG. 1, the turntable 18 is driven by a motor 86 provided in the gantry 12 and rotates the two workpiece holding units 20 and the column 34. Accordingly, one workpiece holding unit 20 is moved from a standby position where the workpiece 100 can be supplied and discharged to a grinding position where the workpiece 100 is ground, and the other workpiece holding unit 20 at the grinding position is moved to the standby position. Can do. In FIG. 1, the position of the left work holding unit 20 is a standby position, and the position of the right work holding unit 20 is a grinding position. In this embodiment, the turntable 18 and the motor 86 constitute moving means.

  The control unit 22 controls the operation of each component of the grinding apparatus 10. Specifically, the air pump 58 that supplies air to the air cylinder 56 is controlled so that the work 100 is not bent by the thrust applied to the work 100 by each pressing member 54.

  Next, the holding operation of the workpiece 100 in the grinding apparatus 10 will be described in detail with reference to FIGS. In the grinding apparatus 10, since the pressing portion 32 is disposed above the support portion 30, the protruding amount of the small diameter portion 54 b of each pressing member 54 is initially maximized by gravity or air from the air pump 58. That is, the tip of each pressing member 54 is initially closer to the workpiece 100 than the tip of the pressing member 52.

  First, from the state shown in FIG. 3, the cylinder 78 advances the piston 78 a, whereby the pressing portion 32 advances toward the workpiece 100. The small diameter portion 54 b of each pressing member 54 comes into contact with the upper surface of the annular protrusion 106 before the pressing member 52. At this time, the supply of air to each air cylinder 56 by the air pump 58 is stopped, and the protruding amount of each small diameter portion 54 b becomes smaller as the pressing portion 32 advances. When the pressing portion 32 further advances, the pressing member 52 comes into contact with the central portion of the other main surface 102b of the workpiece 100 as shown in FIG.

  Subsequently, when it is detected from the protruding amount (movement amount) of the piston 78a or the like that the locked state is detected, the driving of the cylinder 78 is stopped. Then, air is supplied to the cylinder chamber 56 b of each air cylinder 56 by the air pump 58, and the work 100 is pressed by each urging pressing member 54. Since the thrust applied to the workpiece 100 by each pressing member 54 is the cross-sectional area of the cylinder chamber 56b × the air pressure, the thrust is constant regardless of the height difference of the annular protrusion 106. The pressure of the air supplied to each air cylinder 56 is controlled according to the thickness and material of the workpiece 100 so that the workpiece 100 is not bent by the pressing of the pressing member 54.

  Thereafter, as shown in FIG. 6, the cylinder 72 moves the piston 72 a backward, whereby the rod-like member 60 and the taper member 62 urged by the spring 68 move upward. Along with this, the taper member 62 presses each fixing member 74 outward against the bias of the spring 76, and the state shown in FIG. 4 is changed to the state shown in FIG. That is, when each fixing member 74 is radially expanded in the through hole 48a, the large-diameter portion 54a of each pressing member 54 is pressed against the recessed portion 48b, and each pressing member 54 is fixed. Since the taper member 62 and each fixing member 74 are in contact with each other on the inclined surface, the force by which the spring 68 moves the rod-shaped member 60 and the taper member 62 upward is amplified by application of the wedge driving principle. 74. Specifically, as shown in FIG. 8, the force P for moving the taper member 62 upward is amplified to P / tan θ = F and applied to each fixing member 74.

  In the grinding apparatus 10, the grindstone unit 14 is moved upward while rotating the grindstone 28 while holding the workpiece 100 in this manner, whereby the grindstone 28 is cut into the one main surface 102 a of the workpiece 100. On the other hand, the main surface 102a is ground.

  The releasing operation of the workpiece 100 may be performed in the reverse order of the above holding operation. Specifically, the fixing of each pressing member 54 is released by advancing the piston 72a, the urging to each pressing member 54 is released by stopping the supply of air to each air cylinder 56, and then The pressing portion 32 may be retracted by retracting the piston 78a.

  According to such a grinding apparatus 10, the pressing member 52 presses the central portion of the other main surface 102 b of the workpiece 100, and the plurality of pressing members 54 advance and retract according to the height of the annular protrusion 106, respectively. The upper surface is pressed, and the workpiece 100 is sandwiched between the support portion 30 and the pressing portion 32. As a result, even the thin workpiece 100 in which the annular projection 106 is provided on the other main surface 102b can be held without being deformed during standby. Further, since the thrust applied to the workpiece 100 from the one main surface 102a side during grinding can be received by the pressing member 52 and the plurality of pressing members 54, the thin workpiece 100 in which the annular protrusion 106 is provided on the other main surface 102b. Even so, it can be held without being deformed during processing. That is, escape of the workpiece 100 can be prevented.

Applying a force for moving the tapered member 62 in the application of the driving principle of the wedge by amplifying the respective fixing member 74, since the pressing members 54 can be firmly fixed, given the other hand the main surface 1 02a side during grinding the workpiece 100 The thrust force to be received can be reliably received by each pressing member 54, and the escape of the workpiece 100 can be reliably prevented.

  The pressing members 54 are urged toward the workpiece 100 to such an extent that the air cylinders 56 do not deflect the workpiece 100, and thrust is applied to the workpiece 100 from the other main surface 102b side by the pressing members 54, so that during the grinding process. On the other hand, the thrust applied to the workpiece 100 from the main surface 102b side can be reduced, and the escape of the workpiece 100 can be effectively prevented.

  Regardless of the height of the protrusion formed on the other main surface of the workpiece, each air cylinder 56 biases the pressing member 54 so that the thrust applied to the workpiece by each pressing member 54 is always constant. The workpiece can be held without being deformed by the thrust applied by each pressing member 54. That is, it can respond to various workpieces.

  By using the air cylinder 56, the thrust applied to the workpiece 100 by each pressing member 54 can be easily made constant.

  The grinding apparatus 10 that holds a workpiece by the workpiece holding unit 20 is preferably used for grinding a workpiece used in an automobile clutch armature such as the workpiece 100.

  Moreover, according to such a grinding apparatus 10, since the workpiece | work 100 can be hold | maintained without deforming at the time of a grinding process, the rotational speed and cutting speed of the grindstone 28 can be made quick, and production efficiency can be improved.

  Since the two workpiece holding units 20 can be moved between the standby position and the grinding position by the turntable 18, the workpiece is ground at the grinding position, and the ground workpiece and the unground workpiece at the standby position. And can be exchanged. Therefore, production efficiency can be further improved.

  In addition, although the above-mentioned embodiment demonstrated the case where the support part 30 and the press part 32 were arrange | positioned up and down and the workpiece | work 100 was pinched from the upper and lower sides, this invention is not limited to this. For example, the support part and the pressing part may be arranged on the left and right sides, and the work may be sandwiched from the left and right sides.

  Moreover, although the above-mentioned embodiment demonstrated the case where the air cylinder 56 which urges | biases the press member 54 with an air pressure as an urging | biasing means was demonstrated, an urging | biasing means is not limited to this. For example, a hydraulic cylinder that urges the pressing member 54 by hydraulic pressure may be used. Further, a spring may be arranged in the cylinder chamber 56b.

It is a front solution figure showing a grinding device to which a work holding device of this invention is applied. It is a perspective view solution figure which shows an example of a workpiece | work. It is a partial cross section solution figure which shows an example of a workpiece | work holding unit. It is XX (FIG. 3) sectional illustration solution figure of a press part. It is a partial cross section solution figure which shows the workpiece holding unit of the state which pinched | interposed the workpiece | work with the support part and the press part. It is a partial cross section solution figure which shows the workpiece holding unit of the state which fixed the piston of the air cylinder. It is X1-X1 (FIG. 6) sectional illustration solution of a press part. It is an illustration figure which shows the direction of the force given to a fixing member by the urging | biasing to a rod-shaped member. It is a partial cross section solution figure which shows the grinding device of a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Grinding device 14 Grinding wheel unit 20 Work holding unit 28 Grinding wheel 30 Support part 32 Press part 44 Main body 46a, 48a, 50a Through hole 48, 50 Plate 52, 54 Press member 56 Air cylinder 60 Rod-shaped member 62 Taper member 68 Spring 72, 78 Cylinder 74 Fixing member 100 Work 102a One main surface 102b The other main surface

Claims (7)

Support portion for supporting the middle portion of the workpiece from the one main surface side of the workpiece, and the supporting part disposed opposite said support work holding the Ru a pressing portion for pressing the said workpiece from the other main surface side of the workpiece A device,
The pressing portion is provided on the main body, a first pressing member provided on the main body for pressing the central portion of the work from the other main surface side, and provided on the main body so as to be capable of advancing and retreating with respect to the work. a plurality of second pressing member for pressing a peripheral portion near the workpiece from the side, and a first driving means for advancing and retracting the body relative to the workpiece viewed including,
The work holding device further includes a fixing means for fixing the positions of the plurality of second pressing members with respect to the main body,
The fixing means has a through-hole and a plate through which the plurality of second pressing members are inserted, and is formed in a truncated cone shape so as to be surrounded by the plurality of second pressing members. A plurality of fixing members disposed between the plurality of second pressing members and the taper member in the through-holes, each having a slope contacting the outer peripheral surface of the taper member; And a second driving means for moving the taper member in a direction in which the second pressing member advances and retreats . The workpiece holding apparatus according to claim 1, further comprising a biasing unit that biases the plurality of second pressing members toward the workpiece. The work holding device according to claim 2 , wherein the urging unit urges the plurality of second pressing members toward the work so that a thrust applied to the work by the plurality of second pressing members is constant. . The work holding apparatus according to claim 3 , wherein the urging means is a cylinder that is operated by a fluid pressure. The workpiece is the armature of the clutch, the workpiece holding device according to any one of claims 1 to 4. Workpiece holding device according to any one of claims 1 to 5, and a grinding wheel for grinding the one main surface of the workpiece held by the workpiece holding device, a grinding apparatus. Comprising at least two workpiece holding devices;
Moving means for moving one of the workpiece holding devices from a standby position where the workpiece can be supplied and discharged to a grinding position for grinding the workpiece, and for moving the workpiece holding device at the grinding position to the standby position; The grinding apparatus according to claim 6 , comprising:

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