Workpiece-holding device

Abstract

A workpiece-holding device (1) comprises: a workpiece-holding member (14) having a shape in which the outer contour of a cross-section orthogonal to a central axis is circular and in which a curved surface (141e) is formed in part of a peripheral wall of the workpiece-holding member (14); a first support member (20) that is cylindrical, has formed on part of the inner wall thereof a recessed surface portion into which the portion of the workpiece-holding member where the curved surface (141e) is formed is fitted, and supports the workpiece-holding member (14) so that the inclination of the central axis of the workpiece-holding member (14) is variable; and a second support member (18) that is cylindrical, has an inner flange portion (172) protruding inward from one end portion thereof, and supports the first support member (20) so that the first support member (20) can slide in a direction orthogonal to the cylinder-axis direction thereof.

Description

Work holding device

[0001] The present invention relates to a workpiece holding device.

[0002] A work holding device has been proposed, which includes: a first cylindrical member fixed to a base member with its inner surface facing the outer peripheral surface of a first holding member via a first elastic member; a first swing regulating unit that restricts the first oscillating member from swinging about a first swing axis extending along a first direction relative to the base member and from moving in the first direction by expanding the first elastic member and pressing the entire outside of the first elastic member against the inner surface of the first cylindrical member; a second cylindrical member fixed to the first oscillating member with its inner surface facing the outer peripheral surface of a second holding member via a second elastic member; and a second swing regulating unit that restricts the second oscillating member, to which a work holding member that holds a work is fixed, from swinging about a second swing axis extending along a second direction perpendicular to the first direction relative to the first oscillating member and from moving in the second direction by expanding the second elastic member and pressing the entire outside of the second elastic member against the inner surface of the second cylindrical member (see, for example, Patent Document 1).

[0003] Patent No. 7310046

[0004] However, in order to facilitate maintenance of the workpiece holding device as described in Patent Document 1, it is desirable to simplify the structure.

[0005] The present invention has been made in view of the above-mentioned circumstances, and has an object to provide a workpiece holding device with a simplified structure.

[0006] In order to achieve the above object, the work holding device of the present invention comprises: a work holding member that holds a workpiece in a state in which the workpiece is fitted into a hole that is drilled in a peripheral wall and extends along one central axis, the work holding member having a shape in which the outer shape of a cross section perpendicular to the central axis is circular and a curved surface is formed on a part of the peripheral wall such that a central portion in the central axis direction protrudes in a direction away from the central axis compared to both end portions in the central axis direction; a first support member that is cylindrical and has a part of its inner wall that surrounds a first cylindrical axis and has a concave surface portion that is curved so that it is recessed in a direction away from the first cylindrical axis as it approaches the central portion in the first cylindrical axis direction, and into which the portion of the work holding member where the curved surface is formed is fitted, and supports the work holding member so that the inclination of the central axis of the work holding member with respect to the first cylindrical axis direction is variable; a second support member that is cylindrical, protrudes inward from one end in the second cylinder axis direction, and has an inner flange portion that faces the other end in the second cylinder axis direction around the entire periphery of the first support member when viewed from the second cylinder axis direction, restricting movement of the first support member along the second cylinder axis direction, and supports the first support member so that the first support member can slide freely in a direction perpendicular to the second cylinder axis direction.

[0007] According to the present invention, the workpiece holding member is supported by the first support member so that the inclination of its central axis relative to the first support member is variable, and the second support member supports the first support member so that it is slidable in a direction perpendicular to the cylindrical axis direction of the second support member. This makes it easier to reduce the number of parts compared to a structure in which the first support member and the second support member are axially supported, and therefore makes it possible to simplify the structure of the entire workpiece holding device.

[0008] FIG. 3A is a perspective view of a work holding device according to a first embodiment of the present invention. FIG. 4 is a cross-sectional perspective view of a work holding device according to a first embodiment. FIG. 5 is an exploded cross-sectional view of a work holding device according to a first embodiment. FIG. 6 is a cross-sectional view of a work holding device according to a first embodiment. FIG. 7A is a cross-sectional view of a work holding device according to a first embodiment. FIG. 8 is a cross-sectional view of a work holding device according to a first embodiment.

[0009] (Embodiment 1) A workpiece holding device according to an embodiment of the present invention will be described below with reference to the drawings. The workpiece holding device according to this embodiment is a device that holds a workpiece during, for example, honing. The workpiece holding device includes a workpiece holding member, a first support member, and a second support member. The workpiece holding member holds a workpiece by fitting the workpiece into a hole extending along a central axis formed in a peripheral wall. The workpiece holding member has a circular outer shape in a cross section perpendicular to the central axis, and a curved surface formed on a portion of the peripheral wall such that a central portion in the central axis direction protrudes in a direction away from the central axis compared to both end portions in the central axis direction. The first support member is cylindrical, and a portion of the inner wall is formed with a concave surface that surrounds the first cylindrical axis and is curved in a direction away from the first cylindrical axis as it approaches the central portion in the first cylindrical axis direction. When the portion of the workpiece holding member where the curved surface is formed is fitted into the concave surface, the workpiece holding member is supported so that the inclination of the central axis of the workpiece holding member with respect to the first cylindrical axis direction is variable. The second support member is cylindrical, protrudes inward from one end in the second cylinder axis direction, and has an inner flange portion that faces the other end in the second cylinder axis direction around the entire periphery of the first support member when viewed from the second cylinder axis direction, restricting movement of the first support member along the second cylinder axis direction, and supports the first support member so that it can slide freely in a direction perpendicular to the second cylinder axis direction.

[0010] 1A and 1B , the workpiece holding device 1 according to this embodiment is incorporated into, for example, a honing machine and used. The workpiece holding device 1 includes a base member 11, a workpiece holding member 14 for holding a workpiece W, a first elastic member 15, a first support member 20, a second elastic member 16, a guide member 12, and a second support member 18. The workpiece holding device 1 also includes a swing restriction portion 21 for restricting swinging of the workpiece holding member 14 relative to the first support member 20, and a slide restriction portion 22 for restricting sliding of the first support member 20 relative to the second support member 18. As shown in FIG. 2 , the base member 11 has a flat, generally rectangular plate shape, and is provided with an opening 11a at its center, which is circular in plan view and penetrates the base member 11 in the thickness direction. The base member 11 also has two grooves 11b extending away from each other along the X-axis direction from two opposing locations on the periphery of the opening 11a across a central axis J11 along the thickness direction of the opening 11a.

[0011] The guide member 12 is a member for guiding movement of the first support member 20 in a direction perpendicular to the Z-axis direction, and includes a cylindrical guide member main body 121, two ribs 122 erected at the end of the guide member main body 121 on the −Z direction side, and two ribs 123 erected at the end of the guide member main body 121 on the +Z direction side. The two ribs 122 are erected toward the −Z direction from two opposing locations on the −Z direction end of the guide member main body 121, sandwiching the cylindrical axis J12 of the guide member main body 121 in the X-axis direction. The two ribs 123 are erected toward the +Z direction from two opposing locations on the +Z direction end of the guide member main body 121, sandwiching the cylindrical axis J12 of the guide member main body 121 in the Y-axis direction. The two ribs 122 are fitted into two grooves 11b provided in the base member 11, respectively. The guide member 12 is movable in the X-axis direction with the two ribs 122 moving along the groove 11b.

[0012] The workpiece holding member 14 includes a holding member main body 141 that holds the workpiece W by fitting it into a hole 141a extending along a central axis J14 formed in the peripheral wall, and two protrusions 142 that protrude from the holding member main body 141. The holding member main body 141 has a circular cross section perpendicular to the central axis J14, and a curved surface 141e formed on part of the peripheral wall such that the central portion in the central axis direction protrudes further away from the central axis than both end portions in the central axis direction. An annular groove 141b is formed in the curved surface 141e of the workpiece holding member 14 so as to surround the central axis J14. As shown in FIG. 3A , the workpiece holding member also includes a first gas introduction passage 141c for introducing gas into the annular groove 141b. The first gas introduction passage 141c extends in the +Z direction from the -Z end of the holding member main body 141, bends from a position on the -Z side of the +Z end of the holding member main body 141 toward the curved surface 141e, and extends to the curved surface 141e, communicating with the annular groove 141b. A connector 31 for introducing gas from the swing restriction unit 21 into the first gas introduction passage 141c is attached to the opening of the first gas introduction passage 141c at the -Z end of the holding member main body 141. Furthermore, two protrusions 142 each protrude outward from a portion of the curved surface 141e of the holding member main body 141. The protrusion directions of the two protrusions 142 intersect with each other. That is, one of the two protrusions 142 protrudes along the Y-axis direction, and the other protrudes along the X-axis direction.

[0013] 2, the first elastic member 15 is annular, and as shown in Fig. 3B, is fitted into the annular groove 141b of the work holding member 14. The first elastic member 15 is made of an elastic material such as rubber or elastomer.

[0014] Returning to FIG. 2 , the first support member 20 includes an inner sub-support member 13 and an outer sub-support member 17. The inner sub-support member 13 is cylindrical, and a portion of its inner wall is formed with a concave surface 13e that surrounds the cylindrical axis J13 and curves in a direction away from the cylindrical axis J13 as it approaches the center in the direction of the first cylindrical axis J13. The inner sub-support member 13 supports the workpiece holding member 14 so that the inclination of the central axis J14 of the workpiece holding member 14 relative to the cylindrical axis J13 is variable when the portion of the workpiece holding member 14 where the curved surface 141e is formed is fitted into the concave surface 13e. An annular groove 13b is formed in the outer wall of the inner sub-support member 13 so as to surround the cylindrical axis J13. Furthermore, the concave surface 13e of the inner sub-support member 13 is formed with two recesses 13c into which two protrusions 142 of the workpiece holding member 14 are respectively fitted. As a result, one of the two protrusions 142 limits the rotation of the workpiece holding member 14 around the central axis J14 and the X-axis, but not the Y-axis. The other of the two protrusions 142 limits the rotation of the workpiece holding member 14 around the Y-axis. Two notches 13a are formed at each of two opposing locations on the -Z-direction end of the inner sub-support member 13, sandwiching the cylindrical axis J13 of the inner sub-support member 13 in the Y-axis direction. As shown in FIG. 4 , two ribs 123 provided on the guide member 12 engage with the insides of the two notches 13a. The inner sub-support member 13 is movable in the Y-axis direction with the two ribs 123 engaged with the two notches 13a.

[0015] Returning to FIG. 2 , the outer sub-support member 17 includes a cylindrical sub-support member main body 171 and an inner flange 172 extending from the entire circumference of the +Z-direction end of the sub-support member main body 171 toward the cylindrical axis J17 of the sub-support member main body 171. As shown in FIGS. 3A and 3B , the outer sub-support member 17 holds the inner sub-support member 13 with the tip of the inner flange 172 fitted into an annular groove 13b formed in the outer wall of the inner sub-support member 13. An annular groove 171a is formed on one end of the sub-support member main body 171 in the cylindrical axis J17 direction, i.e., the end on the −Z side, so as to surround the cylindrical axis J17. The annular groove 171a is formed such that the cross-sectional area of ​​the inner region perpendicular to the cylindrical axis J17 direction and surrounded by the annular groove 171a decreases toward the bottom of the annular groove 171a in the cylindrical axis J17 direction. That is, the annular groove 171a is formed so that the inner diameter of the cross section of the inner side of the annular groove 171a perpendicular to the direction of the cylindrical axis J17 decreases toward the bottom side of the annular groove 171a. Also, as shown in FIG. 3A , the sub-support member main body 171 is formed with a second gas inlet passage 171b for introducing gas into the inside of the annular groove 171a. This second gas inlet passage 171b extends from the end of the sub-support member main body 171 on the +Z direction side to the end of the sub-support member main body 171 on the −Z direction side and communicates with the annular groove 171a. A connector 32 for introducing gas from the slide restriction portion 22 into the second gas inlet passage 171b is attached to a portion of the second gas inlet passage 171b that opens at the end of the sub-support member main body 171 on the +Z direction side.

[0016] The second elastic member 16 is annular, and is fitted into the annular groove 171a of the outer sub-support member 17. The second elastic member 16 is made of an elastic material such as rubber or elastomer.

[0017] The second support member 18 has a cylindrical support body 181 and an inner flange 182 that protrudes inward from the entire circumference of one end of the support body 181 in the second cylinder axis J18 direction, i.e., the end on the +Z direction side, and supports the outer sub-support member 17 so that the outer sub-support member 17 can slide in a direction perpendicular to the second cylinder axis J18 direction. Here, the inner flange 182 faces the entire circumference of the outer sub-support member 17 on the other end side in the second cylinder axis J18 direction, i.e., the −Z direction side, when the outer sub-support member 17 is viewed from the cylinder axis J18 direction, and restricts movement of the outer sub-support member 17 along the second cylinder axis J18 direction.

[0018] Returning to FIG. 1 , the swing regulating unit 21 restricts the swing of the workpiece holding member 14 relative to the inner sub-support member 13 by expanding the first elastic member 15 and pressing the first elastic member 15 against the concave portion 13e of the inner sub-support member 13. As shown in FIG. 5 , the swing regulating unit 21 includes a gas source 211 that outputs compressed air, a tube 212 connected to a connector 31 attached to the workpiece holding member 14, a connector 215 provided at the tip of the tube 212, a pressure control valve 213 interposed between the gas source 211 and the tube 212 for adjusting the air pressure inside the tube 212, and a pressure control unit 214. Examples of the gas include air, nitrogen, and rare gases. The pressure control unit 214 controls the pressure control valve 213 to adjust the pressure of the gas supplied from the gas source 211 to the connector 31, thereby restricting the swing of the workpiece holding member 14 relative to the inner sub-support member 13.

[0019] 1 , the sliding restriction unit 22 restricts sliding of the outer sub-support member 17 relative to the second support member 18 by pushing the second elastic member 16 in a direction protruding outward from the annular groove 171a of the outer sub-support member 17 and pressing it against the +Z direction side of the base member 11. Here, as shown in FIG. 5 , the sliding restriction unit 22 includes a gas source 211, a tube 222 connected to the connector 32 of the outer sub-support member 17, a connector 225 provided at the tip of the tube 222, a pressure control valve 223 interposed between the gas source 211 and the tube 222 for adjusting the air pressure in the tube 222, and a pressure control unit 214. The sliding restriction unit 22 restricts sliding of the outer sub-support member 17 relative to the second support member 18 by the pressure control unit 214 controlling the pressure control valve 223 to adjust the pressure of the air supplied from the gas source 211 to the connector 32.

[0020] 3A and 3B , the operation of the workpiece holding device 1 according to this embodiment will be described. When the first elastic member 15 is not in contact with the recessed surface 13e of the inner sub-support member 13, the workpiece holding member 14 is free to swing relative to the inner sub-support member 13. When the swing restricting unit 21 restricts the swinging of the workpiece holding member 14 relative to the inner sub-support member 13, it supplies air from the connector 31 through the first gas introduction path 141c to the region formed between the first elastic member 15 and the inside of the annular groove 141b. This expands the first elastic member 15, pressing the entire outer side of the first elastic member 15 against the recessed surface 13e of the inner sub-support member 13, thereby restricting the swinging of the workpiece holding member 14 relative to the inner sub-support member 13. Furthermore, when the oscillation regulating portion 21 stops supplying gas to the area formed between the first elastic member 15 and the inside of the annular groove 141b, the first elastic member 15 contracts and becomes immersed inside the annular groove 141b.

[0021] Furthermore, when the second elastic member 16 is not in contact with the +Z direction side of the base member 11, the outer sub-support member 17 is freely slidable relative to the second support member 18 in a direction perpendicular to the Z-axis direction. When restricting the sliding of the outer sub-support member 17 relative to the second support member 18, the sliding restriction unit 22 supplies gas from the connector 32 through the second gas introduction path 171b to the region formed between the second elastic member 16 and the inside of the annular groove 171a. This pushes the second elastic member 16 outward from the annular groove 171a, and the entire +Z direction side portion of the second elastic member 16 is pressed against the +Z direction side of the base member 11. At this time, the second elastic member 16 is in an expanded state compared to when it is disposed on the bottom side of the annular groove 171a. At this time, the upper end surface of the periphery on the +Z direction side of the outer sub-support member 17 is pressed against the −Z direction side of the inner flange 182 of the second support member 18, thereby restricting sliding of the outer sub-support member 17 relative to the second support member 18. Furthermore, when the sliding restriction portion 22 stops the supply of gas to the region formed between the second elastic member 16 and the inside of the annular groove 171a, the second elastic member 16 returns to its contracted state, and moves along the annular groove 171a toward the bottom side of the annular groove 171a, becoming immersed inside the annular groove 171a.

[0022] The pressure control unit 214 can change the pressure of the air supplied to the connectors 31, 32 in a stepwise or continuous manner by controlling the pressure control valves 213, 223. This makes it possible to adjust the braking force of the work holding member 14 on the inner sub-support member 13 and the braking force of the outer sub-support member 17 on the second support member 18 in a stepwise or continuous manner.

[0023] As described above, in the work holding device 1 according to this embodiment, the work holding member 14 is supported by the inner sub-support member 13 of the first support member 20 so that the inclination of its central axis J14 with respect to the inner sub-support member 13 is variable. In addition, the second support member 18 supports the outer sub-support member 17 of the first support member 20 so that the outer sub-support member 17 is slidable in a direction perpendicular to the cylindrical axis J18 of the second support member 18. This makes it easier to reduce the number of parts compared to a structure in which the first support member 20 and the second support member 18 are axially supported, thereby simplifying the overall structure of the work holding device 1.

[0024] In a workpiece holding device such as that described in the aforementioned Patent Document 1, from the viewpoint of workpiece machining accuracy, it is required to uniformize the restricting force restricting the movement of the workpiece holding member along the first and second directions, and to uniformize the restricting force restricting the workpiece holding member's swing about the first swing axis and the second swing axis. However, in the case of the workpiece holding device described in Patent Document 1, the first swing member and the second swing member have different masses. Therefore, it is necessary to precisely adjust the force pressing the first elastic member against the inside of the first cylindrical member and the force pressing the second elastic member against the inside of the second cylindrical member, taking into account the difference in mass, so that the aforementioned restricting forces are uniform between the first swing restricting unit and the second swing restricting unit. This may complicate the control of the workpiece holding device.

[0025] In contrast to this, in the work holding device 1 according to this embodiment, the sliding of the first support member 20 relative to the second support member 18 is restricted by pressing the entire outer sub-support member 17 of the first support member 20 against the second support member 18 and the base member 11 in a direction perpendicular to the sliding direction of the first support member 20 relative to the second support member 18. This eliminates the need to adjust the restricting force according to the sliding direction in order to make uniform the restricting force in the sliding direction of the first support member 20 relative to the second support member 18, thereby simplifying the control of the work holding device 1.

[0026] Furthermore, the work holding device 1 according to this embodiment is equipped with a swing regulating unit 21 that regulates the swing of the work holding member 14, and a slide regulating unit 22 that regulates the movement of the work holding member 14 and the first support member 20 that supports it in a direction perpendicular to the Z-axis direction. The swing regulating unit 21 and the slide regulating unit 22 are each capable of adjusting the pressure of the gas supplied to the connectors 31, 32. This makes it possible to change the ratio between the braking force of the work holding member 14 in the direction perpendicular to the Z-axis direction and the braking force against the swing of the work holding member 14 by adjusting the pressure of the gas supplied to the connectors 31, 32, which has the advantage of making it easier to control the optimal braking force against the movement and swing of the work holding member 14 in the direction perpendicular to the Z-axis direction.

[0027] Incidentally, there is a demand for a so-called free-floor type work holding device that can move only in a direction perpendicular to the Z-axis direction. In response to this demand, the work holding device 1 according to this embodiment can be converted into the above-mentioned free-floor type work holding device simply by changing the work holding member 14 and the inner sub-support member 13 to a configuration that does not include a swing mechanism. Therefore, parts can be shared between the work holding device 1 according to this embodiment and the above-mentioned free-floor type work holding device, thereby improving the convenience of management and maintenance of multiple types of work holding devices, including the work holding device 1.

[0028] Furthermore, the swing regulating unit 21 according to this embodiment introduces gas into the region formed between the first elastic member 15 and the inside of the annular groove 141b of the workpiece holding member 14 through the first gas inlet path 141c formed in the workpiece holding member 14, thereby uniformly expanding the entire first elastic member 15 by air pressure. Furthermore, the sliding regulating unit 22 introduces gas into the region formed between the second elastic member 16 and the inside of the annular groove 171a of the outer sub-support member 17 through the second gas inlet path 171b formed in the outer sub-support member 17, thereby pressing the entire second elastic member 16 against the base member 11 with uniform force by air pressure. Therefore, it is possible to eliminate bias in the braking force caused by unevenness in the magnitude of the force pressing the first elastic member 15 against the concave surface portion 13e of the inner sub-support member 13 and the force pressing the second elastic member 16 toward the +Z direction of the base member 11.

[0029] (Embodiment 2) A work holding device according to this embodiment differs from the work holding device 1 according to embodiment 1 in that it includes a first guide member and a second guide member that guide the sliding of the first support member relative to the second support member. Here, the first guide member has a cylindrical guide member main body having one end in the cylindrical axis direction fixed to the base member, and two ribs that protrude in the cylindrical axis direction from two opposing locations on the other end of the guide member main body in the cylindrical axis direction. Also, the second guide member has a cylindrical shape and four grooves extending in the cylindrical axis direction are formed in four opposing locations on the outer wall of the second guide member that are on either side of the cylindrical axis.

[0030] 6A and 6B, the work holding device 2 according to this embodiment includes a base member 2011, a work holding member 14, a first elastic member 15, a first support member 2020, a second elastic member 16, a first guide member 2012, a second guide member 2019, and a second support member 18. In Fig. 6A and 6B, the same components as those in the first embodiment are denoted by the same reference numerals as in Fig. 1A and 1B. The base member 2011 is a flat, substantially rectangular plate, and has an opening 2011a, which is circular in plan view and penetrates through the center in the thickness direction.

[0031] The first guide member 2012 is cylindrical, and as shown in Figures 7A and 7B, includes a guide member main body 2121 whose one end in the cylinder axis direction, i.e., the end on the -Z direction side, is fixed to the +Z direction side of the base member 2011, and two ribs 2123. In Figures 7A and 7B, components similar to those in embodiment 1 are denoted by the same reference numerals as in Figures 3A and 3B. The two ribs 2123 protrude in the +Z direction from two opposing locations on either side of the cylinder axis of the first guide member 2012 at the other end in the cylinder axis J12 direction of the guide member main body 2121, i.e., the end on the +Z direction side.

[0032] The second guide member 2019 is cylindrical and placed on the +Z direction side of the first guide member 2012. As shown in FIG. 8 , the second guide member 2019 has four grooves 2019a and 2019b formed in its outer wall, extending along the cylindrical axis of the second guide member 2019. Each of the two grooves 2019a extends from one end to the other end of the second guide member 2019 in the Z axis direction at two opposing locations on the outer wall of the second guide member 2019 in the Y axis direction, sandwiching the cylindrical axis J19 of the second guide member 2019 therebetween. Each of the two grooves 2019b extends from one end to the other end of the second guide member 2019 in the Z axis direction at two opposing locations on the outer wall of the second guide member 2019 in the X axis direction, sandwiching the cylindrical axis J19 of the second guide member 2019 therebetween. Here, the two ribs 2123 of the first guide member 2012 are engaged with the inside of the two grooves 2019b of the second guide member 2019. With the two ribs 2123 engaged with the inside of the grooves 2019b, the second guide member 2019 is movable in the X-axis direction relative to the first guide member 2012.

[0033] 7A and 7B , the first support member 2020 includes an inner sub-support member 2013 and an outer sub-support member 17. The inner sub-support member 2013 is cylindrical and includes a sub-support member main body 2131 that supports the workpiece holding member 14 such that the inclination of the central axis J14 of the workpiece holding member 14 relative to the cylindrical axis J13 is variable when the portion of the workpiece holding member 14 on which the curved surface 141e is formed is fitted into a concave surface portion 2013e formed in part of the inner wall, and two ribs 2132. The concave surface portion 2013e of the sub-support member main body 2131 has two recesses 2013c into which the two protrusions 142 of the workpiece holding member 14 are respectively fitted. The two ribs 2132 protrude in the −Z direction from two locations at the end of the sub-support member main body 2131 on the −Z direction side that face each other in the Y-axis direction across the cylindrical axis J13 of the sub-support member main body 2131. The two ribs 2132 are respectively engaged with the inside of two grooves 2019a of the second guide member 2019. With the two ribs 2132 engaged with the inside of the grooves 2019a, the inner sub-support member 2013 is movable in the Y-axis direction relative to the second guide member 2019. The tip of the inner flange 172 of the outer sub-support member 17 abuts against the outer wall of the inner sub-support member 13, restricting movement of the inner sub-support member 13 relative to the outer sub-support member 17 in a direction perpendicular to the Z-axis direction.

[0034] As described above, in the work holding device 2 according to this embodiment, the work holding member 14 is also supported by the inner sub-support member 2013 of the first support member 2020 so that the inclination of its central axis J14 is variable relative to the inner sub-support member 2013 of the first support member 2020. Furthermore, the second support member 18 supports the outer sub-support member 17 of the first support member 20 so that the outer sub-support member 17 is slidable in a direction perpendicular to the cylindrical axis J18 of the second support member 18. This makes it easier to reduce the number of parts compared to a structure in which the first support member 2020 and the second support member 18 are axially supported, thereby simplifying the overall structure of the work holding device 2.

[0035] Although the above describes an embodiment of the present invention, the present invention is not limited to the configuration of the above embodiment. For example, as shown in Figures 9A and 9B , a workpiece holding device 3 may have an annular groove 3171a formed in the +Z direction end of the outer sub-support member 3017 of the first support member 3020 so as to surround the cylindrical axis J17. Note that in Figures 9A and 9B , components similar to those in embodiment 1 are denoted by the same reference numerals as in Figures 3A and 3B . The outer sub-support member 3017 includes a cylindrical sub-support member main body 3171 and an inner flange 172. The annular groove 3171a is formed in the +Z direction end of the sub-support member main body 3171. The annular groove 3171a is formed so that the cross-sectional area of ​​the inner region perpendicular to the cylindrical axis J17 direction and surrounded by the annular groove 3171a decreases toward the bottom of the annular groove 3171a in the cylindrical axis J17 direction of the sub-support member main body 3171. That is, the annular groove 3171a is formed so that the inner diameter of the cross section of the inner side of the annular groove 3171a perpendicular to the cylindrical axis J17 direction of the sub-support member main body J17 decreases toward the -Z direction. In addition, the sub-support member main body 3171 is formed with a second gas inlet passage 3171b for introducing gas into the inside of the annular groove 3171a. This second gas introduction path 3171b extends from the inside of the annular groove 3171a at the end on the +Z direction side of the sub-support member main body 171 to a position on the −Z direction side of the sub-support member main body 171, extends from that position to a position on the −Z direction side of the annular groove 3171a, and extends from that position to the annular groove 3171a, thereby communicating with the inside of the annular groove 3171a. In addition, a connector 32 for introducing gas from the slide restriction part 22 into the second gas introduction path 3171b is attached to the part of the second gas introduction path 3171b that opens at the end on the +Z direction side of the sub-support member main body 3171.

[0036] The second support member 3018 has a cylindrical support body 3181 and an inner flange 3182 that protrudes inward from the entire circumference of the end of the support body 3181 on the +Z direction side, and supports the outer sub-support member 3017 so that the outer sub-support member 3017 can slide freely in a direction perpendicular to the direction of the cylindrical axis J18. Here, the inner flange 3182 covers the +Z direction side of the entire annular groove 3171a formed at the end of the outer sub-support member 3017 on the +Z direction side when the outer sub-support member 3017 is viewed from the direction of the second cylindrical axis J18.

[0037] Here, the sliding control part 22 pushes the second elastic member 16 in a direction protruding outward from the annular groove 3171a by introducing gas into the area formed between the annular groove 3171a and the second elastic member 16 through the second gas introduction passage 3171b.

[0038] In each embodiment, at least one of the first elastic member 15 and the second elastic member 16 may be present in plurality. For example, in the work holding devices 1 and 2 according to each embodiment, a plurality of annular grooves 141d may be formed in the curved surface 141e of the holding member body 141 of the work holding member 14 so as to surround the central axis J14, and a first elastic member 15 may be fitted into each of the plurality of annular grooves 141d. Alternatively, a plurality of annular grooves 171a may be formed in the -Z side end of the sub-support member body 171 of the outer sub-support member 17 so as to surround the cylindrical axis J17 and be arranged concentrically with the cylindrical axis J17 as the center, and a second elastic member 16 may be fitted into each of the plurality of annular grooves 171a.

[0039] According to this configuration, when restricting the swinging of the work holding member 14 relative to the inner sub-support member 13, 2013, the multiple first elastic members 15 can be pressed against the concave portions 13e, 2013e of the inner sub-support member 13, 2013. Furthermore, when restricting the sliding of the outer sub-support member 17 relative to the second support member 18, the multiple second elastic members 16 can be pressed against the +Z direction side of the base member 11, 2011. This makes it possible to improve the braking force that restricts the swinging of the work holding member 14 relative to the inner sub-support member 13, 2013, or the control force that restricts the sliding of the outer sub-support member 17 relative to the second support member 18.

[0040] In each embodiment, an example has been described in which the workpiece holding member 14 has two protrusions 142, but the number of protrusions 142 is not limited to two and may be three or more. In this case, it is sufficient that the concave surface portion 13e, 2013e of the inner sub-support member 13, 2013 has a plurality of recesses 13c, 2013c formed therein, the number of which is at least equal to the number of protrusions 142. Furthermore, when the number of protrusions 142 is one, a swing limiting member (not shown) that controls the swing range of the workpiece holding member 14 may be provided on the outside of the workpiece holding member 14.

[0041] In each embodiment, an example has been described in which the pressure of the gas supplied from the gas source 211 to the connector 31 of the work holding member 14 is adjusted to restrict the oscillation of the work holding member 14 relative to the inner sub-support member 13, and the pressure of the gas supplied from the gas source 211 to the connector 32 of the outer sub-support member 17 is adjusted to restrict the sliding of the outer sub-support member 17 relative to the second support member 18. However, the fluid supplied to the connectors 31, 32 is not limited to gas, and may be a liquid such as water or oil.

[0042] Although the embodiments and modifications of the present invention have been described above, various embodiments and modifications of the present invention are possible without departing from the broad spirit and scope of the present invention. Furthermore, the above-described embodiments are intended to explain the present invention and do not limit the scope of the present invention. That is, the scope of the present invention is defined by the claims, not the embodiments. Various modifications made within the scope of the claims and the meaning of the invention equivalent thereto are considered to be within the scope of the present invention.

[0043] This application is based on Japanese Patent Application No. 2023-220228, filed on December 27, 2023. The entire specification, claims and drawings of Japanese Patent Application No. 2023-220228 are incorporated herein by reference.

[0044] The present invention is suitable for a honing device that processes gears, injector parts, and the like used in transmissions.

[0045] 1, 2, 3: workpiece holding device, 11, 2011: base member, 11a, 2011a: opening, 11b, 2019a, 2019b: groove, 12: guide member, 13, 2013: inner sub-support member, 13a: notch, 13b, 141d, 171a, 3171a: annular groove, 13c, 2013c: recess, 13e, 2013e: concave surface, 14: workpiece holding member, 15: first elastic member, 16: second elastic member, 17, 3017: outer sub-support member, 18, 3018: second support member, 20, 2020, 3020: first support member, 21: swing regulation portion, 22: slide regulation portion, 31, 32: connector, 121, 212 1: guide member body, 122, 123, 2123, 2132: rib, 141: holder body, 141a: hole, 142: protrusion, 141e: curved surface, 141b: annular groove, 141c: first gas introduction passage, 171, 2131, 3171: sub-support member body, 171b, 3171b: second gas introduction passage, 172, 182, 3182: inner flange, 181, 3181: support body, 211: gas source, 212, 222: tube, 213, 223: pressure control valve, 214: pressure control unit, 2012: first guide member, 2019: second guide member, J11, J14: central axis, J12, J13, J17, J18: cylindrical axis, W: workpiece

Claims

1. A work holding device comprising: a work holding member that holds a work in a state where the work is fitted into a hole extending along one central axis bored in a peripheral wall, the outer shape of a cross section orthogonal to the central axis being circular, and having a shape in which a curved surface is formed in a part of the peripheral wall, the central part in the central axis direction bulging in a direction away from the central axis compared to both end parts in the central axis direction; a first support member that is cylindrical, surrounds a first cylindrical axis in a part of an inner wall, and is curved so as to be recessed in a direction away from the first cylindrical axis as it approaches the central part in the first cylindrical axis direction from both end parts in the first cylindrical axis direction, and a concave part into which the part where the curved surface of the work holding member is formed is fitted is formed, and supports the work holding member so that the inclination of the central axis of the work holding member with respect to the first cylindrical axis direction can be freely changed; and a second support member that is cylindrical, projects inward from one end part in a second cylindrical axis direction, and has an inner flange part that faces the entire peripheral part of the first support member when the first support member is viewed from the second cylindrical axis direction, and restricts movement along the second cylindrical axis direction of the first support member on the other end part side in the second cylindrical axis direction, and supports the first support member so that the first support member can slide freely in a direction orthogonal to the second cylindrical axis direction.

2. The work holding device according to claim 1, further comprising: a first annular groove formed so as to surround the central axis in at least a part of the curved surface of the work holding member; a first elastic member that is annular and fitted into the first annular groove; and a swing restricting part that restricts the swing of the work holding member with respect to the first support member by expanding the first elastic member and pressing the first elastic member against the concave part of the first support member.

3. The work holding device according to claim 2, wherein a first gas introduction path for introducing gas is further formed inside the first annular groove in the work holding member, and the swing restricting part expands the first elastic member by introducing gas into a region formed between the first annular groove and the first elastic member through the first gas introduction path.

4. At least one of both ends of the first support member in the first cylinder axis direction is formed with a second annular groove so as to surround the first cylinder axis, a second elastic member that is annular and is fitted into the second annular groove, a base member to which the second support member is fixed, and a sliding restriction portion that restricts sliding of the first support member with respect to the second support member by pushing the second elastic member in a direction protruding outward from the second annular groove and pressing it against the base member or the inner flange portion. The work holding device according to any one of claims 1 to 3.

5. The first support member is further formed with a second gas introduction passage for introducing gas inside the second annular groove. The sliding restriction portion pushes the second elastic member in a direction protruding outward from the second annular groove by introducing gas into a region formed between the second annular groove and the second elastic member through the second gas introduction passage. The work holding device according to claim 4.

6. The second annular groove is formed such that, in the first cylinder axis direction, the cross-sectional area of the inner region that is orthogonal to the first cylinder axis direction and surrounded by the second annular groove becomes smaller as it is located closer to the bottom side of the second annular groove. The work holding device according to claim 4.

7. The work holding member has a plurality of protrusions protruding outward from a part of the curved surface. A plurality of recesses into which the plurality of protrusions are fitted are formed in portions of the concave surface portion of the first support member that face the plurality of protrusions respectively. The swing range of the work holding member is limited to a range in which each of the plurality of protrusions can move inside each of the plurality of recesses. The work holding device according to any one of claims 1 to 3.

8. The work holding device according to any one of claims 1 to 3 further includes a guide member for guiding movement of the first support member in a direction orthogonal to the first cylinder axis direction.

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