Clamping device and clamping system

Abstract

Clamping device (10), comprising: a first movable part (14) and a second movable part (16) configured to grip a workpiece (W); and a cylinder device (18, 18a) configured to cause the first movable part and the second movable part to move toward and away from each other; wherein the cylinder device is arranged between the first movable part and the second movable part in a moving direction in which the first movable part and the second movable part can approach and move away from each other; wherein the cylinder device comprises a cylinder body (28) having a cylinder hole (44) therein extending in the direction of movement; and wherein a dimension of the cylinder hole along a width direction of the cylinder device perpendicular to the movement direction is larger than a dimension of the cylinder hole along a height direction perpendicular to the movement direction and the width direction.

Description

BACKGROUND OF THE INVENTION FIELD OF THE INVENTION

[0001] The present invention relates to a clamping device (chuck) and a clamping system. DESCRIPTION OF THE STATE OF THE ART

[0002] JP 2002-079486 A discloses a clamping device equipped with a first movable part and a second movable part for gripping a workpiece, and a cylinder device that causes the first movable part and the second movable part to mutually move toward and away from each other. The first movable part and the second movable part are arranged relative to the cylinder device in a direction (a direction in the height of the clamping device) perpendicular to a moving direction in which the first movable part and the second movable part can mutually move toward and away from each other. SUMMARY OF THE INVENTION

[0003] There has long been a need for a clamping device and a clamping system capable of expanding a maximum opening width of the first movable part and the second movable part while minimizing the dimension in the height direction of the clamping device.

[0004] The present invention aims to solve the above-mentioned problem.

[0005] A first aspect of the present invention is characterized by a clamping device comprising a first movable part and a second movable part configured to grip a workpiece, and a cylinder device configured to cause the first movable part and the second movable part to move toward and away from each other, wherein in a moving direction in which the first movable part and the second movable part can move toward and away from each other, the cylinder device is arranged between the first movable part and the second movable part, the cylinder device comprises a cylinder body having a cylinder hole formed therein extending in the moving direction,and a dimension of the cylinder hole along a width direction of the cylinder device perpendicular to the movement direction is larger than a dimension of the cylinder hole along a height direction perpendicular to the movement direction and the width direction.

[0006] A second aspect of the present invention is characterized by a clamping system comprising the clamping device according to the first aspect and a fluid circuit configured to supply a compressed fluid to the clamping device for driving the cylinder device.

[0007] According to the present invention, it is possible to increase the maximum opening width of the first movable part and the second movable part while reducing the dimension in the height direction of the cylinder device.

[0008] The above and other objects, features and advantages of the present invention will become more apparent from the following description when taken in conjunction with the accompanying drawings in which a preferred embodiment of the present invention is shown by way of illustrative example. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view of a clamping device according to an embodiment to which a first gripping element and a second gripping element are attached; Fig. 2 is an exploded perspective view of a portion of the clamping device; Fig. 3 is a cross-sectional view of the clamping device; Fig. 4 is a cross-sectional view along the line IV-IV of Fig. 3; Fig. 5 is a cross-sectional view along the line VV of Fig. 3; Fig. 6 is a side view of the clamping device; Fig. 7 is a schematic diagram of a clamping system; Fig. 8 is a schematic diagram of the clamping system; Fig. 9 is a diagram for describing the operation of the clamping device; Fig. 10 is a diagram for describing the operation of the clamping device; Fig. 11 is a diagram for describing the operation of the clamping device; Fig. 12 is a diagram describing the operation of the clamping device; and Fig. 13 is a cross-sectional view of the clamping device equipped with a cylinder device according to an exemplary modification. DETAILED DESCRIPTION OF THE USE MODEL

[0009] Hereinafter, a clamping device 10 and a clamping system 144 according to an embodiment of the present invention will be described with reference to the accompanying drawings. Fig. 1 is a perspective view of the clamping device 10 according to the embodiment, to which a first gripping element 300 and a second gripping element 302 are attached. Fig. 2 is an exploded perspective view of a portion of the clamping device 10.

[0010] As in Fig. 1, the clamping device 10 is a device for clamping a workpiece W (see Fig. 12) by means of the first gripping element 300 and the second gripping element 302. The clamping device 10 can, for example, be attached to and detached from a robot hand (not shown). The clamping device 10 can be attached to and detached from a clamping device other than a robot hand.

[0011] As in Fig. 1 and Fig. As shown in Figure 2, the clamping device 10 is equipped with a chuck main body 12, a first movable part 14, and a second movable part 16. The chuck main body 12 is equipped with a cylinder device 18, a first support portion 20, a second support portion 22, a first guide member 24, and a second guide member 26. The cylinder device 18 causes the first movable part 14 and the second movable part 16 to reciprocally move toward and away from each other.

[0012] Both the first movable part 14 and the second movable part 16 have a plate-like shape. As shown in Fig. As shown in Figure 1, a first gripping member (a first fixture) 300 can be attached to and detached from the first movable part 14. A second gripping member (a second fixture) 302 can be attached to and detached from the second movable part 16. The size, shape, or the like of the first gripping member 300 and the second gripping member 302 can be adjusted according to the size, shape, or the like of the workpiece W.

[0013] FIG. 3 is a cross-sectional view of the clamping device 10. Fig. 4 is a cross-sectional view along the line IV-IV of Fig. 3. As in Fig. 3 and Fig. 4, the cylinder device 18 causes the first movable part 14 and the second movable part 16 to move in a moving direction (the X direction) in which they approach and move away from each other. The clamping device 10 is capable of gripping the workpiece W through the cylinder device 18, thereby moving the first movable part 14 and the second movable part 16 in directions in which they approach each other. Specifically, the clamping device 10 is capable of gripping the workpiece W by causing the cylinder device 18 to move the first movable part 14 in a first direction (the X2 direction) approaching the second movable part 16 and, together with it, moving the second movable part 16 in a second direction (the X1 direction) approaching the first movable part 14.

[0014] Furthermore, the clamping device 10 is capable of releasing the workpiece W by causing the cylinder device 18 to move the first movable part 14 and the second movable part 16 in directions away from each other. Specifically, the clamping device 10 is capable of releasing the workpiece W by causing the cylinder device 18 to move the first movable part 14 in a second direction (the X1 direction) and, together with it, to move the second movable part 16 in the first direction (the X2 direction).

[0015] As in the Fig. 1 to 4, the cylinder device 18 is arranged between the first movable part 14 and the second movable part 16 in the moving direction (the X direction). In other words, the first movable part 14 is positioned in the X1 direction of the cylinder device 18. The second movable part 16 is positioned in the X2 direction of the cylinder device 18. In the present embodiment, the first movable part 14, the cylinder device 18, and the second movable part 16 are arranged in this order in the X2 direction. According to this feature, in the height direction (the Z direction) of the cylinder device 18, since the first movable part 14 and the second movable part 16 do not overlap with the cylinder device 18, the size of the clamping device 10 in the height direction can be made compact.

[0016] In addition, the height direction of the cylinder device 18 is perpendicular to the X-direction. In other words, the height direction of the cylinder device 18 in a state where the clamping device 10 has gripped the workpiece W (see Fig. 12), a direction in which the workpiece W and the cylinder device 18 are arranged side by side. Since the cylinder device 18 is arranged between the first movable part 14 and the second movable part 16, the maximum opening width between the first movable part 14 and the second movable part 16 can be made relatively large. Therefore, the clamping device 10 is capable of gripping a comparatively wide workpiece W (see Fig. 12).

[0017] As in the Fig. 3 and Fig. 4, the cylinder device 18 is provided with a cylinder body 28, a first end member (end link) 30, a second end member (end link) 32, an intermediate wall portion 34, a first piston portion 36, a second piston portion 38, a first rod 40, and a second rod 42.

[0018] The cylinder body 28 extends in the X direction. The cylinder body 28 includes a cylinder hole (cylinder bore) 44 extending in the X direction. The cylinder hole 44 extends in the movement direction (X direction). The cylinder hole 44 penetrates the cylinder body 28 in the X direction. The cylinder hole 44 extends in the width direction (the Y direction) of the cylinder device 18. Furthermore, the Y direction is a direction perpendicular to the X direction and the Z direction (the height direction of the cylinder device 18).

[0019] Fig. 5 is a cross-sectional view along the line VV of Fig. 3. As in Fig. 5, the dimension of the cylinder hole 44 in the width direction (the Y direction) of the cylinder device 18 is larger than the dimension of the cylinder hole 44 in the height direction (the Z direction) of the cylinder device 18. According to this feature, it is possible to reduce the height dimension of the clamping device 10. In a cross section viewed from the X direction, a central portion of the cylinder hole 44 extends in the Y direction in a rectangular shape. In a cross section viewed from the X direction, both ends of the cylinder hole 44 in the Y direction are formed in a semicircular shape that protrudes outward in the Y direction. The shape of the cylinder hole 44 is not limited to this shape and may be, for example, a rectangular shape, an elliptical shape, or the like.

[0020] As in Fig. 3 and Fig. 4, the first end member 30 is a plate-like member attached to one end portion (one end portion in the X1 direction of the cylinder body 28) of the cylinder body 28. One end portion of the cylinder body 28 is positioned in the Z1 direction of the first end member 30. The first end member 30 is fixed to one end portion of the cylinder body 28 by a plurality (two in the present embodiment) of screw members 46 (see Fig. 1 and Fig. 2). The first end member 30 covers the cylinder hole 44 from the X1 direction. The first end member 30 and the first movable part 14 are arranged facing each other in the X direction.

[0021] The second end member 32 is a plate-like member attached to another end portion (an end portion in the X2 direction of the cylinder body 28) of the cylinder body 28. The other end portion of the cylinder body 28 is positioned in the Z1 direction of the second end member 32. The second end member 32 is fixed to another end portion of the cylinder body 28 by a plurality (two in the present embodiment) of screw members 48 (see Fig. 1 and Fig. 2). The second end member 32 covers the cylinder hole 44 from the X2 direction. The second end member 32 and the second movable part 16 are arranged facing each other in the X direction.

[0022] The partition wall portion 34 is disposed within the cylinder hole 44. The partition wall portion 34 divides the cylinder hole 44 in the axial direction (the X direction) of the cylinder body 28. The partition wall portion 34 is hermetically fixed to the inner peripheral surface of the cylinder body 28. A sealing member (not shown) is provided between the outer peripheral surface of the partition wall portion 34 and the inner peripheral surface of the cylinder body 28.

[0023] The first piston portion 36 and the second piston portion 38 are arranged so that they can slide in the cylinder bore 44. The first piston portion 36 and the second piston portion 38 are arranged side by side in the direction of movement (X direction). The first piston portion 36 is arranged in the X1 direction of the second piston portion 38. The first piston portion 36 includes an inner side piston 50 and an outer side piston 52. The inner side piston 50 is arranged between the intermediate wall part 34 and the second piston portion 38. A piston seal (not shown), which ensures an airtight seal between the inner side piston 50 and the cylinder body 28, is attached to an outer peripheral surface of the inner side piston 50. The outer side piston 52 is positioned in the opposite direction to the second piston portion 38 with respect to the intermediate wall portion 34.In other words, the outer side piston 52 is mounted on the first rod 40 so that it is positioned in the opposite direction to the inner side piston 50 with respect to the intermediate wall portion 34. The outer side piston 52 is disposed between the intermediate wall portion 34 and the first end member 30. A piston seal (not shown) that provides an airtight seal between the outer side piston 52 and the cylinder body 28 is attached to an outer peripheral surface of the outer side piston 52.

[0024] The second piston portion 38 is disposed between the inner side piston 50 and the second end member 32. A piston seal (not shown) is attached to an outer peripheral surface of the second piston portion 38 to ensure an airtight seal between the second piston portion 38 and the cylinder body 28.

[0025] The first rod 40 connects the first piston portion 36 and the first movable member 14. The X2-direction end portion of the first rod 40 is fixed to the inner side piston 50. The first rod 40 extends in the X1 direction from the inner side piston 50 and penetrates the intermediate wall portion 34, the outer side piston 52, and the first end member 30. A sealing member (not shown) that provides an airtight seal between the first rod 40 and the intermediate wall portion 34 is attached to the inner surface of a hole within the intermediate wall portion 34 through which the first rod 40 passes. The outer side piston 52 is fixed to an X-direction intermediate portion of the first rod 40.A sealing member 54, which provides an airtight seal between the first rod 40 and the first end member 30, is attached to the inner surface of a hole within the first end member 30 through which the first rod 40 passes. The X1-direction end portion of the first rod 40 is fixed to the first movable member 14.

[0026] The second rod 42 connects the second piston portion 38 and the second movable member 16. The X1-direction end portion of the second rod 42 is fixed to the second piston portion 38. The second rod 42 extends in the X2 direction from the second piston portion 38 and penetrates the second end member 32. A sealing member 56, which provides an airtight seal between the second rod 42 and the second end member 32, is attached to the inner surface of a hole within the second end member 32 through which the second rod 42 passes. The X2-direction end portion of the second rod 42 is fixed to the second movable member 16.

[0027] As shown in Figs. 2 and 3, the first support portion 20 supports the first movable part 14. The first support portion 20 is a plate-shaped portion that protrudes from one end portion (an end portion in the X1 direction) of the cylinder body 28 in an opposite direction (the X1 direction) to the second movable part 16. The second support portion 22 supports the second movable part 16. The second support portion 22 is a plate-shaped portion that protrudes in an opposite direction (the X2 direction) to the first movable part 14 from the other end portion (an end portion in the X2 direction). The cylinder body 28, the first support portion 20, and the second support portion 22 are integrally molded products formed from a metal material.Hereinafter, the member formed by the cylinder body 28, the first support portion 20 and the second support portion 22 may be referred to as “main body 58” (or base body 58).

[0028] The main body 58 does not necessarily have to be an integrally molded product. Specifically, the cylinder body 28, the first support portion 20, and the second support portion 22 may be molded as separate components, and the main body 58 may be formed by connecting these components together with screw members or the like. When the main body 58 is an integrally molded product, the number of components can be reduced because components such as screws or the like are not required.

[0029] As in Fig. 4, a pair of first mounting holes 60 for mounting the clamping device 10 to a mounting object not shown are arranged side by side in the Y direction at an end part (a portion adjacent to the cylinder device 18) in the X2 direction of the first support portion 20.

[0030] As in Fig. 2 and Fig. 3, the first support portion 20 includes a first guide support portion 62 positioned further in the X1 direction than a pair of first mounting holes 60, which supports the first guide member 24. A first concave portion 64 for arranging the first guide member 24 is formed on a surface (a surface facing the Z2 direction) of the first guide support portion 62, the surface facing the first movable part 14. The first concave portion 64 penetrates the first guide support portion 62 in the X direction.

[0031] As in Fig. 2, the first guide member 24 includes a pair of first guide rails 66 and a first slider 68. The pair of first guide rails 66 are arranged within the first concave portion 64 so as to face each other in the Y direction. Each of the respective first guide rails 66 extends in the X direction. The first slider 68 is arranged between the pair of first guide rails 66. The first movable part 14 is fixed to the first slider 68 by a plurality of screw members 70. A plurality of balls (not shown) are arranged between the pair of first guide rails 66 and the first slider 68. The pair of first guide rails 66 serves to guide the first slider 68 in the X direction.

[0032] As in Fig. 4, a pair of second mounting holes 72 for mounting the clamping device 10 to a mounting object not shown are arranged side by side in the Y direction at an end part (a portion adjacent to the cylinder device 18) in the X1 direction of the second support part 22.

[0033] As in Fig. 2 and Fig. 3, the second support portion 22 includes a second guide support portion 74 positioned further in the X2 direction than the pair of second mounting holes 72, which supports the second guide member 26. A second concave portion 76 for arranging the second guide member 26 is formed on a surface (a surface facing the Z2 direction) of the second guide support portion 74, the surface facing the second movable part 16. The second concave portion 76 penetrates the second guide support portion 74 in the X direction.

[0034] As in Fig. 2, the second guide member 26 includes a pair of second guide rails 78 and a second slider 80. The pair of second guide rails 78 are disposed within the second concave portion 76 so as to face each other in the Y direction. Each of the respective second guide rails 78 extends in the X direction. The second slider 80 is disposed between the pair of second guide rails 78. The second movable part 16 is fixed to the second slider 80 by a plurality of screw members 82. A plurality of balls (not shown) are disposed between the pair of second guide rails 78 and the second slider 80. The pair of second guide rails 78 serves to guide the second slider 80 in the X direction.

[0035] The clamping device 10 is equipped with an adjustment mounting portion 86 for mounting an adjuster 84 that comes into contact with the first movable part 14 and thereby adjusts a movement limit position (a stroke end position of the first piston portion 36) in the first direction of the first movable part 14. The adjustment mounting portion 86 includes a pair of first mounting portions 88 and a pair of second mounting portions 90.

[0036] The pair of first mounting portions 88 are provided on the first guide support portion 62. The pair of first mounting portions 88 are respectively provided on each of a pair of surfaces of the first guide support portion 62, the surfaces facing in the Y direction. The first mounting portions 88 include a first positioning concave portion 92 and two first screw holes 94. The first positioning concave portion 92 extends the entire length in the Z direction of the first guide support portion 62. The two first screw holes 94 are formed in a bottom surface of the first positioning concave portion 92. The two first screw holes 94 are arranged to be spaced apart from each other in the X direction.

[0037] The pair of second mounting portions 90 are provided on the first movable part 14. The pair of second mounting portions 90 are respectively provided on each of a pair of surfaces of the first movable part 14, the surfaces facing in the Y direction. The second mounting portions 90 include three second screw holes 96 and two second positioning concave portions 98. The three second screw holes 96 are arranged to be spaced apart from each other at intervals in the X direction. The two second positioning concave portions 98 are positioned between the adjacent second screw holes 96. The second positioning concave portions 98 extend over the entire length in the Z direction of the first movable part 14.

[0038] The adjuster 84 includes an adjuster main body 100 and a contact piece 102. The adjuster main body 100 can be attached to and detached from the first attachment portions 88. The user can select which of the two first attachment portions 88 the adjuster main body 100 is attached to. The adjuster main body 100 includes a holding member 104, a bolt support portion 105, a nut 106, and an adjustment bolt 108. The holding member 104 has a shape corresponding to the first concave positioning portion 92.

[0039] Two first insertion holes 110 are provided on the holding member 104. In a state where the holding member 104 is arranged in the first concave positioning portion 92, the two first insertion holes 110 of the holding member 104 overlap with the two first screw holes 94 when viewed from the Y direction. The holding member 104 is fixed to the first mounting portions 88 by two screw members 112. The bolt support portion 105 protrudes from the holding member 104 in the Z2 direction. The bolt support portion 105 is provided with a bolt insertion hole 114 penetrating it in the X direction. The adjusting screw 108 is inserted into the bolt insertion hole 114.

[0040] The nut 106 is attached to the bolt support portion 105. The adjusting screw 108 is screwed to the nut 106. By rotating the adjusting screw 108 relative to the nut 106, it is possible to adjust the protruding length of the adjusting screw 108 in the X1 direction relative to the bolt support portion 105.

[0041] The contact piece 102 can be attached to and detached from the second mounting portions 90. The user mounts the contact piece 102 on the second mounting portions 90, which correspond to the first mounting portions 88 to which the adjustment body 100 is attached. The contact piece 102 has, for example, a rectangular parallelepiped shape. The contact piece 102 is provided with a convex positioning portion 116 and two second insertion holes 118. The convex positioning portion 116 can be inserted into the second concave positioning portions 98. In a state where the convex positioning portion 116 is inserted into the second concave positioning portions 98, the two second insertion holes 118 of the contact piece 102 overlap with two adjacent second screw holes 96 out of the three second screw holes 96 when viewed from the Y direction.The contact piece 102 is attached to the second fastening sections 90 by two screw elements 120.

[0042] As in Fig. 4, the cylinder device 18 is provided with a first chamber 122a, a first chamber 122b, a second chamber 124, a third chamber 126, and a fourth chamber 128. The first chamber 122a is formed between the outer piston 52 and the first end member 30. The first chamber 122b is formed between the intermediate wall portion 34 and the inner piston 50. The second chamber 124 is formed between the second piston portion 38 and the second end member 32. The third chamber 126 is formed between the outer side piston 52 and the intermediate wall portion 34. The fourth chamber 128 is formed between the inner side piston 50 and the second piston portion 38.

[0043] The compressed fluid in the first chamber 122a pushes the outer side piston 52 in the X2 direction. The compressed fluid in the first chamber 122b pushes the inner side piston 50 in the X2 direction. More specifically, the first piston portion 36 is pushed in the X2 direction by the compressed fluid in the first chamber 122a and the compressed fluid in the first chamber 122b. The compressed fluid in the second chamber 124 pushes the second piston portion 38 in the X1 direction.

[0044] The first piston portion 36 includes a first pressure-receiving surface 130. The first pressure-receiving surface 130 is pressed in the X2 direction (the first direction) by the compressed fluid in the first chamber 122a and the compressed fluid in the first chamber 122b. The first pressure-receiving surface 130 includes a pressure-receiving surface 132 facing the X1 direction inside the outer side piston 52 and a pressure-receiving surface 134 facing the X1 direction inside the inner side piston 50. The second piston portion 38 includes a second pressure-receiving surface 136. The second pressure-receiving surface 136 is pressed in the X1 direction (the second direction) by the compressed fluid in the second chamber 124. The second pressure-receiving surface 136 is a surface facing the X1 direction inside the second piston portion 38.The area of ​​the first pressure receiving surface 130 (the sum of the area of ​​the pressure receiving surface 132 and the area of ​​the pressure receiving surface 134) is larger than the area of ​​the second pressure receiving surface 136. More specifically, a first thrust force of the first piston portion 36 in the X2 direction (the first direction) is larger than a second thrust force of the second piston portion 38 in the X1 direction (the second direction).

[0045] Fig. 6 is a cross-sectional view of the clamping device 10. In other words, Fig. 6 a side view of the clamping device 10 from the X2 direction. As in Fig. 1, Fig. 2, Fig. 5 and Fig. 6, the main body 58 is formed with a first port 138, a second port 140, and a third port 142. The first port 138 communicates with the first chamber 122a and the first chamber 122b. The second port 140 communicates with the second chamber 124. The third port 142 communicates with the third chamber 126 and the fourth chamber 128. Each of the first port 138, the second port 140, and the third port 142 opens to both end surfaces in the X direction of the main body 58, respectively. In other words, each of the first opening 138, the second opening 140, and the third opening 142 opens on the outer surface of the first support portion 20 and the outer surface of the second support portion 22, respectively.

[0046] Fig. 7 and Fig. 8 are schematic representations of the clamping system 144. As in Fig. 7 and Fig. As shown in Figure 8, the clamping device 10 described above is provided in the clamping system 144. The clamping system 144 is equipped with the clamping device 10 and a fluid circuit 146. The fluid circuit 146 is equipped with a fluid supply source 148, a supply flow path 150, a switching valve 152, an outlet flow path 154, an outlet port 156, a first circuit section 158, and a second circuit section 160.

[0047] The fluid supply source 148 may provide a compressed fluid, such as high-pressure air. The outlet port 156 is provided with a silencer 162. The fluid circuit 146 does not necessarily have to be equipped with the silencer 162. The supply flow path 150 serves to direct the compressed fluid supplied from the fluid supply source 148 to the switching valve 152. The outlet flow path 154 serves to direct the compressed fluid discharged from the switching valve 152 to the outlet port 156.

[0048] The first circuit section 158 includes a connecting flow path 164, a first flow path 166, a first flow control valve 168, a second flow path 170, a second flow control valve 172, and a third flow control valve 174. The connecting flow path 164 is connected to the switching valve 152. The first flow path 166 and the second flow path 170 are connected to the connecting flow path 164.

[0049] The first flow path 166 connects the connecting flow path 164 and the first port 138. The first flow path 166 communicates with the first chamber 122a and the first chamber 122b via the first port 138. The first flow control valve 168 is provided in the first flow path 166. The first flow control valve 168 performs discharge control to adjust the flow rate of the compressed fluid discharged from the first chamber 122a and the first chamber 122b of the clamping device 10. The first flow control valve 168 includes a throttle portion 178 and a check valve 180. The throttle portion 178 and the check valve 180 are arranged in parallel. The throttle portion 178 is, for example, a variable throttle portion capable of adjusting the flow rate discharged from the clamping device 10.The check valve 180 allows the compressed fluid to flow in a direction from the switching valve 152 to the tensioner 10 through the check valve and prevents the compressed fluid from flowing in a direction from the tensioner 10 to the switching valve 152 through the check valve.

[0050] The second flow path 170 connects the connecting flow path 164 and the second port 140. The second flow path 170 communicates with the second chamber 124 via the second port 140. The second flow control valve 172 and the third flow control valve 174 are provided in series in the second flow path 170. The second flow control valve 172 performs inlet control to adjust the flow rate of the compressed fluid introduced into the second chamber 124 of the tensioner 10. The second flow control valve 172 includes a throttle portion 182 and a check valve 184. The throttle portion 182 and the check valve 184 are arranged in parallel. The throttle portion 182 is, for example, a variable throttle portion capable of adjusting the flow rate introduced into the tensioner 10.The check valve 184 prevents the compressed fluid from flowing in one direction from the switching valve 152 to the tensioner 10 and allows the compressed fluid to flow in one direction from the tensioner 10 to the switching valve 152.

[0051] The third flow control valve 174 performs discharge control to adjust the flow rate of the compressed fluid discharged from the second chamber 124 of the tensioner 10. The third flow control valve 174 is similar in structure to the first flow control valve 168. Therefore, a description of the structure of the third flow control valve 174 will be omitted.

[0052] The second circuit section 160 includes a third flow path 186 and a fourth flow control valve 188. The third flow path 186 connects the switching valve 152 and the third port 142. The third flow path 186 communicates with the third chamber 126 and the fourth chamber 128 via the third port 142. The fourth flow control valve 188 is provided in the third flow path 186. The fourth flow control valve 188 performs spill control to adjust the flow rate of the compressed fluid discharged from the third chamber 126 and the fourth chamber 128 of the tensioner 10. The fourth flow control valve 188 is similar in structure to the first flow control valve 168. Therefore, a description of the configuration of the fourth flow control valve 188 is omitted.

[0053] The first flow path 166, the second flow path 170, and the third flow path 186 are each connected to the first port 138, the second port 140, and the third port 142 via pipe connections (not shown). In the present embodiment, each of the first ports 138, the second ports 140, and the third ports 142 opens on the outer surface of the first support portion 20 and the outer surface of the second support portion 22 (see Fig. 1, Fig. 2 and Fig. 6). Therefore, depending on the environment in which the clamping device 10 is used, the pipe joint can be arranged to be adjacent to the first support portion 20 or the second support portion 22.

[0054] The switching valve 152 is a solenoid valve that can switch between a first state and a second state. As shown in Fig. 7, the switching valve 152 in the first state causes the supply flow path 150 and the third flow path 186 to mutually communicate with each other, and together causes the outlet flow path 154 and the connecting flow path 164 to mutually communicate with each other. As shown in Fig. 8, in the second state, the switching valve 152 causes the supply flow path 150 and the connecting flow path 164 to communicate with each other, and together causes the outlet flow path 154 and the third flow path 186 to communicate with each other. The switching valve 152 is, for example, an electromagnetic pilot switching valve, but the present invention is not necessarily limited to this feature.

[0055] Next, a description of the operation of the clamping device 10 is given. Fig. 9 to Fig. 12 are diagrams describing the operation of the clamping device 10. As in Fig. 9, in an initial state, the first gripping element 300 and the second gripping element 302 are attached to the clamping device 10.

[0056] When the workpiece W is gripped by the clamping device 10, the first movable part 14 and the second movable part 16 are moved in directions in which they are separated from each other, thereby increasing the gap between the first gripping element 300 and the second gripping element 302. In particular, as shown in Fig. 7, the switching valve 152 is placed in the first state. At this time, the compressed fluid supplied from the fluid supply source 148 to the supply flow path 150 is directed to the third flow path 186 via the switching valve 152. The compressed fluid directed to the third flow path 186, after flowing through the check valve 180 of the fourth flow control valve 188, is directed to the third chamber 126 and the fourth chamber 128 via the third port 142.

[0057] The compressed fluid directed to the third chamber 126 pushes the outer side piston 52 in the X1 direction. The compressed fluid directed to the fourth chamber 128 pushes the inner side piston 50 in the X1 direction and, together with it, pushes the second piston portion 38 in the X2 direction. According to this feature, the first piston portion 36 (the outer piston 52 and the inner piston 50) moves in the X1 direction, and accordingly, the first movable part 14 and the first gripping element 300 move in the X1 direction. Further, the second piston portion 38 moves in the X2 direction, and accordingly, the second movable part 16 and the second gripping element 302 move in the X2 direction. According to this feature, the first gripping element 300 and the second gripping element 302 separate from each other.

[0058] When the first piston portion 36 moves in the X1 direction, the compressed fluid in the first chamber 122a and the compressed fluid in the first chamber 122b are directed to the first flow path 166 via the first port 138. The compressed fluid directed to the first flow path 166 flows through the throttle portion 178 of the first flow control valve 168 and into the connecting flow path 164.

[0059] When the second piston portion 38 moves in the X2 direction, the compressed fluid in the second chamber 124 is directed to the second flow path 170 via the second port 140. The compressed fluid directed to the second flow path 170 flows through the throttle portion 178 of the third flow control valve 174 and the check valve 184 of the second flow control valve 172 and is directed to the connecting flow path 164. The compressed fluid directed to the connecting flow path 164 is discharged to the outside from the outlet port 156 via the switching valve 152 and the outlet flow path 154. In the present embodiment, the moving speed of the first piston portion 36 and the second piston portion 38 can be adjusted by the first discharge control flow control valve 168 and the third discharge control flow control valve 174.

[0060] Then the workpiece W is machined as shown in Fig. 9, positioned between the first gripping element 300 and the second gripping element 302. Thereafter, as shown in Fig. 8, the switching valve 152 is placed in the second state. As a result, the pressurized fluid supplied from the fluid supply source 148 to the supply flow path 150 is directed to the connecting flow path 164 via the switching valve 152. The pressurized fluid directed to the connecting flow path 164 is divided and flows into the first flow path 166 and the second flow path 170.

[0061] The compressed fluid that has flowed through the first flow path 166 after passing through the check valve 180 of the first flow control valve 168 is supplied to the first chamber 122a and the first chamber 122b via the first port 138. The compressed fluid that has been supplied to the second flow path 170 after passing through the throttle portion 182 of the second flow control valve 172 and the check valve 180 of the third flow control valve 174 is supplied to the second chamber 124 via the second port 140. In this case, since the second flow control valve 172 of the inflow controller is provided in the second flow path 170, the compressed fluid is supplied to the first chamber 122a and the first chamber 122b before being supplied to the second chamber 124.More specifically, the time at which the compressed fluid is introduced into the first chamber 122a and the first chamber 122b is earlier than the time at which the compressed fluid is introduced into the second chamber 124.

[0062] The compressed fluid supplied to the first chamber 122a pushes the outer side piston 52 in the X2 direction. The compressed fluid supplied to the first chamber 122b pushes the inner side piston 50 in the X2 direction. According to this function, the first piston portion 36 (the outer piston 52 and the inner piston 50) moves in the X2 direction, and accordingly, the first movable part 14 and the first gripping element 300 move in the X2 direction (the first direction). Furthermore, the compressed fluid supplied to the second chamber 124 pushes the second piston portion 38 in the X1 direction. According to this feature, the second piston portion 38 moves in the X1 direction, and accordingly, the second movable part 16 and the second gripping element 302 move in the X1 direction (the second direction).

[0063] In the present embodiment, the second piston portion 38 begins to move after the first piston portion 36 begins to move. Furthermore, since the first thrust of the first piston portion 36 is greater than the second thrust of the second piston portion 38, the moving speed of the first piston portion 36 is faster than the moving speed of the second piston portion 38.

[0064] Accompanying the movement of the first piston section 36, the first gripping element 300 comes into play during the movement of the first movable part 14 and the first gripping element 300 in the X2 direction, as shown in Fig. 10, comes into contact with the workpiece W. In addition, the contact piece 102 attached to the first movable part 14 comes into contact with the adjusting screw 108, thereby preventing the first movable part 14 from moving in the X2 direction (see Fig. 11). In other words, the first movable part 14 reaches the travel limit position. In other words, the first piston section 36 is positioned at the stroke end.

[0065] In a state where the first movable part 14 has reached the movement limit position, the second movable part 16 has not reached the movement limit position. Therefore, in a state where the movement of the first movable part 14 and the first gripping member 300 is stopped, the second movable part 16 and the second gripping member 302 move in the X1 direction. As shown in Fig. 12, the second gripping member 302 presses the workpiece W in the X1 direction by contacting it with the workpiece W. Accordingly, the workpiece W is clamped between the first gripping member 300 and the second gripping member 302. In this case, since the first thrust of the first piston portion 36 is greater than the second thrust of the second piston portion 38, the workpiece W pressed by the second gripping member 302 does not return in the X1 direction. According to this feature, the gripping position of the workpiece W in the moving direction (X direction) can be maintained unchanged. Furthermore, in the present embodiment, by adjusting the contact position between the contact piece 102 and the adjusting screw 108, the position at which the workpiece W is gripped (the moving limit position of the first movable part 14) can be adjusted accordingly.Therefore, the workpiece W can be gripped in the X direction in a balanced manner at a central position of the clamping device 10. (Example variation)

[0066] Fig. 13 is a cross-sectional view of the clamping device 10 equipped with a cylinder device 18a according to an exemplary modification. As shown in Fig. 13, the clamping device 10 may be equipped with the cylinder device 18a according to the first exemplary modification instead of the cylinder device 18. Furthermore, in the present exemplary modification, the same reference numerals are used to denote substantially the same constituent elements as those described above, and detailed descriptions of such elements are omitted.

[0067] According to the present embodiment, the cylinder device 18a is arranged between the first movable part 14 and the second movable part 16 in the moving direction of the first movable part 14 and the second movable part 16. Accordingly, since the first movable part 14 and the second movable part 16 and the cylinder device 18a do not overlap in the height direction (Z direction) of the clamping device 10, it is possible to minimize the dimension in the height direction of the clamping device 10. Furthermore, it is possible to expand the maximum opening width of the first movable part 14 and the second movable part 16.

[0068] The cylinder device 18a is equipped with the cylinder body 28, the first end member 30, the second end member 32, a first piston portion 36a, the second piston portion 38, a first rod 40a, and the second rod 42. It should also be noted that the cylinder device 18a does not include the above-mentioned partition wall portion 34. In this case, the cylinder device 18a is provided with a first chamber 190, the second chamber 124, and a third chamber 192. The first chamber 190 is formed between the first piston portion 36a and the first end member 30. The second chamber 124 is formed between the second piston portion 38 and the second end member 32. The third chamber 192 is formed between the first piston portion 36a and the second piston portion 38.

[0069] The first piston portion 36a is configured similarly to the inner side piston 50 described above. In the exemplary modification, the first piston portion 36a is not equipped with the above-mentioned outer side piston 52. The outer diameter of the first rod 40a is smaller than the outer diameter of the second rod 42. Therefore, the area of ​​the first pressure-receiving surface 130 of the first piston portion 36a is larger than the area of ​​the second pressure-receiving surface 136 of the second piston portion 38. Therefore, the first thrust of the first piston portion 36a in the X2 direction (the first direction) is greater than the second thrust of the second piston portion 38 in the X1 direction (the second direction).

[0070] With the cylinder device 18a according to the exemplary modification, the same advantageous effects as those of the cylinder device 18 described above are achieved.

[0071] The present embodiment is not necessarily limited to the configuration described above. The clamping device 10 does not necessarily need to include the adjustment fixing portion 86.

[0072] The following supplementary notes are further disclosed with respect to the embodiment described above. (Supplementary Note 1)

[0073] The clamping device (10) of the present invention comprises the first movable part (14) and the second movable part (16) which grip the workpiece (W), and the cylinder device (18, 18a) which causes the first movable part and the second movable part to move towards and away from each other. In the moving direction in which the first movable part and the second movable part can approach and move away from each other, the cylinder device is arranged between the first movable part and the second movable part. The cylinder device comprises the cylinder body (28) with the cylinder hole (44) therein, which extends in the moving direction, and the dimension of the cylinder hole along a width direction of the cylinder device perpendicular to the moving direction is larger than a dimension of the cylinder hole along the height direction.which is perpendicular to the direction of movement and the width direction.

[0074] According to such a configuration, since the first movable part and the second movable part and the cylinder device do not overlap in the height direction of the clamping device, it is possible to minimize the dimension in the height direction of the clamping device. Furthermore, it is possible to expand the maximum opening width of the first movable part and the second movable part. Furthermore, since the width dimension of the cylinder hole is larger than the height dimension of the cylinder hole, it is possible to further reduce the height dimension of the clamping device. (Supplementary Note 2)

[0075] The clamping device according to Supplementary Note 1, wherein the cylinder device may include the first piston portion (36, 36a) and the second piston portion (38) arranged to slide in the cylinder bore, the first rod (40, 40a) connecting the first piston portion and the first movable member, and the second rod (42) connecting the second piston and the second movable member, and the first piston portion and the second piston portion may be arranged side by side in the moving direction.

[0076] With such a configuration, the diameter (outer diameter) of the first piston portion and the second piston portion can be made relatively large, while reducing the size of the cylinder device in directions (the height direction and the width direction of the clamping device) perpendicular to the movement direction. In other words, while making the cylinder device compact, the thrust of the first piston portion and the second piston portion can be increased. (Supplementary Note 3)

[0077] The clamping device according to Supplementary Note 2, wherein the first thrust force of the first piston portion in the first direction in which the first movable part approaches the second movable part may be greater than the second thrust force of the second piston portion in the second direction in which the second movable part approaches the first movable part.

[0078] With such a configuration, it is possible to cause the first piston portion to move in the first direction before the second piston portion starts to move in the second direction because the first thrust is greater than the second thrust. Further, it is possible to make the moving speed at which the first piston moves in the first direction faster than the moving speed at which the second piston moves in the second direction. In addition, the workpiece can be pushed in the second direction by the second piston portion in a state where the first piston portion is moved to the stroke end. More specifically, the workpiece can be gripped in a state where the first piston portion is positioned at the stroke end. According to this feature, the gripping position of the workpiece in the moving direction can be maintained unchanged. (Supplementary Note 4)

[0079] The tensioner according to Supplementary Note 3, wherein the first piston portion may include the first pressure receiving surface (130) pressed in the first direction by the compressed fluid, the second piston portion may include the second pressure receiving surface (136) pressed in the second direction by the compressed fluid, and the area of ​​the first pressure receiving surface may be larger than the area of ​​the second pressure receiving surface.

[0080] With such a configuration and by means of a simple structure, the first thrust can be made larger than the second thrust. (Supplementary Note 5)

[0081] The clamping device according to Supplementary Note 4, wherein the intermediate wall portion (34) is attachable to the cylinder body dividing the cylinder hole in the axial direction of the cylinder body, and the first rod is insertable into the intermediate wall portion, and the first piston portion may include the inside piston (50) attached to the first rod in a state positioned between the intermediate wall portion and the second piston portion, and the outside piston (52) attached to the first rod in a state positioned in an opposite direction to the inside piston with respect to the intermediate wall portion.

[0082] With such a configuration, the area of ​​the first pressure receiving surface can be made larger than the area of ​​the second pressure receiving surface by a simple structure. (Supplementary Note 6)

[0083] The clamping device according to Supplementary Note 4, wherein the outer diameter of the first rod may be shaped to be smaller than the outer diameter of the second rod, such that the area of ​​the first pressure receiving surface is larger than the area of ​​the second pressure receiving surface.

[0084] With such a configuration, the area of ​​the first pressure receiving surface can be made larger than the area of ​​the second pressure receiving surface by a simple structure. (Supplementary Note 7)

[0085] The clamping device according to any one of Supplementary Notes 3 to 6 may further be provided with the adjustment fixing part (86) for fixing the adjuster (84) capable of contacting the first movable part and thereby adjusting the movement limit position in the first direction of the first movable part.

[0086] With such a configuration, by adjusting the movement limit position in the first direction of the first movable part, the gripping position of the workpiece can be adjusted. (Supplementary Note 8)

[0087] The clamping device according to any one of Supplementary Notes 2 to 7 may be equipped with the first support portion (20) protruding from the cylinder body in the opposite direction to the second movable part, the first guide member (24) provided on the first support portion and serving to guide the first movable part, the second support portion (22) protruding from the cylinder body in the opposite direction to the first movable part, and the second guide member (26) provided on the second support portion and serving to guide the second movable part, wherein the first support portion, the cylinder main body and the second support portion may be integrally molded products.

[0088] With such a configuration, it is possible to reduce the number of components and reduce the weight of the clamping device because the first support portion, the cylinder body, and the second support portion are integrally molded products, compared with a case where these elements are formed as separate components. (Supplementary Note 9)

[0089] The clamping device according to Supplementary Note 8, wherein the opening (138, 140, 142) for circulating the compressed fluid for driving the cylinder device can open on each of the respective outer surfaces of the first support portion and the second support portion.

[0090] With such a configuration, the member (e.g., the pipe joint) connected to the terminal can be arranged adjacent to the first support portion or the second support portion, depending on the environment in which the clamping device is used. (Additional Note 10)

[0091] The clamping system (144) according to the present invention may be equipped with the clamping device according to any one of Supplementary Notes 3 to 9 and the fluid circuit (146) which supplies the clamping device with the compressed fluid for driving the cylinder device.

[0092] With such a configuration, it is possible to obtain the clamping system equipped with the clamping device according to one of the Supplementary Notes 3 to 9. (Supplementary Note 11)

[0093] The clamping system according to Supplementary Note 10, wherein the cylinder device may comprise the first chamber (122a, 122b, 190) and the second chamber (124), a compressed fluid is introduced into the first chamber, whereby the first piston portion can be pushed in the first direction in which the first movable part approaches the second movable part, a compressed fluid is introduced into the second chamber, whereby the second piston portion can be pushed in the second direction in which the second movable part approaches the first movable part, and the fluid circuit may include the second flow path (170) communicating with the second chamber, the first flow control valve (168) performing metering control may be provided in the first flow path (166), and the second flow control valve (172) performing metering control and the third flow control valve (174),which carries out the dosing control, can be connected in series in the second flow path.,

[0094] With such a configuration, the compressed fluid can be introduced into the first chamber before being introduced into the second chamber through a simple structure. According to this feature, it is possible to make the timing at which the first piston portion starts to move in the first direction earlier than the timing at which the second piston portion starts to move in the second direction. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2002-079486 A

[0002] Cited non-patent literature

[0000] The first flow path 166 connects the connecting flow path 164 and the first port 138

[0049] The second flow path 170 connects the connecting flow path 164

[0050]

Claims

[1] Clamping device (10), comprising: a first movable part (14) and a second movable part (16) configured to grip a workpiece (W); and a cylinder device (18, 18a) configured to cause the first movable part and the second movable part to move toward and away from each other; wherein the cylinder device is arranged between the first movable part and the second movable part in a moving direction in which the first movable part and the second movable part can approach and move away from each other; wherein the cylinder device comprises a cylinder body (28) having a cylinder hole (44) therein extending in the direction of movement; and wherein a dimension of the cylinder hole along a width direction of the cylinder device perpendicular to the movement direction is larger than a dimension of the cylinder hole along a height direction perpendicular to the movement direction and the width direction. [2] Clamping device according to claim 1, wherein the cylinder device comprises: a first piston portion (36, 36a) and a second piston portion (38) arranged to slide in the cylinder bore; a first rod (40, 40a) connecting the first piston portion and the first movable member; and a second rod (42) connecting the second piston and the second movable part, and wherein the first piston section and the second piston section are arranged next to each other in the direction of movement. [3] The clamping device according to claim 2, wherein a first thrust force of the first piston portion in a first direction in which the first movable part approaches the second movable part is greater than a second thrust force of the second piston portion in a second direction in which the second movable part approaches the first movable part. [4] Clamping device according to claim 3, wherein the first piston portion comprises a first pressure-receiving surface (130) which is pressed in the first direction by the compressed fluid, the second piston portion comprises a second pressure-receiving surface (136) which is urged in the second direction by the compressed fluid, and an area of ​​the first pressure-receiving surface is larger than an area of ​​the second pressure-receiving surface. [5] Clamping device according to claim 4, wherein an intermediate wall portion (34) is attached to the cylinder body, which divides the cylinder hole in the axial direction of the cylinder body, the first rod is inserted into the partition wall section and the first piston section comprises: an inner side piston (50) attached to the first rod in a state where it is positioned between the intermediate wall portion and the second piston portion; and an outer side piston (52) attached to the first rod in a state of being positioned in an opposite direction to the inner side piston with respect to the intermediate wall portion. [6] The clamping device according to claim 4, wherein an outer diameter of the first rod is formed to be smaller than an outer diameter of the second rod such that an area of ​​the first pressure receiving surface is larger than an area of ​​the second pressure receiving surface. [7] The clamping device according to any one of claims 3 to 6, further comprising an adjustment mounting portion (86) configured to mount an adjuster (84) capable of contacting the first movable member and thereby adjusting a movement limit position in the first direction of the first movable member. [8] Clamping device according to one of claims 2 to 7, comprising: a first support portion (20) projecting from the cylinder body in a direction opposite to the second movable part; a first guide member (24) provided on the first support portion and configured to guide the first movable part; a second support portion (22) projecting from the cylinder body in a direction opposite to the first movable part; and a second guide member (26) provided on the second support portion and configured to guide the second movable part, wherein the first support portion, the cylinder main body and the second support portion are integrally molded products. [9] The clamping device according to claim 8, wherein an opening (138, 140, 142) configured to circulate a compressed fluid for driving the cylinder device opens on each of the respective outer surfaces of the first support portion and the second support portion. [10] Clamping system (144), comprising: the clamping device according to one of claims 3 to 9; and a fluid circuit (146) configured to supply a compressed fluid to the clamping device for driving the cylinder device. [11] Clamping system according to claim 10, wherein: the cylinder device comprises a first chamber (122a, 122b, 190) and a second chamber (124); a compressed fluid is introduced into the first chamber, thereby urging the first piston portion in a first direction in which the first movable part approaches the second movable part; and a compressed fluid is introduced into the second chamber, thereby urging the second piston portion in a second direction in which the second movable part approaches the first movable part; and wherein the fluid circuit comprises: a first flow path (166) communicating with the first chamber; and a second flow path (170) communicating with the second chamber, wherein a first flow control valve (168) configured to perform metering control is provided in the first flow path, and a second flow control valve (172) configured to perform metering control and a third flow control valve (174) configured to perform metering control are connected in series in the second flow path.

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