Hand device

Abstract

To provide a hand device capable of gripping various objects having different dimensions and obtaining a sufficient gripping force.SOLUTION: A hand device (310) includes a first gripping claw (320A), a second gripping claw (320B) that faces the first gripping claw (320A) with a gap therebetween and grips an object together with the first gripping claw (320A), a first driving mechanism (351) that includes a motor (340) and slides at least one gripping claw (320) of the first gripping claw (320A) and the second gripping claw (320B) by using an output from the motor (340) as a driving force, and a second driving mechanism (352) that includes a pneumatic piston cylinder (330) and slides at least one gripping claw (320) of the first gripping claw (320A) and the second gripping claw (320B) by using an output from the piston cylinder (330) as a driving force.SELECTED DRAWING: Figure 28

Description

[Technical Field]

[0001] The present invention relates to a hand device. [Background technology]

[0002] For example, Japanese Patent Application Laid-Open No. 2017-102825 (Patent Document 1) discloses a composite system that includes a machine tool having a workpiece fixing jig that can move integrally with a table, a workpiece stocker that stores the workpieces, and a robot system that includes a robot that supplies and removes the workpieces between the workpiece fixing jig and the workpiece stocker. The robot is equipped with a robot hand for grasping the workpiece to be handled. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-102825 Summary of the Invention [Problem to be solved by the invention]

[0004] As disclosed in the aforementioned Patent Document 1, a hand device equipped with a pair of gripping claws for gripping an object such as a workpiece is known. Such a hand device is required to have increased versatility by being able to grip various objects of different dimensions. It is also required to ensure sufficient gripping force to prevent the object from falling from the hand device.

[0005] An object of the present invention is to provide a hand device that is capable of gripping various objects of different sizes and that can obtain a sufficient gripping force. [Means for solving the problem]

[0006] A hand device according to the present invention includes a first gripping claw, a second gripping claw that faces the first gripping claw with a gap therebetween and grips an object together with the first gripping claw, a first drive mechanism that includes a motor and uses output from the motor as a driving force to slide at least one of the first gripping claw and the second gripping claw, and a second drive mechanism that includes an air-operated piston cylinder and uses output from the piston cylinder as a driving force to slide at least one of the first gripping claw and the second gripping claw. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a hand device that is capable of gripping various objects of different sizes and that can obtain a sufficient gripping force. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a top view showing the transport system. [Figure 2] FIG. 2 is a simplified top view of the transport system in FIG. [Figure 3] FIG. 10 is a perspective view showing the relationship between the master hand, the pallet, the work hand, the shelf board, and the teaching hand. [Figure 4] FIG. 2 is a perspective view showing a master hand. [Figure 5] FIG. 10 is another perspective view showing the master hand. [Figure 6] FIG. 2 is a diagram for explaining the structure of a master hand. [Figure 7] FIG. 2 is a perspective view showing a pallet stocker in FIG. [Figure 8] 8 is a perspective view showing a pallet stocker in the area surrounded by a two-dot chain line VIII in FIG. 7. [Figure 9] FIG. 2 is a block diagram showing a control system of the transport system in FIG. [Figure 10] FIG. 10 is a top view showing the first step of workpiece machining using the workpiece stocker. [Figure 11]FIG. 10 is a top view showing a second step of workpiece machining using the workpiece stocker. [Figure 12] FIG. 10 is a top view showing a third step of workpiece machining using the workpiece stocker. [Figure 13] FIG. 10 is a top view showing a fourth step of workpiece machining using the workpiece stocker. [Figure 14] FIG. 10 is a top view showing a fifth step of workpiece machining using the workpiece stocker. [Figure 15] FIG. 10 is a top view showing a sixth step of workpiece machining using the workpiece stocker. [Figure 16] FIG. 1 is a top view showing the first step of workpiece machining using the setup station. [Figure 17] FIG. 10 is a top view showing a second step of workpiece machining using the setup station. [Figure 18] FIG. 10 is a top view showing a third step of workpiece machining using the setup station. [Figure 19] FIG. 10 is a top view showing the fourth step of workpiece machining using the setup station. [Figure 20] FIG. 10 is a top view showing the fifth step of workpiece machining using the setup station. [Figure 21] FIG. 10 is a top view showing the first step of loading a pallet into the pallet stocker. [Figure 22] FIG. 10 is a top view showing a second step of loading pallets into the pallet stocker. [Figure 23] FIG. 10 is a top view showing a third step of loading pallets into the pallet stocker. [Figure 24] FIG. 2 is a perspective view showing a work hand. [Figure 25] FIG. 25 is a front view showing the work hand in FIG. 24. [Figure 26] FIG. 25 is a top view showing the work hand in FIG. 24. [Figure 27] FIG. 25 is a side view showing the work hand in FIG. 24. [Figure 28]25 is a cross-sectional view showing the work hand as seen in the direction of the arrows on line XXVIII-XXVIII in FIG. 24. [Figure 29] 29 is a cross-sectional view showing the work hand as seen in the direction of the arrows on line XXIX-XXIX in FIG. 28. [Figure 30] 29 is a cross-sectional view showing the work hand as seen in the direction of the arrows on the line XXX-XXX in FIG. 28. [Figure 31] 29 is a cross-sectional view showing the work hand as seen in the direction of the arrows on XXXI-XXXI in FIG. 28. [Figure 32] FIG. 29 is a cross-sectional view showing the internal structure of the piston cylinder in FIG. 28. [Figure 33] 4A and 4B are diagrams illustrating a sliding operation of the first gripping claw and the second gripping claw caused by the first drive mechanism (servo motor). [Figure 34] 10 is a diagram schematically showing the sliding operation of the first gripping jaw and the second gripping jaw caused by the second drive mechanism (piston cylinder). FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the accompanying drawings, in which the same or corresponding elements are designated by the same reference numerals.

[0010] Fig. 1 is a top view showing a transfer system, and Fig. 2 is a top view showing a simplified version of the transfer system shown in Fig. 1.

[0011] 1 and 2, the transport system 100 includes a robot 21 and a robot base 22. The robot 21 and the robot base 22 are connected to each other.

[0012] As a typical example, the robot 21 is a six-axis articulated robot. The robot 21 has a base unit 26, a first arm 27, a second arm 28, a hand attachment unit 29, and a master hand 210.

[0013] The robot base 22 is a support platform that supports the robot 21 and is fixed to the floor of a factory or the like. The robot base 22 is made of metal. The base unit 26 is connected to the robot base 22 so as to be rotatable around a central axis of rotation 101. The central axis of rotation 101 is an imaginary straight line that corresponds to the center of rotation of the robot 21 and extends in the vertical direction.

[0014] The first arm 27 is attached to the base 26. The first arm 27 is rotatable about a rotation center axis 102 located at the attachment portion (joint) of the first arm 27 to the base 26. The second arm 28 is attached to the first arm 27. The second arm 28 is rotatable about a rotation center axis 103 located at the attachment portion (joint) of the second arm 28 to the first arm 27, and is capable of rotating the hand attachment portion 29 about a rotation center axis 104 along the second arm 28. The hand attachment portion 29 is attached to the second arm 28. The hand attachment portion 29 is rotatable about a rotation center axis 105 located at the attachment portion (joint) of the hand attachment portion 29 to the second arm 28, and is capable of rotating the master hand 210 about a rotation center axis 106 along the hand attachment portion 29.

[0015] The master hand 210 is attached to a hand attachment portion 29 as an end effector. The master hand 210 is attached to the second arm 28 so as to be rotatable around a rotation center axis 105. The master hand 210 is attached to the second arm 28 via the hand attachment portion 29. The second arm 28 is attached to the first arm 27 so as to be rotatable around a rotation center axis 103.

[0016] The robot 21 further has a plurality of drive servo motors 23 for operating the base 26, the first arm 27, the second arm 28, the hand attachment part 29 and the master hand 210 around the above-mentioned plurality of axes (rotation center axis 101, rotation center axis 102, rotation center axis 103, rotation center axis 104, rotation center axis 105 and rotation center axis 106) (see Figure 9 described below).

[0017] 1, a two-dot chain line 111 indicates the area in which the master hand 210 moves (the operating area of ​​the master hand 210) in the transport system 100. In addition, a two-dot chain line 112 extending in an arc shape around the central pivot axis 101 indicates the maximum area in which the master hand 210 can move.

[0018] The transfer system 100 further includes a machine tool 10 (10S, 10T), a pallet stocker 31 (31S, 31T), a work stocker 71, a hand stocker 81, and a setup station 61 (61S, 61T).

[0019] The machine tool 10 (10S, 10T), pallet stocker 31 (31S, 31T), workpiece stocker 71, hand stocker 81, and setup station 61 (61S, 61T) are provided around the robot base 22. The machine tool 10 (10S, 10T), pallet stocker 31 (31S, 31T), workpiece stocker 71, hand stocker 81, and setup station 61 (61S, 61T) are lined up in the circumferential direction of the turning center axis 101. In the top view shown in FIG. 1 , at least a portion of each of the machine tool 10 (10S, 10T), pallet stocker 31 (31S, 31T), workpiece stocker 71, hand stocker 81, and setup station 61 (61S, 61T) overlaps with the operating area of ​​the master hand 210 indicated by the two-dot chain line 111.

[0020] The robot in the present invention is not limited to the six-axis articulated robot described above, but may be, for example, a robot (gantry loader) capable of moving an object to be transported in three mutually perpendicular axis directions. Also, the machine tool, pallet stocker, work stocker, hand stocker, and setup station may be arranged in a straight line.

[0021] Machine tool 10 is a machining center that processes a workpiece by bringing a rotating tool into contact with the workpiece. Machine tool 10 is an NC (Numerically Controlled) machine tool in which various operations for processing the workpiece are automated by computer numerical control.

[0022] Machine tool 10 may be a multi-tasking machine having a turning function using a fixed tool and a milling function using a rotary tool, or may be an AM / SM hybrid machine capable of additive manufacturing and subtractive manufacturing of a workpiece. Machine tool 10S and machine tool 10T may be the same type of machine tool, or may be different types of machine tools.

[0023] Machine tool 10 has a cover body 14. Cover body 14 defines the exterior of machine tool 10 and defines machining area 12. Machining area 12 is a space where workpiece machining is performed, and is sealed by cover body 14 to prevent foreign matter such as chips or cutting oil resulting from workpiece machining from leaking outside the machining area.

[0024] An opening 16 is provided in the cover body 14. The robot 21 transports an object to be transported, such as a workpiece W or a pallet 410, to the processing area 12 through the opening 16. The opening 16 is provided with a door or shutter that can be opened and closed.

[0025] The machining area 12 is provided with a tool spindle for rotating a tool, a table for holding a pallet 410, and the like.

[0026] Machine tool 10 further has an operation panel 18. Operation panel 18 includes a control device that controls the operation of machine tool 10, a display unit (display) for displaying various information related to machining, and an operation unit that accepts various operations on machine tool 10.

[0027] Machine tool 10S and machine tool 10T are provided at positions facing each other across robot base 22. Machine tool 10S and machine tool 10T are provided at angular positions offset by 180° in the circumferential direction about central turning axis 101.

[0028] Pallet stocker 31 is a device for storing pallets 410. Pallet stocker 31 is provided between machine tool 10S and machine tool 10T in the circumferential direction centered on turning central axis 101. Pallet stocker 31S and pallet stocker 31T are provided adjacent to each other in the circumferential direction centered on turning central axis 101.

[0029] The work stocker 71 is a device for storing the workpieces W. The workpiece stocker 71 has a shelf structure on which the workpieces W can be placed. The hand stocker 81 is a device for storing various hands such as the workpiece hand 310 and teaching hand 710, which will be described later. The hand stocker 81 has a shelf structure on which the various hands can be placed.

[0030] The workpiece stocker 71 and the hand stocker 81 are provided between the machine tool 10S and the machine tool 10T in the circumferential direction centered on the central turning axis 101. The workpiece stocker 71 and the hand stocker 81 are provided in a position facing the pallet stocker 31 (31S, 31T) across the robot base 22. The workpiece stocker 71 and the hand stocker 81 are provided next to each other above and below.

[0031] Setup station 61 is a device that mainly performs the work of attaching and detaching workpieces W to and from pallets 410. A pallet placement table (not shown) on which pallets 410 can be placed is installed in setup station 61. Setup station 61 is provided between workpiece stocker 71 and hand stocker 81 and machine tool 10 in the circumferential direction about turning central axis 101. Setup station 61 is provided adjacent to workpiece stocker 71 and hand stocker 81 in the circumferential direction about turning central axis 101.

[0032] The setup station 61S and the setup station 61T are provided on both sides of the work stocker 71 and the hand stocker 81 in the circumferential direction about the central axis of rotation 101.

[0033] The number of each of the machine tools 10, pallet stockers 31, work stockers 71, hand stockers 81 and setup stations 61 provided in the transport system 100 is not particularly limited.

[0034] The transport system 100 further has a plurality of fences 56 (56h, 56i, 56j, 56k). The fences 56 rise from the floor of a factory or the like. In the top view shown in FIG. 1, fence 56h extends between the machine tool 10S and the pallet stocker 31S. In the top view shown in FIG. 1, fence 56i extends between the pallet stocker 31T and the machine tool 10T. In the top view shown in FIG. 1, fence 56j extends between the machine tool 10T and the setup station 61T. In the top view shown in FIG. 1, fence 56k extends between the setup station 61S and the machine tool 10S.

[0035] The robot 21 is placed in a space 113 surrounded by a plurality of fences 56 (56h, 56i, 56j, 56k), machine tools 10 (10S, 10T), pallet stockers 31 (31S, 31T), work stockers 71, hand stockers 81, and setup stations 61 (61S, 61T). The operating area of ​​the master hand 210 indicated by a two-dot chain line 111 is included in the space 113.

[0036] An operator cannot access the pallet stocker 31 from outside the space 113. An operator can load a pallet 410 into the pallet stocker 31 or retrieve a pallet 410 from the pallet stocker 31 through the setup station 61. An operator can access the work stocker 71 and the hand stocker 81 from outside the space 113. An operator can load an unprocessed workpiece W into the conveyance system 100 or retrieve a processed workpiece W' from the conveyance system 100 through the work stocker 71. An operator can load various hands into the conveyance system 100 or retrieve them from the conveyance system 100 through the hand stocker 81.

[0037] The transport system 100 further includes a transport operation panel 51. The transport operation panel 51 includes a control device 610 that controls the operation of the robot 21, a display unit 670 that displays various information related to transport by the robot 21, and an operation unit that accepts various operations for the robot 21 (see FIG. 9 described later). In this embodiment, the display unit 670 is configured with a touch panel display that can be operated by an operator, and performs part of the function of the operation unit. The operation unit may be configured with various buttons that can be pressed, numeric keys that can input numbers, a dial, or the like.

[0038] The transfer operation panel 51 is attached to the work stocker 71 and the hand stocker 81. The location where the transfer operation panel 51 is provided is not particularly limited.

[0039] Fig. 3 is a perspective view showing the relationship between the master hand, the pallet, the work hand, the shelf board, and the teaching hand. Fig. 4 and Fig. 5 are perspective views showing the master hand. Fig. 6 is a diagram for explaining the structure of the master hand.

[0040] 3 to 6, the master hand 210 has a clamping mechanism 220. The clamping mechanism 220 is configured to be operable between a clamped state in which the gripping portion 120 is held and an unclamped state in which the gripping portion 120 is released.

[0041] 4 to 6, grip portion 120 has a grip shape centered on central axis 126. Grip portion 120 is provided with groove portion 121. Groove portion 121 is recessed from the outer circumferential surface of grip portion 120 and has a groove shape that circles around central axis 126.

[0042] The clamp mechanism 220 has the appearance of a block body. The clamp mechanism 220 is provided with a grip insertion hole 221. The grip insertion hole 221 is open facing in one direction.

[0043] The clamp mechanism 220 is made up of a cylinder piston. The clamp mechanism 220 has a pair of pistons 226. The pair of pistons 226 extend in a shaft-like manner along a central axis 231 that is perpendicular to the central axis 126 and intersects with the grip insertion hole 221. The pair of pistons 226 face each other with a gap in between in the axial direction of the central axis 231. The pair of pistons 226 are supported so as to be slidable in the axial direction of the central axis 126. A protrusion 227 that can engage with the groove 121 is provided at the tip of each piston 226.

[0044] When the master hand 210 grips the gripping portion 120, the master hand 210 is positioned so that the clamping mechanism 220 faces the gripping portion 120. The master hand 210 is moved linearly in a direction approaching the gripping portion 120, thereby inserting the gripping portion 120 into the grip insertion hole 221. By supplying air pressure or the like, the pair of pistons 226 are slid toward each other, thereby operating the clamping mechanism 220 from the unclamped state to the clamped state. As a result, the protrusions 227 of the pair of pistons 226 advance into the grip insertion hole 221 and engage with the grooves 121.

[0045] When the master hand 210 releases the gripping portion 120, the pair of pistons 226 are slid away from each other, thereby operating the clamping mechanism 220 from the clamped state to the unclamped state. This causes the protrusions 227 of the pair of pistons 226 to retract from the grip insertion holes 221 and come out of the grooves 121. The master hand 210 is moved linearly away from the gripping portion 120, thereby removing the gripping portion 120 from the grip insertion hole 221.

[0046] 5, the conveyance system 100 further includes a sensor 230. The sensor 230 is a sensor capable of detecting the presence or absence of an object, and is, for example, a non-contact photoelectric sensor. The sensor 230 may be a proximity sensor or a contact sensor such as a limit switch.

[0047] The sensor 230 is mounted on the robot 21. The sensor 230 is mounted on the master hand 210. When the sensor 230 is a photoelectric sensor, the direction of light emitted from the sensor 230 may be parallel to the direction in which the gripper 120 moves forward and backward relative to the master hand 210.

[0048] 3, the transport system 100 further includes a pallet 410 for holding the workpiece. The transport system 100 includes a plurality of pallets 410.

[0049] Pallet 410 is made of a metal plate and has a generally rectangular shape when viewed from above. A clamping mechanism for holding pallet 410 is built into a table provided in machine tool 10. A jig such as a tombstone or a clamping device is attached to pallet 410, and a workpiece is held on pallet 410 via the jig.

[0050] The pallet 410 has a first gripping portion 120A. The first gripping portion 120A corresponds to the gripping portion 120 described above, and is configured to be able to be gripped by the master hand 210. The first gripping portion 120A is provided on a side surface of the pallet 410. The first gripping portion 120A is provided so as to be detachable from the pallet 410.

[0051] The master hand 210 grips the first gripping portion 120A, whereby the robot 21 can transport the pallet 410.

[0052] Fig. 7 is a perspective view showing the pallet stocker in Fig. 1. Fig. 8 is a perspective view showing the pallet stocker in the area surrounded by the two-dot chain line VIII in Fig. 7.

[0053] 7 and 8, as well as other figures showing the pallet stocker 31, show X-, Y-, and Z-axes, which are coordinate axes of the pallet stocker 31. The X-axis extends horizontally corresponding to the width direction (left-right direction) of the pallet stocker 31, the Y-axis extends vertically, and the Z-axis extends horizontally corresponding to the depth direction (front-rear direction) of the pallet stocker 31. The X-, Y-, and Z-axes are three axes that are perpendicular to one another.

[0054] 3, 7 and 8, pallet stocker 31 has a frame body 550, a plurality of support portions 560, and a plurality of shelf boards 510. As shown in FIG.

[0055] The frame body 550 is a rectangular parallelepiped frame body. The frame body 550 is a rectangular parallelepiped frame body with the X-axis direction and the Y-axis direction as its longitudinal direction and the Z-axis direction as its lateral direction. The frame body 550 has four pillars 551. The four pillars 551 are arranged at the four corners of the frame body 550 when viewed from above. Each pillar 551 extends in the Y-axis direction (up and down direction).

[0056] The support portion 560 is configured to be able to support the shelf board 510. The multiple support portions 560 are arranged at intervals from one another in the vertical direction.

[0057] The support portion 560 has a pair of plates 561 on the left and right. The pair of plates 561 are provided with a gap between them in the X-axis direction. The plate 561 extends in the Z-axis direction while forming an L-shaped cross section when cut along the X-axis-Y-axis plane. Both ends of the plate 561 in the Z-axis direction are respectively connected to two pillars 551 aligned in the Z-axis direction.

[0058] The shelf board 510 is configured to be able to place the pallet 410. When viewed from above, the shelf board 510 has a rectangular shape with the X-axis direction as the longitudinal direction and the Z-axis direction as the lateral direction, and has a plate shape with the Y-axis direction as the thickness direction.

[0059] The shelf board 510 has a pair of vertical frames 532 on the left and right sides and a pair of horizontal frames 531 on the front and back sides. The pair of vertical frames 532 are provided at a distance from each other in the X-axis direction. The pair of vertical frames 532 are provided at both ends of the shelf board 510 in the X-axis direction. The vertical frames 532 are made of plate material whose thickness direction is in the Y-axis direction and extend in the Z-axis direction. The pair of horizontal frames 531 are provided at a distance from each other in the Z-axis direction. The horizontal frame 531 extends in the X-axis direction and is connected at both ends to the pair of vertical frames 532.

[0060] 7 and 8, the shelf board 510 is supported by a support portion 560. A pair of vertical frames 532 is placed on a pair of plates 561. The pair of vertical frames 532 supports the weight of the shelf board 510.

[0061] As shown in FIG. 8 , the support portion 560 further has a pin 562. The pin 562 is provided on a plate 561. The pin 562 protrudes upward from the top surface of the plate 561. The vertical frame 532 has a pin hole 533. The pin hole 533 is a through-hole that penetrates the vertical frame 532 in the Y-axis direction. The pin 562 is disposed in the pin hole 533. This configuration prevents the shelf board 510 from shifting position relative to the support portion 560.

[0062] As shown in FIG. 3, the shelf 510 further includes a plurality of pallet supports 520 (520p, 520q, 520r).

[0063] Each pallet support portion 520 is configured to be able to support a pallet 410. Each pallet support portion 520 is configured with four tapered cone receiving portions 525 that are arranged at intervals in the X-axis direction and the Z-axis direction. The tapered cone receiving portions 525 are provided on a horizontal frame 531. The tapered cone receiving portions 525 protrude upward from the top surface of the horizontal frame 531. The tapered cone receiving portions 525 have a concave shape that can receive a tapered cone provided on the bottom surface of the pallet 410.

[0064] Pallet support portion 520p, pallet support portion 520q, and pallet support portion 520r are aligned in the X-axis direction in the order listed.

[0065] The shelf 510 is capable of supporting pallets 410 of different sizes. For example, the shelf 510 is capable of supporting pallets 410 of 400 mm x 400 mm and pallets 410 of 500 mm x 500 mm. When the pallets 410 are 400 mm x 400 mm in size, three pallets 410 can be placed on the shelf 510 using the pallet support portions 520p, pallet support portion 520q, and pallet support portion 520r. When the pallets 410 are 500 mm x 500 mm in size, two pallets 410 can be placed on the shelf 510 using the pallet support portions 520p and pallet support portion 520r.

[0066] As shown in FIGS. 3 and 7, the shelf board 510 has a second gripping portion 120B. The second gripping portion 120B corresponds to the gripping portion 120 described above and is configured to be grippable by the master hand 210. The second gripping portion 120B is provided at the center position of the shelf board 510 in the X-axis direction. The second gripping portion 120B protrudes in the Z-axis direction from the front surface of the shelf board 510 (horizontal frame 531). The second gripping portion 120B is provided below the pallet support portion 520 (tapered cone receiving portion 525). The second gripping portion 120B is provided detachably with respect to the shelf board 510.

[0067] The master hand 210 grips the second gripping portion 120B, thereby enabling the robot 21 to transport the shelf board 510. The robot 21 changes the position of the shelf board 510 among the plurality of supports 560 in the pallet stocker 31.

[0068] 7, the pallet stocker 31 further has a fixed shelf 515. The fixed shelf 515 basically has the same structure as the shelf 510, but differs from the shelf 510 in that it is not provided with the second gripping portion 120B. The fixed shelf 515 cannot be moved between the multiple support portions 560, and its position in the pallet stocker 31 is fixed.

[0069] The pallet stocker 31 has two fixed shelves 515. The two fixed shelves 515 are arranged at the top and bottom of the pallet stocker 31. The shelves 510 can be repositioned within a range in the vertical direction between the fixed shelf 515 arranged at the top and the fixed shelf 515 arranged at the bottom.

[0070] 3, the work hand 310 is configured to be able to grip the work W. The work hand 310 has a pair of gripping claws 320. The pair of gripping claws 320 face each other with a gap therebetween.

[0071] The workpiece hand 310 is configured to be operable between a clamped state in which the workpiece W is gripped by the pair of gripping jaws 320, and an unclamped state in which the pair of gripping jaws 320 release the workpiece W. By sliding the pair of gripping jaws 320 in directions in which they approach each other, the workpiece hand 310 moves from the unclamped state to the clamped state. By sliding the pair of gripping jaws 320 in directions in which they move away from each other, the workpiece hand 310 moves from the clamped state to the unclamped state.

[0072] The work hand 310 has a piston cylinder 330 and a servo motor 340 (see Figs. 9 and 24 described later) as a power source for sliding the pair of gripping jaws 320. The structure of the work hand 310 will be described in detail later.

[0073] The workpiece hand 310 further has a third gripping portion 120C. The third gripping portion 120C corresponds to the gripping portion 120 described above, and is configured to be able to grip the master hand 210. The third gripping portion 120C has a grip shape that extends in a direction perpendicular to the sliding direction of the pair of gripping jaws 320. The third gripping portion 120C is provided detachably with respect to the workpiece hand 310.

[0074] The master hand 210 grips the third gripping portion 120C, thereby making it possible to attach the workpiece hand 310 to the robot 21. The robot 21 can transport the workpiece W using the workpiece hand 310.

[0075] The teaching hand 710 has a touch probe 720. The teaching hand 710 is used for teaching the robot 21 using the touch probe 720.

[0076] The teaching hand 710 further has a fourth gripping portion 120D. The fourth gripping portion 120D corresponds to the gripping portion 120 described above and is configured to be able to be held by the master hand 210. The touch probe 720 has a pin-shaped contactor 720g that comes into contact with the measurement object. The fourth gripping portion 120D has a grip shape that extends in a direction perpendicular to the direction in which the pin-shaped contactor 720g extends. The fourth gripping portion 120D is detachably provided to the teaching hand 710.

[0077] The teaching hand 710 can be attached to the robot 21 by the master hand 210 gripping the fourth gripping portion 120D.

[0078] The first gripping portion 120A, the second gripping portion 120B, the third gripping portion 120C, and the fourth gripping portion 120D have the same grip shape. The master hand 210 is configured to be able to selectively hold one of the gripping portions 120: the first gripping portion 120A, the second gripping portion 120B, the third gripping portion 120C, and the fourth gripping portion 120D.

[0079] Fig. 9 is a block diagram showing a control system of the transfer system in Fig. 1. Referring to Fig. 9, the transfer system 100 further includes a control device 610.

[0080] Each component of the control device 610 is realized by hardware including computing units such as a CPU (Central Processing Unit) and various computer processors, storage devices such as memory or storage, and wired or wireless communication lines connecting them, as well as software stored in the storage devices and supplying processing instructions to the computing units. The computer programs constituting the software may be composed of device drivers, an operating system, various application programs located at higher layers thereof, or libraries that provide common functions to these programs. The computer programs may be recorded on a computer-readable storage medium or a non-transitory computer-readable storage medium. The computer programs may be included in a computer program product. Each block described below represents a functional unit block.

[0081] The control device 610 has an operation receiving unit 660 and a robot control unit 620. The operation receiving unit 660 receives an operation from the worker via a display unit 670 (operation unit) formed of, for example, a touch panel display. The operation receiving unit 660 outputs a signal corresponding to the operation by the worker to the robot control unit 620.

[0082] The robot control unit 620 controls the operation of the robot 21 (including the operation of the workpiece hand 310 attached to the master hand 210).

[0083] The robot control unit 620 includes a program storage unit 621 , a program analysis unit 622 , an axis control unit 623 , a hand control unit 624 , and a parameter storage unit 625 .

[0084] The program storage unit 621 stores various operation programs 641 that command the operation of the robot 21. The operation programs 641 stored in the program storage unit 621 include, for example, operation commands that define the movement and stopping of the robot 21, position commands that define the position and orientation (posture) of the master hand 210, path commands that define movement paths such as linear movement and circular movement, and speed commands that define the movement speed. The operation programs 641 are input via an input / output device 630 connected to the robot control unit 620 and stored in the program storage unit 621.

[0085] The operation program 641 is written in, for example, a language called SLIM (Standard Language for Industrial Manipulators). The specific position and orientation (posture) of each position command included in the operation program 641 is obtained by operating the robot 21 through a manual operation called a teaching operation. As the robot 21 operates through the teaching operation, the rotation angle positions of each drive servo motor 23 built into the robot 21 are acquired as parameters, and the acquired parameters are stored in the parameter storage unit 625 via the input / output device 630.

[0086] In response to a signal from the operation receiving unit 660, the program analysis unit 622 reads out the operation program 641 to be executed from the operation program 641 stored in the program storage unit 621. The program analysis unit 622 analyzes the operation program 641, extracts commands related to movement, and transmits the commands to the axis control unit 623. The program analysis unit 622 analyzes the operation program 641, extracts commands related to hand operation, and transmits the commands to the hand control unit 624.

[0087] The axis control unit 623 controls the multiple drive servo motors 23 in response to commands from the program analysis unit 622. The hand control unit 624 controls the master hand 210 and / or the workpiece hand 310 in response to commands from the program analysis unit 622.

[0088] Specifically, the axis control unit 623 reads out parameters corresponding to each position command from the parameter storage unit 625, generates rotation commands (control signals) for each drive servo motor 23, and transmits them to each drive servo motor 23 so that the rotation angle position of each drive servo motor 23 becomes the read rotation angle position, the movement path of the master hand 210 becomes the commanded movement path (linear movement or circular movement), and further, moves at the commanded speed. The plurality of drive servo motors 23 move the master hand 210 to the commanded position by being supplied with drive currents corresponding to the rotation commands from the axis control unit 623.

[0089] In response to a command from the program analysis unit 622, the hand control unit 624 generates an open / close command for an air valve so that the pair of pistons 226 slides, and sends the open / close command to the clamp mechanism 220. In response to a command from the program analysis unit 622, the hand control unit 624 generates an open / close command for an air valve so that the pair of gripping jaws 320 slides, and sends the open / close command to the piston cylinder 330, and generates a rotation command (control signal) for the servo motor 340 and sends the rotation command to the servo motor 340.

[0090] Next, a specific example of how the robot 21 is used in the transport system 100 will be described. Figures 10 to 15 are top views showing steps in workpiece machining using a workpiece stocker. Figures 10 to 15 correspond to Figure 2.

[0091] Referring to Fig. 2, in an initial state, a plurality of pallets 410 are stored in the pallet stocker 31. A jig (not shown), such as a tombstone or a clamping device, is mounted on the pallets 410. Unmachined workpieces W are stored in the work stocker 71. A plurality of work hands 310 and a teaching hand 710 are stored in the hand stocker 81. The work hands 310 may have a pair of gripping jaws 320 that differ in shape or size among the plurality of work hands 310.

[0092] 9 and 10, the control device 610 (robot control unit 620) controls the robot 21 so that the master hand 210 grips the first gripper 120A of the pallet 410 stored in the pallet stocker 31.

[0093] In this step, the master hand 210 moves toward the pallet stocker 31 and is positioned so as to face the first gripping portion 120A of the pallet 410 in the Z-axis direction. As the master hand 210 moves in the Z-axis direction, the first gripping portion 120A is inserted into the grip insertion hole 221. The master hand 210 grips the first gripping portion 120A. As the master hand 210 moves upward, the pallet 410 is lifted from the shelf board 510.

[0094] 9 and 11, next, the control device 610 (robot control unit 620) controls the robot 21 so that the pallet 410 gripped by the master hand 210 moves to the processing area 12 of the machine tool 10.

[0095] In this step, the master hand 210 enters the processing area 12 and places the pallet 410 on a table (not shown). The pallet 410 is held to the table by a clamping mechanism built into the table. The master hand 210 releases the first gripping portion 120A and exits the processing area 12.

[0096] 9 and 12, next, the control device 610 (robot control unit 620) controls the robot 21 so that the master hand 210 grips the third gripping portion 120C of the work hand 310 stored in the hand stocker 81.

[0097] In this step, the master hand 210 moves toward the hand stocker 81. The master hand 210 attaches the workpiece hand 310 to the robot 21 by gripping the third gripping portion 120C.

[0098] 9 and 13, next, the control device 610 (robot control unit 620) controls the robot 21 and the workpiece hand 310 so that the workpiece hand 310 grips the workpiece W.

[0099] In this step, the workpiece hand 310 moves toward the workpiece stocker 71. The workpiece hand 310 grips the unmachined workpiece W.

[0100] Referring to Figures 9 and 14, next, the control device 610 (robot control unit 620) controls the robot 21 and the work hand 310 so that the work W grasped by the work hand 310 is held by the pallet 410 arranged in the processing area 12 of the machine tool 10.

[0101] In this step, the workpiece hand 310 enters the processing area 12 and places the workpiece W on the jig on the pallet 410. The jig holds the workpiece W, and the workpiece hand 310 releases the workpiece W. The workpiece hand 310 exits the processing area 12. Following this step, the machine tool 10 processes the workpiece W in the processing area 12.

[0102] 9 and 15, next, the control device 610 (robot control section 620) controls the robot 21 and the workpiece hand 310 so as to store the machined workpiece W′ in the workpiece stocker 71.

[0103] In this step, the work hand 310 enters the processing area 12. The work hand 310 grips the processed workpiece W', and the jig on the pallet 410 releases the workpiece W'. The work hand 310 gripping the workpiece W' leaves the processing area 12 and moves toward the workpiece stocker 71. The work hand 310 places the workpiece W' in the workpiece stocker 71 and releases the workpiece W'. Through the above steps, work processing using the workpiece stocker 71 is completed.

[0104] 16 to 20 are top views showing steps in workpiece machining using the setup station, and correspond to FIG.

[0105] Referring to FIG. 2, the initial state is the same as that of the workpiece machining using the workpiece stocker 71 described above.

[0106] 9 and 16, the control device 610 (robot control unit 620) controls the robot 21 so that the master hand 210 grips the first gripper 120A of the pallet 410 stored in the pallet stocker 31. The control device 610 (robot control unit 620) controls the robot 21 so that the pallet 410 gripped by the master hand 210 moves to the setup station 61.

[0107] In this step, the master hand 210 moves toward the setup station 61 and places the pallet 410 on a pallet placement table (not shown) installed in the setup station 61. The master hand 210 releases the first gripping portion 120A. The master hand 210 exits the setup station 61.

[0108] 9 and 17, next, an operator sets the workpiece W on the pallet 410. In this step, the unmachined workpiece W is held on the pallet 410 using a jig on the pallet 410.

[0109] 9 and 18, next, the control device 610 (robot control unit 620) controls the robot 21 so that the master hand 210 grips the first gripper 120A of the pallet 410 arranged in the setup station 61.

[0110] 9 and 19, next, the control device 610 (robot control unit 620) controls the robot 21 so that the pallet 410 grasped by the master hand 210 moves to the processing area 12. Following this step, the machine tool 10 performs processing of the workpiece W in the processing area 12.

[0111] 9 and 20, next, the control device 610 (robot control unit 620) controls the robot 21 so that the master hand 210 grips the first gripper 120A of the pallet 410 arranged in the processing area 12. The control device 610 (robot control unit 620) controls the robot 21 so that the pallet 410 gripped by the master hand 210 moves to the setup station 61. Following this step, the worker removes the machined workpiece W' from the jig on the pallet 410. Through the above steps, workpiece processing using the setup station 61 is completed.

[0112] 21 to 23 are top views showing steps for inserting pallets into the pallet stocker. Figures 21 to 23 correspond to Figure 2.

[0113] 9 and 21, in an initial state, no pallet 410 is stored in pallet stocker 31. An operator places pallet 410 on a pallet placement table (not shown) in setup station 61.

[0114] 9 and 22, the control device 610 (robot control unit 620) controls the robot 21 so that the master hand 210 grips the first gripper 120A of the pallet 410 arranged in the setup station 61. The control device 610 (robot control unit 620) controls the robot 21 so that the pallet 410 gripped by the master hand 210 moves to the pallet stocker 31.

[0115] 9 and 22, next, the control device 610 (robot control unit 620) controls the robot 21 to place the pallet 410 gripped by the master hand 210 on the shelf board 510.

[0116] By repeating the above steps, a plurality of pallets 410 can be loaded into the pallet stocker 31.

[0117] Next, the structure of the work hand 310 will be described in detail. Fig. 24 is a perspective view showing the work hand. Fig. 25 is a front view showing the work hand in Fig. 24. Fig. 26 is a top view showing the work hand in Fig. 24. Fig. 27 is a side view showing the work hand in Fig. 24.

[0118] 24 to 27 and later-described Figures 28 to 34 show coordinate axes consisting of the x-axis, y-axis, and z-axis for the convenience of explaining the structure of the workpiece hand 310. The x-axis extends in the sliding direction of the gripping jaws 320, the y-axis extends in a direction perpendicular to the x-axis and in the extension direction of the gripping jaws 320, and the z-axis extends in a direction perpendicular to the x-axis and the y-axis.

[0119] 24 to 27, the workpiece hand 310 has a pair of gripping claws 320, which are a first gripping claw 320A and a second gripping claw 320B.

[0120] Each of the gripping jaws 320, the first gripping jaw 320A and the second gripping jaw 320B, extends in the y-axis direction. The first gripping jaw 320A and the second gripping jaw 320B face each other with a gap in the x-axis direction. The workpiece hand 310 is configured to be able to grip a workpiece W between the first gripping jaw 320A and the second gripping jaw 320B.

[0121] The workpiece hand 310 has a first drive mechanism 351 and a second drive mechanism 352. The first drive mechanism 351 has the servo motor 340 described above. The first drive mechanism 351 uses the output from the servo motor 340 as a driving force to slide the first gripping jaws 320A and the second gripping jaws 320B along the x-axis direction. The second drive mechanism 352 has the piston cylinder 330 described above. The second drive mechanism 352 uses the output from the piston cylinder 330 as a driving force to slide the first gripping jaws 320A and the second gripping jaws 320B along the x-axis direction.

[0122] In addition, the present invention may be configured such that either the first gripping jaw or the second gripping jaw remains stationary while the other of the first gripping jaw or the second gripping jaw slides. Also, the object gripped by the first gripping jaw and the second gripping jaw is not limited to a workpiece, and may be, for example, a tool or a jig for holding a workpiece or a tool.

[0123] The workpiece hand 310 further includes a support base 311. The support base 311 is generally made of a plate member that is arranged parallel to the x-axis-z-axis plane and whose thickness direction corresponds to the y-axis direction. The support base 311 supports a pair of gripping jaws 320, a first drive mechanism 351, and a second drive mechanism 352. The third gripping unit 120C is connected to the support base 311. The third gripping unit 120C is detachably attached to the support base 311. The third gripping unit 120C has a grip shape centered on a central axis 126. The central axis 126 extends in the z-axis direction.

[0124] In a side view seen in the x-axis direction in Fig. 27, the pair of gripping claws 320 are provided at positions offset in the z-axis direction and the y-axis direction from the third gripping unit 120C. The first drive mechanism 351 is disposed between the pair of gripping claws 320 and the second drive mechanism 352 in the y-axis direction. In a top view seen in the y-axis direction in Fig. 26, the third gripping unit 120C is provided at a central position between the first gripping claw 320A and the second gripping claw 320B in the x-axis direction.

[0125] The support base 311 is further equipped with a connector 312 for detachably connecting various wiring and piping between the robot 21 (master hand 210) and the work hand 310, and an air valve 337 for controlling the supply of air to the piston cylinder 330.

[0126] Fig. 28 is a cross-sectional view showing the work hand as seen in the direction of the arrows on line XXVIII-XXVIII in Fig. 24. Fig. 29 is a cross-sectional view showing the work hand as seen in the direction of the arrows on line XXIX-XXIX in Fig. 28. Fig. 30 is a cross-sectional view showing the work hand as seen in the direction of the arrows on line XXX-XXX in Fig. 28.

[0127] Referring to Figures 24 to 30, the work hand 310 has a first slide body 361A and a second slide body 361B (hereinafter, when there is no particular distinction between the first slide body 361A and the second slide body 361B, they will be referred to as "slide body 361").

[0128] The first slide body 361A and the second slide body 361B are arranged side by side with a gap between them in the x-axis direction. The first slide body 361A supports the first gripping claw 320A so that it can slide along the x-axis direction. The second slide body 361B supports the second gripping claw 320B so that it can slide along the x-axis direction.

[0129] As shown in Figures 28 and 30, the gripping claw 320 has a claw main body 321 and a base 322. The base 322 is a portion supported by the slide body 361. The base 322 has a pair of protrusions 323. The pair of protrusions 323 are provided on both ends of the base 322 in the z-axis direction. Each protrusion 323 has a convex shape that protrudes in the z-axis direction. The claw main body 321 is the main body portion of the gripping claw 320 that grips the workpiece W, and extends from the base 322 in the y-axis direction.

[0130] The slide body 361 has a slide main body portion 366 and a guide portion 362. The slide main body portion 366 is a portion to which a driving force is applied from the second drive mechanism 352. The guide portion 362 is a portion that guides the gripping claws 320. The guide portion 362 is connected to an end of the slide main body portion 366 in the y-axis direction.

[0131] The slide body 361 is provided with a groove 367. The groove 367 has a depth direction in the y-axis direction, and extends in the x-axis direction while forming a concave shape that opens in one direction along the y-axis direction. The groove 367 penetrates the guide part 362 in the y-axis direction, enters the slide main body part 366, and forms a groove bottom inside the slide main body part 366.

[0132] The guide portion 362 is provided with a pair of guide grooves 363. The guide portion 362 has a pair of inner walls that face each other in the z-axis direction and form both side walls of the groove portion 367. Each of the pair of guide grooves 363 extends in the x-axis direction while forming a recessed shape recessed in the z-axis direction from the pair of inner walls. A pair of protrusions 323 is fitted into each of the pair of guide grooves 363.

[0133] 31 is a cross-sectional view showing the work hand as seen in the direction of the arrows on XXXI-XXXI in FIG.

[0134] 28 to 31, the first drive mechanism 351 further includes a first screw 343A and a second screw 343B (hereinafter, when there is no need to distinguish between the first screw 343A and the second screw 343B, they will be referred to as "screw 343").

[0135] The screw 343 extends along a predetermined axis 127. The predetermined axis 127 is an imaginary straight line extending in the x-axis direction and corresponds to the center of rotation of the screw 343. A screw (male screw) extending spirally around the predetermined axis 127 is provided on the outer circumferential surface of the screw 343. The screw provided on the first screw 343A and the screw provided on the second screw 343B are oriented in opposite directions in the circumferential direction of the predetermined axis 127.

[0136] The first screw 343A is supported by the first slide body 361A so as to be rotatable around a predetermined axis 127. The first screw 343A is supported by the first slide body 361A via a bearing 347. The first screw 343A is disposed in a groove portion 367 of the first slide body 361A. Rotational motion is input to the first screw 343A from the servo motor 340.

[0137] Servo motor 340 is configured to output rotational motion in forward and reverse directions around central axis 128. Central axis 128 is an imaginary straight line extending in the x-axis direction and corresponds to the center of rotation of the rotational motion output from servo motor 340. Central axis 128 is disposed at an interval from predetermined axis 127 in the z-axis direction. Servo motor 340 is provided at a position facing first screw 343A in the z-axis direction.

[0138] The first drive mechanism 351 further includes a first gear 371 and a second gear 372. The first gear 371 is disposed about the central axis 128. The first gear 371 is connected to the output shaft of the servo motor 340. The second gear 372 is disposed about the predetermined axis 127. The second gear 372 is connected to the end of the first screw 343A in the x-axis direction. The second gear 372 meshes with the first gear 371. The rotational motion from the servo motor 340 is transmitted to the first screw 343A via the first gear 371 and the second gear 372.

[0139] The second screw 343B is aligned with the first screw 343A in the x-axis direction. The second screw 343B is supported by the second slide body 361B so as to be rotatable around the predetermined axis 127. The second screw 343B is supported by the second slide body 361B via a bearing 348. The second screw 343B is disposed in a groove portion 367 of the second slide body 361B.

[0140] The first drive mechanism 351 further includes a first nut 344A and a second nut 344B (hereinafter, when there is no need to distinguish between the first nut 344A and the second nut 344B, they will be referred to as "nuts 344").

[0141] The first nut 344A is threaded onto the first screw 343A. The first nut 344A is connected to the first gripping jaw 320A. The first nut 344A slides in the x-axis direction together with the first gripping jaw 320A. The second nut 344B is threaded onto the second screw 343B. The second nut 344B is connected to the second gripping jaw 320B. The second nut 344B slides in the x-axis direction together with the second gripping jaw 320B.

[0142] The nut 344 is provided integrally with the base 322 of the gripping claw 320. The nut 344 is provided on the opposite side of the claw body 321 from the base 322 in the y-axis direction. The first nut 344A is disposed in a groove 367 of the first slide body 361A. The first nut 344A is supported by the inner wall of the first slide body 361A that forms the groove 367 so as to be slidable in the x-axis direction. The first nut 344A is paired with the first screw 343A to form a ball screw. The second nut 344B is disposed in a groove 367 of the second slide body 361B. The second nut 344B is supported by the inner wall of the second slide body 361B that forms the groove 367 so as to be slidable in the x-axis direction. The second nut 344B is paired with the second screw 343B to form a ball screw.

[0143] The first drive mechanism 351 further includes a connecting portion 342. The connecting portion 342 connects the first screw 343A and the second screw 343B. The connecting portion 342 is configured to restrict the relative rotational movement of the first screw 343A and the second screw 343B around the predetermined axis 127, and to allow the relative sliding movement of the first screw 343A and the second screw 343B in the axial direction of the predetermined axis 127.

[0144] The connecting portion 342 regulates the relative rotational movement of the first screw 343A and the second screw 343B around the specified axis 127, so that when the first driving mechanism 351 slides the first gripping claw 320A and the second gripping claw 320B, the rotational movement of the first screw 343A around the specified axis 127 is transmitted to the second screw 343B.

[0145] The connecting portion 342 allows the first screw 343A and the second screw 343B to slide relative to each other in the axial direction of the specified axis 127, so that when the second driving mechanism 352 slides the first gripping claw 320A and the second gripping claw 320B, the first slide body 361A and the second slide body 361B can slide relative to each other in the axial direction of the specified axis 127.

[0146] More specifically, the first screw 343A and the second screw 343B have a first tip portion 346A and a second tip portion 346B, respectively (hereinafter, when there is no particular distinction between the first tip portion 346A and the second tip portion 346B, they will be referred to as "tip portion 346").

[0147] The tip portion 346 is an end of the screw 343 in the x-axis direction and extends along the predetermined axis 127. The first tip portion 346A and the second tip portion 346B face each other with a gap in between in the x-axis direction. The tip portion 346 has a non-circular cross-sectional shape when cut by a plane perpendicular to the predetermined axis 127. The tip portion 346 has a rectangular cross-sectional shape when cut by a plane perpendicular to the predetermined axis 127.

[0148] Note that tip portion 346 may have a cross-sectional shape of a polygon other than a rectangle when cut by a plane perpendicular to predetermined axis 127. Tip portion 346 may be configured as a spline shaft on which a plurality of teeth are arranged in the circumferential direction of predetermined axis 127, and each tooth extends in the axial direction of predetermined axis 127.

[0149] The connecting portion 342 is made of a cylindrical body extending in the x-axis direction. When the connecting portion 342 is cut along a plane perpendicular to the predetermined axis 127, the opening shape corresponds to the cross-sectional shape of the tip portion 346. When the connecting portion 342 is cut along a plane perpendicular to the predetermined axis 127, the opening shape is rectangular. A first tip portion 346A is fitted into one end of the connecting portion 342 in the x-axis direction. A second tip portion 346B is fitted into the other end of the connecting portion 342 in the x-axis direction.

[0150] Tip portion 346 can slide in the x-axis direction when fitted to connecting portion 342. Tip portion 346 cannot rotate relative to connecting portion 342 around predetermined axis 127 when fitted to connecting portion 342.

[0151] In this configuration, when first drive mechanism 351 is driven, forward rotational motion from servo motor 340 is transmitted to first screw 343A via first gear 371 and second gear 372, causing first screw 343A and second screw 343B, which is connected to first screw 343A by connecting portion 342, to rotate in one direction about predetermined axis 127. At this time, the threads of first screw 343A and the threads of second screw 343B are oriented in opposite directions in the circumferential direction of predetermined axis 127, so first nut 344A and second nut 344B move toward each other in the x-axis direction. As a result, first gripping jaw 320A and second gripping jaw 320B slide toward each other in the x-axis direction.

[0152] Furthermore, when reverse rotational motion from servo motor 340 is transmitted to first screw 343A via first gear 371 and second gear 372, first screw 343A and second screw 343B, which is connected to first screw 343A by connecting portion 342, rotate in opposite directions about predetermined axis 127. At this time, first nut 344A and second nut 344B move in directions away from each other in the x-axis direction. As a result, first gripping jaw 320A and second gripping jaw 320B slide in directions away from each other in the x-axis direction.

[0153] It should be noted that when the servo motor 340 causes the first gripping claw 320A and the second gripping claw 320B to slide, the first slide body 361A and the second slide body 361B remain stationary in the x-axis direction.

[0154] Figure 32 is a cross-sectional view showing the internal structure of the piston cylinder in Figure 28. With reference to Figures 28, 30, and 32, second drive mechanism 352 slides first slide body 361A and second slide body 361B in the x-axis direction. At this time, first gripping claw 320A slides in the x-axis direction integrally with first slide body 361A, and second gripping claw 320B slides in the x-axis direction integrally with second slide body 361B.

[0155] Piston cylinder 330 is supported by support base 311. Piston cylinder 330 is disposed between support base 311 and slide body 361 in the y-axis direction. Gripping claw 320 (claw main body portion 321) extends from slide body 361 on the opposite side to piston cylinder 330 in the y-axis direction. Piston cylinder 330 is provided at a position spaced apart from connecting portion 342 radially outward of predetermined axis 127.

[0156] Piston cylinder 330 has piston 332 and power transmission unit 334. Piston 332 moves linearly (reciprocates) along the y-axis direction. Piston cylinder 330 is an air type that operates piston 332 using air pressure. Power transmission unit 334 converts the linear motion from piston 332 along the y-axis direction into linear motion along the x-axis direction, and transmits this linear motion to first slide body 361A and second slide body 361B.

[0157] The power transmission unit 334 has a first wedge block 331A and a second wedge block 331B (hereinafter, when there is no need to distinguish between the first wedge block 331A and the second wedge block 331B, they will be referred to as "wedge blocks 331"). The first wedge block 331A and the second wedge block 331B are spaced apart from each other in the x-axis direction. The wedge block 331 is supported by a guide block 336 so as to be slidable in the x-axis direction.

[0158] The first wedge block 331A is connected to the first slide body 361A. The first wedge block 331A is fastened to the slide main body portion 366 of the first slide body 361A using bolts. The second wedge block 331B is connected to the second slide body 361B. The second wedge block 331B is fastened to the slide main body portion 366 of the second slide body 361B using bolts.

[0159] The first wedge block 331A has a first tapered surface 331a. The second wedge block 331B has a second tapered surface 331b. The first tapered surface 331a and the second tapered surface 331b face each other with a gap in the x-axis direction. The first tapered surface 331a and the second tapered surface 331b are inclined with respect to the y-axis so that the distance between the first tapered surface 331a and the second tapered surface 331b in the x-axis direction changes in the y-axis direction. The distance between the first tapered surface 331a and the second tapered surface 331b in the x-axis direction decreases as the block approaches the slider 361 and increases as the block moves away from the slider 361 in the y-axis direction.

[0160] The power transmission unit 334 further includes a third wedge block 333. The third wedge block 333 is connected to the tip of the piston 332 in the y-axis direction. The third wedge block 333 is disposed between the first wedge block 331A and the second wedge block 331B in the x-axis direction. The first wedge block 331A and the second wedge block 331B are biased against the third wedge block 333 in the x-axis direction by the elastic force of a spring member (not shown).

[0161] The third wedge block 333 has a third tapered surface 333a and a fourth tapered surface 333b. The third tapered surface 333a is parallel to the first tapered surface 331a. The third tapered surface 333a is in surface contact with the first tapered surface 331a. The fourth tapered surface 333b is parallel to the second tapered surface 331b. The fourth tapered surface 333b is in surface contact with the second tapered surface 331b.

[0162] In this configuration, when the piston 332 moves linearly in the y-axis direction away from the slider 361 as shown by the arrow 132 in Fig. 32 (when the piston cylinder 330 is driven to retract) during driving of the second drive mechanism 352, the first wedge block 331A and the second wedge block 331B move in directions approaching each other in the x-axis direction as shown by the arrow 134 in Fig. 32. As a result, the first gripping claw 320A and the second gripping claw 320B slide in directions approaching each other in the x-axis direction.

[0163] Furthermore, when the piston 332 makes a linear movement in the y-axis direction toward the slider 361 (when the piston cylinder 330 is extended), as shown by the arrow 131 in Fig. 32, the first wedge block 331A and the second wedge block 331B move in directions away from each other in the x-axis direction, as shown by the arrow 133 in Fig. 32. As a result, the first gripping claw 320A and the second gripping claw 320B slide in directions away from each other in the x-axis direction.

[0164] Furthermore, when the first gripping claw 320A and the second gripping claw 320B are slid by the second drive mechanism 352 (piston cylinder 330), the first gripping claw 320A and the second gripping claw 320B remain stationary in the x-axis direction relative to the first slide body 361A and the second slide body 361B, respectively.

[0165] Fig. 33 is a diagram showing a sliding movement of the first gripping claw and the second gripping claw caused by the first drive mechanism (servo motor), and Fig. 34 is a diagram showing a sliding movement of the first gripping claw and the second gripping claw caused by the second drive mechanism (piston cylinder).

[0166] 9, 33, and 34, the operator inputs in advance the width of the workpiece W in the x-axis direction via a display unit 670 (operation unit) made up of a touch panel display. The input width of the workpiece W is stored in a parameter storage unit 625. The parameter storage unit 625 further stores a stroke length St of the piston cylinder 330 in the second drive mechanism 352.

[0167] 33 and 34, it is assumed that first gripping jaws 320A and second gripping jaws 320B grip a workpiece W having a width of third length Lc. In the initial state, the distance between first gripping jaws 320A and second gripping jaws 320B in the x-axis direction is first length La. First length La is greater than third length Lc (La>Lc).

[0168] The first length La may be the maximum distance between the first gripping jaws 320A and the second gripping jaws 320B. In this case, the first length La is determined by the specifications of the workpiece hand 310 attached to the robot 21.

[0169] Next, the control device 610 (robot control unit 620) controls the robot 21 so that the workpiece W is placed between the first gripping jaws 320A and the second gripping jaws 320B.

[0170] Next, the robot control unit 620 reads out the third length Lc, which is the width of the workpiece W, and the stroke length St of the piston cylinder 330 from the parameter storage unit 625. The robot control unit 620 calculates the sum of the third length Lc and the stroke length St of the first gripping claws 320A and the second gripping claws 320B by the piston cylinder 330, and sets the calculated value as the second length Lb (Lb = Lc + St).

[0171] The second length Lb is smaller than the first length La and larger than the third length Lc (Lc < Lb < La). The stroke length St is the slide length of the first wedge block 331A and the second wedge block 331B in the x-axis direction, which is determined by the specifications of the piston cylinder 330. The stroke length St may be, for example, 10 mm or less, 5 mm or less, or 3 mm or less.

[0172] Next, the control device 610 (robot control unit 620) controls the first drive mechanism 351 (servo motor 340) so that the distance between the first gripping claws 320A and the second gripping claws 320B in the x-axis direction changes from the first length La to the second length Lb.

[0173] In this step, when the servo motor 340 in the first drive mechanism 351 is driven, the first gripping claws 320A and the second gripping claws 320B slide in a direction approaching each other.

[0174] Next, the control device 610 (robot control unit 620) controls the second drive mechanism 352 (piston cylinder 330) so that the distance between the first gripping claws 320A and the second gripping claws 320B in the x-axis direction changes from the second length Lb to the third length Lc.

[0175] In this step, when the piston cylinder 330 in the second drive mechanism 352 is driven to shorten, the first gripping claws 320A and the second gripping claws 320B slide in a direction approaching each other.

[0176] In this embodiment, the slide length (St = Lb - Lc) of the first gripping claws 320A and the second gripping claws 320B by the second drive mechanism 352 is smaller than the slide length (La - Lb) of the first gripping claws 320A and the second gripping claws 320B by the first drive mechanism 351 (Lb - Lc < La - Lb). Depending on the dimensions of the workpiece W, the slide length (St = Lb - Lc) of the first gripping claws 320A and the second gripping claws 320B by the second drive mechanism 352 may be equal to or greater than the slide length (La - Lb) of the first gripping claws 320A and the second gripping claws 320B by the first drive mechanism 351 (Lb - Lc ≧ La - Lb).

[0177] When the first gripping claws 320A and the second gripping claws 320B release the workpiece W, the above steps for gripping the workpiece W may be executed in the reverse order.

[0178] Summarizing the structure of the workpiece hand 310 in the embodiment of this invention described above, the workpiece hand 310 as a hand device in this embodiment includes a first gripping claw 320A, a second gripping claw 320B that faces the first gripping claw 320A at an interval and grips the workpiece W as an object together with the first gripping claw 320A, a servo motor 340 as a motor, and uses the output from the servo motor 340 as a driving force to slide at least one of the gripping claws 320 of the first gripping claw 320A and the second gripping claw 320B. The first drive mechanism 351, an air-type piston cylinder 330, and uses the output from the piston cylinder 330 as a driving force to slide at least one of the gripping claws 320 of the first gripping claw 320A and the second gripping claw 320B. And a second drive mechanism 352.

[0179] If the work hand 310 has only a motor as a power source for sliding the gripping jaws 320, in this case, problems arise such as the gripping jaws 320 not being able to obtain sufficient gripping force for the work W due to the small thrust of the motor, or the motor having to be significantly larger in order to obtain sufficient gripping force. On the other hand, if the work hand 310 has only a piston cylinder as a power source for sliding the gripping jaws 320, in this case, problems arise such that various workpieces W with different dimensions cannot be gripped by a single work hand due to limitations on the stroke of the piston cylinder, reducing the versatility of the work hand.

[0180] In contrast to this, in the work hand 310 of this embodiment, by using a first drive mechanism 351 that uses output from a servo motor 340 as a driving force for the sliding movement of the gripping jaws 320, it is possible to ensure a sufficient sliding length for the gripping jaws 320. This makes it possible to grip various workpieces W with different dimensions without preparing a large number of workpiece hands 310. Furthermore, by using a second drive mechanism that uses output from a piston cylinder 330 as a driving force for the sliding movement of the gripping jaws 320, it is possible to obtain a sufficient gripping force for the workpiece W. This makes it possible to more reliably prevent the workpiece W from falling off the workpiece hand 310.

[0181] Furthermore, when gripping the workpiece W with the first gripping claws 320A and the second gripping claws 320B, the first drive mechanism 351 slides the gripping claws 320 so that the distance between the first gripping claws 320A and the second gripping claws 320B changes from a first length La to a second length Lb that is smaller than the first length La, and the second drive mechanism 352 slides the gripping claws 320 so that the distance between the first gripping claws 320A and the second gripping claws 320B changes from the second length Lb to a third length Lc that is smaller than the second length Lb.

[0182] According to this configuration, by adjusting the second length Lb to match the dimensions of the workpiece W, first, the first driving mechanism 351 is driven to position the first gripping claws 320A and the second gripping claws 320B relative to the workpiece W, and then, by driving the second driving mechanism 352, the first gripping claws 320A and the second gripping claws 320B can grip the workpiece W with sufficient gripping force.

[0183] Furthermore, the sliding length (Lb-Lc) of first gripping claw 320A and second gripping claw 320B by second drive mechanism 352 is shorter than the sliding length (La-Lb) of first gripping claw 320A and second gripping claw 320B by first drive mechanism 351.

[0184] According to this configuration, by relatively reducing the stroke length St (=Lb-Lc) of the piston cylinder 330 when gripping the workpiece W, it is possible to prevent excessive force from being applied to the workpiece W from the first gripping jaws 320A and the second gripping jaws 320B. This makes it possible to prevent damage to the workpiece W.

[0185] The workpiece hand 310 further includes a first slide body 361A that supports the first gripping jaw 320A so as to be slidable along the x-axis direction as a first direction, and is slid in the x-axis direction by the second drive mechanism 352, and a second slide body 361B that supports the second gripping jaw 320B so as to be slidable along the x-axis direction, and is slid in the x-axis direction by the second drive mechanism 352. The first drive mechanism 351 includes a first screw 343A that is supported by the first slide body 361A so as to be rotatable about a predetermined axis 127 that is parallel to the x-axis direction, and to which rotational motion from the servo motor 340 is input, a first nut 344A that is threaded onto the first screw 343A and connected to the first gripping jaw 320A, and a second slide body 361B that is supported by the second slide body 361B so as to be rotatable about the predetermined axis 127, and is provided with a thread that is threaded in the opposite direction to the thread provided on the first screw 343A. The screw 343B, a second nut 344B threaded onto the second screw 343B and connected to the second gripping claw 320B, and a connecting portion 342 connecting the first screw 343A and the second screw 343B so as to restrict the relative rotational movement of the first screw 343A and the second screw 343B around the specified axis 127 and allow the relative sliding movement of the first screw 343A and the second screw 343B in the axial direction of the specified axis 127.

[0186] According to this configuration, by restricting the relative rotational movement of the first screw 343A and the second screw 343B around the predetermined axis 127, it is possible to transmit rotational movement around the predetermined axis 127 between the first screw 343A and the second screw 343B when the first driving mechanism 351 slides the first gripping jaws 320A and the second gripping jaws 320B. Furthermore, by allowing the relative sliding movement of the first screw 343A and the second screw 343B in the axial direction of the predetermined axis 127, it is possible to enable the relative sliding movement of the first slide body 361A and the second slide body 361B in the axial direction of the predetermined axis 127 when the second driving mechanism 352 slides the first gripping jaws 320A and the second gripping jaws 320B.

[0187] The piston cylinder 330 also includes a piston 332 that moves linearly along the y-axis direction, which is a second direction perpendicular to the x-axis direction, and a power transmission unit 334 that converts the linear motion from the piston 332 along the y-axis direction into linear motion along the x-axis direction and transmits the linear motion to the first slide body 361A and the second slide body 361B.

[0188] According to this configuration, the piston cylinder 330 can be configured compactly in the x-axis direction.

[0189] In the work hand 310 of this embodiment, it is also possible to slide the gripping jaws 320 using only the first drive mechanism 351, which uses the output from the servo motor 340 as a driving force. In this case, the control device 610 (robot control unit 620) may monitor the torque load through the current value of the servo motor 340 and perform control according to the torque load.

[0190] As one example, the first drive mechanism 351 slides the gripping jaws 320 to grip a workpiece W made of resin or a thin object. At this time, the control device 610 (robot control unit 620) stops the servo motor 340 when the current value of the servo motor 340 exceeds a threshold value. This prevents the gripping jaws 320 from applying an excessive gripping force to the workpiece W, and as a result, damage to the workpiece W can be avoided.

[0191] As another example, the workpiece W is gripped by sliding the gripping jaws 320 using the first drive mechanism 351. At this time, the control device 610 (robot control unit 620) detects the angular position of the servo motor 340 when the current value of the servo motor 340 exceeds a threshold value from an encoder of the servo motor 340 or the like. The control device 610 (robot control unit 620) calculates the dimensions of the workpiece W based on the detected angular position of the servo motor 340.

[0192] As yet another example, a block for positioning the workpiece W is installed in the workpiece stocker 71. The first drive mechanism 351 slides the gripping jaws 320, causing the gripping jaws 320 to press the workpiece W against the positioning block. At this time, the control device 610 (robot control unit 620) stops the servo motor 340 when the current value of the servo motor 340 exceeds a threshold value. This allows the workpiece W to be pressed against the positioning block with an appropriate force, and the workpiece W can be placed in an appropriate position in the workpiece stocker 71.

[0193] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0194] 10, 10S, 10T machine tool, 12 processing area, 14 cover body, 16 opening, 18 operation panel, 21 robot, 22 robot base, 23 drive servo motor, 26 base part, 27 first arm, 28 second arm, 29 hand attachment part, 31, 31S, 31T pallet stocker, 51 transport operation panel, 56, 56h, 56i, 56j, 56k fence, 61, 61S, 61T setup station, 71 work stocker, 81 hand stocker, 100 transport system, 101 turning center axis, 102, 103, 105 rotation center axis, 104, 106 rotation center axis, 113 space, 120 gripping part, 120A first gripping part, 120B second gripping part, 120C Third gripping portion, 120D Fourth gripping portion, 121, 367 Groove portion, 126, 128, 231 Central axis, 127 Predetermined axis, 210 Master hand, 220 Clamping mechanism, 221 Grip insertion hole, 226, 332 Piston, 227, 323 Protrusion portion, 230 Sensor, 310 Work hand, 311 Support base, 320 Grip jaw, 320A First gripping jaw, 320B Second gripping jaw, 321 Claw main body portion, 322 Base portion, 330 Piston cylinder, 331 Wedge block, 331A First wedge block, 331B Second wedge block, 331a First tapered surface, 331b Second tapered surface, 333 Third wedge block, 333a Third tapered surface, 333b Fourth tapered surface, 334 power transmission part, 336 guide block, 337 air valve, 340 servo motor, 342 connection part, 343 screw, 343A first screw, 343B second screw, 344 nut, 344A first nut, 344B second nut, 346 tip part, 346A first tip part, 346B second tip part, 347, 348 bearing, 351 first drive mechanism, 352 second drive mechanism, 361 slide body, 361A first slide body, 361B second slide body, 362 guide part, 363 guide groove, 366 slide main body part, 371 first gear, 372 second gear, 410 pallet, 510 shelf, 515 fixed shelf, 520, 520p, 520q,520r pallet support part, 525 taper cone receiving part, 531 horizontal frame, 532 vertical frame, 533 pin hole, 550 frame body, 551 column, 560 support part, 561 plate, 610 control device, 620 robot control part, 621 program memory part, 622 program analysis part, 623 axis control part, 624 hand control part, 625 parameter memory part, 630 input / output device, 641 operation program, 660 operation acceptance part, 670 display part, 710 teaching hand, 720 touch probe, 720g contactor, La first length, Lb second length, Lc third length, St stroke length, W workpiece.

Claims

1. A first gripping claw; a second gripping claw that faces the first gripping claw with a gap therebetween and grips an object together with the first gripping claw; a first drive mechanism including a motor, the first drive mechanism using an output from the motor as a driving force to slide at least one of the first gripping claw and the second gripping claw; a second drive mechanism that includes an air-operated piston cylinder and uses output from the piston cylinder as a driving force to slide at least one of the first gripping claw and the second gripping claw.

2. When the object is gripped by the first gripping claw and the second gripping claw, the first drive mechanism slides the gripping jaws so that a distance between the first gripping jaw and the second gripping jaw changes from a first length La to a second length Lb that is smaller than the first length La; 2. The hand device according to claim 1, wherein the second drive mechanism slides the gripping claws so that a distance between the first gripping claw and the second gripping claw changes from the second length Lb to a third length Lc that is smaller than the second length Lb.

3. 3. The hand device according to claim 2, wherein a sliding length (Lb-Lc) of the first gripping claw and the second gripping claw caused by the second drive mechanism is shorter than a sliding length (La-Lb) of the first gripping claw and the second gripping claw caused by the first drive mechanism.

4. a first slider that supports the first gripping claw so as to be slidable along a first direction and is slid in the first direction by the second drive mechanism; a second slider that supports the second gripping claw so as to be slidable along the first direction and is slid in the first direction by the second drive mechanism, The first drive mechanism a first screw supported by the first slider so as to be rotatable about a predetermined axis parallel to the first direction, and receiving rotational motion from the motor; a first nut that is threaded onto the first screw and connected to the first gripping jaw; a second screw supported by the second slide body so as to be rotatable about the predetermined axis, and having threads threaded in an opposite direction to the threads threaded on the first screw; a second nut that is threaded onto the second screw and connected to the second gripping jaw; 4. The hand device according to claim 1, further comprising: a connecting portion that connects the first screw and the second screw so as to restrict relative rotational movement of the first screw and the second screw about the predetermined axis and allow relative sliding movement of the first screw and the second screw in the axial direction of the predetermined axis.

5. The piston cylinder is a piston that moves linearly along a second direction perpendicular to the first direction; 5. The hand device according to claim 4, further comprising: a power transmission unit that converts linear motion from the piston along the second direction into linear motion along the first direction and transmits the linear motion to the first slide body and the second slide body.

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