JPWO2015145577A1 - Hydraulic clamping device with rotation function - Google Patents

Abstract

A hydraulic clamping device (42) with a rotation function that suppresses the influence of a check valve, an actuator (54) that is operated by hydraulic oil, and a plurality of chuck claws (51) that are operated in conjunction with the actuator (54), A rotation support unit (56) for rotatably mounting an apparatus main body (50) including an actuator (54) and a chuck claw (51), and a rotating apparatus on a hydraulic oil flow path for operating the actuator (54) And a check valve (70) disposed on the rotation axis (510) of the main body (50).

Description

  The present invention relates to a hydraulic clamping device with a rotation function provided with a check valve.

  When a workpiece is processed through a plurality of automatic processing machines, an automatic transfer robot that delivers the workpiece to and from each automatic processing machine is used. Such an automatic transfer robot includes a clamp device that opens and closes a plurality of chuck claws to hold a workpiece. Such a clamping device is also disclosed in the conveyance device disclosed in Patent Document 1 proposed by the present applicant.

Japanese Utility Model Publication No. 64-46146

  A pinion rack is used in the conventional hydraulic clamping device with a rotation function, and the chuck pawl is operated by hydraulic pressure of hydraulic oil. A check valve for maintaining the clamped state is provided so that the gripped workpiece is not dropped even when the hydraulic pressure supply by the hydraulic oil is interrupted. Conventionally, such a hydraulic clamping device with a rotation function has been required to stop at a correct angle quickly while increasing the rotation speed for drive control. Further, the hydraulic clamping device with a rotation function has a tendency that the check valve takes up space and the device main body becomes large.

  Therefore, an object of the present invention is to provide a hydraulic clamping device with a rotation function that suppresses the influence of a check valve in order to solve such a problem.

  A hydraulic clamp device with a rotation mechanism according to an aspect of the present invention rotatably attaches an actuator that operates with hydraulic oil, a plurality of chuck claws that operate in conjunction with the actuator, and an apparatus main body that includes the actuator and the chuck claws. And a check valve disposed on the rotation axis of the rotating device main body and on the flow path of the hydraulic oil for operating the actuator.

  According to the present invention, since the check valve is disposed on the rotating shaft of the apparatus main body, the center of gravity of the check valve when the apparatus main body is rotating is close to the rotating shaft and is generated by the check valve. Centrifugal force can be kept small. Therefore, the inertial force generated when the rotation of the apparatus main body is stopped can be suppressed, so that the apparatus can be quickly stopped at the correct angle.

It is the perspective view which showed the processing machine line which consists of a some machine tool. It is the perspective view which showed the processing module which is an internal structure of a machine tool. It is the perspective view which showed the autoloader. It is a partial sectional view showing a robot hand which is a hydraulic clamp device with a rotation function. It is the figure which showed the robot hand of the state seen from the upper direction of FIG. It is sectional drawing which expanded and showed the rotation support part of the robot hand.

  Next, an embodiment of the present invention will be described below with reference to the drawings. The hydraulic clamping device with a rotation function is used for an automatic transfer robot or the like as described above. In the present embodiment, a description will be given by taking as an example one incorporated in an autoloader (automatic transfer robot) of a processing machine line including a plurality of machine tools.

  First, FIG. 1 is a perspective view showing a processing machine line including a plurality of machine tools. In this processing machine line 1, four machine tools 10 (10A, 10B, 10C, 10D) are mounted on a base 2. The four machine tools 10 are all NC lathes of the same type, and have the same internal structure and overall shape and dimensions. In addition, an autoloader for delivering a workpiece to each machine tool 10 is provided. Here, the “machining machine line” refers to a group of machine tools in which a plurality of machine tools having a certain relationship transfer workpieces by an autoloader.

  The machine tool 10 is entirely covered with the exterior cover 3, and a machining module is provided inside. FIG. 2 is a perspective view showing a processing module 20 that is an internal structure of the machine tool 10. The machine tool 10 is a turret lathe provided with a turret holding a rotary tool such as an end mill or a drill or a cutting tool such as a cutting tool. Therefore, the machining module 20 includes a headstock 12 having a chuck 11 for gripping a workpiece (workpiece), a turret device 13 to which a tool is attached, and a Z that moves the turret device 13 along the Z axis or the X axis. A shaft drive device, an X-axis drive device, a control device 15 for controlling the drive unit, and the like are provided.

  Here, the Z-axis is a horizontal axis parallel to the rotation axis (main axis) of the headstock 12 that rotates the gripped workpiece. The X axis is perpendicular to the Z axis, and is a movement axis that moves the tool of the turret device 13 forward and backward with respect to the Z axis, and is a vertical direction. The X-axis direction is the vertical direction for both the machine tool 10 and the processing machine line 1 shown in FIG.

  The headstock 12 is configured such that a chuck 11 is provided on a main shaft rotatably supported, and the chuck 11 is rotated by a main shaft servomotor 18. The turret device 13 is mounted on a Z-axis slide 22, and the Z-axis slide 22 is further mounted on an X-axis slide 26. The rotary motion of the Z-axis servomotor 23 is converted into the linear motion of the ball nut, and the Z-axis slide 22 is configured to move in a direction parallel to the Z-axis. An X-axis slide 26 is slidably attached to the column 25, and the rotational movement of the X-axis servomotor 28 is converted into the linear movement of the ball nut, so that the X-axis slide 26 moves up and down.

  3 is a perspective view showing the autoloader 30. FIG. The autoloader 30 is arranged on the front side of the processing machine line 1 and is configured as a moving range between the four machine tools 10A to 10D. FIG. 3 is a diagram showing the range of the two vehicles. The autoloader 30 includes a reversing device 45 for reversing a workpiece, a delivery device 40 for delivering a workpiece between the reversing device 45 and a machine tool, and the reversing device 45 and the delivery device 40. A traveling device 35 that moves between the machines 10 is provided. In the traveling device 35, a support plate 31 is fixed to the front surface portion of the base 2 on which the machine tool 10 is mounted, and the rack 32 extending in the Y-axis direction that is the direction from the machine tool 10A to 10D is supported on the support plate 31. Two rails 33 are fixed. A traveling slide that slides while gripping the rail 33 is provided on the traveling table 34, and a pinion 36 that meshes with the rack 32 and a traveling motor 37 that rotates the pinion 36 are provided.

  Further, a turning motor 39 is fixed to the traveling base 34, and a turning table 38 is configured to turn 180 ° on a horizontal plane. A delivery device 40 and a reversing device 45 are mounted on the turning table 38. The delivery device 40 is provided with a robot hand 42 at the tip of a robot arm 41. In the robot arm 41, a pair of support plates 411 arranged on the turning table 38 at a predetermined interval rises in the vertical direction, and an upper arm portion 412 is connected to an upper end portion of the robot arm 41 via a first joint mechanism 413. A forearm portion 415 is connected to the portion 412 via a second joint mechanism 416. For this reason, the first joint mechanism 413 and the second joint mechanism 416 are driven to change the state between the standing folded state and the stretched state shown in the drawing. The robot hand 42 has a clamp mechanism that operates a plurality of chucks, and is configured to be able to grip and release a workpiece.

  Such a delivery device 40 can deliver workpieces to and from the reversing device 45 mounted on the turning table 38 in addition to delivering workpieces to and from the chuck 11 of the machine tool 10. The reversing device 45 is disposed between a pair of support plates 411 disposed at a predetermined interval when viewed in the Z-axis direction. Therefore, the workpiece is transferred to and from the reversing device 45 so as to pass through the crotch of the transferring device 40. The reversing device 45 includes a cylinder 452 in which a pair of gripping claws 451 are opened and closed, and a rotary actuator 453 that rotates the gripping mechanism 180 ° on a horizontal plane.

  Next, FIG. 4 is a partial cross-sectional view showing a robot hand which is a hydraulic clamping device with a rotation function. FIG. 5 is a view showing the robot hand as seen from above in FIG. The robot hand 42 is configured with a gripping portion for gripping a workpiece on both surfaces of the first clamp surface and the second clamp surface on the back side shown in FIG. The gripping portion is composed of three chuck claws for gripping a workpiece, the first clamp surface is configured with a first clamp mechanism 501, and the second clamp surface is configured with a second clamp mechanism 502. .

  The first clamp mechanism 501 and the second clamp mechanism 502 are configured in the same manner. In each case, three chuck claws 51 are arranged on the circumference centered at the point P at equal intervals of 120 °. A chuck slide 52 is slidably attached to the apparatus main body 50, and a chuck claw 51 is fixed to the chuck slide 52. The chuck claw 51 is configured to reciprocate linearly in the radial direction of a circle around the point P, and the workpiece can be gripped and released by operating the three chuck claws 51 simultaneously.

  The first clamp mechanism 501 and the second clamp mechanism 502 are provided with a clamping gear 53 and a rack piston 54 in the apparatus main body 50. The point P that is the center of the clamp is the rotational axis of the clamp gear 53. Then, the rack piston 54 meshes with the clamping gear 53, and the clamping gear 53 is rotated in a predetermined direction by linear movement along the axial direction of the rack piston 54.

  In the clamping gear 53, three guide grooves 531 corresponding to the three chuck claws 51 are formed, and slide protrusions 521 protruding from the chuck slide 52 are inserted therein. The guide groove 531 has a curved shape inclined with respect to the radial direction. The chuck slide 52 is restricted from moving in the circumferential direction. Accordingly, when the clamping gear 53 rotates and the position of the guide groove 531 changes in the radial direction, the chuck slide 52 and the chuck pawl 51 move in the radial direction via the slide protrusion 521 constrained by the guide groove 531. Will be. Since the shape, size, and arrangement of the three guide grooves 531 are the same, the movements of the three chuck claws 51 coincide with each other, and the workpiece is gripped and released by this operation.

  By the way, the apparatus main body 50 is rotatably attached to the robot arm 41. This is because it is necessary to adjust the angle of the first clamp surface of the first clamp mechanism 501 and the second clamp surface of the second clamp mechanism 502 in accordance with the mating chuck surface when transferring the workpiece. At this time, it is desired to increase the rotation speed of the apparatus main body 50. This is because a processing machine such as a machine tool is required to shorten the cycle time until the processing is completed, and it is necessary to increase the operating speed of each drive mechanism for the autoloader.

  However, if the rotational speed is increased, the centrifugal force increases, and the inertial force at the time of stop increases, so that accurate stop control becomes difficult. Further, if priority is given to the rotation speed, the load on the motor for the robot hand increases, so the motor itself must be enlarged, and it is difficult to reduce the size of the robot arm 41. Therefore, the inventor of the present application reviews the structure of the robot hand 42 and proposes a robot hand 42 having a new structure in which the inertial force due to rotation is reduced, that is, a hydraulic clamping device with a rotation mechanism. The robot hand 42 of this embodiment uses a rack piston 54 by hydraulic pressure, and a check valve is incorporated on the hydraulic circuit. The inventor of the present application has examined the check valve and the like.

  In the robot hand 42, rotation support portions 56 are formed on the left and right sides of the apparatus main body 50, and are supported by the forearm portion 415. The rotation axes 510 of the left and right rotation support portions 56 are on the same straight line, and the rotation center P of the clamping gear 53 is located on the rotation axis 510. The rack piston 54 has a stroke direction orthogonal to the rotation axis 510, and the center of the stroke area is located on the rotation axis 510. The cubic device body 50 has a symmetrical shape with respect to the rotation axis 510.

  In the rotation support portion 56, a cylindrical shaft main body 58 is fixed to the forearm portion 415, and a shaft member 59 is inserted in a rotatable state through a bearing. The flange portion of the shaft member 59 is fixed to the apparatus main body 50 with screws. Further, the shaft member 59 on the right side of the drawing has a pulley 61 fixed to a portion that penetrates the shaft main body 58. On the other hand, a robot hand motor is attached to the robot arm 41, and a belt 62 is stretched between the pulley 61. Therefore, the angle of the robot hand 42 is adjusted by driving control of the robot hand motor.

  Next, a cylinder bore 65 is loaded into the apparatus main body 50, and a rack piston 54 is inserted so as to slide in the cylinder bore 65. The rack piston 54 has piston portions 541 and 542 at both ends, and pressurizing chambers 651 and 652 whose volumes are changed by the movement of the piston portions 541 and 542 are formed in the cylinder bore 65. Here, the chuck pawl 51 is clamped by the hydraulic oil supplied to the pressurizing chamber 651, and the chuck pawl 51 is unclamped by the hydraulic oil supplied to the opposite pressurizing chamber 652. The pressurizing chambers 651 and 652 are sealed by O-rings provided in the piston portions 541 and 542, and are kept airtight.

  The cylindrical cylinder bore 65 is cut out at a central portion that does not overlap the movable range of the piston portions 541 and 542, and a part of the clamping gear 53 enters from the cutout portion. On the other hand, the rack-shaped rack piston 54 has a rack gear portion 543 formed at the center portion excluding the piston portions 541 and 542 at both ends. Then, the clamping gear 53 is engaged with the rack gear portion 543. Accordingly, when the rack piston 54 moves in the linear direction in the cylinder bore 65, rotation is given to the clamping gear 53, and linear movement is given to the chuck slide 52 and the chuck pawl 51 by the rotation.

  By the way, the rack piston 54 is formed at the end of the apparatus main body 50 close to the rotation support portion 56, and a hydraulic circuit is connected via the rotation support portion 56. As shown in the figure, the first clamp surface (the same as the second clamp surface) of the apparatus main body 50 is a rectangular shape close to a square, and there is a rotation center P of the clamping gear 53 near the center, and the rotation on the right side of the drawing. A rack piston 54 is disposed on the support portion 56 side.

  On the other hand, when the apparatus main body 50 is rotated 180 ° and the second clamp mechanism 502 on the back side of the drawing (second clamp surface side) is viewed, the clamp gear 53 is centered on the clamp gear 53 of the first clamp mechanism 501. And coaxial. The rack piston 54 of the second clamp mechanism 502 is on the rotation support portion 56 side on the left side of the drawing, and a hydraulic circuit is connected via the rotation support portion 56. That is, both the first clamp mechanism 501 and the second clamp mechanism 502 are configured substantially symmetrically with the rotation axis 510 interposed therebetween. Further, when the first and second clamp mechanisms 501 and 502 are viewed together, the configurations on the left and right sides of the drawing are substantially symmetrical with respect to an orthogonal line 520 passing through the center of the clamp gear 53.

  Next, the hydraulic circuit will be described. Here, FIG. 6 is an enlarged sectional view showing the rotation support portion 56 of the robot hand 42. As shown in FIG. 5, a clamp side joint 65 and an unclamp side joint 66 are attached to the rotation support part 56, and a pipe is connected between the hydraulic pump and the tank side. The clamp side joint 65 and the unclamp side joint 66 are connected to the clamp side flow path 581 and the unclamp side flow path 582 in the shaft main body 58. The clamp-side channel 581 and the unclamp-side channel 582 are separate channels although they overlap in the drawing.

  A swivel joint is configured between the shaft body 58 and the shaft member 59 so that hydraulic oil flows through the rotating portion. That is, the shaft main body 58 is formed with a clamp-side annular groove 67 and an unclamp-side annular groove 68 on the inner wall side, and a clamp-side flow path and an unclamp-side flow path described below formed in the shaft member 59. An opening is provided at the position of the annular grooves 67 and 68. The clamp-side annular groove 67 and the unclamp-side annular groove 68 are sealed by two O-rings arranged so as to sandwich both of them in the axial direction.

  A check valve 70 is provided in the clamp-side flow path formed in the shaft member 59. This check valve 70 prevents the hydraulic pressure in the pressurizing chamber 651 on the clamp side from being released even if the hydraulic oil is released upstream of the clamp-side flow path for some reason, and the workpiece is clamped by the chuck pawl 51. It is for maintaining. Particularly in the present embodiment, such a check valve 70 is provided inside the shaft member 59. The shaft member 59 is formed with an assembly hole opened on the apparatus main body 50 side, and a check valve 70 is incorporated therein. The center of the assembly hole having a circular cross section overlaps the axis of the shaft member 59 (the rotation axis 510 of the rotation support portion 56).

  In the check valve 70, a cylindrical valve body 71 is inserted into a shaft member 59, and the valve body 71 is positioned by a lid member 72 fitted in the opening of the assembly hole. A first through hole 711 and a second through hole 712 are formed in the valve body 71, a cylindrical space 715 is formed in the first through hole 711, and an annular groove is formed in the second through hole 712. 716 is formed. As a result, when the valve body 71 is mounted in the assembly hole of the shaft member 59, the first through hole 711 naturally communicates with the first flow path 81 of the shaft member 59 via the cylindrical space 715 and the annular groove 716. The second through hole 712 communicates with the second flow path 82 of the shaft member 59.

  A valve seat 718 protruding in an annular shape is formed between the first through hole 711 and the second through hole 712 inside the valve body 71. A pilot piston 73 is inserted into the valve body 71 on the first through hole 711 side, and a spherical valve body 75 is inserted into the second through hole 712 side. The valve body 75 is urged toward the valve seat 718 by a spring 76 disposed between the valve body 72 and the valve body 75 is normally pressed against the valve seat 718 in a closed state. However, when hydraulic fluid is supplied from the first through-hole 711 side, the spring 76 contracts due to the hydraulic pressure, and the valve body 75 is separated from the valve seat 718 and is opened. Thus, the flow of hydraulic oil from the first through hole 711 side to the second through hole 712 side is allowed, but the reverse flow is restricted.

  However, when the chuck pawl 51 is unclamped, it is necessary to allow the flow of hydraulic oil from the second through hole 712 side to the first through hole 711 side in order to discharge the hydraulic oil. Therefore, a pilot piston 73 is provided to open the valve when hydraulic oil flows in the same direction. The pilot piston 73 is formed with a piston portion 731 that slides inside the valve body 71 under the hydraulic pressure of the hydraulic oil, and a projection 732 smaller than the inner peripheral diameter of the valve seat 718. The protrusion 732 pushes the valve body 75 through the hole (valve hole) of the valve seat 718, whereby the valve body 75 is separated from the valve seat 718 (the state shown in FIG. 6). However, since the pilot piston 73 is urged away from the valve seat 718 by the spring 77, the check valve 70 in the normal state is closed when the valve body 75 is pressed against the valve seat 718 as described above. It is a valve state.

  The pilot piston 73 has a surface on the opposite side of the spring 77 in the piston portion 731 in the unclamp side flow path 83, and receives the pressure of hydraulic oil supplied to the unclamp side flow path 83 to the valve seat 718 side. It is supposed to move. In addition to the flow path from the unclamping annular groove 68 of the shaft body 58 to the rack piston 54, the unclamping flow path 83 is branched from a pilot flow path 831 that communicates with the assembly hole of the shaft member 59. . As described above, in this hydraulic circuit, hydraulic oil is supplied to and discharged from the pressurizing chambers 651 and 652 of the rack piston 54 through the flow passages formed in the shaft member 59 and the apparatus main body 50.

  By the way, the apparatus main body 50 is provided with a detachable cylinder lid 85 for loading the rack piston 54 into the cylinder bore 65, as shown in FIG. In particular, an opening is formed on both sides of the apparatus main body 50 by a cylindrical cylinder bore 65, and a pair of cylinder lids 85 are provided so as to close the opening on both sides. The pair of cylinder lids 85 are also symmetric with respect to the rotation axis 510 of the apparatus main body 50. Further, since the flow path is formed in the cylinder lid 85, the flow path formed in the apparatus main body 50 is a simple straight flow path. This flow path is also symmetric with respect to the rotation axis 510.

  Then, the effect | action of this embodiment is demonstrated. In the processing machine line 1, the workpiece is taken out from the supply pallet by the autoloader 30, and is sequentially transferred from the machine tool 10A to the machine tool 10D. In the autoloader 30, the pinion 36 that rotates by driving of the traveling motor 37 rolls on the rack 32 and moves in the Y-axis direction. At this time, the traveling slide grabs and slides on the rail 33 to move while maintaining the posture of the robot arm 41 and the like.

  When the workpiece is taken out from the supply pallet or delivered to the machine tool 10, the robot arm 41 is extended and contracted. That is, the first joint mechanism 413 and the second joint mechanism 416 adjust the angles of the upper arm portion 412 and the forearm portion 415 by controlling the rotation of the joint motor, and an extended state as shown in FIG. 3 is formed. Further, the forearm portion 415 is folded so that the forearm portion 415 can be accommodated in the standing upper arm portion 412 by reverse rotation of the joint motor. The robot hand 42 grips or releases the workpiece, and delivers the workpiece to and from each unit.

  The workpiece may be processed on both the front and back sides. In that case, it is necessary to reverse the processing surface between the pre-process and the post-process. For this purpose, the workpiece is delivered from the delivery device 40 to the reversing device 45, and the delivered workpiece 40 is delivered to the next machine tool 10 by the delivery device 40. In particular, since the delivery device 40 and the reversing device 45 are mounted on the same platform 34, the reversing operation is performed while moving between the machine tools 10.

  Next, in the robot hand 42 when the workpiece is transferred, the apparatus main body 50 is rotated by driving the robot hand motor, and the angle adjustment of the first clamp mechanism 501 and the second clamp mechanism 502 is performed. In other words, the rotation of the robot hand motor is transmitted to the pulley 61 via the belt 62, and the apparatus main body 50 rotates via the shaft member 59. When gripping the workpiece, hydraulic oil is fed from the clamp side joint 65. The hydraulic fluid flows from the clamp-side channel 581 of the shaft body 58 to the clamp-side annular groove 67 and is sent to the first channel 81 of the rotating shaft member 59. Further, the hydraulic oil passes through the valve body 71 and is sent to the second flow path 82. At that time, in the valve main body 71, the hydraulic oil flows from the first through hole 711 through the valve hole to the second through hole 712, and the valve body 75 resists the urging force of the spring by the hydraulic pressure. The check valve 70 is open.

  Thus, hydraulic oil is supplied to the pressure chamber 651 on the clamp side, the piston portion 541 is pressurized, and the rack piston 54 moves. On the other hand, as the rack piston 54 moves, the hydraulic oil filled in the unclamping pressure chamber 652 is pushed out and discharged through the unclamping flow path 83. As a result, the clamping gear 53 shown in FIG. 4 rotates in the clockwise direction. Along with the movement of the guide groove 531, a radial linear motion is given to the chuck slide 52 through the slide protrusion 521 entering the guide groove 531. At this time, since the three chuck claws 51 simultaneously move in the direction of the rotation center P of the clamping gear 53, the workpiece located at the central portion is clamped.

  In the robot hand 42, even if the upstream side hydraulic oil is removed in such a clamped state, the hydraulic oil filled in the pressurizing chamber 651 is prevented from being discharged by the check valve 70. Therefore, the workpiece is prevented from falling. That is, in the check valve 70, the valve body 75 is pressed against the valve body 75 by the spring and is in the closed state, so that the operation in the pressurizing chamber side 651 is performed even if the hydraulic oil is drained upstream. The flow of oil is blocked by the check valve 70. Thereby, the movement of the rack piston 54 is restricted and the clamp state of the chuck pawl 51 is maintained.

  On the other hand, when releasing the gripped work, the hydraulic oil must be discharged from the pressurizing chamber 651 on the clamp side. When releasing the chuck, the check valve is driven by the hydraulic oil fed from the unclamp side joint 66. 70 is opened. The hydraulic oil supplied to the unclamp side flow path 582 of the shaft body 58 is sent from the unclamp side annular groove 68 to the unclamp side flow path 83. Then, hydraulic oil is supplied to the unclamping pressure chamber 652 and the piston portion 542 of the rack piston 54 is pressurized.

  Further, the hydraulic oil supplied to the unclamp side flow path 83 also flows to the pilot flow path 831 side, and the pilot piston 73 is pressurized by the hydraulic oil. The pressurized pilot piston 73 moves toward the valve seat 718 against the urging force of the spring 77. Therefore, as shown in FIG. 6, the valve body 75 is pushed by the protrusion 732 and is separated from the valve seat 718, and the check valve 70 is opened. When the rack piston 54 is pressurized and moved, the hydraulic oil filled in the pressure chamber 651 on the clamp side can be discharged.

  The movement of the rack piston 54 causes the clamping gear 53 shown in FIG. 4 to rotate counterclockwise. Along with the movement of the guide groove 531, a radial linear motion is given to the chuck slide 52 through the slide protrusion 521 entering the guide groove 531. At this time, since the three chuck claws 51 simultaneously move in a direction away from the rotation center P of the clamping gear 53, the chuck claws 51 are separated from the gripped workpiece and unclamping is performed.

  As described above, according to the hydraulic clamping device with a rotation function (robot hand 42) according to the present embodiment, since the configuration is substantially symmetrical with respect to the rotation axis 510 of the apparatus main body 50, the centrifugal force when rotating is generally the target. Distribution. That is, since the gravity center position of each component member is close to the rotation axis 510, the inertial force accompanying the start and stop of rotation can be suppressed. In particular, the check valve 70 has been arranged at a distance from the rotation axis 510 until now, but in the present embodiment, the check valve 70 is arranged on the rotation axis 510, so that the check valve 70 starts and stops rotation. The inertial force associated with is extremely small.

  As a result, the load on the robot hand motor is reduced, and accurate rotation stop control can be performed in a short time. In other words, the rotation speed of the robot hand 42 can be increased, and still a fine adjustment is not necessary or only a small amount is required for stopping at a predetermined angle. Further, since the load on the motor is reduced, the robot hand motor can be reduced in size, which contributes to the reduction in the size of the robot arm 41 on which the robot hand 41 is mounted.

  By the way, in the conventional robot hand 42, the position of the pilot piston 73 is away from the rotation axis 510 of the robot hand 42, or the center axis of the pilot piston 73 is orthogonal to the rotation axis 510. 73 could move. If the pilot piston 73 moves, the valve body 75 may be displaced during clamping and the hydraulic oil may leak. In this regard, the check valve 70 of the present embodiment is hardly affected by the centrifugal force because the central axis of the pilot piston 73 is superimposed on the rotation axis 510 of the robot hand 42. Therefore, it is possible to prevent the pilot piston 73 from moving during the rotation of the robot hand 42 and to secure a stable clamped state.

  Further, the check valve 70 is configured in the rotation support portion 56 of the robot hand 42. Specifically, it is assembled inside the shaft member 59 of the robot hand 42. Therefore, the apparatus main body 50 does not need to provide a space for the check valve 70, so that the size can be reduced and the robot hand 42 can be downsized. In addition, since the rack piston 54 (cylinder bore 65) is incorporated in accordance with the size of one side of the rectangular device main body 50, the size of the device main body 50 can be reduced in this respect to reduce the size of the robot hand 42. it can.

As mentioned above, although one Embodiment of this invention was described, this invention is not limited to these, A various change is possible in the range which does not deviate from the meaning.
In the embodiment, the rack piston is used as the actuator of the robot hand 42, but a clamping mechanism using a hydraulic cylinder or the like may be configured.
In the above embodiment, the three chuck claws 51 are arranged at intervals of 120 °. However, when only the three chuck claws 51 are captured and the center of gravity at the time of rotation is viewed, the rotation axis 510 is closer. It is preferable to arrange in. In other words, it does not necessarily have to be equally spaced by 120 ° as long as it does not affect the clamp.

1: Machine tool line 10: Machine tool 40: Delivery device 41: Robot arm 42: Robot hand 50: Device main body 51: Chuck claw 53: Clamping gear 54: Rack piston 56: Rotation support 58: Shaft main body 59: Shaft Member 70: Check valve 73: Pilot piston 75: Valve body

Claims (5)

An actuator operated by hydraulic fluid;
A plurality of chuck claws that operate in conjunction with the actuator;
A rotation support unit for rotatably mounting the apparatus main body including the actuator and the chuck claw;
A hydraulic clamping device with a rotation mechanism, comprising a check valve disposed on a rotation axis of the device main body that is on a flow path of hydraulic oil that operates the actuator.   The hydraulic clamp device with a rotation mechanism according to claim 1, wherein the check valve is provided inside the rotation support portion.   The check valve has a piston member that acts to open and close the valve, and the piston member is arranged such that its axial center substantially overlaps the rotation axis of the apparatus main body. The hydraulic clamp device with a rotation mechanism according to claim 1 or 2.   4. The actuator according to claim 1, wherein the actuator is a rack piston, a movement direction thereof is orthogonal to a rotation axis of the apparatus main body, and a central portion of the movement range substantially overlaps the rotation axis. The hydraulic clamp device with a rotation mechanism according to any one of the above. Both side openings of a cylinder bore into which the rack piston is slidably inserted are formed in the apparatus main body, and a cylinder lid for closing the both side openings is detachable from the apparatus main body. The hydraulic clamp device with a rotation mechanism according to claim 4.

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