JP6284129B2 - Compliance device - Google Patents

Description

  The present invention relates to a gripping claw that is attached to the tip of a robot arm and that grips a component one by one from among a plurality of components that are stored in a complicated manner mainly in a component box, and an opening / closing operation that opens and closes the gripping claw. The present invention relates to a compliance device for an end effector including a mechanism, an adapter interposed between the gripping claw and the opening / closing mechanism, and a compliance device exhibiting compliance with impact.

  Production lines such as automobile manufacturing factories are required to operate 24 hours a day in order to shorten the capital investment recovery period. To that end, a technology has been developed relating to a mechanism for gripping one by one from the inside of the component box, the components stored in a stacked state in a component box supplied to the production line.

  For example, in Patent Document 1, as a compliance device, a pair of brackets respectively attached to a holding part and a support part, and a through hole provided in one bracket are passed through, and one bracket is attached to the other bracket. A guide shaft that is movably supported so as to be close to / separated from each other, and a biasing means that applies a biasing force so that both brackets are separated from each other, and the diameter of the guide shaft is the same as that of the through hole And a compliance device having a small diameter constricted portion smaller than the diameter of the through hole is disclosed.

  Patent Document 2 includes a robot hand having a structure in which a chuck having a rigid gripping claw is movable with respect to a hand body, and the chuck is supported on the hand body via an elastic body in the moving direction. A method for taking out a workpiece to be grasped using the robot, wherein the gripping claw is pressed against the target workpiece until the elastic body is compressed by a predetermined amount, and the gripping claw applies a preload to the workpiece to be grasped. An unloading method is disclosed in which the gripping claw is inserted in the vicinity of the side of the workpiece to be gripped by opening the chuck in a state.

  Patent Document 3 discloses a compliance module that compensates for a positional deviation of a finger module that is attached to a robot hand and grips a workpiece, and that rotates horizontally in compliance with X and Y directions orthogonal to each other. In a compliance module that executes a compliance operation in the θ direction, a neutral position holding mechanism that is slidably or pivotably connected to each plate in each movement direction and that returns the movement. A compliance module is disclosed.

Japanese Patent No. 5706665 Japanese Patent No. 5383847 Japanese Patent No. 4684160

  In the invention described in Patent Document 1, a gap is generated between the outer peripheral wall of the small diameter portion of the guide shaft and the inner peripheral wall of the hole portion having a diameter larger than the diameter of the small diameter portion of the bracket. There is a problem that the compliance device is liable to be damaged because the small-diameter portion is liable to be cracked due to repetitive stress caused by the collision with the guide shaft. Further, in the case where the length of the small diameter portion of the guide shaft is short, there is a problem that the amount of displacement in the vertical direction is insufficient and a shearing force is repeatedly applied to the small diameter portion of the guide shaft, and the small diameter portion is likely to crack. It was.

  Since the invention described in Patent Document 2 has a structure that exhibits only compliance in one direction, for example, the vertical direction, there is a problem in that compliance cannot be exhibited when the gripping claw collides with the component box from the lateral direction. It was.

  The invention described in Patent Document 3 has a problem that the structure becomes complicated and the manufacturing cost increases because independent mechanisms such as a compliance mechanism in the X-axis direction and a compliance mechanism in the Y-axis direction are provided for each axial direction. Since the compliance with the X-axis direction, the Y-axis direction, and the horizontal rotation direction is exhibited, the plate is tilted in three dimensions, which occurs when the tip of the robot hand hits the component box from an oblique direction. In such a case, there was a problem that sufficient compliance could not be exhibited.

  The present invention has been conceived in view of these problems, and even if the end effector that grips the components one by one from the plurality of components that are stored in a complicated manner in the component box is misaligned, It is an object of the present invention to provide a compliance device that realizes an end effector that can alleviate the impact on the end effector and the robot even if it abuts on the part, can securely grip the part, does not easily stop, and does not easily cause repeated fatigue. .

The compliance device 1 according to claim 1 is a compliance device 1 that is a component of an end effector 3 having a gripping mechanism 2 that is attached to the tip of an arm 4 of a robot 11 that picks a component 5. Includes a first plate 21 and a second plate 22 provided in parallel, and spherical bearings fitted in at least three opposing positions in the vertical direction with respect to the first plate 21 and the second plate 22, respectively. 40 and the spherical bearing 40 fitted at the opposite position are connected to both ends, and the nest 31 is slid to allow the interval between the first plate 21 and the second plate 22 to be enlarged or reduced. There is an urging force in the direction in which the nested structure 30 and the interval provided in the nested structure 30 are enlarged. The telescopic tilting mechanism 20 including the biasing means 33 is provided, and is disposed on the first plate 21 side on the cylindrical body 32 side of the nested structure 30 along the nested structure 30. A slide member 51 that slides and a spherical bearing 40 fitted on the first plate 21 are disposed on the slide member 51 side, and a surface parallel to the first plate 21 is formed on the surface facing the slide member 51. The slide member 51 is interposed between a reference plane member 52 and the slide-shaped portion 54 formed in the tubular body 32 or a part integrated with the tubular body 32 and the slide member 51. A tilt return mechanism 50 including an elastic body 53 that biases the reference flat member 52 in a pressing direction is provided.

  The compliance device 1 according to a second aspect is the compliance device 1 according to the first aspect, wherein the slide member 51 of the tilt return mechanism 50 follows the nested structure 30, and the slide member 51 is a cylindrical body of the nested structure 30. 32 along the outer peripheral surface of the cylindrical body 55 and / or the outer peripheral surface of the cylindrical body 55 coaxial with the cylindrical body 32 in which the slide member 51 protrudes from the cylindrical body 32 and is fitted into the spherical bearing 40. It is the form which follows.

  According to a third aspect of the present invention, the compliance device 1 according to the first or second aspect is characterized in that either the first plate 21 side or the second plate 22 side is attached to the arm 4 side of the robot 11.

  The compliance device 1 according to claim 4 is the nesting structure according to any one of claims 1 to 3, wherein the nesting structure 30 is slidably fitted into an outer cylinder 32a and an inner cylinder 31a as a nesting 31. A spherical bearing which is a body 30 and is fixed in a state where the outer cylinder 32a and the inner ring 41 of the spherical bearing 40 which is provided close to the outer cylinder 32a side are fixed to the inner cylinder 31a and the inner cylinder 31a side. The inner ring 41 of the 40 is fixed, and the inner cylinder 31a is urged in the pushing direction from the outer cylinder 31a. One end is elastically contacted with the bottom wall 35 of the outer cylinder or the stepped portion 56 of the spring guide, and the other end. By providing an inner cylinder push-out spring 33a elastically contacted with a stop-shaped portion 39 provided on the inner wall of the inner cylinder, the inner cylinder 31a is nested in the outer cylinder 32a to make a relative movement. One plate 21 and the second pre And freely scale the distance between the sheet 22, and is characterized in that a freely tiltably or twisted relative to the first plate 21 and the second plate 22.

  The compliance device 1 according to claim 5 is the nesting structure according to any one of claims 1 to 3, wherein the nesting structure 30 is slidably fitted into a cylinder tube 32b as a piston 31b as a nesting 31. 30. The head cover 36 attached to the end of the cylinder tube 32b and the inner ring 41 of the spherical bearing 40 adjacent to the head cover 36 are fixed, and the tip of the piston rod 37 connected to the piston 31b and the tip The inner ring 41 of the spherical bearing 40 provided close to the piston rod 37 is fixed, and the space S in the cylinder tube 32b is controlled by a preset air pressure, so that the piston 31b is nested in the cylinder tube 32b. The first plate 21 and the second play The distance between the 22 scaling and freely, and is characterized in that a freely tiltably or twisted relative to the first plate 21 and the second plate 22.

  The compliance device 1 according to claim 6 is the compliance device 1 according to claim 5, wherein the air pressure in the space S between the piston 31 b and the head cover 36 in the cylinder tube 32 b is changed from a position before the gripping mechanism 2 enters the component box 6. From the arbitrary timing until immediately before gripping the component 5 to the timing until the gripping mechanism 2 completes gripping the component 5, the end effector 3 is set to an arbitrary air pressure that becomes an air cushion at the time of collision, A section other than the cushion section is set as a holding section and is set to an arbitrary air pressure that does not cause the piston 31b to slide, and the air pressure in the cylinder tube 32b is set at two stages to switch at least between the cushion section and the holding section. It is characterized by.

The compliance device 1 according to a seventh aspect is the compliance device 1 according to the fourth aspect , wherein the distance between the first plate 21 and the second plate 22 is reduced within the inner cylinder 31a of the nested structure 30 to a predetermined distance. Proximity switch or distance sensor 60 for detecting arrival of the inner cylinder is provided, and the proximity switch or distance sensor 60 is suspended from the bottom wall 35 surface of the outer cylinder 32a or the stepped portion 56 of the spring guide. In order to prevent buckling of the spring 33a, the tip of a rod-shaped spring guide 34 inserted into the inner cylinder push-out spring 33a is detected, and position information in the sliding direction of the inner cylinder 31a by the proximity switch or the distance sensor 60 is detected by the robot. It outputs to the control part 13, It is characterized by the above-mentioned.

A compliance device 1 according to an eighth aspect is the compliance device 1 according to the fifth or sixth aspect , wherein a position sensor 61 that detects the position of the piston 31b in the sliding direction is disposed on the outer peripheral wall surface of the cylinder tube 32b. The position information of the sliding direction of the piston 31b is output to the robot control unit 13.

  The compliance device 1 according to any one of claims 1 to 6, for example, grips the surface of the component 5 when the gripping mechanism 2 of the end effector 3 attached to the tip of the arm 4 of the robot 11 collides with the surface of the component 5. 2 can slip and easily reach the target gripping location, and the load applied to the end effector 31 and the robot 11 when it collides with the parts box 6 can be reduced. Further, it is possible to make it difficult to damage the expensive gripping mechanism 2 or the robot 11 which is more easily damaged than other parts.

  By adopting the nesting structure 30 as the enlargement / reduction mechanism, the compliance device 1 can be reduced in size, and the end effector 3 can also be reduced in size, and the degree of freedom of the orientation and posture of the gripping mechanism 2 in the component box 6. By expanding the range, the gripping mechanism 2 can be approached toward the component 5 from the direction in which the component 5 is easily gripped, and the reliability of the component gripping operation is improved. Moreover, the collision frequency can be reduced by reducing the size.

  The compliance device 1 according to claim 3 is configured so that the tip of the arm 4 of the robot 11 or the grip is held on either the nesting 31 side or the cylindrical body 32 side of the nesting structure 30 of the first plate 21 and the second plate 22. Since it is attached to any of the mechanisms 2, the compliance device 1 in the end effector is considered in the end effector depending on the shape of the part 5 to be handled, the form of the part box 6, and the piled form of the parts 5 in consideration of the wiring situation and the like. The mounting direction can be selected.

  The compliance device 1 according to claim 7 or 8 outputs the position of the nesting 31 in the sliding direction to the robot 11 side, so that when the external force P is applied to the gripping mechanism 2, the nesting 31 slides from the normal position. When reaching the specified position, the abnormality can be fed back to the robot 11 side, and the robot 11 can be dealt with in real time. For example, when it is detected that the end effector 3 has collided, the robot 11 is temporarily stopped without proceeding to the next teaching point, and then the operation of returning to the previous teaching point is performed, so that the external force P to the gripping mechanism 2 is applied. The applied time can be minimized, the breakage of the gripping mechanism 2 and the robot 11 can be suppressed, and the chocolate 11 can be prevented from stopping.

It is explanatory drawing of the components extraction system which uses the compliance device of this invention. It is explanatory drawing when an end effector collides with components and external force is added. It is a perspective view of the form of Claim 3 of the compliance device of this invention. It is a perspective view of the form of Claim 4 of the compliance device of this invention. FIG. 4 is an explanatory view of a longitudinal section of the compliance device in a no-load state in the AA section of FIG. 3. It is explanatory drawing which shows a change when the external force of a reduction direction is added to the compliance device of FIG. It is explanatory drawing which shows a change when the external force of the diagonal direction is added to the compliance device of FIG. It is explanatory drawing which shows a form when the compliance device of Claim 3 changes to the horizontal direction by external force. It is explanatory drawing which shows the form at the time of the tilting change of the compliance device of Claim 3 by external force. It is explanatory drawing which shows a form when the compliance device of Claim 3 changes torsion by external force. It is explanatory drawing which shows the form when the compliance device of Claim 3 carries out the composite change of a horizontal direction, tilting, and a twist by external force. FIG. 5 is a longitudinal cross-sectional explanatory diagram of the compliance device in a no-load state in the BB cross section of FIG. 4. It is explanatory drawing which shows a change when the external force of a reduction direction is added to the compliance device of FIG. It is explanatory drawing which shows a change when the external force of the diagonal direction is added to the compliance device of FIG. It is explanatory drawing which shows a form when the compliance device of Claim 4 changes to the horizontal direction by external force. It is explanatory drawing which shows the form at the time of the tilt change of the compliance device of Claim 4 by external force. It is explanatory drawing which shows the form when the compliance device of Claim 4 changes torsion by external force. It is explanatory drawing which shows the form in case the compliance device of Claim 4 carries out the composite change of the horizontal direction, tilting, and a twist by external force. It is a figure which shows the form which extended the inner cylinder extrusion spring to the spherical bearing.

  A compliance device 1 according to the present invention includes, for example, as shown in FIG. 1, a component including an end effector 3, a robot 11, an image sensor 12, a robot control unit 13, and a component recognition unit 14 based on an image. Used in retrieval system 10. The component picking system 10 is installed in a production line such as an automobile manufacturing factory or a semiconductor manufacturing factory, and a robot 11 having an end effector 3 having a compliance device 1 and a gripping mechanism 2 mounted on the tip of an arm 4 is separated into a component box 6. An operation is performed in which a large number of parts 5 stored in a stacked state are gripped and taken out one by one and conveyed to the next process.

  As shown in FIGS. 3 to 18, the compliance device 1 is a compliance device 1 that is a component of an end effector 3 having a gripping mechanism 2 attached to the tip of an arm 4 of a robot 11 that picks a component 5. The compliance device 1 is provided with a first plate 21 and a second plate 22 arranged in parallel, and expands and contracts between the first plate 21 and the second plate 22 so that the first plate 21 and the second plate 22 An expansion / contraction tilt mechanism 20 that changes the relationship from a parallel state to a tilt state, and a tilt return mechanism 50 that returns the mutual relationship between the first plate 21 and the second plate 22 to a parallel state when the expansion / contraction tilt mechanism tilts. .

The compliance device 1 is provided with a first plate 21 and a second plate 22 arranged in parallel, and is fitted in at least three opposing positions in the vertical direction with respect to the first plate 21 and the second plate 22. The gap between the first plate 21 and the second plate 22 is increased by connecting the both ends of the spherical bearing 40 and the spherical bearing 40 fitted at the opposite position, and sliding the insert 31. A telescopic tilting mechanism 20 is provided, which includes a telescopic structure 30 that can be reduced, and a biasing means 33 that has a biasing force in the direction of expanding the interval provided in the telescopic structure 30, and the telescopic structure A slide member 51 which is disposed on the cylindrical body 32 side of the body 30 and on the first plate 21 side and slides along the nested structure 30; A reference plane member 52 disposed on the side of the slide member 51 of the spherical bearing 40 fitted to the seat 21 and having a surface parallel to the first plate 21 on the surface facing the slide member 51; A direction in which the slide member 51 is pressed against the reference flat member 52 by being interposed between a slide-shaped portion 54 formed on a body 32 or a part integrated with the cylindrical body 32 and the slide member 51. And a tilting return mechanism 50 provided with an elastic body 53 that urges the spring.

  An operation mode of the compliance device 1 will be described. In the first form in which the gripping mechanism 2 is in an unloaded state, the first plate 21 and the second plate 22 are in a parallel state, and the distance between the first plate 21 and the second plate 22 is the maximum expanded state. Thus, in the second mode when a load is applied to the gripping mechanism 2, the nesting structure 30 is changed according to the direction and size of the load applied to each of the nesting structure 30 at least at three locations. When the spherical bearing 40 is independently changed to be tiltable or twistable, and each of the nesting structures 30 is independently extended and retractable, the gripping mechanism 2 returns from the loaded state to the unloaded state. The interval between the first plate 21 and the second plate 22 is always increased by the tilt return mechanism 50 that presses the slide member 51 against the reference plane member 52. The biasing means 33 having a biasing force to the direction, it is possible to restore the first plate 21, the state of the second plate 22 and nested structure 30 to the state of the first embodiment.

  The compliance device 1 is a component of the end effector 3 together with the gripping mechanism 2 that grips the components 5 housed in the component box 6 one by one, and the compliance device 1 side of the end effector 3 is the tip of the arm 4 of the robot 11. Install. Due to the compliance of the end effector 3, the gripping mechanism 2 is less likely to be damaged when the gripping mechanism 2 collides with the component box 6, the impact on the robot 11 is reduced, and the robot 11 is prevented from being stopped. Alternatively, when the gripping claw of the gripping mechanism 2 is slightly displaced from the gripped portion of the component 5 and comes into contact with the component 5, the gripping claw can easily support the gripped portion while sliding on the surface of the component 5. .

  The compliance device 1 includes a first plate 21 and a second plate 22 provided in parallel, an expansion / contraction tilt mechanism 20 and a tilt return mechanism 50. The first plate 21 and the second plate 22 form a surface parallel to the tip end surface of the arm 4 of the robot 11, and one of the first plate 21 and the second plate 22 is attached to the tip end of the arm 4 of the robot 11. The gripping mechanism 2 is attached to the other side. The gripping mechanism 2 includes means for opening and closing the gripping claws in addition to the gripping claws for gripping the component 5. A mechanism that exhibits compliance is mounted between the first plate 21 and the second plate 22.

  As shown in FIGS. 3 to 5 and 12, as a mechanism for demonstrating the compliance, the telescopic tilt mechanism 20 and the tilt return mechanism 50 are set as a pair, and at least between the first plate 21 and the second plate 22. Provide 3 or more locations. As shown in FIGS. 8 to 11 and FIGS. 15 to 18, depending on the position and size of the applied load with reference to the plate attached to the arm 4 side of the robot 11 by providing three or more locations, as shown in FIGS. The plate on the mechanism 2 side can be tilted and changed in three dimensions, and the torsion can be changed.

  The telescopic tilting mechanism 20 includes a spherical bearing 40 that constitutes the tilting mechanism and a telescopic structure 30 that is a telescopic telescopic mechanism. As shown in FIG. 5 or FIG. 12, the tilt mechanism includes spherical bearings 40 fitted to the first plate 21 and the second plate 22, respectively, and is nested in an inner ring 41 of one spherical bearing 40. 30 is fixed to the inner ring 41 of the other spherical bearing 40, and the end of the nested structure 30 on the cylindrical body 32 side is fixed. Thereby, when a load due to the external force P is applied to the gripping mechanism 2, the respective tilting states are different depending on the direction of the load applied to each nested structure 30. The spherical bearing 40 includes a fixed outer ring 42 and a rotating inner ring 41. The spherical bearing 40 may be fixed to the first plate 21 or the second plate 22, as shown in FIGS. Alternatively, it may be another part fixed to the first plate 21 or the second plate 22.

  The nesting structure 30 has a structure in which the nesting 31 slides in the cylindrical body 32, and is provided with urging means 33 having a urging force in a direction of pushing out the nesting 31 from the cylindrical body 32. The biasing means 33 includes a spring, air pressure, hydraulic pressure, etc., and any means may be used as long as it has a biasing force in one direction. By inserting the nest structure 30 between the first plate 21 and the second plate 22 in at least three locations in accordance with the number of the fitted spherical bearings 40, the first plate 21 and the second plate 22 are provided. The interval between the one plate 21 and the second plate 22 is always maintained at the maximum, and when a load due to the external force P is applied to the gripping mechanism 2, each differs depending on the magnitude of the load applied to each expansion / contraction mechanism. It will be in a stretched state. Hereinafter, the plate on the cylindrical body 32 side on which the insert 31 is slid will be referred to as the first plate 21, and the plate on the insert 31 side will be described as the second plate 22. The first plate 21 on the cylindrical body 32 side of the compliance device 1 may be attached to either the arm 4 side or the gripping mechanism 2 side of the robot 11, and the second plate 22 on the nesting 31 side is attached to the arm 4 of the robot 11. It may be attached to either the side or the gripping mechanism 2 side.

  When the load due to the external force P is applied to the gripping mechanism 2 as shown in FIG. 2, the expansion / contraction tilting mechanism 20 including the tilting mechanism and the nested structure 30 applies to each of the expansion / contraction tilting mechanisms 20 provided at least at three locations. Depending on the direction and size of the load, the telescopic structure 30 that is the respective expansion / contraction mechanism is in a different expansion / contraction state and a different tilting state, so that either the first plate 21 or the second plate 22 on the gripping mechanism 2 side As shown in FIGS. 6 to 11 and FIGS. 13 to 18 with respect to the plate on the arm 4 side of the robot 11, the robot 11 changes to a tilted state and changes to a twisted state.

  In the nested structure 30, the insert 31 is pushed into the cylindrical body 32 by the load due to the external force P. When no load is applied, the nested structure 30 is biased by a biasing means 33 having a biasing force in a direction of pushing the nested 31 out of the cylindrical body 32. The nest 31 is pushed out and restored to an unloaded state.

  The tilting mechanism is restored to a no-load state by the tilt return mechanism 50 when it becomes unloaded after the telescopic mechanism tilts due to a load by an external force P.

  The tilt return mechanism 50 projects from the slide member 51 that slides in close contact with the outer peripheral wall of the cylindrical body 32 of the nested structure 30 and / or the bottom wall 35 of the cylindrical body 32 and protrudes from the inner ring of the spherical bearing 40. 41 is provided with a slide member 51 that slides in close contact with the outer peripheral surface of a cylindrical body 55 fitted to 41. A surface parallel to the reference plane member 52 is formed on the spherical bearing 40 side of the slide member 51.

  The tilt return mechanism 50 includes a reference flat member 52 that forms a surface parallel to the surface of the first plate 21 on the first plate 21 side in the sliding direction of the slide member 51. Further, the first plate 21 itself may be used as the reference plane member 52.

  The tilt return mechanism 50 includes an impact-shaped portion 54 formed on a portion integrated with the tubular body 32, such as an impact-shaped portion 54 fixed to the tubular body 32 or a lid member 29. 54, and the other is placed on the slide member 51, and is interposed between the stopper-shaped portion 54 and the slide member 51, and the slide member 51 is slid onto the reference plane member 52. An elastic body 53 that biases in the pressing direction is provided. The elastic body 53 may be any means as long as it has a biasing force in one direction, such as a spring or rubber.

  In a no-load state where no external force is applied to the gripping mechanism 2, the slide member 51 is pressed in close contact with the reference flat member 52 by the elastic body 53, and the telescopic structure 30 serving as the expansion / contraction mechanism is a first plate. It becomes the posture of the perpendicular direction to. Next, when a load is applied to the gripping mechanism 2 by an external force, the nesting structure 30 tilts with respect to the first plate 21, whereby an oblique gap K <b> 1 between the slide member 51 and the reference plane member 52. , K2. Next, when the external force P is not applied to the gripping mechanism 2, the slide member 51 is pressed and pressed against the reference flat member 52 by the biasing force of the elastic body 53, and the nested structure 30 that has been tilted thereby. Returns to the vertical posture with respect to the first plate 21.

  Next, as a first embodiment of the compliance device 1, as shown in FIG. 5, the telescopic tilt mechanism 20 has a nested structure in which an inner cylinder 31 a which is a nested 31 is slidably fitted in an outer cylinder 32 a. 30 forms. The tilting mechanism fixes the outer cylinder 32 a and the inner ring 41 of the spherical bearing 40 fitted to the first plate 21, and the spherical bearing 40 fitted to the inner cylinder 31 a and the second plate 22. The inner ring 41 is fixed. The nesting structure 30 urges the inner cylinder 31a in the direction of pushing out the outer cylinder 32a. One end side is elastically contacted with the bottom wall 35 of the outer cylinder or the stepped portion 56 of the spring guide, and the other end side is An inner cylinder push spring 33a elastically contacted with a stop-shaped portion 39 provided on the inner wall of the inner cylinder is provided, and the inner cylinder 31a is nested in the outer cylinder 32a to make a relative movement of the first plate 21. And the second plate 22 can be enlarged or reduced. As a result, of the first plate 21 and the second plate 22, the plate on the gripping mechanism 2 side can be tilted or twisted with respect to the arm 4 side plate of the robot 11. Then, the lid member 29 is fitted after the inner cylinder 31a is inserted into the outer cylinder 32a. The lid member 29 and the outer cylinder 32a may be fastened by any fastening method that fastens members such as bolts.

  In order to reduce the size of the compliance device 1, when it is necessary to ensure the length of the inner cylinder pushing spring 33 a, the inner cylinder pushing spring 33 a is inserted into the spherical bearing 40 as shown in FIG. 19. A space that can be extended can be secured and extended.

  In the unloaded state, as shown in FIG. 5, the inner cylinder 31a is pressed against the outer cylinder 32a by the inner cylinder pushing spring 33a on the end surface, and the interval W1 between the first plate 21 and the second plate 22 is expanded. The first plate 21 and the second plate 22 are in a parallel state.

  When a load in the major axis direction of the nested structure 30 is applied, as shown in FIG. 6, the inner cylinder push spring 33a is compressed, and the inner cylinder 31a is separated from the end surface of the outer cylinder 32a by a distance L1, and The interval with the second plate 22 is reduced from the interval W1 to the interval W12.

  When a load from an oblique direction is applied to the nested structure 30, as shown in FIG. 7, the inner ring 41 rotates with respect to the outer ring 42 of the spherical bearing 40 fitted on the first plate 21 or the second plate 22, A gap K <b> 1 is generated between the slide member 51 and the reference plane member 52.

  As a form change of the compliance device 1 of the first embodiment, FIG. 8 shows a change state in the horizontal direction, FIG. 9 shows a tilt state, FIG. 10 shows a twist state, and FIG. 11 shows a horizontal direction, tilt, twist. And the state where the compound change of reduction was made is shown. Thus, it can change very flexibly.

  The tilt return mechanism 50 is configured such that one of the slide members 51 is elastically provided on the stopper shape portion 54 of the outer peripheral wall of the outer cylinder 32a of the nested structure 30 and the other is elastically provided on the slide member 51. A spring, which is an elastic body 53 that is urged in a direction of sliding and pressing the flat member 52, is provided, and the elastic body 53 allows the nested structure 30 to return to the first plate 21 or the second plate 22 in the vertical direction. it can.

  Further, a proximity switch or distance sensor 60 for detecting that the distance between the first plate 21 and the second plate 22 is reduced and reaches a predetermined distance is provided in the inner cylinder 31a of the nested structure 30. . The proximity switch or distance sensor 60 is a rod-shaped spring guide 34 inserted into the inner cylinder pushing spring 33a so as to prevent buckling of the inner cylinder pushing spring 33a suspended from the surface of the bottom wall 35 in the outer cylinder 32a. The position information in the sliding direction of the inner cylinder 31a by the proximity switch or the distance sensor 60 is output to the robot controller 13 side. As a result, the robot 11 can be prevented from forcibly moving while colliding with the next point taught, and the end effector 3 can be prevented from being damaged, and the robot 11 can be prevented from stopping.

  Next, as a second embodiment of the compliance device 1, as shown in FIG. 12, the telescopic tilt mechanism 20 includes a nested structure 30 in which a piston 31b as a nested 31 is slidably fitted in a cylinder tube 32b. It is a form. The tilting mechanism fixes the cylindrical body 55 projecting from the head cover 36 attached to the end of the cylinder tube 32b toward the spherical bearing 40 and the inner ring 41 of the spherical bearing 40 fitted on the first plate 21. In this state, the tip of the piston rod 37 fixed to the piston 31b sliding in the cylinder tube 32b and the inner ring 41 of the spherical bearing 40 fitted to the second plate 22 are fixed. Then, the nested structure 30 sets the space S between the piston 31b and the head cover 36 in the cylinder tube 32b to an arbitrary air pressure that becomes an air cushion when the end effector 3 collides, and maintains the air pressure. Thus, the piston 31b can be urged in the pushing direction, so that the piston 31b can be nested in the cylinder tube 32b. Thereby, the space | interval of said 1st plate 21 and said 2nd plate 22 can be enlarged / reduced, and among the said 1st plate 21 and said 2nd plate 22, it is in the plate at the side of the arm 4 of the robot 11. On the other hand, the plate on the gripping mechanism 2 side can be tilted or twisted. The rod cover 38 and the cylinder tube 32b may be fastened or the columnar body 55 and the head cover 36 may be fastened by any fastening method that fastens members such as bolts.

  In the unloaded state, as shown in FIG. 12, the piston 31b is pressed against the rod cover 38 at the end of the cylinder tube 32b by the air pressure filled in the space S, and the first plate 21 and the second plate 22 The interval W2 is enlarged, and the first plate 21 and the second plate 22 are in a parallel state.

  When a load in the major axis direction of the nested structure 30 is applied, as shown in FIG. 13, the air filled in the space S is compressed, and the piston 31b is separated from the rod cover 38 by a distance L2, and the first plate 21 And the second plate 22 are reduced from the interval W2 to the interval W22.

  When a load from an oblique direction is applied to the nested structure 30, as shown in FIG. 14, the inner ring 41 rotates with respect to the outer ring 42 of the spherical bearing 40 fitted on the first plate 21 or the second plate 22, A gap K <b> 2 is generated between the slide member 51 and the reference plane member 52.

  Then, the tilt return mechanism 50 is elastically mounted on the reference flat member 52, one of which is elastically mounted on the cylindrical body 55 fixed to the head cover 36 and the other of which is elastically mounted on the slide member 51. A spring which is an elastic body 53 urging in the pressing direction is provided, and the vertical structure of the nested structure 30 can be returned to the first plate 21 or the second plate 22 by the spring.

  As a change of the compliance device 1 of the second embodiment, FIG. 16 shows a changed state in the lateral direction, FIG. 16 shows a tilted state, FIG. 17 shows a twisted state, FIG. 18 shows a lateral direction, tilted, twisted and It shows a state in which multiple reductions have been made. Thus, it can change very flexibly.

The air pressure in the space S between the piston 31b and the head cover 36 in the cylinder tube 32b is determined from an arbitrary timing from the position immediately before the gripping mechanism 2 enters the component box 6 to immediately before the component 5 is gripped. 2 until the timing until 2 completes gripping the part 5, the end effector 3 is set to an arbitrary air pressure that becomes an air cushion at the time of collision, and the piston 31b is slid using a section other than the cushion section as a holding section. The air pressure in the cylinder tube 32b is set to an arbitrary air pressure that does not move, and the air pressure in the cylinder tube 32b is set in two steps to switch at least between the cushion section and the holding section. By this two-step control of the air pressure, when the gripping mechanism 2 collides, damage to the gripping mechanism 2 can be suppressed, and the robot 11 can be prevented from being stopped. After the part 5 is gripped, the part 5 Can be securely gripped and transported safely.

  A magnet 62 is fitted on the outer peripheral surface of the piston 31b, and a position sensor 61 for detecting the position of the piston 31b in the sliding direction is fitted in a groove formed on the outer peripheral wall surface of the cylinder tube 32b. Thereby, the position information in the sliding direction of the piston 31b by the position sensor 61 can be output to the robot control unit 13 side, and the robot 11 can forcibly advance while colliding with the next point taught. Stopping in real time can prevent the end effector 3 or the robot 11 from being damaged.

DESCRIPTION OF SYMBOLS 1 Compliance device 2 Grasp mechanism 3 End effector 4 Arm 5 Parts 6 Parts box 10 Parts pick-up system 11 Robot 12 Image sensor 13 Robot control part 14 Parts recognition means 20 Telescopic tilt mechanism 21 First plate 22 Second plate 29 Cover member 30 Nesting Structure 31 Nested 31a Inner cylinder 31b Piston 32 Cylindrical body 32a Outer cylinder 32b Cylinder tube 33 Biasing means 33a Inner cylinder push-out spring 34 Spring guide 35 Bottom wall 36 Head cover 37 Piston rod 38 Rod cover 39 Impact shape section 40 Spherical bearing 41 Inner ring 42 Outer ring 50 Tilt return mechanism 51 Slide member 52 Reference plane member 53 Elastic body 54 Impact-shaped part 55 Columnar body 56 Stepped part 60 Proximity switch or distance sensor 61 Position sensor 62 Magnet P External force

Claims (8)

A compliance device, which is a component of an end effector having a gripping mechanism, which is attached to the tip of a robot arm that picks up a component,
The compliance device is:
A first plate and a second plate are provided in parallel,
Both ends are connected to a spherical bearing fitted in at least three opposite positions in the vertical direction with respect to the first plate and the second plate, and a spherical bearing fitted in the opposite position, respectively. , A nesting structure that allows the interval between the first plate and the second plate to be enlarged and reduced by sliding the nesting, and an urging force that has an urging force in the direction of enlarging the interval provided in the nesting structure And a telescopic tilt mechanism provided with means,
And a slide member that is arranged on the first plate side on the cylindrical body side of the nesting structure and slides along the nesting structure, and on the slide member side of the spherical bearing fitted on the first plate. A reference plane member that is disposed and has a surface parallel to the first plate on a surface facing the slide member, and a stopper-shaped portion formed in the cylindrical body or a part integrated with the cylindrical body And a tilting return mechanism provided with an elastic body that urges the slide member in a direction in which the slide member is pressed against the reference plane member.   The form in which the slide member of the tilt return mechanism follows the nested structure, the form in which the slide member follows the outer peripheral surface of the tubular body of the nested structure, and / or the slide member protrudes from the tubular body. The compliance device according to claim 1, wherein the compliance device is in a form along an outer peripheral surface of a cylindrical body that is provided and fitted into the spherical bearing and coaxial with the cylindrical body.   The compliance device according to claim 1, wherein either the first plate side or the second plate side is attached to the arm side of the robot.   The nesting structure is a nesting structure in which a nesting inner cylinder is slidably fitted in an outer cylinder, and fixes the outer cylinder and an inner ring of a spherical bearing arranged close to the outer cylinder side. The inner cylinder and the inner ring of the spherical bearing adjacent to the inner cylinder side are fixed, and the inner cylinder is urged in the direction of pushing out from the outer cylinder. One end side is the bottom of the outer cylinder An inner cylinder push-out spring is provided in which the inner cylinder is elastically contacted with a stepped portion of a wall or a spring guide and the other end is elastically contacted with a stop-shaped portion provided on the inner wall of the inner cylinder, and the inner cylinder is nested in the outer cylinder. The distance between the first plate and the second plate can be enlarged and reduced by relative movement, and can be tilted and twisted with respect to the first plate and the second plate. Item 4. The compliance device according to any one of Items 1 to 3.   The nesting structure is a nesting structure in which a piston as a nesting is slidably fitted in a cylinder tube, and a head cover attached to an end of the cylinder tube and an inner ring of a spherical bearing provided close to the head cover In a fixed state, the tip of the piston rod connected to the piston and the inner ring of the spherical bearing adjacent to the piston rod are fixed, and the space in the cylinder tube is controlled with a preset air pressure. The interval between the first plate and the second plate can be enlarged and reduced by nesting the piston in the cylinder tube and tilted with respect to the first plate and the second plate 4. The compliance device according to claim 1, wherein the compliance device is freely and twistable. .   The air pressure in the space between the piston and the head cover in the cylinder tube is the timing from the arbitrary position from the position before the gripping mechanism enters the parts box to just before gripping the part until the gripping mechanism finishes gripping the part. Is set to an arbitrary air pressure that becomes an air cushion when the end effector collides, and is set to an arbitrary air pressure that does not slide the piston with a section other than the cushion section as a holding section. The compliance device according to claim 5, wherein the air pressure in the tube is set in two steps to switch at least between the cushion section and the holding section. Proximity switch or distance sensor for detecting that the distance between the first plate and the second plate is reduced and reaches a predetermined distance is provided in the inner cylinder of the nested structure, and the proximity switch or distance sensor Is configured to detect the tip of a rod-shaped spring guide inserted into the inner cylinder extruding spring to prevent buckling of the inner cylinder extruding spring, suspended from the bottom wall surface of the outer cylinder or a stepped portion of the spring guide, The compliance device according to claim 4 , wherein position information in a sliding direction of the inner cylinder by the proximity switch or a distance sensor is output to a robot control unit.
A position sensor for detecting a position in a sliding direction of a piston is disposed on an outer peripheral wall surface of the cylinder tube, and position information in a sliding direction of the piston by the position sensor is output to a robot control side. 5. The compliance device according to 5 or 6.

Images