TWI764807B - Buffer clamp structure of robotic arm - Google Patents

Abstract

The present invention relates to a buffer clamp structure of mechanical arm, which includes a main body, a clamp, and at least one spring. The main body has a coupling end, on which an accommodation space is provided in an axle direction. Moreover, three hollow guiding grooves are provided on the periphery of the coupling end in the same axle direction. The clamp has one end provided with a claw, and the other end provided with a push block. A coupling base is fitted on the push block and fixed to the coupling end. Three position limiting members protrudes from the periphery of the push block and are inserted into the three guiding grooves, respectively. The at least one spring applies an elastic force to the clamp to offset the reaction force that the claw subject to in the axle direction and a non-axle direction, thereby producing a buffer effect. The accuracy and stability of the robotic arm, therefore, can be improved during the process of clamping workpiece, even to a level that can simulate human hands.

Description

The structure of the buffer jig of the robot arm

The present invention relates to a clamping jaw structure of a mechanical arm which can counteract the reaction force to produce a buffering effect.

The current general mechanical arm structure, such as the new patent No. M600237 "self-propelled gripper" announced on August 21, 109, discloses: a self-driven gripper is mounted on a robotic arm, the The mechanical arm includes a main body and an end shaft, and the self-driving gripper includes a casing, a rotating part, a moving part and at least one claw body. The shell is fixedly connected with the body. The rotating part is arranged in the casing and is fixedly connected with the end shaft. The moving piece is movably arranged in the casing, is connected with the rotating piece, and has at least one groove. The claw body is movably pivoted on the casing, and partially abuts against the corresponding groove. Wherein, when the rotating member rotates with the end shaft, the rotating member drives the moving member to move linearly along a rotation center line, and links the claw body to pivot the claw body on the housing.

The clamping jaw and the mechanical arm in the previous case of the patent are rigidly connected in the axial direction, so the clamping jaw can only rotate in the axial direction relative to the mechanical arm, and cannot swing at any angle to produce a buffering effect. Because the robot arm needs to rotate the workpiece into the mold or fixture for processing after clamping the workpiece, but the clamping jaw and the robot arm rotate coaxially, and there is no relative torsion angle or tilt, and there is no buffering effect, making the workpiece When rotating into the mold or fixture, the workpiece will be scratched by the contact surface of the mold or fixture, which will affect the appearance or quality.

Therefore, there is the patent case of Invention No. CN105058373 "Compliant Docking Device of Robot Arm Based on Double Hook Hinge Mechanism" announced in mainland China on October 19, 2016, which discloses: in order to solve the existing problems The conventional docking device has the problems of complicated control and large contact force of the mechanism, and it is not easy to protect the docking device. The end effector of the mechanical arm is installed on the upper end of the end effector storage device, the upper end of the connecting piece is connected with the external mechanical arm through the connecting hole, the first cross shaft is installed on the upper part of the tool joint, and the inner ring is installed on the inner side wall of the upper end of the tool joint , the outer ring is installed on the outer side wall of the upper end of the tool joint, and the lower end of the connecting piece is connected with the tool joint through the outer ring; the end effector storage device includes a Hook hinge mechanism and a buffer reset mechanism, and the Hook hinge mechanism is installed on the buffer reset mechanism. Thereby, it is suitable for the docking of mechanical structures in space.

In the previous case of the patent, a buffer spring and a return spring are coaxially arranged between the connecting seat and the connecting base, so as to buffer the force of the axial expansion and contraction. However, when the workpiece is clamped and rotated, when the jaws are tilted against a unilateral force in any direction, the buffering effect is poor, and it is difficult to ensure the accuracy and stability of the jaws.

There is also a patent case of Invention No. CN109773812 "Automatic Quick-Change Robot-Specific Flexible Fixture Device" published in mainland China on May 21, 2019, which discloses: including a gripper connection end and a floating gripper, one end of the gripper connection end The robot is connected to the robot through the robot connecting flange, and the other end is freely connected to the floating gripper through the cooperation of the male and female disks of the robot gun changer. The floating gripper is also provided with a gun changer mounting plate, a floating mechanism, a cylinder mounting plate, The three-claw cylinder and the fingers of the gripper, the robot gun changer mother plate is installed on the gun changer mounting plate, the gun changer mounting plate is floatingly connected to the cylinder mounting plate through a floating mechanism, the three-claw cylinder is installed on the cylinder mounting plate, and the three-claw cylinder is installed on the cylinder mounting plate. The piston head is connected to the fingers of the gripper, and the fingers of the gripper are used to grip the workpiece. The robot automatically switches between different grippers to match and reclaim the material by automatically changing the gun tray, which solves the problem of matching the gripper and the workpiece and the problem that the existing gripper is not flexible, and improves the versatility and clamping effect of the gripper.

In the previous case of the patent, three springs are connected between the connecting end of the gripper and the floating gripper, so as to provide a buffering effect when tilting under unilateral force in any direction. However, the three springs do not have any limiting elements, which will cause the tilting to exceed, but lose the precise buffering effect, so it is not ideal in use.

Therefore, in view of the above-mentioned shortcomings of the current gripper claw buffer structure of the robotic arm. Therefore, the present invention provides a buffer clamp structure for a mechanical arm, which includes: a body, which is provided with a joint end, the joint end is provided with an accommodating groove in the axial direction, and the periphery of the joint end is respectively provided with three hollow holes in the same axial direction. A guide groove; a clamp, which is combined with the main body, one end of the clamp is provided with a clamping claw, and the other end is fixed with a push block, the push block is sleeved with a combination seat, the combination seat is fixed with the combination end, so that The clamp can move relative to the main body, the push block is set in the accommodating groove, and the periphery of the push block is protruded with three limiting pieces, and the three limiting pieces protrude into the three guide grooves ; At least one spring is arranged between the body and the clamp, the spring provides an elastic force for the clamp, so as to counteract a reaction force that the clamping claw bears, so that the clamping claw produces a buffering effect.

The above-mentioned accommodating groove is connected with a first groove with a smaller diameter in the same axial direction, the spring system includes a first spring, the elastic force includes a first elastic force, and the first spring is installed in the In the first groove, the first elastic force is provided for the pushing block.

Three second grooves are arranged around the peripheral edge of the first groove, the spring system includes three second springs, the elastic force includes a second elastic force, and the three second springs are respectively set in the In the three second grooves, the second elastic force is provided for the three limiting members respectively.

The two sides of each of the guide grooves on the above-mentioned joint end are correspondingly provided with two third grooves, and the two sides of the joint seat are respectively provided with a positioning block corresponding to the three limiting members, and the positioning blocks are correspondingly set in the In the third grooves, the axial rotation of the three limiting members is prevented.

The above-mentioned positioning block is designed to be spherical.

The width of the three guide grooves is greater than the diameter of the three limiting members, so that a clearance fit is formed between the three limiting members and the three guide grooves.

The above-mentioned limiting member is set in a cylindrical shape.

The above technical features have the following advantages:

1. The first elastic force provided by the first spring and the second elastic force provided by the three second springs can counteract the axial reaction force together, thereby producing an axial buffering effect on the workpiece. , can avoid scratching the surface of the workpiece, and affect the appearance or quality.

2. By the first elastic force provided by the first spring, and the second elastic force provided by the three second springs, the non-axial reaction force is counteracted together, so that the workpiece can be tilted. A buffering effect can avoid scratching the surface of the workpiece and affect the appearance or quality.

3. With the first spring, the second spring and the positioning block, the fixture can be positioned at the center point, thereby improving the precision and stability of clamping the workpiece, and at the same time, the three limiting pieces move in the three guiding grooves. The clamp can have some elasticity when twisting, so as to achieve the effect of simulating the operator's feel.

1: Ontology

11: Binding end

12: accommodating slot

13: The first groove

14: Second groove

15: Guide groove

16: Third groove

2: The first spring

3: The second spring

4: Fixtures

41: Gripper

42: Push Block

43: Combination seat

44: Limiter

45: Positioning block

A: Workpiece

[Figure 1] is an exploded perspective view of an embodiment of the present invention.

[Second Figure] is an exploded perspective view of the embodiment of the present invention from another perspective.

[Figure 3] is a three-dimensional combined view of an embodiment of the present invention.

[FIG. 4] is a combined cross-sectional view of an embodiment of the present invention.

[FIG. 5] is a schematic diagram of the combined structure of the first spring and the second spring according to the embodiment of the present invention.

[Fig. 6] is a schematic diagram of the position of the limiting member and the positioning block according to the embodiment of the present invention.

[Fig. 7] is a schematic diagram of an embodiment of the present invention that offsets the axial reaction force to produce a buffering effect.

[Fig. 8] is a schematic diagram of an embodiment of the present invention that offsets the non-axial reaction force to generate a buffering effect.

Please refer to the first, second and third figures, the embodiment of the present invention includes: a main body 1, a first spring 2, a second spring 3 and a clamp 4, wherein:

The main body 1 is provided with a coupling end 11, the coupling end 11 is axially provided with an accommodating groove 12, and the accommodating groove 12 is connected with a first groove 13 with a smaller diameter in the same axial direction. The end 11 is provided with three second grooves 14 on the periphery of the first groove 13 . In addition, at the periphery of the joint end 11 corresponding to the positions of the three second grooves 14 , a hollow guide groove 15 is provided coaxially with each other. In addition, two third grooves 16 are correspondingly formed on two sides of each of the guide grooves 15 on the joint end 11 .

The first spring 2 is installed in the first groove 13 (as shown in the fourth and fifth figures) to provide a first elastic force.

The second spring 3 is provided with three of the second springs 3, which are respectively set in the second groove 14 (as shown in the fourth and fifth figures) to provide a second elastic force.

The clamp 4 is combined with the main body 1 . One end of the clamp 4 is protruded with a clamping claw 41 , and the other end is fixed with a push block 42 , and a combination seat 43 is sleeved on the push block 42 . The clamp 4 is movable relative to the body 1 . The pushing block 42 is disposed in the accommodating groove 12 and corresponding to the first spring 2 (as shown in the fourth and fifth figures), so as to be able to bear the first elastic force. The peripheral edge of the push block 42 is protruded with three cylindrical limiting members 44 , the three limiting members 44 protrude into the three guiding grooves 15 , and the width of the guiding groove 15 is larger than the limiting member 44 . The diameter of the piece 44 can form a clearance fit between the limiting piece 44 and the guide groove 15 . In addition, the three limiting members 44 are respectively disposed corresponding to the three second springs 3 so as to be able to bear the second elastic force. In addition, a spherical positioning block 45 is correspondingly provided on the two sides of the three limiting members 44 on the coupling seat 43 , so as to prevent the three limiting members 44 from rotating axially (as shown in the sixth figure). The positioning blocks 45 are correspondingly disposed in the third grooves 16 .

In use, the main body 1 is combined with a mechanical arm (not shown in the figure), through which the clamping jaw 41 of the fixture 4 can be automatically controlled to clamp and release. As shown in the first, second and fourth figures, when the clamping jaw 41 is used to grip a workpiece A for processing, when the workpiece A is directly sent into a mold or jig (not shown in the figure) ], and when it contacts the mold or the jig, the workpiece A will generate an axial reaction force on the clamping jaw 41 . The reaction force is transmitted to the push block through the jaw 41 42, so that the pushing block 42 and the three limiting members 44 move in the three guide grooves 15, and press the first spring 2 and the three second springs 3 evenly respectively, so that the first spring 2 is in the The first groove 13 compresses and moves (as shown in FIG. 7 ), and causes the three second springs 3 to compress and move in the three second grooves 14 . In this way, the first elastic force provided by the first spring 2 and the second elastic force provided by the three second springs 3 can counteract the axial reaction force together, so as to generate the workpiece A A buffering effect in the axial direction.

As shown in Figure 1, Figure 2 and Figure 4, when the workpiece A is gripped by the jaws 41 for processing, when the workpiece A is sent into the mold or jig for rotation, it touches the workpiece A. When reaching the contact surface of the mold or jig, the workpiece A will generate a non-axial reaction force to the jaw 41 . The non-axial reaction force is transmitted to the push block 42 through the clamping jaw 41 , causing the push block 42 to tilt relative to the coupling end 11 , so that the push block 42 and the three limiting members 44 are in the The three guide grooves 15 move inside, and press the first spring 2 and the three second springs 3 unevenly, respectively. By the non-axial reaction force, a partial force can be applied to make the first spring 2 in the first recess. The groove 13 compresses and moves (as shown in the eighth figure), and through the non-axial reaction force, partial force can be applied to make the three second springs 3 compress and move differently in the three second grooves 14 respectively. distance. In this way, the non-axial reaction force can be counteracted by the first elastic force provided by the first spring 2 and the second elastic force provided by the three second springs 3, so as to generate the workpiece A A cushioning effect for tilting.

In this way, through the first elasticity provided by the first spring 2 and the second elastic force provided by the three second springs 3 . And using the method of three-point positioning of the center of the circle, the two sides of the three limiting members 44 are respectively provided with the positioning blocks 45, in addition to preventing the axial rotation of the three limiting members 44, the first spring 2, the third The two springs 3 and the positioning blocks 45 position the clamp 4 at the center point, which can improve the precision and stability of clamping the workpiece A, and at the same time, the three limiting pieces 44 are matched with the three guiding grooves 15 Inward movement, the clamp 4 can have some elasticity when twisting, so as to achieve the effect of simulating the operator's hand feeling.

At the same time, when the workpiece A is clamped directly or rotated into the mold or fixture for processing, the axial reaction force provided by clamping the workpiece A and the non-axial reaction force generated when the workpiece is swayed at any angle can be counteracted respectively. , so as to produce the buffering effect on the workpiece A, which can avoid scratching the surface of the workpiece A and affect the appearance or quality.

Based on the descriptions of the above embodiments, one can fully understand the operation, use and effects of the present invention, but the above-mentioned embodiments are only preferred embodiments of the present invention, which should not limit the implementation of the present invention. Scope, that is, simple equivalent changes and modifications made according to the scope of the patent application of the present invention and the contents of the description of the invention, all fall within the scope of the present invention.

1: Ontology

11: Binding end

12: accommodating slot

13: The first groove

14: Second groove

15: Guide groove

16: Third groove

2: The first spring

3: The second spring

4: Fixtures

41: Gripper

42: Push Block

43: Combination seat

44: Limiter

45: Positioning block

Claims (6)

A buffer clamp structure of a mechanical arm, comprising: a main body with a joint end, the joint end is provided with an accommodating groove in the axial direction, and the periphery of the joint end is respectively provided with three hollow guide grooves in the same axial direction; a The clamp is combined with the body, one end of the clamp is provided with a clamping claw, the other end is fixed with a push block, the push block is sleeved with a combination seat, the combination seat is fixed with the combination end, so that the clamp can be relatively When the body moves, the push block is set in the accommodating groove, and the periphery of the push block is protruded with three limiting pieces, the three limiting pieces protrude from the three guide grooves; at least one spring , arranged between the body and the clamp, the spring provides an elastic force for the clamp, so as to offset a reaction force that the clamping jaw bears, so that the clamping jaw produces a buffering effect; wherein, each Two third grooves are correspondingly provided on two sides of the guide groove, and a positioning block is correspondingly disposed on the two sides of the three limiting members, and the positioning blocks are correspondingly disposed in the third grooves inside, so as to prevent the axial rotation of the three limiting members. The buffer clamp structure of a robotic arm according to claim 1, wherein the accommodating groove is coaxially connected with a first groove with a smaller diameter, the spring includes a first spring, and the elastic force includes A first elastic force, the first spring is set in the first groove, so as to provide the first elastic force to the push block. The buffering fixture structure of a robotic arm according to claim 2, wherein three second grooves are arranged around the peripheral edge of the first groove, the spring system includes three second springs, and the elastic force includes a first groove. Two elastic forces, the three second springs are respectively set in the three second grooves, so as to respectively provide the second elastic forces to the three limiting members. The structure of the buffer clamp for a robotic arm according to claim 1, wherein the positioning blocks are spherical. The buffer clamp structure for a robotic arm according to claim 1, wherein the width of the three guide grooves is greater than the diameter of the three limiters, so that a clearance fit is formed between the three limiters and the three guide grooves. The structure of the buffer clamp for a robotic arm according to claim 1, wherein the limiting member is configured in a cylindrical shape.

Images