Compliant mechanism for industrial robot polishing end effector

Abstract

The utility model belongs to the technical field of industrial robots, and relates to a compliant mechanism for grinding an end effector by an industrial robot, which comprises a device main body, a rotating shaft penetrates through the center of the device main body, a grinding head is mounted at the bottom end of the rotating shaft, and an adjusting mechanism is arranged in the device main body; the adjusting mechanism comprises a movable cavity formed in the device body, a sliding disc is installed in the movable cavity, the rotating shaft is sleeved with the sliding disc, a plurality of guide rods are installed on the outer edge of the sliding disc in a penetrating mode, the two ends of each guide rod are sleeved with springs, and a first installation ring and a second installation ring which are fixed to the rotating shaft are arranged on the upper side and the lower side of the sliding disc respectively. When the grinding head abuts against the grinding face, the first mounting ring and the second mounting ring slide upwards along with the rotating shaft and drive the sliding disc, the springs on the upper side of the sliding disc are compressed, the grinding head makes flexible contact with the grinding face, and under the interaction of the springs on the upper side and the lower side of the sliding disc, the buffering effect is formed in the grinding process; and the grinding head performs smooth grinding.

Description

Technical Field

[0001] This utility model belongs to the field of industrial robot technology, specifically relating to a compliant mechanism for an end effector used in industrial robots for grinding. Background Technology

[0002] With the continuous development of the manufacturing industry, industrial robots have been widely used in various industrial fields, and robot-assisted manufacturing has become an important means to improve process efficiency and product quality. Among many manufacturing processes, grinding is one of the key links, and its efficiency directly affects product quality. Traditional grinding methods mostly rely on manual operation, which has problems such as low efficiency, unstable quality, and high labor intensity. In recent years, industrial robots have gradually replaced manual grinding operations. Their processing is more flexible, efficient, and economical. They can be equipped with actuators, sensors, and different end effectors to achieve precise force control, and can process large workpieces. They can process complex curved surface workpieces without special fixtures, reducing processing costs.

[0003] Active compliance mechanisms detect force and displacement information in real time through sensors, and the controller performs real-time control based on the feedback information to achieve the desired compliance characteristics. Their advantages include the ability to flexibly adjust compliance parameters according to different processing tasks and workpiece surface conditions, offering high precision and adaptability. However, active compliance control algorithms are complex, requiring high performance from sensors and controllers, making system implementation difficult and costly. Passive compliance mechanisms rely on their own mechanical structure characteristics to achieve compliance. Common examples include elastic elements such as springs and rubber, as well as some specially designed linkage mechanisms. Their advantages include simple structure, low cost, high reliability, lower precision requirements for the robot, decentralized force and position control, ease of implementation, and high cost-effectiveness, making them widely applicable in industrial applications. Therefore, a compliant mechanism for industrial robot grinding end effectors is needed to meet these requirements. Utility Model Content

[0004] In view of the shortcomings of the existing technology, this utility model proposes a compliant mechanism for the end effector of an industrial robot grinding, so as to solve the problems mentioned in the background art.

[0005] This utility model is achieved through the following technical solution:

[0006] A compliant mechanism for a grinding end effector of an industrial robot includes a device body, a rotating shaft passing through the center of the device body, a grinding head being installed at the bottom end of the rotating shaft, and an adjustment mechanism being provided inside the device body.

[0007] The adjustment mechanism includes a movable cavity within the main body of the device. A sliding plate is installed inside the movable cavity and is rotatably mounted on a rotating shaft. The sliding plate can slide up and down within the movable cavity. Multiple guide rods are evenly distributed in a ring along the central axis of the sliding plate through its outer edge, and the sliding plate can slide along the axial direction of the guide rods. Springs are mounted at both ends of each guide rod, with the two springs on the guide rods located on the upper and lower sides of the sliding plate, respectively. A first mounting ring is provided on the upper side of the sliding plate, and a second mounting ring is provided on its lower side. Both the first and second mounting rings are fixed on the rotating shaft. The sliding plate is in clearance contact with both the first and second mounting rings, and both the sliding plate and the first and second mounting rings can rotate relative to each other. When the first and second mounting rings move up and down within the movable cavity with the rotating shaft, they can drive the sliding plate to move up and down within the movable cavity.

[0008] When the grinding head comes into contact with the grinding surface, the first and second mounting rings slide upwards along the rotation axis within the movable cavity, thereby causing the slide to move upwards. Under the limiting action of the guide rod, multiple springs on the upper side of the slide are compressed, allowing the grinding head to make flexible contact with the grinding surface. When the grinding head leaves the grinding surface, multiple springs on the upper side of the slide rebound, and multiple springs on the lower side of the slide prevent the slide from moving excessively downwards. Under the interaction of multiple springs on the upper and lower sides of the slide, a buffering effect is formed during the grinding process, allowing the grinding head to perform smooth grinding.

[0009] Furthermore, the top surface of the slide plate and the bottom surface of the first mounting ring are both provided with vertically opposite annular semicircular grooves, and the bottom surface of the slide plate and the top surface of the second mounting ring are both provided with vertically opposite annular semicircular grooves. Annular grooves are formed between the top surface of the slide plate and the bottom surface of the first mounting ring, and between the bottom surface of the slide plate and the top surface of the second mounting ring. Multiple balls are installed in each annular groove, and each ball can roll within the annular groove, thereby reducing the frictional force when the slide plate rotates relative to the first and second mounting rings.

[0010] Furthermore, in the initial state, the two ends of the spring fitted at the top of each guide rod are in gap contact with the top surface of the movable cavity and the top surface of the slide, respectively. In the initial state, the two ends of the spring fitted at the bottom of each guide rod are in gap contact with the bottom surface of the movable cavity and the bottom surface of the slide, respectively. Through the multiple springs on the upper and lower sides of the slide, a buffering effect is formed during the grinding process, so that the grinding head performs smooth grinding and prevents hard collisions from damaging the robot.

[0011] Furthermore, a force sensor is fixedly installed at the top of the main body of the device. The force sensor is mounted on the rotating shaft. The force sensor can help the robot collect the force situation in real time and adjust the grinding position according to the force situation to improve the processing accuracy and quality.

[0012] Furthermore, a shock-absorbing pad is provided between the top surface of the main body of the device and the bottom surface of the force sensor.

[0013] Furthermore, a connector is fixedly connected to the bottom end of the rotating shaft, and a mounting ring is fixed to the top end of the grinding head. The connector and the mounting ring are detachably connected for easy assembly and disassembly.

[0014] As can be seen from the above technical solution, the compliant mechanism for an end effector used in grinding industrial robots provided by this utility model has the following advantages:

[0015] I. This utility model, by setting up a sliding plate and guide rod, etc., when the grinding head on the rotating shaft at the bottom of the main body of the device rotates and grinds, the grinding head abuts against the grinding surface. At this time, the rotating shaft drives the first mounting ring and the second mounting ring to move axially in the movable cavity, and drives the sliding plate to move axially in the movable cavity. The guide rod in the movable cavity guides the extension and retraction of the springs. Multiple springs are compressed and rebounded to cancel out the force of the grinding head abutting against the grinding surface, preventing the grinding head from hard abutting against the grinding surface and causing damage to the robot. Through the spring rebound force, the grinding head can have a buffering effect during grinding.

[0016] II. This utility model, by setting an annular groove between the slide and the first and second mounting rings, allows the first and second mounting rings to rotate when the rotating shaft rotates. Multiple balls in the annular groove roll, reducing the friction between the slide and the first and second mounting rings during rotation. The spring force causes the slide to move axially within the movable cavity, moving the first and second mounting rings axially, which in turn moves the rotating shaft up and down, creating a buffering effect during grinding. The rotating shaft drives the connector to rotate, thereby adjusting the grinding head for grinding. Based on the detachable connection structure between the connector and the mounting rings, the replaceable grinding head facilitates the operator's disassembly and assembly of the grinding head. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0018] Figure 1 This is a three-dimensional structural diagram of the present invention.

[0019] Figure 2 This is a schematic diagram showing the disassembled structure of the mounting ring and the connector in this utility model.

[0020] Figure 3 This is a partial three-dimensional structural diagram of the adjustment mechanism in this utility model.

[0021] Figure 4 for Figure 2 Enlarged structural diagram at point A in the middle.

[0022] In the diagram: 1. Main body of the device; 2. Adjustment mechanism; 21. Movable cavity; 22. Slide plate; 23. Guide rod; 24. Spring; 25. First mounting ring; 26. Second mounting ring; 27. Annular semi-circular groove; 28. Ball bearing; 3. Rotating shaft; 4. Connector; 5. Mounting ring; 6. Grinding head; 7. Shock-absorbing pad; 8. Force sensor; 9. Internal threaded hole. Detailed Implementation

[0023] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0024] In the description of this application, it should be understood that the terms "upper", "lower", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0025] Example 1

[0026] A compliant mechanism for an end effector used in an industrial robot for grinding, such as Figure 1 and Figure 2 As shown, the device includes a main body 1, a rotating shaft 3 is inserted through the center of the main body 1, a grinding head 6 is installed at the bottom end of the rotating shaft 3, and an adjustment mechanism 2 is provided inside the main body 1.

[0027] like Figures 2 to 4As shown, the adjustment mechanism 2 includes a movable cavity 21 formed within the main body 1 of the device. A slide plate 22 is installed within the movable cavity 21, and the slide plate 22 is rotatably mounted on a rotating shaft 3. The slide plate 22 can slide up and down within the movable cavity 21. A plurality of guide rods 23 are evenly distributed in a ring along its central axis through the outer edge of the slide plate 22, and the slide plate 22 can slide along the axial direction of the guide rods 23. Springs 24 are fitted at both ends of each guide rod 23, and the two springs 24 on the guide rod 23 are located on the upper and lower sides of the slide plate 22, respectively. A first mounting ring 25 is provided on the upper side of the slide plate 22, and a second mounting ring 26 is provided on its lower side. Both the first mounting ring 25 and the second mounting ring 26 are fixed on the rotating shaft 3. There is a gap contact between the slide plate 22 and the first mounting ring 25 and the second mounting ring 26. The slide plate 22 and the first mounting ring 25 and the second mounting ring 26 can rotate relative to each other. When the first mounting ring 25 and the second mounting ring 26 move up and down in the movable cavity 21 with the rotating shaft 3, they can drive the slide plate 22 to move up and down in the movable cavity 21. It should be noted that... Figure 3 The first mounting ring 25 on the upper side of the slide block 22 shown is a partially exploded view, away from the slide block 22. To reveal the ball bearing 28, it is actually as shown... Figure 4 The first mounting ring 25 is in clearance contact with the slide plate 22;

[0028] like Figures 2 to 4 As shown, the top surface of the slide plate 22 and the bottom surface of the first mounting ring 25 are both provided with vertically opposite annular semicircular grooves 27. The bottom surface of the slide plate 22 and the top surface of the second mounting ring 26 are both provided with vertically opposite annular semicircular grooves 27. Annular grooves are formed between the top surface of the slide plate 22 and the bottom surface of the first mounting ring 25, and between the bottom surface of the slide plate 22 and the top surface of the second mounting ring 26. Multiple balls 28 are installed in each annular groove. Each ball 28 can roll in the annular groove, thereby reducing the frictional force when the slide plate 22 rotates relative to the first mounting ring 25 and the second mounting ring 26.

[0029] Specifically, to ensure the installation of the adjustment mechanism 2 in the movable cavity 21, the bottom of the main body 1 of the device is a detachable baffle. After removing the baffle, the adjustment mechanism 2 can be installed in the movable cavity 21. The baffle is connected by screws or threads, which are conventional connection structures and will not be described in detail here.

[0030] like Figure 2 and Figure 4As shown, the two ends of the spring 24 fitted at the top of each guide rod 23 are in initial contact with the top surface of the movable cavity 21 and the top surface of the slide 22 respectively. The two ends of the spring 24 fitted at the bottom of each guide rod 23 are in initial contact with the bottom surface of the movable cavity 21 and the bottom surface of the slide 22 respectively. The multiple springs 24 on the upper and lower sides of the slide 22 form a buffer effect during the grinding process, so that the grinding head 6 performs smooth grinding and prevents hard collisions from damaging the robot.

[0031] like Figure 1 and Figure 2 As shown, a force sensor 8 is fixedly installed at the top of the main body 1 of the device. A shock-absorbing pad 7 is provided between the top surface of the main body 1 and the bottom surface of the force sensor 8. Both the force sensor 8 and the shock-absorbing pad 7 are mounted on the rotating shaft 3. The force sensor 8 can help the robot collect the force in real time and adjust the grinding position according to the force, thereby improving the accuracy and quality of the processing.

[0032] When the grinding head 6 comes into contact with the grinding surface, the first mounting ring 25 and the second mounting ring 26 slide upward with the rotating shaft 3 within the movable cavity 21, thereby causing the slide 22 to move upward. Under the limit of the guide rod 23, the slide 22 moves upward, compressing the multiple springs 24 on the upper side of the slide 22, allowing the grinding head 6 to make flexible contact with the grinding surface. When grinding curved surfaces, the multiple springs 24 on the upper side of the slide 22 rebound, while the multiple springs 24 on the lower side of the slide 22 prevent the slide 22 from moving excessively downward. The rebound extension of the grinding head 6 causes it to come into contact with the grinding surface, which provides a certain buffering effect when the grinding head 6 comes into contact with the grinding surface, preventing damage to the robot due to hard contact; under the interaction of multiple springs 24 on the upper and lower sides of the slide plate 22, a buffering effect is formed during the grinding process, allowing the grinding head 6 to perform smooth grinding; a force sensor 8 is installed at the top of the main body 1, which can help the robot collect the force situation in real time, and adjust the grinding position according to the force situation to improve the processing accuracy and quality.

[0033] Example 2

[0034] A compliant mechanism for an end effector used in grinding industrial robots differs from Embodiment 1 in that: Figure 1 and Figure 2 As shown, the bottom end of the rotating shaft 3 is fixedly connected to the connector 4, and the top end of the grinding head 6 is fixed to the mounting ring 5. The connector 4 and the mounting ring 5 are detachably connected for easy assembly and disassembly. When the robot performs grinding, the rotating shaft 3 rotates to drive the connector 4, the mounting ring 5 and the grinding head 6 to perform grinding operations on the grinding surface.

[0035] Specifically, the bottom end of the connector 4 is provided with an external thread, and the top end of the mounting ring 5 is provided with an internal thread hole 9. The bottom end of the connector 4 is threadedly connected to the top end of the mounting ring 5. To prevent the connector 4 and the mounting ring 5 from disengaging during grinding, the rotation direction of the grinding head 6 is the same as the tightening direction between the connector 4 and the mounting ring 5. Alternatively, a radially extending pin can be provided between the connector 4 and the mounting ring 5. In addition, the connector 4 and the mounting ring 5 can also be connected by bolts.

[0036] The working principle is as follows: When the robot is grinding, the internal threaded hole 9 at the top of the mounting ring 5 is threaded to the bottom of the connector 4, and the grinding head 6 is installed at the end of the actuator. The rotation of the rotating shaft 3 drives the connector 4 and the mounting ring 5 to rotate, thereby driving the grinding head 6 to perform the grinding operation. The first mounting ring 25 and the second mounting ring 26 on the rotating shaft 3 rotate with the rotating shaft 3 in the movable cavity 21. Multiple balls 28 in the annular groove roll under the action of friction, reducing the friction between the first mounting ring 25 and the second mounting ring 26 and the slide 22 when they rotate. When the grinding head 6 comes into contact with the grinding surface, the first mounting ring 25 and the second mounting ring 26 move upward with the rotating shaft 3 in the slide 22, thereby moving the slide 22 upward. Under the limiting action of the guide rod 23, the slide 22 moves downward. Multiple springs 24 on the side of the slide 22 rebound and extend, while multiple springs 24 on the upper side of the slide 22 are compressed, allowing the grinding head 6 to make flexible contact with the grinding surface. When grinding curved surfaces, multiple springs 24 on the upper side of the slide 22 rebound, while multiple springs 24 on the lower side of the slide 22 prevent the slide 22 from moving excessively downward. The rebound and extension of the springs 24 cause the grinding head 6 to come into contact with the grinding surface, providing a certain buffering effect when the grinding head 6 comes into contact with the grinding surface, preventing damage to the robot due to hard contact. Under the interaction of multiple springs 24 on the upper and lower sides of the slide 22, a buffering effect is formed during the grinding process, allowing the grinding head 6 to perform smooth grinding. A force sensor 8 is installed at the top of the main body 1, which can help the robot collect the force situation in real time and adjust the grinding position according to the force situation, thereby improving the processing accuracy and quality.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model, and they should all be covered within the scope of the claims and specification of this utility model.

Claims

1. A compliant mechanism for an end effector used in grinding of an industrial robot, comprising a device body (1), characterized in that: A rotating shaft (3) is inserted through the center of the main body (1) of the device, and a grinding head (6) is installed at the bottom end of the rotating shaft (3). An adjustment mechanism (2) is provided inside the main body (1). The adjustment mechanism (2) includes a movable cavity (21) opened in the main body (1) of the device. A slide (22) is installed in the movable cavity (21), and the slide (22) is rotatably mounted on the rotating shaft (3). Multiple guide rods (23) are evenly distributed in a ring along the central axis of the slide (22) through the outer edge of the slide (22). Each guide rod (23) has a spring (24) mounted at both ends. The two springs (24) on the guide rod (23) are located on the upper and lower sides of the slide (22) respectively. A first mounting ring (25) is provided on the upper side of the slide (22), and a second mounting ring (26) is provided on the lower side. The first mounting ring (25) and the second mounting ring (26) are both fixed on the rotating shaft (3). The slide (22) is in clearance contact with the first mounting ring (25) and the second mounting ring (26).

2. The compliant mechanism for an end effector for grinding in an industrial robot according to claim 1, characterized in that: The top surface of the slide (22) and the bottom surface of the first mounting ring (25) are provided with annular semicircular grooves (27) that are opposite each other. The bottom surface of the slide (22) and the top surface of the second mounting ring (26) are provided with annular semicircular grooves (27) that are opposite each other. Annular grooves are formed between the top surface of the slide (22) and the bottom surface of the first mounting ring (25), and between the bottom surface of the slide (22) and the top surface of the second mounting ring (26). Multiple balls (28) are installed in each annular groove.

3. The compliant mechanism for an end effector for grinding in an industrial robot according to claim 1 or 2, characterized in that: In the initial state, the two ends of the spring (24) fitted at the top of each guide rod (23) are in gap contact with the top surface of the movable cavity (21) and the top surface of the slide (22), respectively. In the initial state, the two ends of the spring (24) fitted at the bottom of each guide rod (23) are in gap contact with the bottom surface of the movable cavity (21) and the bottom surface of the slide (22), respectively.

4. The compliant mechanism for an end effector for grinding in an industrial robot according to claim 1, characterized in that: A force sensor (8) is fixedly installed at the top of the main body (1) of the device.

5. The compliant mechanism for an end effector for grinding in an industrial robot according to claim 4, characterized in that: A shock-absorbing pad (7) is provided between the top surface of the main body (1) of the device and the bottom surface of the force sensor (8).

6. The compliant mechanism for an end effector for grinding in an industrial robot according to claim 1, characterized in that: The bottom end of the rotating shaft (3) is fixedly connected to a connector (4), and the top end of the grinding head (6) is fixed with a mounting ring (5). The connector (4) and the mounting ring (5) are detachably connected.

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