Heavy-load robot joint structure

Abstract

The invention relates to the technical field of robots, in particular to a heavy-load robot joint structure which comprises a base, a screw hole, a rotating seat, a mounting frame, a large arm, a small arm and a first spring balance cylinder, the screw hole is formed in the surface of the base, the rotating seat is movably mounted at the top of the base, and the mounting frame is fixedly mounted on the upper surface of the rotating seat; the large arm is movably installed on the inner side of the installation frame, the small arm is movably installed on the large arm, the end, extending outwards, of the small arm is provided with a machine claw, and the number of the first spring balance cylinders is two. And then the stretching stroke of the small arm drive to the second spring balance cylinder is reduced, the situation that a spring in the second spring balance cylinder is excessively stretched is avoided, meanwhile, the driving torque can be reduced, the gravity center of the robot is adjusted when the small arm grabs and lifts the workpiece, and the stability of the robot is improved.

Description

Technical Field

[0001] The invention relates to the technical field of robots, in particular to a large-load robot joint structure. Background Art

[0002] The manipulator is the earliest industrial robot and also the earliest modern robot. The manipulator can imitate certain movements of human hands and arms to grasp, move objects or operate tools according to a fixed procedure. In order to reduce the driving torque of the robot and increase the robot's movement balance, balancing devices are often installed at the joints of the robot's upper and lower arms, thereby reducing the load on the robot during use and improving the balance of the robot. Among the existing balancing technologies, mass balancing method, spring balancing method, pneumatic or hydraulic balancing method and other technologies are usually used.

[0003] Among them, the spring balancing method achieves the balance of the robot arm by stretching the spring or compressing the spring, that is, when the robot does not grab the object, the spring achieves the balance of the robot arm by stretching. When the robot grabs the object, the spring continues to stretch to maintain the balance of the robot, thereby reducing or offsetting the load generated by the robot grabbing the object. However, the elastic force of the spring is uncontrollable. Within the elastic limit, the elastic force of the spring is proportional to the elongation of the spring. Once the elastic limit is exceeded, it will cause spring fatigue and damage to the spring, thereby affecting the robot's balancing effect and reducing working stability. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a large-load robot joint structure, which solves the problems raised in the above-mentioned background technology.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions: a large-load robot joint structure, including a base, a screw hole, a swivel, a mounting frame, a large arm, a small arm and a first spring balancing cylinder, the screw hole is opened on the surface of the base, the swivel is movably mounted on the top of the base, the mounting frame is fixedly mounted on the upper surface of the swivel, the large arm is movably mounted on the inner side of the mounting frame, the small arm is movably mounted on the large arm, and a machine claw is installed at one end extending outward, the first spring balancing cylinder is two in number and is located on both sides of the large arm, a first rotating shaft is fixedly mounted on one side of the top of the connecting rod on the first spring balancing cylinder, the first rotating shaft is movably mounted between the large arm, the bottom of the first spring balancing cylinder is movably mounted between the mounting frame, a following component is arranged on the swivel, the following component includes a servo motor, and the servo motor is fixedly mounted at the bottom of the swivel; A lead screw is fixedly mounted on the output shaft of the servo motor, a screw sleeve is spirally connected to the outer surface of the lead screw, sliders are fixedly mounted on both sides of the screw sleeve, a slide is movably mounted on the outer surface of the slider, and the slide is fixedly connected to the rotating seat; A counterweight is fixedly installed on one side of the screw sleeve, a second spring balancing cylinder is movably connected to the upper surface of the counterweight, a hydraulic rod is installed inside the second spring balancing cylinder, a connecting piece is movably installed on the output shaft of the hydraulic rod, and an end of the connecting piece away from the hydraulic rod is fixedly connected to the forearm; A load balancing component is arranged on the rotating seat, and the load balancing component is used to improve the load-bearing performance of the robot.

[0006] Optionally, the load balancing assembly includes a fixing frame, the number of the fixing frames is two, and the fixing frames are respectively located on both sides of the big arm, one end of the fixing frame is fixedly connected to the upper surface of the rotating seat, and the other end is fixedly connected to the running rail; One end of the inner cavity of the running rail is fixedly connected to a first balance spring, the other end of the first balance spring is fixedly connected to a power block, the power block is movably installed in the inner cavity of the running rail, and the top of the first spring balance cylinder connecting rod is fixedly connected to an electric push rod on the side away from the first rotating shaft, and the output shaft of the electric push rod corresponds to the initial position of the power block.

[0007] Optionally, the servo motor is provided with a counterweight assembly, the counterweight assembly includes a first rotating wheel, the first rotating wheel is fixedly sleeved on the outer surface of the servo motor output shaft, the outer surface of the first rotating wheel is transmission-connected with a transmission belt, and the side of the transmission belt away from the first rotating wheel is transmission-connected with a second rotating wheel; A gear is fixedly mounted on the bottom of the second rotating wheel, and the gear is movably mounted on the upper surface of the rotating seat. A gear ring is meshed on one side of the gear, and the gear ring is movably mounted on the upper surface of the rotating seat. A balancing block is fixedly mounted on the surface of the gear ring, and an adapting groove is opened on the surface of the balancing block. The adapting groove is adapted to the rotating seat, and the adapting groove and the rotating seat are movably mounted.

[0008] Optionally, a second rotating shaft is movably installed on both sides of the slide, a stress piece is fixedly sleeved on the outer surface of the second rotating shaft, a second balance spring is fixedly connected to the top of the stress piece, and a connecting plate is fixedly connected to the end of the second balance spring away from the stress piece, and the connecting plate is fixedly connected to the counterweight block.

[0009] Optionally, the initial position of the balancing block is in the middle of the side of the swivel seat, and the initial position of the screw sleeve is in the middle of the lead screw.

[0010] Optionally, the shape of the running rail is arc-shaped, and the inner track of the running rail is adapted to the operating track of the boom.

[0011] Optionally, a socket hole adapted to the output shaft of the electric push rod is provided on a side of the power block close to the electric push rod.

[0012] Optionally, a slide groove is provided on the inner side of the slide, and the slide groove is adapted to the slide.

[0013] The present invention provides a large-load robot joint structure, which has the following beneficial effects: 1. The large-load robot joint structure can make the second spring balance cylinder follow the movement of the forearm through the following component, thereby reducing the stretching stroke of the forearm drive on the second spring balance cylinder, avoiding excessive stretching of the spring in the second spring balance cylinder, and at the same time reducing the driving torque. When the forearm grabs and lifts the workpiece, the center of gravity of the robot is adjusted to improve the stability of the robot.

[0014] 2. The joint structure of the large-load robot can enable the power block to follow the drive of the big arm through the load balancing component, and stretch the first balance spring. After the forearm grabs the large-load workpiece, the tension of the first balance spring is used to balance the load generated by the large-load workpiece, thereby achieving additional balance of the big arm. By starting the hydraulic rod to pull the connecting piece, the end of the forearm away from the workpiece is pulled to achieve additional balance of the forearm, thereby achieving the purpose of reducing the additional driving torque after grabbing the workpiece.

[0015] 3. The joint structure of the large-load robot can flexibly adjust the position of the balance block through the counterweight assembly during the process of the forearm grasping and lifting the workpiece, thereby adjusting the center of gravity of the robot and further improving the stability of the robot. In combination with the stress piece and the second balance spring, the stress piece can press down the base during the process of grasping the workpiece, reducing the stress between the base and the fixing screws in the screw hole, and reducing the wear on the base. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The structure of the present invention is shown in FIG. Figure 1 ; Figure 2 The structure of the present invention is shown in FIG. Figure 2 ; Figure 3 The structure of the present invention is shown in FIG. Figure 3 ; Figure 4 It is a schematic diagram of the positional relationship between the counterweight assembly and the follower assembly of the present invention; Figure 5 It is a structural schematic diagram of the load balancing component of the present invention; Figure 6 For the present invention Figure 4 Schematic diagram of the structure with a partial enlargement at point A in the middle.

[0017] In the figure: 1. base; 11. screw hole; 12. swivel seat; 13. mounting frame; 14. upper arm; 15. lower arm; 16. first spring balancing cylinder; 17. first rotating shaft; 2. servo motor; 21. lead screw; 22. screw sleeve; 23. slider; 24. slide; 25. counterweight; 26. second spring balancing cylinder; 27. hydraulic rod; 28. connecting piece; 29. ​​slide; 3. fixing frame; 31. rail; 32. first balancing spring; 33. power block; 34. electric push rod; 4. first rotating wheel; 41. transmission belt; 42. second rotating wheel; 43. gear; 44. gear ring; 45. balancing block; 46. adapter groove; 5. second rotating shaft; 51. stress piece; 52. second balancing spring; 53. connecting plate. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0019] Example 1: Please refer to Figures 1 to 4 The present invention provides a technical solution: a large-load robot joint structure, including a base 1, a screw hole 11, a swivel seat 12, a mounting frame 13, a large arm 14, a small arm 15 and a first spring balancing cylinder 16, the screw hole 11 is opened on the surface of the base 1, the swivel seat 12 is movably mounted on the top of the base 1, the mounting frame 13 is fixedly mounted on the upper surface of the swivel seat 12, the large arm 14 is movably mounted on the inner side of the mounting frame 13, the small arm 15 is movably mounted on the large arm 14, and a machine claw is installed at one end extending outward, the first spring balancing cylinder 16 is two in number, and is located on both sides of the large arm 14, a first rotating shaft 17 is fixedly mounted on one side of the top of the connecting rod of the first spring balancing cylinder 16, the first rotating shaft 17 is movably mounted between the large arm 14, the bottom of the first spring balancing cylinder 16 is movably mounted between the mounting frame 13, a following component is arranged on the swivel seat 12, and the following component includes a servo motor 2, and the servo motor 2 is fixedly mounted at the bottom of the swivel seat 12; A lead screw 21 is fixedly mounted on the output shaft of the servo motor 2, a screw sleeve 22 is spirally connected to the outer surface of the lead screw 21, sliders 23 are fixedly mounted on both sides of the screw sleeve 22, a slide 24 is movably mounted on the outer surface of the slide 23, and the slide 24 is fixedly connected to the rotating seat 12; A slide groove 29 is provided on the inner side of the slide 24, and the slide groove 29 is adapted to the slide 24; A counterweight block 25 is fixedly installed on one side of the screw sleeve 22, and a second spring balancing cylinder 26 is movably connected to the upper surface of the counterweight block 25. A hydraulic rod 27 is installed inside the second spring balancing cylinder 26. A connecting piece 28 is movably installed on the output shaft of the hydraulic rod 27. One end of the connecting piece 28 away from the hydraulic rod 27 is fixedly connected to the arm 15. A load balancing component is provided on the swivel seat 12, and the load balancing component is used to improve the load-bearing performance of the robot.

[0020] Specifically, when in use, the base 1 needs to be fixed to the base through the screw hole 11 by using the fixing screw to complete the installation of the robot. When the robot is in a balanced state, the load of the small arm 15 itself is balanced by the tension provided by the second spring balance cylinder 26. When the robot starts to work, it first adjusts the direction through the swivel seat 12, and then the big arm 14 starts to flip. When the big arm 14 flips counterclockwise, its own balance is broken, but at the same time, it will pull the connecting rod on the first spring balance cylinder 16, so that the connecting rod stretches the spring, so as to use the tension of the spring to balance the load of the big arm 14 when it is working, thereby reducing the driving torque; When the upper arm 14 rotates, the lower arm 15 starts to rotate counterclockwise to grab the workpiece. After the upper arm 14 rotates, the lower arm 15 also rotates. At this time, the spring in the second spring balance cylinder 26 is in a re-stretched state. When the lower arm 15 rotates, the spring in the second spring balance cylinder 26 will be stretched again, which is easy to exceed the stretching limit, causing spring fatigue and affecting the performance of the second spring balance cylinder 26. At the same time, during the driving process of the lower arm 15, the driving torque needs to overcome the spring tension of the second spring balance cylinder 26, resulting in an increase in the driving torque. At this time, after the arm 15 is driven for one to two seconds, the spring in the second spring balance cylinder 26 is stretched for a distance, and then the system starts the servo motor 2 to drive the lead screw 21 to rotate, so that the lead screw 21 drives the screw sleeve 22, so that the screw sleeve 22 drives the counterweight 25 to rise, so that the second spring balance cylinder 26 moves with the arm 15, and then the stretching stroke of the arm 15 driving the second spring balance cylinder 26 is reduced, so as to avoid the spring in the second spring balance cylinder 26 from being overstretched, and at the same time, the driving torque can be reduced; Furthermore, when the forearm 15 is reset, the elastic force generated by the spring reset in the second spring balancing cylinder 26 can assist the forearm 15 in resetting. When the forearm 15 is reset to the position before the second spring balancing cylinder 26 is stretched again, the servo motor 2 is started again to reset the second spring balancing cylinder 26. When the forearm 15 is also reset, the forearm 15 is balanced again. Furthermore, when the forearm 15 needs to be lifted upward, the driving torque needs to overcome the gravity of the forearm 15. Before the forearm 15 recovers its balance, the power of the servo motor 2 needs to be increased so that the second spring balancing cylinder 26 descends faster than the lifting speed of the forearm 15, so that the spring in the second spring balancing cylinder 26 is stretched again, and the driving torque for lifting the forearm 15 is reduced again by using the tension provided by the spring. It should be noted that the stretching distance of the spring in the second spring balancing cylinder 26 must be controlled to avoid exceeding the stretching limit. More specifically, when the forearm 15 grasps the workpiece and rotates downward, and when the forearm 15 lifts the workpiece and moves upward, the center of gravity of the robot will lower and rise accordingly, and the opposite movement of the counterweight block 25 will balance the center of gravity of the robot and improve the stability of the robot.

[0021] Example 2: Please refer to Figures 1 to 5 The load balancing assembly includes a fixing frame 3, the number of the fixing frames 3 is two, and they are respectively located on both sides of the big arm 14, one end of the fixing frame 3 is fixedly connected to the upper surface of the rotating seat 12, and the other end is fixedly connected to the rail 31; One end of the inner cavity of the rail 31 is fixedly connected with a first balance spring 32, and the other end of the first balance spring 32 is fixedly connected with a power block 33. The power block 33 is movably installed in the inner cavity of the rail 31. The top of the connecting rod of the first spring balance cylinder 16 is fixedly connected with an electric push rod 34 on the side away from the first rotating shaft 17. The output shaft of the electric push rod 34 corresponds to the initial position of the power block 33. The shape of the rail 31 is arc-shaped, and the inner track of the rail 31 is adapted to the working track of the arm 14; A socket hole adapted to the output shaft of the electric push rod 34 is provided on one side of the power block 33 close to the electric push rod 34 .

[0022] On the basis of Example 1, when the small arm 15 grabs a heavy-load workpiece, the balance between the large arm 14 and the small arm 15 will be further destroyed, resulting in an increase in the driving torque; Among them, for the reduction of the torque of the upper arm 14, the workpiece load can be determined first. If a large-load workpiece is to be grabbed, the electric push rod 34 can be started before the upper arm 14 is driven, so that the electric push rod 34 is inserted into the power block 33 and is locked and fixed by screws. When the upper arm 14 is started, the first spring balance cylinder 16 is driven to rotate, so that the first spring balance cylinder 16 drives the electric push rod 34 to rotate, and the power block 33 can slide in the rail 31 and stretch the first balance spring 32. In this way, after the small arm 15 grabs the large-load workpiece, the tension of the first balance spring 32 can be used to balance the load generated by the large-load workpiece on the upper arm 14; The increased portion of the stretching of the first balance spring 32 caused by the driving torque will be offset by the first balance spring 32 when the upper arm 14 is reset, so that the overall torque generated by the stretching of the first balance spring 32 remains unchanged; Among them, in order to reduce the torque of the forearm 15, the present invention replaces the connecting rod on the second spring balancing cylinder 26 with a hydraulic rod 27. When the forearm 15 grabs a large-load workpiece, the hydraulic rod 27 is started to pull the connecting piece 28, thereby pulling the end of the forearm 15 away from the workpiece, thereby achieving additional balance of the forearm 15, and further achieving the purpose of reducing the driving torque.

[0023] Example 3: Please refer to Figure 1 and Figure 6 The servo motor 2 is provided with a counterweight assembly, which includes a first rotating wheel 4, which is fixedly sleeved on the outer surface of the output shaft of the servo motor 2, and the outer surface of the first rotating wheel 4 is transmission-connected with a transmission belt 41, and the side of the transmission belt 41 away from the first rotating wheel 4 is transmission-connected with a second rotating wheel 42; A gear 43 is fixedly mounted on the bottom of the second rotating wheel 42, and the gear 43 is movably mounted on the upper surface of the rotating seat 12. A gear ring 44 is meshed with one side of the gear 43, and the gear ring 44 is movably mounted on the upper surface of the rotating seat 12. A balancing block 45 is fixedly mounted on the surface of the gear ring 44. An adapting groove 46 is provided on the surface of the balancing block 45. The adapting groove 46 is adapted to the rotating seat 12, and the adapting groove 46 and the rotating seat 12 are movably mounted. The initial position of the balancing block 45 is located in the middle of the side of the rotating seat 12 , and the initial position of the screw sleeve 22 is located in the middle of the lead screw 21 .

[0024] On the basis of the above embodiment, when the small arm 15 grabs the load, due to the inclination of the large arm 14 and the small arm 15, plus the weight of the load, the center of gravity of the robot will shift toward the side of the grabbing workpiece, thereby causing the stress between the side of the base 1 away from the workpiece and the fixing screw in the screw hole 11 to increase, thereby affecting the fixing position of the base 1; During the grasping process of the forearm 15, the start of the servo motor 2 will drive the first rotating wheel 4 to rotate, so that the first rotating wheel 4 drives the transmission belt 41, so that the transmission belt 41 drives the second rotating wheel 42 to rotate, and the second rotating wheel 42 can drive the gear 43 to rotate, so that the gear 43 drives the ring gear 44 to rotate, and the ring gear 44 can drive the balancing block 45 to rotate, so that the balancing block 45 rotates to the side of the rotating seat 12 away from the workpiece, so as to achieve the balance of the center of gravity of the robot and reduce the wear of the fixed position of the base 1; Similarly, when the forearm 15 is lifted, the balance block 45 will rotate to the side of the swivel base 12 close to the workpiece, and the center of gravity can be flexibly adjusted when the workpiece grasped by the forearm 15 is in different positions.

[0025] Example 4: Please refer to Figures 1 to 4 A second rotating shaft 5 is movably installed on both sides of the slide 24, a stress piece 51 is fixedly sleeved on the outer surface of the second rotating shaft 5, a second balance spring 52 is fixedly connected to the top of the stress piece 51, and a connecting plate 53 is fixedly connected to the end of the second balance spring 52 away from the stress piece 51, and the connecting plate 53 is fixedly connected to the counterweight block 25.

[0026] On the basis of Example 3, when the forearm 15 grabs the workpiece, the second spring balance cylinder 26 will rise. When the second spring balance cylinder 26 rises, it will pull the second balance spring 52, so that the second balance spring 52 pulls the upper end of the stress piece 51 upward, thereby causing the lower end of the stress piece 51 to move downward, and then contact the base 1, and press down on the base 1, further reducing the stress between the base 1 and the fixing screw in the screw hole 11, and reducing the wear on the base 1.

[0027] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A large-load robot joint structure, comprising a base (1), a screw hole (11), a swivel seat (12), a mounting frame (13), a large arm (14), a small arm (15) and a first spring balancing cylinder (16), wherein the screw hole (11) is opened on the surface of the base (1), the swivel seat (12) is movably mounted on the top of the base (1), the mounting frame (13) is fixedly mounted on the upper surface of the swivel seat (12), the large arm (14) is movably mounted on the inner side of the mounting frame (13), the small arm (15) is movably mounted on the large arm (14), and a machine claw is mounted on one end of the small arm (15) extending outward, and the number of the first spring balancing cylinders (16) is two and they are located on both sides of the large arm (14), characterized in that: A first rotating shaft (17) is fixedly mounted on one side of the top of the connecting rod of the first spring balancing cylinder (16); the first rotating shaft (17) is movably mounted between the upper arm (14); the bottom of the first spring balancing cylinder (16) is movably mounted between the mounting frame (13); a following component is arranged on the rotating seat (12); the following component comprises a servo motor (2); and the servo motor (2) is fixedly mounted on the bottom of the rotating seat (12); A lead screw (21) is fixedly mounted on the output shaft of the servo motor (2); a screw sleeve (22) is spirally connected to the outer surface of the lead screw (21); sliders (23) are fixedly mounted on both sides of the screw sleeve (22); a slide bracket (24) is movably mounted on the outer surface of the slider (23); and the slide bracket (24) is fixedly connected to the rotating seat (12); A counterweight block (25) is fixedly mounted on one side of the screw sleeve (22); a second spring balancing cylinder (26) is movably connected to the upper surface of the counterweight block (25); a hydraulic rod (27) is mounted inside the second spring balancing cylinder (26); a connecting piece (28) is movably mounted on the output shaft of the hydraulic rod (27); an end of the connecting piece (28) away from the hydraulic rod (27) is fixedly connected to the forearm (15); A load balancing component is provided on the rotating seat (12), and the load balancing component is used to improve the load-bearing performance of the robot.

2. A large load robot joint structure according to claim 1, characterized in that: The load balancing assembly comprises a fixing frame (3), the fixing frames (3) being two in number and respectively located on both sides of the upper arm (14), one end of the fixing frame (3) being fixedly connected to the upper surface of the rotating seat (12), and the other end being fixedly connected to a running rail (31); One end of the inner cavity of the travel rail (31) is fixedly connected to a first balance spring (32), the other end of the first balance spring (32) is fixedly connected to a power block (33), the power block (33) is movably mounted in the inner cavity of the travel rail (31), and a side of the top of the connecting rod of the first spring balance cylinder (16) away from the first rotating shaft (17) is fixedly connected to an electric push rod (34), the output shaft of the electric push rod (34) corresponds to the initial position of the power block (33).

3. A large load robot joint structure according to claim 2, characterized in that: The servo motor (2) is provided with a counterweight assembly, the counterweight assembly comprising a first rotating wheel (4), the first rotating wheel (4) being fixedly sleeved on the outer surface of the output shaft of the servo motor (2), the outer surface of the first rotating wheel (4) being drivingly connected to a transmission belt (41), and the side of the transmission belt (41) away from the first rotating wheel (4) being drivingly connected to a second rotating wheel (42); A gear (43) is fixedly mounted on the bottom of the second rotating wheel (42), and the gear (43) is movably mounted on the upper surface of the rotating seat (12); a gear ring (44) is meshed on one side of the gear (43), and the gear ring (44) is movably mounted on the upper surface of the rotating seat (12); A balancing block (45) is fixedly mounted on the surface of the gear ring (44), and an adapting groove (46) is provided on the surface of the balancing block (45). The adapting groove (46) is adapted to the rotating seat (12), and the adapting groove (46) and the rotating seat (12) are movably mounted.

4. A large load robot joint structure according to claim 3, characterized in that: A second rotating shaft (5) is movably mounted on both sides of the slide (24); a stress piece (51) is fixedly sleeved on the outer surface of the second rotating shaft (5); a second balancing spring (52) is fixedly connected to the top end of the stress piece (51); an end of the second balancing spring (52) away from the stress piece (51) is fixedly connected to a connecting plate (53); and the connecting plate (53) is fixedly connected to the counterweight (25).

5. A large-load robot joint structure according to claim 4, characterized in that: The initial position of the balancing block (45) is located in the middle of the side of the rotating seat (12), and the initial position of the screw sleeve (22) is located in the middle of the lead screw (21).

6. A large-load robot joint structure according to claim 5, characterized in that: The shape of the running rail (31) is arc-shaped, and the inner track of the running rail (31) is adapted to the operating track of the upper arm (14).

7. A large-load robot joint structure according to claim 6, characterized in that: A socket hole adapted to the output shaft of the electric push rod (34) is provided on a side of the power block (33) close to the electric push rod (34).

8. A large-load robot joint structure according to claim 7, characterized in that: A slide groove (29) is provided on the inner side of the slide bracket (24), and the slide groove (29) is adapted to fit the slide bracket (24).

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