Connecting rod type mechanical arm with multi-direction limiting function

Abstract

The invention belongs to the technical field of mechanical equipment, and relates to a connecting rod type mechanical arm with multi-directional limiting, which comprises a base, a mechanical arm structure and a connecting rod mechanism, and the connecting rod mechanism comprises a driving rod and a bottom connecting rod; the limiting unit comprises a boss and a sunken part, the boss is arranged on the base and located below the bottom connecting rod, a through groove is formed in the upper portion of the boss in the length direction of the bottom connecting rod, and the sunken part is arranged at the position, close to the through groove, of the lower portion of the bottom connecting rod. Displacement of the bottom connecting rod in the width direction, the length direction and the vertical direction can be limited, the mechanical arm is precisely limited in multiple directions during movement, meanwhile, the bottom connecting rod is in point contact with the through groove, relative friction between the bottom connecting rod and the through groove is reduced, abrasion of the bottom connecting rod is reduced, the limiting precision is improved, and meanwhile, the mechanical arm is prevented from being damaged. And the rotating angle of the mechanical arm can be limited, so that the mechanical arm rotates and operates within a specified range.

Description

Technical Field

[0001] The present invention belongs to the technical field of mechanical equipment and relates to a link-type robotic arm with multi-directional limiting means. Background Art

[0002] The limiting structure plays an extremely important role in mechanical design, product structure design, manufacturing, and its use process. The application of the limiting structure is a key point during the movement of the moving mechanism. In a link mechanism robotic arm, to avoid interference between the link mechanism and other components during movement, it is necessary to clarify the range, direction, and accuracy of the movement that needs to be restricted according to the type, movement mode, and working requirements of the link mechanism, and design a suitable limiting structure; compared with sensor limiting, the mechanical limiting structure is simpler and has a lower cost.

[0003] Currently, the existing limiting structure of a robotic arm includes a fixed stop block and a link mechanism. When the link mechanism moves to the position of the stop block, the stop block prevents it from moving further to achieve the limiting purpose. However, since the fixed stop block can only limit in one direction, it cannot ensure the precise multi-directional limiting of the robotic arm during movement. Moreover, during long-term use, the accuracy of the limiting structure and the moving link decreases due to wear and other reasons, resulting in inaccurate limiting, causing the robotic arm to deviate at multi-directional angles during movement and affecting the normal use of the robotic arm. Summary of the Invention

[0004] The purpose of the present invention is to provide a link-type robotic arm with multi-directional limiting means, which can not only perform precise limiting in multiple directions but also reduce the reduction in accuracy caused by wear and other reasons between the limiting structure and the moving link during use, improving the accuracy of limiting.

[0005] To achieve the above purpose, the specific technical solution of a link-type robotic arm with multi-directional limiting means provided by the present invention is as follows:

[0006] A link-type robotic arm with multi-directional limiting means, including a base. An arm structure and a link mechanism are arranged on the upper part of the base. The link mechanism includes a driving rod and a bottom link. The driving rod is arranged between the arm structure and the base. One end of the driving rod is rotatably connected to the arm structure. The bottom link is arranged between the other end of the driving rod and the base. One end of the bottom link is rotatably connected to the other end of the driving rod. It is characterized in that it further includes:

[0007] A limiting unit. The limiting unit includes a boss and a recess. The boss is arranged on the base and is located below the bottom link. A through groove is opened along the length direction of the bottom link on the upper part of the boss. The recess is arranged at a position on the lower part of the bottom link close to the through groove;

[0008] When the bottom link swings downward into the through slot, the displacement of the bottom link in the vertical direction is restricted by the cooperation between the bottom link and the bottom of the through slot, the displacement of the bottom link in its width direction is restricted by the cooperation between the bottom link and the side wall of the through slot, and the displacement of the bottom link in its length direction is restricted by the cooperation between the recessed portion and the through slot.

[0009] The features of the present invention also lie in:

[0010] Among them, the recessed portion is a smooth arc surface along the length direction of the bottom link.

[0011] Among them, the positions where the inner walls on both sides of the through slot are connected to the upper surface of the convex platform are both smooth arc surfaces.

[0012] Among them, a rotating platform is provided at the lower part of the base. A circular hole is provided at a position near the base on the upper part of the rotating platform. A turntable is horizontally arranged in the circular hole. The upper part of the turntable is connected to the lower part of the base. A second driving structure is provided at the lower part of the turntable for driving the turntable to rotate. A first convex block is provided at a position on the inner wall of the circular hole near the turntable. A second convex block is provided at the edge position of the turntable. The second convex block can touch the first convex block during the rotation of the turntable.

[0013] Among them, the robotic arm structure includes:

[0014] The boom, arranged above the base;

[0015] The forearm, vertically arranged between the boom and the base. The lower end of the forearm is located inside the base and is connected to a third driving structure. The upper end of the forearm is rotatably connected to the lower part of the boom. The upper end of the active rod is rotatably connected to the end of the boom near the forearm.

[0016] Among them, the link mechanism further includes:

[0017] The tripod, vertically arranged. The tripod has three ends and all three ends are in the same vertical plane. The first end of the tripod is rotatably connected to a position on the side of the boom near the forearm;

[0018] The first driven rod, vertically arranged between the tripod and the base. The upper end of the first driven rod is rotatably connected to the second end of the tripod. The lower end of the first driven rod is rotatably connected to the base;

[0019] The second driven rod, arranged on one side of the boom near the tripod. One end of the second driven rod is rotatably connected to the third end of the tripod. The other end of the second driven rod is rotatably connected to the rudder engine compartment.

[0020] Among them, both the robotic arm structure and the link mechanism are made of engineering plastics.

[0021] A link-type robotic arm with multi-directional limit of the present invention has the following advantages:

[0022] First, through the cooperation of the bottom link, the boss, the through groove and the recess, the displacement of the bottom link in its width direction, its length direction and the vertical direction can be restricted, and precise limit in multiple directions can be carried out during the movement of the robotic arm. At the same time, the bottom link is in point contact with the through groove, reducing the relative friction between the bottom link and a groove, thereby reducing the wear of the bottom link, improving the accuracy of the limit, and ensuring the normal use of the robotic arm.

[0023] Second, through the cooperation of the rotating platform, the turntable, the first convex block and the second convex block, the further rotation of the second convex block can be blocked by the first convex block, and the rotation angle of the robotic arm can be limited, so that the rotation angle of the robotic arm does not exceed 330°. Thus, the robotic arm rotates and operates within the specified range, and there will be no excessive rotation or endless rotation due to operation errors or other mistakes, further ensuring the normal use of the robotic arm. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic diagram of the overall structure of the present invention;

[0025] Figure 2 is an enlarged schematic diagram of the bottom link and the boss in the present invention;

[0026] Figure 3 is a top view schematic diagram of the turntable and the rotating platform of the present invention.

[0027] REFERENCE NUMERALS:

[0028] 1, base; 2, first servo; 3, second servo; 4, large arm; 5, small arm; 6, active rod; 7, tripod; 8, bottom link; 9, boss; 10, through groove; 11, recess; 12, first driven rod; 13, second driven rod; 14, round hole; 15, turntable; 16, third servo; 17, first convex block; 18, second convex block; 19, rotating platform; 20, servo cabin. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] Next, the technical solutions in the present application will be clearly and elaborately described with reference to the drawings. Among them, in the description of the embodiments of the present application, unless otherwise specified, " / " means "or". For example, A / B can mean A or B: "and / or" in the text is only a description of the relationship between associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of the present application, "a plurality of" means two or more than two. The following terms "first" and "second" are only for descriptive purposes and cannot be construed as implying or indicating relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features.

[0030] As shown in Figure 1 , Figure 2 the present invention provides a link-type robotic arm with multi-directional limiting. There is a base 1, and an arm structure and a link mechanism are arranged on the upper part of the base 1. The link mechanism includes a driving rod 6, a bottom link 8 and a limiting unit. The driving rod 6 is arranged between the arm structure and the base 1. One end of the driving rod 6 is rotatably connected to the arm structure. The bottom link 8 is arranged between the other end of the driving rod 6 and the base 1. One end of the bottom link 8 is rotatably connected to the other end of the driving rod 6. A first driving structure is connected to one end of the bottom link 8. The first driving structure is used to drive the bottom link 8 to swing up and down, so as to drive the robotic arm through the driving rod 6. The limiting unit includes a boss 9 and a recess 11. The boss 9 is arranged on the base 1 and is located below the bottom link 8. A through groove 10 is opened along the length direction of the bottom link 8 on the upper part of the boss 9. The recess 11 is arranged at a position on the lower part of the bottom link 8 close to the through groove 10. When the bottom link 8 swings downward and enters the through groove 10, the displacement of the bottom link 8 in the vertical direction is restricted by the cooperation between the bottom link 8 and the bottom of the through groove 10. The displacement of the bottom link 8 in its width direction is restricted by the cooperation between the bottom link 8 and the side wall of the through groove 10. The displacement of the bottom link 8 in its length direction is restricted by the cooperation between the recess 11 and the through groove 10. Thus, through the cooperation between the bottom link 8 and the limiting unit, the displacement of the bottom link 8 in its width direction, its length direction and the vertical direction can be restricted, and precise multi-directional limiting can be carried out on the robotic arm during movement. At the same time, the bottom link 8 is in point contact with the through groove 10, reducing the relative friction between the bottom link 8 and the through groove 10, thereby reducing the wear of the bottom link 8 and improving the limiting accuracy, ensuring the normal use of the robotic arm.

[0031] As shown in Figure 2 the recess 11 is a smoothly transitional arc surface along the length direction of the bottom link 8, reducing the relative friction between the bottom link 8 and the boss 9, thereby reducing the wear of the boss 9 and the bottom link 8, and further improving the limiting accuracy.

[0032] As shown in Figure 2 the positions where the inner walls on both sides of the through groove 10 are connected to the upper surface of the boss 9 are both smoothly transitional arc surfaces. While limiting the bottom link 8, it enables the bottom link 8 to smoothly enter the through groove 10 and plays a guiding role for the bottom link 8.

[0033] As shown in Figure 1 , Figure 3As shown in the figure, a rotating table 19 is provided at the lower part of the base 1. A circular hole 14 is opened at the upper part of the rotating table 19 near the base 1. A turntable 15 is horizontally arranged in the circular hole 14. The upper part of the turntable 15 is connected to the lower part of the base 1. A second driving structure is arranged at the lower part of the turntable 15 and is used to drive the turntable 15 to rotate. A first convex block 17 is arranged at the inner wall of the circular hole 14 near the turntable 15. A second convex block 18 is arranged at the edge position of the turntable 15. The second convex block 18 can touch the first convex block 17 during the rotation of the turntable 15. Initially, the first convex block 17 is at the 0° position and the second convex block 18 is at the 180° position, that is, the first convex block 17 and the second convex block 18 are opposite to each other. The second driving structure drives the turntable 15 to rotate, and the turntable 15 drives the robotic arm structure and the connecting rod mechanism to rotate. During the rotation of the turntable 15 driving the second convex block 18 in the circular hole 14, the second convex block 18 can contact the first convex block 17. The first convex block 17 is of an arc structure with a central angle of 30°. By blocking the further rotation of the second convex block 18 with the first convex block 17, the rotation angle of the turntable 15 will not exceed 330°, so that the turntable 15 rotates and operates within the specified range, and there will be no excessive rotation or endless rotation due to operation errors or other mistakes, which is also beneficial to the debugging during the assembly of the second driving structure.

[0034] As Figure 1 shown in the figure, the robotic arm structure includes a large arm 4 and a small arm 5. The large arm 4 is arranged above the base 1. The small arm 5 is vertically arranged between the large arm 4 and the base 1. The lower end of the small arm 5 is located inside the base 1 and is connected to a third driving structure, which is used to drive the small arm 5 to swing back and forth. The upper end of the small arm 5 is rotatably connected to the lower part of the large arm 4. The upper end of the active rod 6 is rotatably connected to the end of the large arm 4 close to the small arm 5, so as to drive the large arm 4 to swing up and down by the up and down movement of the active rod 6 and adjust the angle between the large arm 4 and the small arm 5.

[0035] As Figure 1 shown in the figure, the connecting rod mechanism further includes a tripod 7, a first driven rod 12 and a second driven rod 13. The tripod 7 is vertically arranged. The tripod 7 has three ends and all three ends are in the same vertical plane. The first end of the tripod 7 is rotatably connected to the side of the large arm 4 close to the small arm 5. The first driven rod 12 is vertically arranged between the tripod 7 and the base 1. The upper end of the first driven rod 12 is rotatably connected to the second end of the tripod 7. The lower end of the first driven rod 12 is rotatably connected to the base 1. The second driven rod 13 is arranged on the side of the large arm 4 close to the tripod 7. One end of the second driven rod 13 is rotatably connected to the third end of the tripod 7, and the other end of the second driven rod 13 is rotatably connected to the rudder engine cabin 20.

[0036] As Figure 1 、 Figure 2As shown in the figure, the first driving structure is the first servo motor 2. The first servo motor 2 is arranged on the base 1 and is close to the bottom connecting rod 8. The output end of the first servo motor 2 is connected to the end of the bottom connecting rod 8. The second driving structure is the second servo motor 3. The second servo motor 3 is arranged inside the rotating platform and is located below the turntable 15. The output end of the second servo motor 3 is connected to the lower part of the turntable 15. The third driving structure is the third servo motor 16. The third servo motor 16 is arranged on the base 1 and is close to the lower end of the small arm 5. The output end of the third servo motor 16 is connected to the lower end of the small arm 5.

[0037] Among them, the height of the convex platform 9 is 10 mm, the thickness of the convex platform 9 is 2.2 mm, the depth of the through groove 10 is 2.5 mm, the width of the through groove 10 is 8 mm, and the arc length of the concave part 11 is 9 mm and the radius is 10 mm. During the movement of the robotic arm, when reaching the limit height, the through groove 10 just abuts against the midpoint of the arc of the concave part 11. Through the setting of the 2.5 mm depth of the through groove, when the bottom connecting rod 8 abuts against the through groove 10, the small arm 5 and the base 1 just form an angle of nearly 90°. At this time, the large arm 4 and the small arm 5 also nearly form an angle of 90°. Such dimensional values will make the robotic arm in a horizontal state with the ground at the highest point, making the preliminary debugging of the first servo motor 2 and the third servo motor 16 more convenient and accurate during product assembly, and the robotic arm is also more stable and smooth during movement.

[0038] Among them, a fourth servo motor is arranged inside the servo motor cabin 20. A cylinder is arranged at the output end of the fourth servo motor. There is a suction nozzle at the lower part of the cylinder. The suction nozzle is connected to an air pump through a hose. A solenoid valve is arranged on the hose. The fourth servo motor is used to drive the cylinder and the lower suction nozzle to rotate. The air pump provides suction for the suction nozzle to suck objects. A camera is arranged on one side of the servo motor cabin 20 away from the large arm 4.

[0039] As Figure 1 shown, both the robotic arm structure and the connecting rod mechanism are made of engineering plastics, making the robotic arm structure and the connecting rod mechanism have buffering performance. When the concave part 11 contacts the convex platform 9, it can play a certain buffering effect, further reducing the wear of the convex platform 9 and the bottom connecting rod 8.

[0040] Working principle: When in use, start the second servo motor 3. The second servo motor 3 drives the turntable 15 to rotate. The turntable 15 drives the robotic arm structure to rotate. At the same time, when the turntable 15 drives the second convex block 18 to rotate in the round hole 14, it can contact the first convex block 17. By the first convex block 17 blocking the further rotation of the second convex block 18, the rotation angle of the turntable 15 will not exceed 330°. Thus, the rotation angle of the robotic arm structure is limited by the first convex block 17 and the second convex block 18.

[0041] Start the first servo 2. The first servo 2 drives the bottom link 8 to swing up and down. The bottom link 8 drives the active rod 6 to move up and down. The active rod 6 drives the boom 4 to swing up and down, adjusting the angle between the boom 4 and the forearm 5. When the bottom link 8 swings downward into the through slot 10, the displacement of the bottom link 8 in its width direction and vertical direction is restricted by the through slot 10, thereby restricting the displacement of the boom 4 in the left-right direction and vertical direction. At the same time, after the bottom link 8 enters the through slot 10, the recessed portion 11 at its lower part is stuck in the boss 9, restricting the displacement of the bottom link 8 in its length direction, thereby restricting the displacement of the boom 4 in the front-back direction.

[0042] Start the third servo 16. The third servo 16 drives the first driven rod 12 to swing back and forth. The first driven rod 12 drives the boom 4 and the forearm 5 to swing back and forth through the tripod 7, adjusting the angle between the forearm 5 and the base 1.

[0043] It can be understood that the present invention is described through some embodiments. As is known to those skilled in the art, without departing from the spirit and scope of the present invention, various changes or equivalent replacements can be made to these features and embodiments. Additionally, under the teachings of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application belong to the scope protected by the present invention.

Claims

1. A linkage type mechanical arm with multi-directional limit, comprising a base (1), a mechanical arm structure and a linkage mechanism being arranged on the upper part of the base (1), the linkage mechanism comprising an active rod (6) and a bottom linkage (8), the active rod (6) being arranged between the mechanical arm structure and the base (1), one end of the active rod (6) being rotatably connected to the mechanical arm structure, the bottom linkage (8) being arranged between the other end of the active rod (6) and the base (1), one end of the bottom linkage (8) being rotatably connected to the other end of the active rod (6), characterized in that: Also includes: A limiting unit, the limiting unit comprising a boss (9) and a recessed portion (11), the boss (9) being arranged on the base (1) and located below the bottom connecting rod (8), a through slot (10) being provided on the upper portion of the boss (9) along the length direction of the bottom connecting rod (8), and the recessed portion (11) being arranged at a position close to the through slot (10) at the lower portion of the bottom connecting rod (8); When the bottom connecting rod (8) swings downward and enters the through slot (10), the bottom connecting rod (8) is limited in displacement in the vertical direction by the cooperation between the bottom connecting rod (8) and the bottom of the through slot (10), the bottom connecting rod (8) is limited in displacement in the width direction by the cooperation between the bottom connecting rod (8) and the side wall of the through slot (10), and the bottom connecting rod (8) is limited in displacement in the length direction by the cooperation between the recessed portion (11) and the through slot (10).

2. The connecting rod type mechanical arm with multi-directional limit according to claim 1, characterized in that: The recessed portion (11) is a smoothly transitioned arc-shaped surface along the length direction of the bottom connecting rod (8).

3. The connecting rod type mechanical arm with multi-directional limit according to claim 1, characterized in that: The positions where the inner walls on both sides of the through groove (10) connect with the upper surface of the boss (9) are both arc-shaped surfaces with smooth transitions.

4. The connecting rod type mechanical arm with multi-directional limit according to claim 1, characterized in that: A rotating platform (19) is arranged at the lower part of the base (1); a circular hole (14) is provided at the upper part of the rotating platform (19) near the base (1); a rotating disk (15) is arranged horizontally in the circular hole (14); the upper part of the rotating disk (15) is connected to the lower part of the base (1); a second driving structure is arranged at the lower part of the rotating disk (15); the second driving structure is used to drive the rotating disk (15) to rotate; a first protrusion (17) is arranged at the inner wall of the circular hole (14) near the rotating disk (15); a second protrusion (18) is arranged at the edge of the rotating disk (15); the second protrusion (18) can touch the first protrusion (17) as the rotating disk (15) rotates.

5. The connecting rod type mechanical arm with multi-directional limit according to claim 1, characterized in that: The mechanical arm structure comprises: A large arm (4) is arranged above the base (1); The forearm (5) is vertically arranged between the upper arm (4) and the base (1); the lower end of the forearm (5) is located in the base (1) and is connected to a third driving structure; the upper end of the forearm (5) is rotatably connected to the lower part of the upper arm (4); and the upper end of the active rod (6) is rotatably connected to the end of the upper arm (4) close to the forearm (5).

6. The connecting rod type mechanical arm with multi-directional limit according to claim 5, characterized in that: The connecting rod mechanism also includes: A tripod (7) is arranged vertically, the tripod (7) has three ends and the three ends are all in the same vertical plane, and the first end of the tripod (7) is rotatably connected to the side of the upper arm (4) near the lower arm (5); A first driven rod (12) is vertically arranged between the tripod (7) and the base (1), wherein the upper end of the first driven rod (12) is rotatably connected to the second end of the tripod (7), and the lower end of the first driven rod (12) is rotatably connected to the base (1); The second driven rod (13) is arranged on a side of the big arm (4) close to the tripod (7), one end of the second driven rod (13) is rotatably connected to the third end of the tripod (7), and the other end of the second driven rod (13) is rotatably connected to the steering gear cabin (20).

7. The connecting rod type mechanical arm with multi-directional limit according to claim 1, characterized in that: The mechanical arm structure and the connecting rod mechanism are both made of engineering plastics.

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