Four-branch-chain high-speed parallel manipulator

Abstract

The invention relates to a four-branch-chain high-speed parallel manipulator which comprises a base and further comprises a fixing plate, branch chains and a movable platform. The four branch chains are located between the base and the fixing plate, and the movable platform is arranged between the output ends of the branch chains. And the movable platform is square. Three-dimensional translation and vertical rotation of the tail end of the mechanical arm are achieved based on the four branch chains, the structure is simple, and movement is reliable; a single-platform movable platform mode is adopted, so that materials are saved, and a complicated transmission device is not included; moving parts are light in weight, high-speed and high-acceleration dynamic performance can be achieved conveniently, and moving precision and stability are high.

Description

Technical Field

[0001] The present invention relates to the technical field of parallel robots, especially a four-link four-degree-of-freedom high-speed parallel manipulator. Background Art

[0002] In today's society, high-speed parallel robots have been successfully applied to the automated production lines in industries such as light industry, food, logistics, medicine, and electronics for high-speed handling, packaging, sorting, etc. of various light, small, scattered materials. Compared with traditional serial robots, high-speed parallel robots can achieve high-speed and high-acceleration movements that serial configuration robots cannot reach because the driving devices can be arranged on the frame and the main and driven arms can be made of lightweight carbon fiber rods, making them the preferred equipment for the automated production lines in the above industries.

[0003] Currently, the most widely used robot is the Delta robot. The traditional Delta robot includes three identical R-(SS)2 links and can only achieve three-dimensional translational motion in space. If the end effector is to rotate about the normal of the moving platform, a UPU link needs to be added between the static and moving platforms of the robot. However, since the UPU link works at the edge of the working space for a long time, the wear is relatively serious, which will inevitably affect the lifespan of the above-mentioned manipulator. Summary of the Invention

[0004] Technical Problems to be Solved by the Invention Currently, to achieve the rotation of the end effector about the normal of the moving platform, a UPU link needs to be added between the static and moving platforms of the robot. Since the UPU link works at the edge of the working space for a long time, the wear is relatively serious, which will affect the lifespan of the above-mentioned manipulator.

[0005] Technical Solutions for Solving the Technical Problems Other advantageous and partially inventive embodiments and extended designs of the present invention are described in the following description.

[0006] A four-link high-speed parallel manipulator includes a base, and also includes a fixing plate, links, and a moving platform; Four links are provided and located between the base and the fixing plate, and the moving platform is arranged between the output ends of the links; The moving platform is square.

[0007] Preferably, the links are evenly distributed in a "circumferential" or "square" array between the base and the fixing plate.

[0008] Preferably, the link includes: A motor, arranged on the upper part of the fixing plate, and a lead screw is provided at its output end, and the lead screw is located between the fixing plate and the base; The guide rod is arranged between the base and the fixed plate and on one side of the lead screw. The moving plate is arranged outside the lead screw, and a nut seat matching the lead screw is arranged on its end face.

[0009] Preferably, the motor and the lead screw are driven by a coupling and / or a speed reducer.

[0010] Preferably, a groove is arranged on the inner wall of the through hole of the moving plate corresponding to the guide rod, and a protrusion matching the groove is arranged on the outer wall of the guide rod.

[0011] Preferably, the branch chain further includes: The driving rods, two in number, are rotatably installed on the upper and lower end faces of the moving plate through the first connecting pieces. The driven rods, two in number, are rotatably installed on the upper and lower end faces of the moving platform through the second connecting pieces. The rod group connecting piece is arranged at the connection of the driving rod and the driven rod, and both the driving rod and the driven rod are rotatably connected to the rod group connecting piece.

[0012] Preferably, the rod group connecting piece includes two parallel support plates and two rotating shafts arranged between the support plates; The end of each driving rod and driven rod is rotatably connected to the outer wall of the corresponding rotating shaft.

[0013] Preferably, the two driving rods and the two driven rods are parallel and coplanar.

[0014] Preferably, each driven rod included in each branch chain is rotatably connected to a vertex of the moving platform, and the extension line of its axis points to another vertex adjacent to the vertex.

[0015] Preferably, an actuator is arranged on the end face of the moving platform.

[0016] Effects of the invention Based on 4 branch chains, three-dimensional translation and vertical rotation of the end of the manipulator are realized, with simple structure and reliable movement; Adopting the moving platform mode of a single platform, materials are saved and there is no complex transmission device; 3. The moving parts are light in weight, facilitating the realization of high-speed and high-acceleration dynamic performance, and having high movement accuracy and stability. Description of the drawings

[0017] The embodiments of the present invention will be elaborated in detail below according to the drawings. In the drawings: Figure 1 is the first structural view of the present invention; Figure 2 is the second structural view of the present invention; Figure 3 is the first structural view of the hidden fixed plate of the present invention; Figure 4 is the top view of the hidden fixed plate of the present invention; Figure 5 is the structural view of the branch chain included in the present invention; Figure 6 above-mentioned Figure 4 partial enlarged view of "A" in; Figure 7 is the side view of the branch chain included in the present invention; Figure 8 is the schematic diagram of the first working state (translation) of the present invention.

[0018] Figure 9 is the schematic diagram of the second working state (translation) of the present invention.

[0019] Figure 10 is the schematic diagram of the third working state (vertical) of the present invention.

[0020] Description of reference numerals Base; 101, Fixed plate; 2, Motor; 201, Lead screw; 202, Guide rod; 202-1, Groove; 3, Moving plate; 301, First connecting member; 302, Active rod; 303, Rod group connecting member; 304, Driven rod; 305, Second connecting member; 4, Moving platform; 401, Actuator. Detailed implementation manners

[0021] Hereinafter, a four-branch-chain high-speed parallel manipulator as an embodiment of the present invention will be described with reference to the accompanying drawings.

[0022] Please refer to Figures 1 - 10 shown, a four-branch-chain high-speed parallel manipulator includes a base 1, a fixed plate 101, a branch chain, and a moving platform 4; Four branch chains are provided, and the branch chains are located between the base 1 and the fixed plate 101, and are distributed in a "circumference" or "square" array, and the moving platform 4 is arranged between the output ends of the branch chains; An actuator 401 is provided on the lower end surface of the moving platform 4; Specifically, the actuator 401 is set as a gripper, an electromagnet or a suction cup; The branch chain includes: A motor 2, which is arranged on the upper part of the fixed plate 101, and its output end penetrates through the fixed plate 101 and points to the base 1; A lead screw 201 is rotatably installed between the fixed plate 101 and the base 1; Specifically, the lead screw 201 is driven by the output end of the motor 2 through a coupling and / or a speed reducer; More specifically, the motor 2, the coupling, and the speed reducer are all arranged on the fixing plate 101 to reduce the mass of the moving components (the moving platform 4, the driving rod 302, the driven rod 304, the rod group connecting piece 303, the first connecting piece 301, and the second connecting piece 305) and improve the dynamic performance. The guiding rod 202 is arranged between the base 1 and the fixing plate 101 and on one side of the lead screw 201, and the axis of the guiding rod 202 is parallel to the axis of the lead screw 201. The moving plate 3 is arranged outside the lead screw 201. Specifically, through holes corresponding to the lead screw 201 and the guiding rod 202 are provided through the moving plate 3. On one side of the through hole corresponding to the lead screw 201, a nut seat matching the lead screw 201 is provided. On the inner wall of the through hole corresponding to the guiding rod 202, a groove 202-1 is provided. Specifically, a protrusion matching the groove 202-1 is provided on the outer wall of the guiding rod 202. During the use process, due to the limitation of the guiding rod 202 and the through holes on the moving plate 3, the moving plate 3 cannot rotate. The output of the motor 2 drives the lead screw 201 to rotate. Based on the lead screw-nut transmission principle, the moving plate 3 is driven to perform a linear displacement along the axis of the lead screw 201 on the outer wall of the lead screw 201. Through the cooperation of the groove and the protrusion, the moving plate is restricted to move only linearly along the axial direction of the lead screw, avoiding deflection friction and significantly reducing the wear of the sliding contact surface.

[0023] The branch chain further includes: The first connecting piece 301 is arranged on the upper and lower end faces of the end of the moving plate 3 away from the lead screw 201. The driving rod 302 is arranged corresponding to the first connecting piece 301 and is rotationally connected to the first connecting piece 301. The rod group connecting piece 303 is arranged at the end of the driving rod 302. Specifically, the rod group connecting piece 303 includes 2 parallel support plates and 2 rotating shafts arranged between the support plates. More specifically, the 2 driving rods 302 are respectively rotationally connected to the outer walls of the 2 rotating shafts. The driving rod 302 is rotationally connected to the rod group connecting piece 303 and the first connecting piece 301 through the driving rod 302 joint. Specifically, the driving rod 302 joint is from the prior art, aiming to achieve rotational connection, which can be realized through a collar and a rotating pair. The driven rod 304 is rotationally connected to the rod group connecting piece 303. Specifically, the number of the driven rods 304 is 2 and they are respectively arranged corresponding to the two rotating shafts. The second connecting piece 305 has a number corresponding to the number of the driven rods 304 and is respectively rotationally connected to the driven rods 304. Specifically, the end of the second connecting member 305 away from the driven rod 304 is rotatably mounted on the upper and lower end faces of the moving platform 4; More specifically, both the first connecting member 301 and the second connecting member 305 are arranged in a "U" shape; The active rod 302, the first connecting member 301 and the support plate included in the rod group connecting member 303 form a parallelogram rod group, and the driven rod 304, the second connecting member 305 and the support plate included in the rod group connecting member 303 form a parallelogram rod group; the active rod 302 and the driven rod 304 of each branch chain form a double parallelogram structure through the rod group connecting member 303 (see Figure 5 , Figure 7 ). When the moving platform 4 moves, the active rod and the driven rod in the branch chain always remain parallel, and the force is evenly transmitted to the vertices of the moving platform through two groups of parallelograms, avoiding unilateral force concentration, thereby reducing stress concentration and wear at the joints.

[0024] Specifically, setting the parallelogram rod group can achieve three-dimensional translation and one-dimensional rotation at the end of the branch chain; More specifically, the active rods 302 are parallel and coplanar, and the driven rods 304 are parallel and coplanar; The moving platform 4 is set as a square, and its four sides are set as arcs; during the rotation process, the force direction at the vertex of the moving platform always points along the tangent direction of the arc, avoiding joint jamming or eccentric wear caused by asymmetric loads in the traditional UPU branch chain.

[0025] Each second connecting member 305 included in the branch chain is rotatably connected to the moving platform 4; Specifically, in the basic assembly state (the branch chain and the moving platform 4 are in the standard position), each driven rod 304 included in the branch chain is rotatably connected to a vertex of the moving platform 4, and the extension line of its axis points to another vertex adjacent to the vertex.

[0026] Two pairs of opposite branch chains move differentially (for example, the moving plates of branch chains 1 and 3 move upward, and the moving plates of branch chains 2 and 4 move downward), and the driven rod (304) pushes the moving platform to rotate around the vertical axis. The kinematic pair only bears small-angle rotation, significantly reducing wear.

[0027] Normal use state The staff assembles the parallel manipulator included in this device at the working position, and its displacement state is as follows: S1. The motors 2 included in the 4 branch chains output synchronously. Based on the principle of the screw nut drive of the lead screw 201, the moving platform 4 can be driven to perform vertical reciprocating motion; S2. Among them, the motors 2 included in two adjacent branches output in the same direction simultaneously, driving the two moving plates to displace vertically in the same direction. The motors 2 included in the other two adjacent branches output in the opposite direction to the aforementioned motors 2, driving the two moving plates 3 to displace vertically in the same direction, and the moving direction is opposite to that of the aforementioned moving plates 3. That is, the aforementioned moving plate 3 moves downward, and the moving plates 3 driven by the other two adjacent branches move upward, enabling the translational movement of the moving platform 4. Based on the cooperation of the active rod 302, the driven rod 304, the rod group connecting piece 303, the first connecting piece 301, and the second connecting piece 305, the moving platform 4 can be driven to move in the direction of the lead screw 201 included in the branch 1 or the branch 2. All four branches move according to the values controlled by the program. The heights of the four moving plates 3 are different, that is, the three-dimensional translational movement of the moving platform 4 can be realized. The four branches output synchronously, driving the four moving plates 3 to move synchronously, then realizing the vertical displacement of the moving platform 4. S3. The motors 2 included in two opposite branches output forward simultaneously, driving the active rod 302 and the driven rod 304 to move towards the center of the branch array. Since the driven rods 304 all pass through a vertex of the moving platform 4 and point to its adjacent vertex under the standard position, the two opposite driven rods 304 move towards each other synchronously, that is, realizing the vertical rotation of the moving platform 4.

[0028] Compared with the prior art, the present invention has the following characteristics: 1. Based on the cooperative drive of four branches, the three-dimensional translational movement and vertical rotation of the end of the manipulator are realized. The structure is simple and the movement is reliable; when the moving plates 3 of the two pairs of opposite branches move in the opposite direction, the active rod 302 pushes the driven rod 304, causing the moving platform 4 to rotate around its central normal, and the vertical rotation can be realized without additional branches.

[0029] 2. Adopt the moving platform 4 of a single platform, saving materials and without complex transmission devices; cancel the UPU branch: The traditional UPU branch requires multiple rotating pairs and moving pairs, while the present invention directly transmits the movement through the parallelogram rod group of four branches (Claim 6), reducing the number of joints by more than 60%.

[0030] The moving parts are light in weight, facilitating the realization of high-speed and high-acceleration dynamic performance, and having high movement accuracy and stability.

[0031] The present invention is not limited to the implementation mode, and various deformations can be implemented as long as its purpose is not violated.

Claims

1. Four-link high-speed parallel manipulator, comprising a base (1), characterized in that: It also includes a fixed plate (101), a branch chain and a moving platform (4); The branch chains are arranged in four numbers and are located between the base (1) and the fixed plate (101), and the moving platform (4) is arranged between the output ends of the branch chains; The moving platform (4) is arranged in a square shape.

2. The four-link high-speed parallel manipulator according to claim 1, wherein: The branch chains are located between the base (1) and the fixing plate (101) and are evenly distributed in a "circular" or "square" array.

3. The four-link high-speed parallel manipulator according to claim 1, characterized in that: The branched chain includes: A motor (2) is arranged on the upper part of the fixing plate (101), and a lead screw (201) is arranged at the output end of the motor (2), and the lead screw (201) is located between the fixing plate (101) and the base (1); A guide rod (202) is provided between the base (1) and the fixing plate (101) and is located on one side of the lead screw (201); The movable plate (3) is arranged outside the lead screw (201), and a nut seat matching the lead screw (201) is arranged on the end surface of the movable plate (3).

4. The four-link high-speed parallel manipulator according to claim 3, characterized in that: The motor (2) and the lead screw (201) are driven via a coupling and / or a reducer.

5. The four-link high-speed parallel manipulator according to claim 3, wherein: The inner wall of the through hole of the movable plate (3) corresponding to the guide rod (202) is provided with a groove (202-1), and the outer wall of the guide rod (202) is provided with a protrusion matching the groove (202-1).

6. The four-link high-speed parallel manipulator according to claim 3, wherein: The branched chain also includes: Active rods (302), two in number, rotatably mounted on the upper and lower end surfaces of the movable plate (3) via a first connecting member (301); Two driven rods (304) are rotatably mounted on the upper and lower end surfaces of the moving platform (4) via a second connecting member (305); The rod group connecting member (303) is arranged at the connection between the active rod (302) and the driven rod (304); the active rod (302) and the driven rod (304) are both rotatably connected to the rod group connecting member (303).

7. The four-link high-speed parallel manipulator according to claim 6, wherein: The rod group connecting member (303) comprises two parallel support plates and two rotating shafts arranged between the support plates; The end of each of the active rod (302) and the driven rod (304) is rotatably connected to the corresponding outer wall of the rotating shaft.

8. The four-link high-speed parallel manipulator according to claim 6, wherein: The two active rods (302) and the two driven rods (304) are arranged in parallel and in the same plane.

9. The four-link high-speed parallel manipulator according to claim 6, characterized in that: The driven rod (304) included in each branch chain is rotatably connected to a vertex of the moving platform (4), and an extended line of its axis points to another vertex adjacent to the vertex.

10. The four-link high-speed parallel manipulator according to claim 1, wherein: An actuator (401) is provided on the end surface of the moving platform (4).

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