Large-angle rotating robot joint

Abstract

A large-angle rotation robot joint includes a thigh and a lower leg. The lower end of the thigh is hinged to the upper part of the lower leg to form a knee joint. A through hole at the upper end of the thigh serves as a hip joint. The lower leg is L-shaped, consisting of a long arm and a short arm. The hinge point between the lower leg and the thigh is at the junction of the long and short arms. A primary link is hinged to the thigh, and the other end of the primary link is hinged to a secondary link. The other end of the secondary link is hinged to the short arm of the lower leg. A hydraulic cylinder is hinged between the thigh and the primary link, with the hinge point between the hydraulic cylinder and the thigh located above the hinge point between the primary link and the thigh. This invention uses a four-bar linkage to meet the needs of large-angle rotation of the hydraulic cylinder-driven robot joint; it uses a double thigh arm design to facilitate component installation and avoid interference; and the left and right drive components are symmetrically arranged for balance.

Description

Technical Field

[0001] This utility model relates to a robot joint, and more particularly to a large-angle rotation robot joint. Background Technology

[0002] Common five-axis and six-axis industrial robots typically use motor-driven rotary axes for their joints. This allows for large and precise transmission angles, but the disadvantage is that the rotation speed is relatively slow, making them unsuitable for fast-moving applications. Articulated hydraulic cylinder-driven robot thigh and calf joints can move quickly, but current designs can only drive a relatively small rotation angle between the thigh and calf, which cannot meet the needs of large-angle rotation. Summary of the Invention

[0003] The purpose of this invention is to provide a large-angle rotating robot joint to solve the problem of small rotation angles in the thigh and lower leg joints of existing hydraulic cylinder driven robots.

[0004] The purpose of this utility model is achieved in the following way: a large-angle rotation robot joint, including a thigh and a lower leg. The lower end of the thigh is hinged to the upper part of the lower leg to form a knee joint. A through hole at the upper end of the thigh serves as a hip joint. The lower leg is L-shaped, consisting of a long arm and a short arm. The hinge point between the lower leg and the thigh is at the connection between the long arm and the short arm. A primary link is hinged to the thigh, and the other end of the primary link is hinged to a secondary link. The other end of the secondary link is hinged to the short arm of the lower leg. A hydraulic cylinder is hinged between the thigh and the primary link. The hinge point between the hydraulic cylinder and the thigh is located above the hinge point between the primary link and the thigh. The secondary link can also be replaced by a curved shape. The knee joint of the lower leg extends outward a certain distance through the short arm of the lower leg, and forms a certain angle with the long arm of the lower leg. This is to obtain a sufficient transmission angle when the legs are folded together in the squatting position of the robot.

[0005] The thigh is composed of two parallel thigh arms located on both sides of the lower leg. A drive device consisting of symmetrical hydraulic cylinders, primary connecting rods, and secondary connecting rods is set on both sides of the thigh and lower leg. Specifically, the same secondary connecting rods are coaxially hinged on both sides of the lower leg, the same primary connecting rods are hinged at the same position on each thigh arm, each primary connecting rod is hinged to the secondary connecting rod on the same side, and the same hydraulic cylinder is hinged between each thigh arm and the primary connecting rod on that side.

[0006] The short arm of the lower leg is located on the outside of the knee joint. The length between the two hinge points of the first-level link is greater than the length between the two hinge points of the second-level link, and the length between the two hinge points of the second-level link is greater than the length between the two hinge points of the lower leg. This four-bar linkage can have the characteristic of a large rotation angle of the driving or driven member while ensuring the force transmission performance. It can be used to amplify or reduce the rotation angle of the driving member.

[0007] The hinge point between the first-stage linkage and the thigh is located on the lower inner side of the hinge point between the hydraulic cylinder and the thigh. This serves two purposes: firstly, it facilitates the installation of the hydraulic cylinder and the first-stage linkage without interference; secondly, it reduces the extension and retraction stroke of the hydraulic cylinder while slightly reducing the rotation angle of the knee joint.

[0008] The hinge point between the hydraulic cylinder and the first-stage connecting rod is located inside the line connecting the hinge points at both ends of the first-stage connecting rod, in order to obtain better force transmission performance and increase the rotation angle of the knee joint.

[0009] When the piston rod is fully extended, the distance between the hinge points at both ends of the hydraulic cylinder is less than the maximum distance between the thigh and the circular hole on the first-stage connecting rod used for hinged hydraulic cylinder when the first-stage connecting rod swings relative to the thigh. When the hinge points of the first-stage connecting rod and the thigh, the hydraulic cylinder and the thigh, and the hydraulic cylinder and the first-stage connecting rod are on the same straight line, a transmission dead angle position is formed. By limiting the length of the hydraulic cylinder, the first-stage connecting rod can be prevented from swinging to this dead angle position.

[0010] The advantages of this invention are: it uses a four-bar linkage to meet the needs of large-angle rotation of the joints of a hydraulic cylinder-driven robot; it uses a double-arm design to facilitate parts installation and avoid interference; and the left and right drive components are symmetrically arranged to facilitate balance. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the structure of this utility model;

[0012] Figure 2 This is the front view of this utility model;

[0013] Figure 3 This is a diagram showing the state of the lower leg during contraction in this utility model.

[0014] Figure 4 This is a diagram showing the state of the lower leg when it is extended.

[0015] In the diagram: 1-thigh; 2-hydraulic cylinder; 3-lower leg; 4-first-stage linkage; 5-second-stage linkage; 6-hip joint; 7-knee joint. Detailed Implementation

[0016] Reference Figures 1-4A large-angle rotation robot joint includes a thigh 1 and a lower leg 3. The lower end of the thigh 1 is hinged to the upper part of the lower leg 3 to form a knee joint 7. A through hole at the upper end of the thigh 1 serves as a hip joint 6. The lower leg 3 is L-shaped, consisting of a long arm and a short arm. The hinge point between the lower leg 3 and the thigh 1 is at the connection between the long arm and the short arm. A primary link 4 is hinged to the thigh 1, and the other end of the primary link 4 is hinged to a secondary link 5. The other end of the secondary link 5 is hinged to the short arm of the lower leg 3. A hydraulic cylinder 2 is hinged between the thigh 1 and the primary link 4, and the hinge point between the hydraulic cylinder 2 and the thigh 1 is located above the hinge point between the primary link 4 and the thigh 1. The thigh 1 is composed of two parallel thigh arms arranged on both sides of the lower leg 3. A drive device consisting of symmetrical hydraulic cylinders 2, primary connecting rods 4, and secondary connecting rods 5 is arranged on both sides; the short arm of the lower leg 3 is located on the outside of the knee joint 7; the length between the two hinge points of the primary connecting rod 4 is greater than the length between the two hinge points of the secondary connecting rod 5, and the length between the two hinge points of the secondary connecting rod 5 is greater than the length between the two hinge points of the lower leg 3; the hinge point between the primary connecting rod 4 and the thigh 1 is located on the lower inner side of the hinge point between the hydraulic cylinder 2 and the thigh 1, and the hinge point between the hydraulic cylinder 2 and the primary connecting rod 4 is located on the inner side of the line connecting the two hinge points at both ends of the primary connecting rod 4; the maximum distance between the two hinge points at both ends of the hydraulic cylinder 2 body is slightly less than the maximum distance between the two circular holes on the thigh 1 and the primary connecting rod 4 used for hinged hydraulic cylinder 2 when the primary connecting rod 4 swings relative to the thigh 1.

Claims

1. A large-angle rotation robot joint, comprising a thigh and a lower leg, wherein the lower end of the thigh is hinged to the upper part of the lower leg to form a knee joint, and a through hole at the upper end of the thigh serves as a hip joint, characterized in that: The lower leg (3) is an L-shaped structure consisting of a long arm and a short arm. The hinge point between the lower leg (3) and the thigh (1) is at the connection between the long arm and the short arm. A first-stage connecting rod (4) is hinged on the thigh (1). The other end of the first-stage connecting rod (4) is hinged to a second-stage connecting rod (5). The other end of the second-stage connecting rod (5) is hinged to the short arm of the lower leg (3). A hydraulic cylinder (2) is hinged between the thigh (1) and the first-stage connecting rod (4). The hinge point between the hydraulic cylinder (2) and the thigh (1) is located above the hinge point between the first-stage connecting rod (4) and the thigh (1).

2. The large-angle rotation robot joint according to claim 1, characterized in that: The thigh (1) is composed of two thigh arms arranged in parallel on both sides of the lower leg (3). A drive device consisting of a symmetrical hydraulic cylinder (2), a first-stage connecting rod (4), and a second-stage connecting rod (5) is set on both sides of the thigh (1) and the lower leg (3).

3. The large-angle rotation robot joint according to claim 1, characterized in that: The short arm of the lower leg (3) is located on the outside of the knee joint (7). The length between the two hinge points of the first-level link (4) is greater than the length between the two hinge points of the second-level link (5). The length between the two hinge points of the second-level link (5) is greater than the length between the two hinge points of the lower leg (3).

4. The large-angle rotation robot joint according to claim 1, characterized in that: The hinge point between the first-stage connecting rod (4) and the thigh (1) is located on the lower inner side of the hinge point between the hydraulic cylinder (2) and the thigh, and the hinge point between the hydraulic cylinder (2) and the first-stage connecting rod (4) is located on the inner side of the line connecting the hinge points at both ends of the first-stage connecting rod (4).

5. The large-angle rotation robot joint according to claim 1, characterized in that: When the piston rod of the hydraulic cylinder (2) is in its maximum extended state, the maximum distance between the hinge points at both ends of the hydraulic cylinder (2) is less than the maximum distance between the round holes on the thigh (1) and the first-stage connecting rod (4) used for hinged hydraulic cylinder (2) when the first-stage connecting rod (4) swings relative to the thigh (1).

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