Spatial three-degree-of-freedom translation mechanism

Abstract

The invention relates to a spatial parallel mechanism, in particular to a spatial three-degree-of-freedom translation mechanism. Comprising a base, a movable platform and at least three branch chains, the movable platform is arranged above the base, and the at least three branch chains are connected between the movable platform and the base in parallel; each branch chain comprises a parallel four-connecting-rod support arm and a tail-end connecting rod, the lower end of the parallel four-connecting-rod support arm is hinged to the base, the upper end of the parallel four-connecting-rod support arm is hinged to one end of the tail-end connecting rod, the other end of the tail-end connecting rod is hinged to the movable platform, and the swing direction of the tail-end connecting rod is perpendicular to the swing direction of the parallel four-connecting-rod support arm; all the branch chains act synchronously, and the three-degree-of-freedom translational motion of the movable platform is achieved. The multi-branch parallel mechanism has the characteristics that the moving branch chains are simple in movement and can be decoupled in movement, and the multi-branch parallel mechanism is small in degree of freedom and high in rigidity, and the precision and quality of the mechanism in the operation process are easily guaranteed.

Description

Technical Field

[0001] The invention relates to a spatial parallel mechanism, in particular to a spatial three-degree-of-freedom translation mechanism. Background Art

[0002] At present, spatial parallel mechanisms are widely used in industrial fields such as handling, sorting, gluing, packaging and welding due to their compact structure, few degrees of freedom, easy integration and high movement speed. With the complex and changeable working conditions in modern production, more flexible or multi-degree-of-freedom parallel mechanisms are needed to meet the work needs. Compared with multi-degree-of-freedom parallel mechanisms such as six-degree-of-freedom, three-degree-of-freedom parallel mechanisms have larger working space, simpler structure, lower cost and wider application range. Therefore, three-degree-of-freedom parallel mechanisms are in great demand in the market and are widely used in training simulation simulator design, complex machine assembly and other aspects. However, the current Del ta parallel robots, such as 2-CRR-SPS, 3-RRRT, 3-PRRU and 3-RRRP (4R) three-translation parallel mechanisms, still have problems such as complex structure, large volume, high kinematic coupling and complex control, which make it difficult to meet the application requirements of lightweight, large load, simple control and working in unstructured environments. Summary of the invention

[0003] In view of the above problems, the purpose of the present invention is to provide a spatial three-degree-of-freedom translation mechanism to solve the problems that the existing parallel mechanism has a complex structure, a large volume, and is difficult to apply in unstructured environments.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] The present invention provides a spatial three-degree-of-freedom translation mechanism, comprising a base, a moving platform and at least three branch chains, wherein the moving platform is arranged above the base, and at least three branch chains are connected in parallel between the moving platform and the base;

[0006] The branch chain includes a parallel four-link support arm and an end link, the lower end of the parallel four-link support arm is hinged to the base, the upper end is hinged to one end of the end link, the other end of the end link is hinged to the moving platform, and the swing direction of the end link is perpendicular to the swing direction of the parallel four-link support arm;

[0007] Each branch chain moves synchronously to realize the three-degree-of-freedom translation movement of the dynamic platform.

[0008] The branch chains are arranged along the circumferential direction, and the swing directions of the parallel four-link support arms in at least two of the branch chains are different.

[0009] The parallel four-link support arm comprises at least two parallel four-link units connected in series.

[0010] The parallel four-link support arm comprises a first parallel four-link unit and a second parallel four-link unit connected in series in sequence;

[0011] The first parallel four-bar linkage unit includes a branch link I, a branch link II and a branch link III, wherein the branch link I and the branch link II are arranged in parallel, and the lower ends of the branch links are hinged to the base, the upper ends of the branch links I and the branch links II are respectively hinged to the two ends of the branch link III, and the branch link III is parallel to the base.

[0012] The second parallel four-bar linkage unit includes a branch link IV, a branch link V and a branch link VI, wherein the branch link IV and the branch link VI are arranged in parallel, and the lower ends are respectively hinged to the two ends of the branch link III, the upper ends of the branch link IV and the branch link VI are respectively hinged to the two ends of the branch link V, the branch link V is parallel to the branch link III, and the lower end of the terminal link is hinged to the branch link V.

[0013] A driving component for driving the branch chain to move is arranged on the rotating joint of each branch chain.

[0014] The advantages and beneficial effects of the present invention are as follows: a spatial three-degree-of-freedom translation mechanism provided by the present invention utilizes the parallel transmission principle of a spatial linkage mechanism to realize translational motion in the x, y, and z directions of space, and has the advantages of small structural size, simple mechanism, simple control, strong load capacity, high rigidity, and fast response speed. The present invention is suitable for unstructured environments, is easy to implement, and has a wide range of uses. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of a spatial three-degree-of-freedom translation mechanism of the present invention;

[0016] Figure 2 Schematic diagram of the structure of the branched chain in the present invention.

[0017] In the figure: 1-base, 2-branch chain, 3-moving platform, 201-branch chain link I, 202-branch chain link II, 203-branch chain link III, 204-branch chain link IV, 205-branch chain link V, 206-branch chain link VI, 207-end link, S1-parallelogram mechanism rotation axis direction, S2-end link lower rotation axis direction, S3-end link upper rotation axis direction. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0019] like Figure 1 to Figure 2As shown, the present invention provides a spatial three-degree-of-freedom translation mechanism, including a base 1, a moving platform 3 and at least three branch chains 2, wherein the moving platform 3 is arranged above the base 1, and at least three branch chains 2 are connected in parallel between the moving platform 3 and the base 1; the branch chain 2 includes a parallel four-bar linkage arm and an end link 207, the lower end of the parallel four-bar linkage arm is hinged to the base 1, the upper end is hinged to one end of the end link 207, the other end of the end link 207 is hinged to the moving platform 3, and the swing direction of the end link 207 is perpendicular to the swing direction of the parallel four-bar linkage arm, and each branch chain 2 moves synchronously to realize the three-degree-of-freedom translation movement of the moving platform 3.

[0020] In the embodiment of the present invention, the branches 2 are arranged along the circumferential direction, and the swing directions of the parallel four-link arms in at least two branches 2 are different to constrain the rotational freedom degrees to each other. The number of branches 2 can be greater than 3, forming a redundantly constrained three-degree-of-freedom parallel mechanism, and multiple branches 2 are connected in parallel to realize the translational motion of the dynamic platform 3 in three directions.

[0021] Specifically, the parallel four-link support arm includes at least two parallel four-link units connected in series.

[0022] like Figure 2 As shown, in an embodiment of the present invention, the parallel four-bar linkage arm includes a first parallel four-bar linkage unit and a second parallel four-bar linkage unit connected in series in sequence; the first parallel four-bar linkage unit includes a branch link Ⅰ201, a branch link Ⅱ202 and a branch link Ⅲ203, wherein the branch link Ⅰ201 and the branch link Ⅱ202 are arranged in parallel, and the lower ends of the branch links Ⅰ201 and the branch link Ⅱ202 are hinged to the base 1, the upper ends of the branch links Ⅰ201 and the branch links Ⅱ202 are respectively hinged to the two ends of the branch link Ⅲ203, and the branch link Ⅲ203 is parallel to the base 1, and the base 1, the branch links Ⅰ201, the branch links Ⅱ202 and the branch links Ⅲ203 form a first parallel four-bar linkage unit.

[0023] The second parallel four-bar linkage unit includes a branch link IV204, a branch link V205 and a branch link VI206, wherein the branch link IV204 and the branch link VI206 are arranged in parallel, and the lower ends are respectively hinged to the two ends of the branch link III203, the upper ends of the branch link IV204 and the branch link VI206 are respectively hinged to the two ends of the branch link V205, the branch link V205 is parallel to the branch link III203, and the branch link III203, the branch link IV204, the branch link V205 and the branch link VI206 form the second parallel four-bar linkage unit. The lower end of the terminal link 207 is hinged to the branch link V205, and the terminal link 207 rotates in a direction perpendicular to the parallelogram arm, that is, the lower rotation axis direction S2 of the terminal link is the same as the upper rotation axis direction S3 of the terminal link, and is parallel to the x-axis. The rotation axis direction S1 of the parallelogram mechanism is parallel to the y-axis.

[0024] Furthermore, a driving component for driving the movement of the branch chain 2 is arranged on the rotating joint of each branch chain 2. In this embodiment, the driving component is a hydraulic rod push rod member arranged on any rotating joint of the branch chain 2, and the hydraulic rod push rod member drives the branch chain 2 to swing.

[0025] In this embodiment, three branch chains 2 are connected in parallel between the base 1 and the moving platform 3. The three branch chains 2 are arranged along the circumferential direction but are not parallel, forming a spatial parallel mechanism with high rigidity, thereby improving the stability of the moving platform 3 during movement and the reliability of operation.

[0026] The present invention provides a spatial three-degree-of-freedom translation mechanism, the working principle of which is:

[0027] Through two parallel four-link arms connected in series, a two-degree-of-freedom translational motion along the x and z directions is formed, and after the end link 207 with two rotating pairs in the same direction is connected in series, the translational motion in the x, y, and z directions and the rotational motion in the y direction are obtained. By distributing the three branch chains 2 along the circumferential direction, as long as at least two of the three branch chains 2 are not coplanar, the rotational freedom of different branch chains 2 relative to themselves in the y direction will be constrained to each other, and after multiple branch chains are connected in parallel, the translational motion of the moving platform 3 in the three directions of x, y, and z can be realized. By arranging three driving motors on the rotating joints of the three branch chains 2 respectively, the mechanism can be driven to realize three-degree-of-freedom motion in space.

[0028] The present invention provides a spatial three-degree-of-freedom translation mechanism, which realizes three-degree-of-freedom translation by using the parallel transmission principle of a spatial linkage mechanism. The mechanism has the advantages of compact size, few degrees of freedom, large rigidity, simple control, strong load capacity, simple motion, low coupling degree, and decoupling of motion, and is easy to ensure the accuracy and quality of the mechanism during operation. The present invention meets the application requirements of lightweight, large load, simple control, and working in an unstructured environment, and can be used in packaging production lines, loading and unloading production lines, high-precision position adjustment platforms, etc., to improve operating efficiency and safety.

[0029] The above description is only an embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, expansion, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. A spatial three-degree-of-freedom translation mechanism, characterized in that: It comprises a base (1), a moving platform (3) and at least three branch chains (2), wherein the moving platform (3) is arranged above the base (1), and the at least three branch chains (2) are connected in parallel between the moving platform (3) and the base (1); The branch chain (2) comprises a parallel four-link support arm and an end link (207), wherein the lower end of the parallel four-link support arm is hinged to the base (1), the upper end is hinged to one end of the end link (207), the other end of the end link (207) is hinged to the moving platform (3), and the swing direction of the end link (207) is perpendicular to the swing direction of the parallel four-link support arm; Each branch chain (2) moves synchronously to realize the three-degree-of-freedom translation movement of the moving platform (3).

2. The spatial three-degree-of-freedom translation mechanism according to claim 1, characterized in that: The branch chains (2) are arranged along the circumferential direction, and the swing directions of the parallel four-link support arms in at least two of the branch chains (2) are different.

3. The spatial three-degree-of-freedom translation mechanism according to claim 1, characterized in that: The parallel four-link support arm comprises at least two parallel four-link units connected in series.

4. The spatial three-degree-of-freedom translation mechanism according to claim 3, characterized in that: The parallel four-link support arm comprises a first parallel four-link unit and a second parallel four-link unit connected in series in sequence; The first parallel four-bar linkage unit comprises a branch link I (201), a branch link II (202) and a branch link III (203), wherein the branch link I (201) and the branch link II (202) are arranged in parallel, and the lower ends of the branch links I (201) and the branch link II (202) are hinged to the base (1), the upper ends of the branch links I (201) and the branch link II (202) are respectively hinged to the two ends of the branch link III (203), and the branch link III (203) is parallel to the base (1).

5. The spatial three-degree-of-freedom translation mechanism according to claim 4, characterized in that: The second parallel four-bar linkage unit comprises a branch link IV (204), a branch link V (205) and a branch link VI (206), wherein the branch link IV (204) and the branch link VI (206) are arranged in parallel, and the lower ends of the branch link IV (204) and the branch link VI (206) are respectively hinged to the two ends of the branch link III (203), the upper ends of the branch link IV (204) and the branch link VI (206) are respectively hinged to the two ends of the branch link V (205), the branch link V (205) is parallel to the branch link III (203), and the lower end of the terminal link (207) is hinged to the branch link V (205).

6. The spatial three-degree-of-freedom translation mechanism according to claim 1, characterized in that: A driving component for driving the branch chain (2) to move is arranged on the rotating joint of each branch chain (2).

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