Regular dodecahedron deployable enveloping mechanism based on seven-rod single-ring mechanism

Abstract

The invention discloses a regular dodecahedron deployable enveloping mechanism based on a seven-rod single-ring mechanism, which belongs to the technical field of mechanism application and comprises a type I rack, a type II rack, a type I connecting rod, a type II connecting rod, a type III connecting rod, a type I bias connecting rod, a type II bias connecting rod, a type III bias connecting rod and a type IV bias connecting rod. Each branch chain of the deployable mechanism comprises three seven-rod single-ring mechanisms, the single-ring mechanisms are connected through I-type offset rods, II-type offset rods and III-type offset rods, and the corresponding seven-rod single-ring rod pieces have the same motion relation. The extensible mechanism can be driven through the rack rod, conversion between a completely-unfolded state and a completely-closed state is achieved, and control is convenient.

Description

Technical Field

[0001] This invention belongs to the field of applied mechanism technology, and specifically designs a single-degree-of-freedom symmetrical seven-bar closed-loop deployable unit and a regular dodecahedral deployable mechanism based thereon. Background Technology

[0002] With the development of aerospace technology and the advancement of deep-sea exploration technology, mechanical grippers with grasping capabilities have been widely used. However, traditional mechanical grippers face serious challenges in grasping irregular objects under extreme conditions due to their complex control, poor adaptability, and concentrated force points on the target object. Deployable mechanisms, with their versatile structure and strong adaptability, necessitate a new technological solution to address this problem. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a single-degree-of-freedom symmetrical seven-bar closed-loop deployable mechanism and the constructed deployable mechanism, which is driven by a connecting rod to realize the mutual transformation between the fully unfolded and fully closed configurations in a plane. This mechanism is a single-degree-of-freedom deployable mechanism with simple motion control.

[0004] The technical solution adopted in this invention is to utilize a face-symmetrical seven-bar single-ring mechanism including: a type I frame (1), a type II frame (2), a type I connecting rod (3), a type II connecting rod (4), a type II offset connecting rod (6), and a type III offset connecting rod (7).

[0005] The type I frame (1) is provided with five branch rods (101), the type II frame (2) is provided with five branch rods (201), the included angle between two adjacent branch rods is 72 degrees, the frame (1) is hinged to the connecting rod (3), and the frame (2) is hinged to the connecting rod (6).

[0006] Two type I connecting rods (3) are provided, including connecting rod (301) and connecting rod (302). Two rotating joints with mutually perpendicular axes are provided at both ends of the connecting rod (3). One end of the connecting rod (301) is hinged to the frame rod (101), and the other end of the connecting rod (301) is hinged to the connecting rod (4). The rotating joint of the connecting rod (302) is hinged to the offset connecting rod (7), and the other end of the connecting rod (302) is hinged to the connecting rod (4).

[0007] There is one type II connecting rod (4). The included angle between the axes of the two rotating joints at both ends of the connecting rod is 60 degrees. One end of the connecting rod is connected to the rotating joint of the connecting rod (301), and the other end is connected to the rotating joint of the connecting rod (302).

[0008] The offset link (6) is provided with an offset revolute joint at its geometric center. The axis is perpendicular to the plane of the link. The revolute joints at both ends are in the plane of the link (6). The included angle between the axes of the revolute joints at both ends is 60 degrees.

[0009] The offset link (7) is provided with an offset revolute joint at its geometric center. Its axis is perpendicular to the plane of the link. The revolute joints at both ends are in the plane of the link (7). The angle between revolute joint I and revolute joint II is 120 degrees.

[0010] The frame (2) and the offset link (6) are mirror-symmetric about the plane A of the angle bisector of their axes; the frame (1) and the offset link (6) are mirror-symmetric about the plane A; the two links (3) are mirror-symmetric about the plane A; the revolute joints at both ends of the link (4) are mirror-symmetric about the plane A.

[0011] A is mirror-symmetric.

[0012] The frame rod (101), frame rod (201), two connecting rods (3), one connecting rod (4), one offset connecting rod (6), and one offset connecting rod (7) form a seven-bar single-ring mechanism.

[0013] This invention comprises a deployable mechanism with complete envelopment performance based on the aforementioned seven-bar single-ring mechanism. Its features include: a type I frame (1), a type II frame (2), a type I connecting rod (3), a type II connecting rod (4), a type I offset connecting rod (5), a type II offset connecting rod (6), a type III offset connecting rod (7), a type IV offset connecting rod (8), and a type V offset connecting rod (9). Each of the offset connecting rods (5), (6), (7), (8), and (9) contains an offset rotating pair.

[0014] The aforementioned seven-bar single-ring mechanism forms a deployable mechanism frame (1) and frame (2) with complete enveloping performance. Each frame has five branch bars, and the included angle between adjacent branch bars is 72 degrees. A rotating pair is set at the geometric center of the frame (1) and frame (2).

[0015] The aforementioned seven-bar single-ring mechanism forms a deployable mechanism with complete enveloping performance, with each branch bar of the frame connected to a single-degree-of-freedom branch, for a total of five branches;

[0016] The above-mentioned seven-bar single-ring mechanism forms a deployable mechanism with full envelopment performance. Each chain contains three single-ring mechanisms composed of seven bars. The first seven-bar mechanism and the second seven-bar mechanism are connected by an offset link (6) and an offset link (7). The second seven-bar mechanism and the third seven-bar mechanism are connected by an offset link (5) and an offset link (7).

[0017] The aforementioned seven-bar single-ring mechanism forms a deployable mechanism with complete envelope performance.

[0018] The frame (1) is provided with five branch rods (101), each of which is hinged to the connecting rod (3);

[0019] The aforementioned seven-bar single-ring mechanism forms a deployable mechanism with complete envelope performance.

[0020] The frame 2 is provided with five branch rods (201), each of which is hinged to the offset link (6);

[0021] In a branch chain, the connecting rod (3) is provided with six rods, and two rotating pairs with mutually perpendicular axes are provided at both ends. The first seven-bar unit connecting rod is hinged to the frame branch rod (101) at one end, the second seven-bar unit connecting rod is hinged to the offset connecting rod (7) at one end, the second seven-bar unit connecting rod is hinged to the offset connecting rod (9) at one end, and the other end of the connecting rod is hinged to the connecting rod (4).

[0022] In a branch chain, there are three connecting rods (4), and the included angle between the rotational axes at both ends of the connecting rod is 60 degrees, and they are all connected to the connecting rod (3);

[0023] In one branch, the offset link (5) is provided with an offset revolute joint at its geometric center. The axis of the offset revolute joint is perpendicular to the plane of the link, and the angle between the two axes of the link is 120 degrees. The revolute joints at both ends are in the plane of the link (5), and the angle between the axes of the revolute joints at both ends is 60 degrees. The axis of the offset revolute joint is perpendicular to the plane of the axes of the revolute joints at both ends. The offset revolute joint is hinged to the offset link (7), and the revolute joints at both ends are hinged to the offset link (6) and the offset link (9), respectively.

[0024] In one branch, the offset link (6) is provided with an offset revolute joint at its geometric center. The axis of the offset revolute joint is perpendicular to the plane of the link, and the angle between the two axes of the link is 120 degrees. The revolute joints at both ends are in the plane of the link (6), and the angle between the axes of the revolute joints at both ends is 60 degrees. The axis of the offset revolute joint is perpendicular to the plane of the axes of the revolute joints at both ends. The offset revolute joint is hinged to the offset link (7), and the revolute joints at both ends are hinged to the frame link (101) and the offset link (5), respectively.

[0025] In one branch, there are two offset connecting rods (7), one of which is an offset revolute joint at the geometric center. The axis is perpendicular to the plane of the rod, and the angle between the two axes of the rod is 120 degrees. The revolute joints at both ends are in the plane of the connecting rod (7), and the angle between the axes of the revolute joints at both ends is 120 degrees. The offset revolute joints are hinged to the offset connecting rod (5) and the offset connecting rod (6) respectively, and the revolute joints at both ends are hinged to the connecting rod (3).

[0026] In one branch, the offset link (8) is provided with an offset rotating joint at one end, the axis of which is perpendicular to the plane of the link, and the rotating joint at the other end is perpendicular to the axis of the offset link (8). The offset rotating joint is hinged to the offset link (9) respectively, and the rotating joint at the other end is hinged to the offset link (5).

[0027] In one branch, the offset link (9) is provided with an offset rotating joint at one end, the axis of which is perpendicular to the plane of the link, and the rotating joint at the other end coincides with the axis of the link (9). The offset rotating joint is hinged to the offset link (8) respectively, and the rotating joint at the other end is hinged to the link (3).

[0028] Each branch of the mechanism consists of three seven-bar single-loop mechanisms. The symmetry relationship of each unit is the same as that of the single single-degree-of-freedom symmetrical seven-bar closed-loop deployable unit, and the corresponding relationship is also the same during the movement of the branch.

[0029] The mechanism consists of five identical branches, each branch corresponding to the same link. During the movement of the deployable mechanism, the movement relationships of each link are identical.

[0030] Under the above construction method, the deployable mechanism branch can form a spatial overlap between the end revolute joint of the third seven-bar single-ring mechanism and the frame revolute joint from the fully deployed movement.

[0031] Under the above construction method, the deployable mechanism can be formed to fully unfold and move to a fully closed state in the plane where the frame is located, and the end points of each branch intersect at a point in the fully closed state, thus forming a deployable mechanism with full enveloping performance.

[0032] Through the above design scheme, this invention can achieve the following: a single-degree-of-freedom symmetrical seven-bar closed-loop deployable mechanism and a constructed dodecahedral deployable mechanism. The five branches of this deployable mechanism have identical motion relationships, and the three single-loop mechanisms on each branch have identical motion relationships. The deployable mechanism is controlled to transition from a fully extended state to a fully closed state by driving the frame rods. This deployable mechanism is simple to control and can grasp different target objects.

[0033] The single-degree-of-freedom symmetrical seven-bar closed-loop deployable mechanism and the constructed dodecahedral deployable mechanism can achieve three states during motion: fully deployed, driven closed motion, and closed full-envelope state. Multiple contact points can be generated when grasping different target objects, making it applicable to various working scenarios. This deployable mechanism with full-envelope performance has broad application prospects in fields such as deep-sea exploration, space exploration, and automation. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the movement of the branch chain in the mechanism of the present invention;

[0035] Figure 2 This is a schematic diagram of the fully deployed state of the mechanism of the present invention;

[0036] Figure 3 This is a schematic diagram of the fully closed state of the mechanism of the present invention;

[0037] Figure 4 This is a schematic diagram of the frame 1 and frame 2 of the present invention;

[0038] Figure 5 This is a schematic diagram of the connecting rod 4 component of the present invention;

[0039] In the diagram, 1-Frame I, 2-Frame II, 3-Link I, 4-Link II, 5-Link III, 6-Offset Link I, 7-Offset Link II, 8-Offset Link III, and 9-Offset Link IV. Detailed Implementation

[0040] The present invention will be further described below with reference to the embodiments:

[0041] A single-degree-of-freedom symmetric seven-bar closed-loop mechanism and a deployable mechanism with complete envelope performance, such as... Figure 1 , Figure 2 , Figure 3 It includes frame 1, frame 2, connecting rod I, connecting rod II, connecting rod III, offset connecting rod I, offset connecting rod II, offset connecting rod III, and offset connecting rod IV;

[0042] The frame 1 has a central hole, and the frame 1 and frame 2 are hinged together at the central hole. The geometric center of the rotating joint coincides with the center of the central hole. The frame 1 has five branch rods, and the included angle between two adjacent branch rods 101 is 72 degrees. Each branch rod 101 is hinged to the connecting rod 7.

[0043] The frame 2 has a central hole, and the frame 1 and the frame 2 are hinged at the central hole. The geometric center of the rotating joint coincides with the center of the central hole. The frame 2 has five branch rods (201), and the included angle between two adjacent branch rods 101 is 72 degrees. Each branch rod is hinged to the offset connecting rod (6).

[0044] In a branch chain, the connecting rod (3) is provided with six rods, and two rotating pairs with mutually perpendicular axes are provided at both ends. The first seven-bar unit connecting rod is hinged to the frame branch rod (101) at one end, the second seven-bar unit connecting rod is hinged to the offset connecting rod (7) at one end, the second seven-bar unit connecting rod is hinged to the offset connecting rod (9) at one end, and the other end of the connecting rod is hinged to the connecting rod (4).

[0045] In a branch chain, there are three connecting rods (4), and the included angle between the rotational axes at both ends of the connecting rod is 60 degrees, and they are all connected to the connecting rod (3);

[0046] In one branch, the offset link (5) is provided with an offset revolute joint at its geometric center. The axis of the offset revolute joint is perpendicular to the plane of the link, and the angle between the two axes of the link is 120 degrees. The revolute joints at both ends are in the plane of the link (5), and the angle between the axes of the revolute joints at both ends is 60 degrees. The axis of the offset revolute joint is perpendicular to the plane of the axes of the revolute joints at both ends. The offset revolute joint is hinged to the offset link (7), and the revolute joints at both ends are hinged to the offset link (6) and the offset link (9), respectively.

[0047] In one branch, the offset link (6) is provided with an offset revolute joint at its geometric center. The axis of the offset revolute joint is perpendicular to the plane of the link, and the angle between the two axes of the link is 120 degrees. The revolute joints at both ends are in the plane of the link (6), and the angle between the axes of the revolute joints at both ends is 60 degrees. The axis of the offset revolute joint is perpendicular to the plane of the axes of the revolute joints at both ends. The offset revolute joint is hinged to the offset link (7), and the revolute joints at both ends are hinged to the frame link (101) and the offset link (5), respectively.

[0048] In one branch, there are two offset connecting rods (7), one of which is an offset revolute joint at the geometric center. The axis is perpendicular to the plane of the rod, and the angle between the two axes of the rod is 120 degrees. The revolute joints at both ends are in the plane of the connecting rod (7), and the angle between the axes of the revolute joints at both ends is 120 degrees. The offset revolute joints are hinged to the offset connecting rod (5) and the offset connecting rod (6) respectively, and the revolute joints at both ends are hinged to the connecting rod (3).

[0049] In a branch, the offset link (8) is provided with an offset rotating joint at one end, the axis of which is perpendicular to the plane of the link, and the rotating joint at the other end is perpendicular to the axis of the offset link (8). The offset rotating joint is hinged to the offset link (9) respectively, and the rotating joint at the other end is hinged to the offset link (5).

[0050] In a branch chain, the offset link (9) is provided with an offset rotating joint at one end, the axis of which is perpendicular to the plane of the link, and the rotating joint at the other end coincides with the axis of the link (9). The offset rotating joint is hinged to the offset link (8) respectively, and the rotating joint at the other end is hinged to the link (3).

[0051] Each branch of the mechanism consists of three seven-bar single-ring mechanisms;

[0052] The mechanism consists of five identical branches;

[0053] This deployable mechanism is a single degree of freedom. The entire deployable mechanism is driven by the rotation of the drive frame 2, thereby realizing the movement from fully unfolded to fully closed. The specific process is as follows: the rotation of the drive frame 2 drives the rotation of the five links 3, which in turn drives the rotation of the link 4. The rotation of the link 4 controls the rotation of the link 3. The rotation of the link 3 drives the rotation of the offset link 7. The offset link 7 transmits to the next seven-bar single-ring mechanism and drives the rotation of the offset link 6. This process continues until the movement of the end offset link (8) is finally transmitted.

[0054] The single-degree-of-freedom symmetrical seven-bar closed-loop deployable mechanism and its construction can achieve three states during motion: fully deployed, driven closed motion, and closed full-envelope state. It can generate multiple contact points when grasping different target objects and can be applied to various working scenarios. This deployable mechanism with full-envelope performance has broad application prospects in fields such as deep-sea exploration, space exploration, and automation.

Claims

1. A mechanism based on a seven-bar single-loop mechanism, which is a regular dodecahedron developable envelope mechanism, characterized in that, Comprise: Type I frame (1), type II frame (2), type I connecting rod (3), type II connecting rod (4), type II offset connecting rod (6), type III offset connecting rod (7); The type I frame (1) is provided with five branch rods (101), the type II frame (2) is provided with five branch rods (201), the included angle between adjacent two branch rods is 72 degrees, the frame (1) is hinged with the connecting rod (3), and the frame (2) is hinged with the connecting rod (6); The type I connecting rod (3) is provided with two, including connecting rod (301), connecting rod (302), both ends of the connecting rod (3) are provided with two rotating pairs with axis perpendicular to each other, one end of the connecting rod (301) is hinged with the frame rod (101), the other end of the connecting rod (301) is hinged with the connecting rod (4); the rotating pair of the connecting rod (302) is hinged with the offset connecting rod (7), and the other end of the connecting rod (302) is hinged with the connecting rod (4).

2. The seven-bar single-loop mechanism-based regular dodecahedron expandable enveloping mechanism according to claim 1, characterized in that: The type II connecting rod (4) is provided with one, the included angle of the rotating pair axes of the two ends of the connecting rod is 60 degrees, one end is connected with the rotating pair of the connecting rod (301), and the other end is connected with the rotating pair of the connecting rod (302).

3. The seven-bar single-loop mechanism-based icosahedron expandable enveloping mechanism according to claim 1, wherein: The type II offset connecting rod (6) is provided with one, the geometric center contains an offset rotating pair, the axis is perpendicular to the plane of the rod, and the two end rotating pairs are in the plane of the connecting rod (6), and the included angle between the two end rotating pair axes is 60 degrees.

4. The seven-bar single-loop mechanism-based regular dodecahedron expandable enveloping mechanism according to claim 1, wherein: The type III offset connecting rod (7) is provided with one, the geometric center contains an offset rotating pair, the axis is perpendicular to the plane of the rod, and the two end rotating pairs are in the plane of the connecting rod (7), and the included angle between the rotating pair I and the rotating pair II is 120 degrees.

5. The seven-bar single-loop-based icosahedron expandable enveloping mechanism according to claim 1, characterized in that: The frame rod (101) and the offset connecting rod (6) are symmetrical about the symmetry plane A of the angle bisector of the axes of the two; the frame rod (2) and the offset connecting rod (7) are symmetrical about the plane A; the connecting rod (301) and the connecting rod (302) are symmetrical about the plane A; the two rotating pairs of the connecting rod (4) are symmetrical about the plane A.

6. The seven-bar single-loop mechanism-based Archimedean solids expandable enveloping mechanism according to claim 1, wherein, The frame rod (101), the frame rod (201) and the two connecting rods (3), one connecting rod (4), one offset connecting rod (6) and one offset connecting rod (7) form a closed single ring developable mechanism.

7. The seven-bar single-loop mechanism-based Archimedean solids expandable enveloping mechanism according to claim 1, wherein, In the completely symmetrical and developed state of the seven-bar single ring mechanism, the frame (1), the frame (2), the connecting rod (3), the connecting rod (4), the offset connecting rod (6) and the offset connecting rod (7) are located in the plane determined by the frame rod.

8. A single degree of freedom symmetrical seven-bar closed-loop mechanism and a developable mechanism with complete enveloping performance constructed by the same, characterized in that, Comprise: Type I frame (1), type II frame (2), type I connecting rod (3), type II connecting rod (4), type I offset connecting rod (5), type II offset connecting rod (6), type III offset connecting rod (7), type IV offset connecting rod (8), type V offset connecting rod (9); The type I frame is provided with five branch rods (101), and the included angle between adjacent two branch rods is 72 degrees, wherein each branch rod is hinged with the connecting rod (3); The type I frame is provided with five branch rods (201), and the included angle between adjacent two branch rods is 72 degrees, wherein each branch rod is hinged with the offset connecting rod (6); In one branch, the connecting rod (3) is provided with six, both ends are provided with two rotating pairs of axes perpendicular to each other, the first seven rod unit connecting rod one end is hinged to the frame branch rod (101), the second seven rod unit connecting rod one end is hinged to the offset connecting rod (7), the second seven rod unit connecting rod one end is hinged to the offset connecting rod (9), the connecting rod the other end is hinged to the connecting rod (4); In one branch, the connecting rod (4) is provided with three, the two ends of the connecting rod rotating pair axis angle is 60 degrees, and is connected with the connecting rod (3); In one branch, the offset connecting rod (5) is provided with one, the geometric center contains an offset rotating pair, the axis is perpendicular to the plane of the rod, the two axis angle of the rod is 120 degrees, the two ends of the rotating pair are in the connecting rod (5) plane, the two ends of the rotating pair axis angle is 60 degrees; and the offset rotating pair axis is perpendicular to the two ends of the rotating pair axis plane; the offset rotating pair is hinged with the offset connecting rod (7), and the two ends of the rotating pair are respectively hinged with the offset connecting rod (6) and the offset connecting rod (9); In one branch, the offset connecting rod (6) is provided with one, the geometric center contains an offset rotating pair, the axis is perpendicular to the plane of the rod, the two axis angle of the rod is 120 degrees, the two ends of the rotating pair are in the connecting rod (6) plane, the two ends of the rotating pair axis angle is 60 degrees; and the offset rotating pair axis is perpendicular to the two ends of the rotating pair axis plane; the offset rotating pair is hinged with the offset connecting rod (7), and the two ends of the rotating pair are respectively hinged with the frame connecting rod (101) and the offset connecting rod (5); In one branch, the offset connecting rod (7) is provided with two, the geometric center contains an offset rotating pair, the axis is perpendicular to the plane of the rod, the two axis angle of the rod is 120 degrees, the two ends of the rotating pair are in the connecting rod (7) plane, the two ends of the rotating pair axis angle is 120 degrees; the offset rotating pair is respectively hinged with the offset connecting rod (5) and the offset connecting rod (6), and the two ends of the rotating pair are respectively hinged with the connecting rod (3); In one branch, the offset connecting rod (8) is provided with one, one end contains an offset rotating pair, the axis is perpendicular to the plane of the rod, the other end rotating pair is perpendicular to the axis of the offset connecting rod (8), the offset rotating pair is respectively hinged with the offset connecting rod (9), and the other end rotating pair is hinged with the offset connecting rod (5); In one branch, the offset connecting rod (9) is provided with one, one end contains an offset rotating pair, the axis is perpendicular to the plane of the rod, the other end rotating pair is coincided with the axis of the connecting rod (9), the offset rotating pair is respectively hinged with the offset connecting rod (8), and the other end rotating pair is hinged with the connecting rod (3).

9. The single degree of freedom symmetrical seven-bar closed-loop mechanism and the developable mechanism with complete enveloping performance having five identical branch chains, characterized in that, The same as claim 7, the branch is respectively hinged with the frame (1) branch rod and the frame (2) branch rod.

10. The degree of freedom symmetrical seven-bar closed-loop mechanism and the developable mechanism with complete enveloping performance constructed according to claim 8, characterized in that, The mechanism is composed of five same branches, each branch contains three single degree of freedom seven rod mechanisms, the seven rod mechanisms are coupled through the offset connecting rod, the motion relationship of the single ring mechanism is same in the developable mechanism conversion process, and the corresponding motion relationship between the branches is also same.

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