Space deployable mechanism with symmetric seven-bar units and tensile surface structure

Abstract

The application discloses a kind of space deployable mechanism containing symmetric seven-bar unit and tensile inflation surface structure, belong to mechanism application technical field;Including rack, driving link, link rack rod, Ⅰ type link rack rod, Ⅱ type link, auxiliary link, slider, cross link, Ⅲ type link, Ⅳ type link, Ⅴ type link, Ⅵ type link, Ⅰ type tensile inflation structure, Ⅱ type tensile inflation structure, Ⅲ type tensile inflation structure, Ⅳ type tensile inflation structure;The mechanism is driven by driving link, and tensile inflation structure is carried on the surface of deployable mechanism consisting of symmetric seven-bar closed loop, effectively improve the grasping ability of small target when mechanism executes grasping task, and by auxiliary link transmission torque, so that the whole mechanism has single degree of freedom, control is convenient, rigid, movement is continuous and smooth and the like, has wide application prospect in space / deep sea exploration, end grasping and the like.

Description

Technical Field

[0001] This invention belongs to the field of mechanical application technology, and specifically relates to a spatial deployable mechanism containing symmetrical seven-bar units and a tensile surface structure. Background Technology

[0002] Spatial deployable mechanisms possess the property of unfolding from a folded state to a predetermined configuration, exhibiting advantages such as high stiffness, high reliability, and high stability. In single-closed-loop mechanisms, all components form a closed loop through kinematic pairs, strictly constraining the relative motion between components and resulting in low system degrees of freedom. Furthermore, because the motion of components in a single-closed-loop mechanism is confined within a single loop, motion transmission is more precise, effectively reducing errors. This aligns perfectly with the requirements of grasping tasks, thus spatial deployable mechanisms constructed using single-closed-loop mechanisms are widely adopted in the design and development of grasping mechanisms. However, gaps exist between the links in spatial deployable mechanisms constructed using single-closed-loop mechanisms. When grasping small targets, the target may slip through the links of most existing mechanisms, making it impossible to complete the grasping task. Therefore, combining the advantages of single-closed-loop deployable mechanisms, a novel technical solution is urgently needed to address this problem. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to propose a spatial deployable mechanism composed of a seven-bar single closed loop, and to install a tensile surface structure on the inner surface of the mechanism. This structure can deform with the deformation of the deployable mechanism and always cover the inner surface of the deployable mechanism to protect the grasped target.

[0004] The technical solution provided by this invention is: A single-degree-of-freedom deployable mechanism comprising a single-degree-of-freedom symmetrical seven-bar closed-loop unit and a tensile surface structure includes: a frame, a drive link, a connecting rod, a type I connecting rod, a type II connecting rod, an auxiliary connecting rod, a slider, a cross link, a type III connecting rod, a type IV connecting rod, a type V connecting rod, a type VI connecting rod, a type I tensile structure, a type II tensile structure, a type III tensile structure, and a type IV tensile structure; The frame has a central hole, and the frame and the drive linkage are hinged at the central hole. The geometric center of the revolute joint coincides with the center of the central hole. The frame has four branch rods, with an included angle of 90 degrees between any two adjacent branches, and each branch rod is hinged to the connecting rod. The drive link is hinged to the frame at the center hole. In addition, the drive link is provided with four branch links, and the included angle between two adjacent branch links is 90 degrees. Each branch link is hinged to the type I link. The connecting rod is provided in four parts. One end of the rod is hinged to the frame branch rod through a rotating joint, and the other end is hinged to the type III connecting rod through a rotating joint. The included angle between the axes of the rotating joints at both ends is 45 degrees. There are eight Type I connecting rods, with the included angle of the axis of rotation of each end being 45 degrees. Each pair of Type I connecting rods forms a group. In each group, one end of a Type I connecting rod is hinged to the branch rod of the drive connecting rod via a rotating joint, and the other end is hinged to a Type II connecting rod via a rotating joint. Another Type I connecting rod is hinged to a Type II connecting rod at one end and to a Type VI connecting rod at the other end. The connection method of the other three groups is the same. The type II connecting rod is provided with eight parts, including one central revolute joint and two external revolute joints. External revolute joint I is parallel to the central revolute joint, and the axis of external revolute joint II is perpendicular to the axis of the central revolute joint. External revolute joint I is hinged to the auxiliary connecting rod, external revolute joint II is hinged to the type I connecting rod, and the central revolute joint is hinged to the cross connecting rod. The auxiliary connecting rod is provided in eight parts. The rotating joints at both ends of the connecting rod are parallel. One end of the connecting rod is hinged to the type II connecting rod, and the other end is hinged to the slider. The slider is provided with four parts. The rotating joints at both ends of the slider are parallel and their axes are perpendicular to the axis of the central cylindrical groove. The two external rotating joints are respectively hinged to the two auxiliary connecting rods, and the cylindrical groove is slidably connected to the cylindrical guide rail of the cross connecting rod. The cross-shaped connecting rod has four branches, each with a revolute joint at its end. The branches are spaced at a 90-degree angle to each other, forming a cross shape. A cylindrical guide rail is located at the center of the cross shape and is slidably connected to the slider. The four branches are divided into two groups, with two opposite revolute joints forming one group. The revolute joints of the same group are parallel, while the two revolute joints of different groups are perpendicular to the axes of the three cylindrical guide rails. Two cross revolute joints I are hinged to two type II connecting rods, and two cross revolute joints II are hinged to two type III connecting rods. There are eight Type III connecting rods, with the axes of the rotating joints at both ends perpendicular to each other. Each pair forms a group, with one end of one rod hinged to the connecting rod and the other end hinged to the cross connecting rod; the other end of one rod hinged to the Type IV connecting rod and the other end hinged to the cross connecting rod. The connection method of the other three groups is the same. The type IV connecting rod is provided in four parts, with the included angle between the two rotating sub-axises being 45 degrees. One end of the connecting rod is hinged to the type III connecting rod, and the other end is hinged to the type V connecting rod. There are four V-type connecting rods, with the axes of the two rotating joints at both ends perpendicular to each other. One end of the connecting rod is hinged to the IV-type connecting rod, and the other end is hinged to the VI-type connecting rod. The VI-type connecting rod is provided in four parts, with the axes of the two rotating joints at both ends perpendicular to each other. One end of the connecting rod is hinged to the V-type connecting rod, and the other end is hinged to the I-type connecting rod. There are eight Type I expansion structures, arranged in groups of two. One of them is fixedly connected to Type V and Type VI connecting rods; the other is fixedly connected to a branch rod of the frame and a branch rod of the drive connecting rod. The connection method of the other three groups is the same. The type II expansion structure is provided in four parts, which are fixedly connected to the type I and type IV connecting rods; The type III expansion structure is provided in four parts, which are fixedly connected to two type II connecting rods and a set of type III connecting rods; Four of the type IV expansion structures are provided and are fixedly connected to the connecting rod and the type I connecting rod; Through the above design scheme, the present invention can bring the following beneficial effects: The spatial deployable mechanism based on a single-degree-of-freedom symmetrical seven-bar closed loop and a tensile surface structure is driven by a driving link. The tensile structure is mounted on the surface of the deployable mechanism composed of a symmetrical seven-bar closed loop, which effectively improves the mechanism's ability to grasp small targets when performing grasping tasks. Moreover, by transmitting torque through an auxiliary link, the mechanism as a whole has the advantages of single-degree-of-freedom, convenient control, good rigidity, and continuous and stable motion. It has broad application prospects in the fields of space / deep-sea exploration and end-effector grasping. Attached Figure Description

[0005] Figure 1 This is a schematic diagram of the fully closed structure of the mechanism of the present invention; Figure 2 This is a schematic diagram of the fully deployed structure of the mechanism of the present invention; Figure 3 This is a schematic diagram of the Type II connecting rod, auxiliary connecting rod, slider, and cross connecting rod of the present invention; Figure 4 This is a schematic diagram of the frame and drive linkage structure of the present invention; Figure 5 This is a schematic diagram of the Type II connecting rod structure of the present invention; In the diagram, 1-frame, 2-drive link, 3-connecting rod, 401-type I link I, 402-type I link II, 5-type II link, 6-auxiliary link, 7-slider, 8-cross link, 901-type III link I, 902-type III link II, 10-type IV link, 11-type V link, 12-type VI link, 1301-type I expansion structure I, 1302-type I expansion structure II, 14-type II expansion structure, 15-type III expansion structure, 16-type IV expansion structure, 101-frame branch rod, 201-drive link branch rod. Detailed Implementation

[0006] The present invention will be further described below with reference to the embodiments: A spatially deployable mechanism with a single degree of freedom, symmetric seven-bar closed-loop structure, and tensile surface structure, such as... Figure 1 , Figure 2 , Figure 3 It includes a frame 1, a drive link 2, a connecting rod 3, a type I link 1 401, a type I link 2 402, a type II link 5, an auxiliary link 6, a slider 7, a cross link 8, a type III link 1 901, a type III link 2 902, a type IV link 10, a type V link 11, a type VI link 12, a type I expansion structure 1 1301, a type I expansion structure 2 1302, a type II expansion structure 14, a type III expansion structure 15, a type IV expansion structure 16, a frame branch rod 101, and a drive link branch rod 201; The frame 1 has a central hole, and the frame 1 and the drive connecting rod 2 are hinged at the central hole. The geometric center of the rotating joint coincides with the center of the central hole. The frame 1 has four branch rods, and the included angle between two adjacent branch rods 101 is 90 degrees. Each branch rod 101 is hinged to the connecting rod 3. The drive link 2 is hinged to the frame 1 at the center hole. In addition, the drive link 2 is provided with four branch links, and the included angle between two adjacent branch links 201 is 90 degrees. Each branch link 201 is hinged to the type I link I401. The connecting rod 3 is provided in four parts. One end of the rod is hinged to the branch rod of the frame 1 through a rotating joint, and the other end is hinged to the type III connecting rod II902 through a rotating joint. The included angle between the axes of the rotating joints at both ends is 45 degrees. Four Type I connecting rods I401 are provided, with the included angle between the axes of the two rotating joints at both ends being 45 degrees. One end of the rod is hinged to the branch rod 201 of the driving connecting rod 2 via a rotating joint, and the other end is hinged to the Type II connecting rod 5 via a rotating joint. The type III connecting rod II902 is provided in four parts, one end of which is hinged to the connecting rod 2, and the other end is hinged to the cross connecting rod 8; The type II connecting rod 5 is provided with eight rods, including one central rotating joint and two external rotating joints. The external rotating joint I is parallel to the central rotating joint, and the axis of the external rotating joint II is perpendicular to the axis of the central rotating joint. The external rotating joint I is hinged to the auxiliary connecting rod 6, the external rotating joint II is hinged to the type I connecting rod I401, and the central rotating joint is hinged to the cross connecting rod 8. The auxiliary connecting rod 6 is provided with eight rods. The rotating joints at both ends of the connecting rod are parallel. One end of the rod is hinged to the type II connecting rod 5, and the other end is hinged to the slider 7. The slider 7 is provided with four parts. The rotating joints at both ends of the slider 7 are parallel and the axis is perpendicular to the axis of the central cylindrical groove. The two rotating joints are respectively hinged to the two auxiliary connecting rods 6, and the cylindrical groove is slidably connected to the cylindrical guide rail of the cross connecting rod 8. The cross link 8 is provided with four branches, each with a revolute joint at its end. The branches are at a 90-degree angle to each other, forming a cross shape. A cylindrical guide rail is provided at the center of the cross, which is slidably connected to the slider 7. The four branches can be divided into two groups, with two opposite revolute joints forming one group. The revolute joints of the same group are parallel, while the two revolute joints of different groups are perpendicular to the axes of the three cylindrical guide rails. The two cross revolute joints I are respectively hinged to the two type II links 5, and the two cross revolute joints II are respectively hinged to type III links I 901 and type III links II 902. The type III connecting rod I901 is provided in four parts, with the axes of the rotating joints at both ends perpendicular to each other. One end is hinged to the type IV connecting rod 10, and the other end is hinged to the cross connecting rod 8. The type I connecting rod II402 is provided in four parts, with the included angle between the two ends of the rotating sub-axis being 45 degrees. One end is hinged to the type II connecting rod 5, and the other end is hinged to the type VI connecting rod 12. The type IV connecting rod 10 is provided in four parts, with the included angle between the two rotating sub-axises being 45 degrees. One end of the connecting rod is hinged to the type III connecting rod I901, and the other end is hinged to the type V connecting rod 11. There are four V-type connecting rods 11, with the axes of the two rotating joints at both ends perpendicular to each other. One end of the connecting rod is hinged to the IV-type connecting rod 10, and the other end is hinged to the VI-type connecting rod 12. There are eight Type I expansion structures 13, with two in each group. Type I expansion structure I 1301 is fixedly connected to a branch rod 101 of frame 1 and a branch rod 201 of drive link 2. Type I expansion structure II 1302 is fixedly connected to Type V link 11 and Type VI link 12. The connection method of the other three groups is the same. Four type II expansion structures 14 are provided, which are fixedly connected to type I connecting rod II 402 and type IV connecting rod 10; The type III expansion structure 15 is provided in four parts, and is fixedly connected to two type II connecting rods 5, one type III connecting rod I 901, and one type III connecting rod II 902; Four of the type IV expansion structures 16 are provided and are fixedly connected to the connecting rod 3 and the type I connecting rod I401; The spatial deployable mechanism is a single-degree-of-freedom mechanism. It is driven by the rotation of the drive link around the central hole of the frame, thereby switching between the folded and unfolded states of the mechanism. The specific process is as follows: the rotation of the drive link 2 is transmitted to the type II link 5 through four type I links I 401, causing it to rotate around its own central rotary joint. The type II link 5 is transmitted to the opposite type II link 5 through the auxiliary link 6 and the slider 7. Finally, it is transmitted to the type V link 11 and the type VI link 12 through the type I link II 402, completing the unfolding / folding of the mechanism. Through the above design scheme, the present invention can bring the following beneficial effects: The spatial deployable mechanism of the present invention, which is a single-degree-of-freedom symmetrical seven-bar closed-loop and tensile surface structure, is driven by a driving link. The tensile structure is mounted on the surface of the deployable mechanism, which effectively improves the mechanism's ability to grasp small targets when performing grasping tasks. Moreover, by transmitting torque through the auxiliary link, the mechanism as a whole has the advantages of single degree of freedom, convenient control, good rigidity, and continuous and stable motion. It has broad application prospects in the fields of space / deep sea exploration and end-effector grasping.

Claims

1. A spatially deployable mechanism comprising symmetrical seven-bar units and a tensile surface structure, characterized in that, include: Frame, drive linkage, connecting rod, type I connecting rod, type II connecting rod, auxiliary connecting rod, slider, cross linkage, type III connecting rod, type IV connecting rod, type V connecting rod, type VI connecting rod, type I expansion structure, type II expansion structure, type III expansion structure and type IV expansion structure; The frame has a central hole, and the frame and the drive linkage are hinged at the central hole. The geometric center of the rotating pair coincides with the center of the central hole. The drive link is hinged to the frame at the center hole. In addition, the drive link is provided with four branch links, and the included angle between two adjacent branch links is 90 degrees. Each branch link is hinged to the type I link. The connecting rod is provided in four parts. One end of the rod is hinged to the frame branch rod through a rotating joint, and the other end is hinged to the type III connecting rod through a rotating joint. The included angle between the axes of the rotating joints at both ends is 45 degrees. There are eight Type I connecting rods, with the included angle of the axis of rotation of each end being 45 degrees. Each pair of Type I connecting rods forms a group. In each group, one end of a Type I connecting rod is hinged to the branch rod of the drive connecting rod via a rotating joint, and the other end is hinged to a Type II connecting rod via a rotating joint. Another Type I connecting rod is hinged to a Type II connecting rod at one end and to a Type VI connecting rod at the other end. The connection method of the other three groups is the same. The type II connecting rod is provided with eight parts, including one central revolute joint and two external revolute joints. External revolute joint I is parallel to the central revolute joint, and the axis of external revolute joint II is perpendicular to the axis of the central revolute joint. External revolute joint I is hinged to the auxiliary connecting rod, external revolute joint II is hinged to the type I connecting rod, and the central revolute joint is hinged to the cross connecting rod. The auxiliary connecting rod is provided in eight parts. The rotating joints at both ends of the connecting rod are parallel. One end of the connecting rod is hinged to the type II connecting rod, and the other end is hinged to the slider. The slider is provided with four parts. The rotating joints at both ends of the slider are parallel and their axes are perpendicular to the axis of the central cylindrical groove. The two external rotating joints are respectively hinged to the two auxiliary connecting rods, and the cylindrical groove is slidably connected to the cylindrical guide rail of the cross connecting rod. The cross-shaped connecting rod has four branches, each with a revolute joint at its end. The branches are spaced at a 90-degree angle to each other, forming a cross shape. A cylindrical guide rail is located at the center of the cross shape and is slidably connected to the slider. The four branches are divided into two groups, with two opposite revolute joints forming one group. The revolute joints of the same group are parallel, while the two revolute joints of different groups are perpendicular to the axes of the three cylindrical guide rails. Two cross revolute joints I are hinged to two type II connecting rods, and two cross revolute joints II are hinged to two type III connecting rods. There are eight Type III connecting rods, with the axes of the rotating joints at both ends perpendicular to each other. They are arranged in groups of two. One end of one Type III connecting rod in each group is hinged to the connecting rod, and the other end is hinged to the cross connecting rod. The other Type III connecting rod is hinged to Type IV connecting rod, and the other end is hinged to the cross connecting rod. The type IV connecting rod is provided in four parts, with the included angle between the two rotating sub-axises being 45 degrees. One end of the connecting rod is hinged to the type III connecting rod, and the other end is hinged to the type V connecting rod. There are four V-type connecting rods, with the axes of the two rotating joints at both ends perpendicular to each other. One end of the connecting rod is hinged to the IV-type connecting rod, and the other end is hinged to the VI-type connecting rod. The VI-type connecting rod is provided in four parts, with the axes of the two rotating joints at both ends perpendicular to each other. One end of the connecting rod is hinged to the V-type connecting rod, and the other end is hinged to the I-type connecting rod. There are eight Type I expansion structures, arranged in groups of two. In each group, one Type I expansion structure is fixedly connected to Type V and Type VI connecting rods; the other Type I expansion structure is fixedly connected to a branch rod of the frame and a branch rod of the drive connecting rod. The type II expansion structure is provided in four parts, which are fixedly connected to the type I and type IV connecting rods; The type III expansion structure is provided in four parts, which are fixedly connected to two type II connecting rods and a set of type III connecting rods.

2. The spatially deployable mechanism containing a symmetrical seven-bar unit and a tensile surface structure according to claim 1, characterized in that, Four of the type IV expansion structures are provided and are fixedly connected to the connecting rod and the type I connecting rod; The frame has four branches, with an angle of 90 degrees between any two adjacent branches, and each branch is hinged to a connecting rod.

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