A square rotating rigid body structure with compression-torsion characteristics

Abstract

The present invention relates to a square rotating rigid body structure with compression-torsion characteristics, which belongs to the field of mechanical metamaterials, and includes two tensegrity cellular structures, wherein the cellular structure includes two parts: a four-bar tensegrity structural component and a degree of freedom constraint component. Under the action of the four-bar twelve-cable tensegrity structure, when the structure is not subjected to external loads, the structure is subjected to the interaction of internal stresses and reaches equilibrium in a self-stable state; when subjected to external loads, the upper and lower surfaces of the cellular structure will produce a torsional effect, and once the external load is removed, the structure will return to its initial state. A square rotating rigid body structure with compression-torsion characteristics has the advantages of adaptability, self-recovery, indentation resistance characteristics, and the like. The present invention combines the tensegrity structure with the mechanical metamaterial structure, enriches the types of existing mechanical metamaterial cellular structures, and opens up a new direction for the design, analysis, and application of tensegrity mechanical metamaterial structures.

Description

Technical Field

[0001] The present invention belongs to the field of mechanical metamaterials and can be applied to the fields of robots, shock absorption, impact resistance, etc. More specifically, it relates to a square rotating rigid body structure with compression torsion characteristics. Background Art

[0002] Metamaterials are non-natural materials whose properties are derived from their structure rather than their chemical composition. They are artificial synthetic materials with special structures that exhibit very unique properties in the fields of mechanics, electromagnetic waves, and sound waves. According to the application field, metamaterials can be divided into four categories: electromagnetic metamaterials, acoustic metamaterials, thermal metamaterials, and mechanical metamaterials. Negative Poisson's ratio metamaterials are a branch of mechanical metamaterials, which means that when they are subjected to pressure, the ratio of the lateral normal strain to the axial normal strain in a certain direction (Poisson's ratio) is negative. This material has many unique properties, such as highly controllable elasticity, light weight, and high strength. It can be used in various fields, such as robotics, medicine, aerospace, etc., making its research and application have great potential and has received widespread attention in recent years.

[0003] At present, the structural design of existing mechanical metamaterials has a single cellular structure, and negative Poisson's ratio metamaterials are mostly integrated structures with low reusability. In addition, many designs to date rely on the deformation or evolution of existing metamaterial structures, and it is impossible to systematically design geometric and topological shapes to obtain new metamaterial structures with negative Poisson's ratio effect.

[0004] Therefore, how to enrich the types of mechanical metamaterials and design a mechanical metamaterial that can be reused, has adjustable self-stiffness, and has adaptability, self-stability, and self-recovery is an urgent problem that technicians in this field need to solve. Summary of the invention

[0005] To this end, the present invention provides a square rotating rigid body structure with compression-torsion characteristics. By combining the tensegrity structure with the mechanical metamaterial structure, the types of negative Poisson's ratio metamaterial cells are enriched and the mechanical properties of traditional mechanical metamaterials are improved.

[0006] The present invention provides a square rotation rigid body structure with compression-torsion characteristics, comprising a first connecting axis and two tensioned cellular structures with different connection modes based on a four-bar tensioned structure: a first tensioned cellular structure and a second tensioned cellular structure; the first tensioned cellular structures have a total of five groups, and the second tensioned cellular structures have a total of four groups, thereby forming a nine-cell structure of a square rotation rigid body structure with compression-torsion characteristics; the nine-cell metamaterial structure is only one of the square rotation rigid body structures with compression-torsion characteristics, and the square rotation rigid body structure with compression-torsion characteristics comprises other multi-cell structures of the square rotation rigid body structure with compression-torsion characteristics which are composed of the first tensioned cellular structure and the second tensioned cellular structure, and are extended by the same connection mode as the first tensioned cellular structure and the second tensioned cellular structure in the nine-cell metamaterial structure; except for the different connection modes, the first tensioned cellular structure and the second tensioned cellular structure have the same components and connection modes of the components.

[0007] Each group of the first tensile cell structure or each group of the second tensile cell structure includes: a degree of freedom constraint component and a four-bar tensile integral structure component; the degree of freedom constraint component includes a square frame, a sliding component, a rod connector and a second connecting shaft; the four-bar tensile integral structure component includes a first tension elastic body, a second tension elastic body and a connecting rod; there are two groups of square frames, which are respectively placed at the upper and lower ends of the entire structure, and hinge holes are arranged at the outer edge positions of the four corners of the square frame. Four regular quadrangular prism structures inside the structure are arranged in a 90° ring array, and an octagonal structure is arranged at the center of the structure and fixedly connected to the regular quadrangular prism structure. The function of the hinge hole position is to enable the cell structure to be hingedly connected through the hinge hole position, the regular quadrangular prism structure plays a guiding role, and the octagonal structure in the middle plays a limiting role.

[0008] Each group of the first tension cell structure or each group of the second tension cell structure includes: there are eight groups of sliding parts, which are respectively installed on the regular quadrangular prism structures of the two groups of square frames, and the short axis is designed at the lower end of the sliding part; there are eight groups of rod connectors, and through holes are provided on the upper end surface of the structure to cooperate with the short axis at the lower end of the sliding part to achieve free rotation; the four groups of sliding parts fixed on the regular quadrangular prism structure of the square frame below are arranged opposite to the four groups of sliding parts fixed on the regular quadrangular prism structure of the square frame above, and the four groups of rod connectors rotatably connected to the four groups of sliding parts below are arranged opposite to the four groups of rod connectors rotatably connected to the four groups of sliding parts above; there are eight groups of second connecting shafts; there are eight groups of first tension elastic bodies, and the two ends of each group of the first tension elastic bodies are respectively fixedly connected to the side surfaces of two adjacent groups of sliding parts arranged on the same group of square frames.

[0009] The four-rod and twelve-cable tensegrity structure has two different connection methods, which can achieve different deformation effects during compression. The first end of the rod of the four-rod and twelve-cable tensegrity structure is connected to a vertex on the bottom surface of a regular tetrahedron in space, and the second end is connected to the diagonal vertex of the side rectangle of the regular tetrahedron, and each rod is spatially staggered and connected in sequence.

[0010] Each group of the first tension cell structure or each group of the second tension cell structure includes: there are four groups of connecting rods, and both ends of each group of connecting rods are respectively hinged to the rod connecting members through the second connecting axis, the spatial position of each group of connecting rods is the same as the spatial position of the rods of the four-rod twelve-cable tensioned integral structure, and each group of connecting rods is spatially staggered in sequence; there are four groups of the second tension elastic bodies, and both ends of each group of the second tension elastic bodies are respectively fixedly connected to the lower end of one group of connecting rods and the upper end of another adjacent group of connecting rods.

[0011] Each group of the first tensioned cellular structures and each group of the second tensioned cellular structures are hingedly connected through hinge holes at four corner positions of the square frame via the first connecting axis.

[0012] It can be known from the above technical solutions that compared with the prior art, the present invention discloses a square rotating rigid body structure with compression-torsion characteristics. Under the action of the four-rod twelve-cable tensegrity structure, when the structure is not subjected to external loads, the structure is subjected to the interaction of internal stresses and reaches equilibrium in a self-stable state; when subjected to external loads, the upper and lower surfaces of the cell structure will produce a torsional effect, and once the external load is removed, the structure will return to its initial state. A square rotating rigid body structure with compression-torsion characteristics has the advantages of adaptability, self-recovery, and indentation resistance characteristics. The present invention enriches the types of existing mechanical metamaterial cell structures by combining the tensegrity structure with the mechanical metamaterial structure, and opens up a new direction for the design, analysis, and application of tensegrity mechanical metamaterial structures.

[0013] Another object of the present invention is to provide a square rotating rigid body structure with compression-torsion characteristics, including a device body and the above-mentioned square rotating rigid body structure with compression-torsion characteristics connected thereto. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0015] Figure 1 The accompanying drawing is a schematic diagram of a first tension cell structure of a square rotating rigid body structure with compression-torsion characteristics provided by the present invention.

[0016] Figure 2 The accompanying drawing is a front view of a first tension cell structure of a square rotating rigid body structure with compression-torsion characteristics provided by the present invention.

[0017] Figure 3 The accompanying drawing is a top view of a first tension cell structure of a square rotating rigid body structure with compression-torsion characteristics provided by the present invention.

[0018] Figure 4 The accompanying drawing is a partial exploded schematic diagram of a first tension cell structure of a square rotating rigid body structure with compression-torsion characteristics provided by the present invention.

[0019] Figure 5 The accompanying drawing is a partial exploded schematic diagram of the connection part of the first tension cell structure degree of freedom constraint component of a square rotating rigid body structure with compression and torsion characteristics provided by the present invention.

[0020] Figure 6 The accompanying drawing is a schematic structural diagram of a first tension cell structure of a square rotating rigid body structure with compression-torsion characteristics provided by the present invention under a loaded state.

[0021] Figure 7 The accompanying drawings are structural diagrams of different connection modes of rod members of a four-rod and twelve-cable tensegrity structure in a square rotating rigid body structure with compression-torsion characteristics provided by the present invention.

[0022] Figure 8 The accompanying drawing is a schematic diagram of a second tension cell structure of a square rotating rigid body structure with compression-torsion characteristics provided by the present invention.

[0023] Fig. 9 The accompanying drawing is a schematic structural diagram of a second tension cell structure of a square rotating rigid body structure with compression-torsion characteristics provided by the present invention under a loaded state.

[0024] Fig.10 The accompanying drawing is a schematic diagram of a square rotating rigid body structure with compression-torsion characteristics provided by the present invention.

[0025] Fig.11 The accompanying drawing is a top view of a square rotating rigid body structure with compression-torsion characteristics provided by the present invention.

[0026] Fig.12 The accompanying drawing is a top view of the structure of a square rotating rigid body structure with compression-torsion characteristics provided by the present invention under a loaded state.

[0027] Among them, 1001-first tensile cell structure; 1002-second tensile cell structure; 300-first connecting axis; 100-degree of freedom constraint component; 101-square frame; 102-sliding component; 103-rod connector; 104-second connecting axis; 200-four-rod tensile integral structure component; 201-first tension elastic body; 202-second tension elastic body; 203-connecting rod. DETAILED DESCRIPTION

[0028] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0029] In the description of the present invention, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0030] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0032] In terms of structural design, existing mechanical metamaterials have a single cell structure, and negative Poisson's ratio metamaterials are mostly integrated structures with low reusability. In addition, many designs to date rely on the deformation or evolution of existing metamaterial structures, and it is impossible to systematically design geometric and topological shapes to obtain new metamaterial structures with negative Poisson's ratio effects.

[0033] In view of this, the embodiment of the present invention discloses a square rotating rigid body structure with compression torsion characteristics, see the attached Figure 1-12 , including a first connecting shaft 300 and two tension cell structures with different connection modes based on a four-bar tension structure: a first tension cell structure 1001 and a second tension cell structure 1002; the first tension cell structure 1001 has five groups, and the second tension cell structure 1002 has four groups, thereby forming a nine-cell structure of a square rotation rigid body structure with compression-torsion characteristics; the nine-cell metamaterial structure is only one of the square rotation rigid body structures with compression-torsion characteristics, and the square rotation rigid body structure with compression-torsion characteristics includes other multi-cell structures of a square rotation rigid body structure with compression-torsion characteristics that are formed by the first tension cell structure 1001 and the second tension cell structure 1002, and are extended by the same connection mode as the first tension cell structure 1001 and the second tension cell structure 1002 in the nine-cell metamaterial structure. Except for the different connection modes, the first tension cell structure 1001 and the second tension cell structure 1002 have the same components and connection modes of the components. Each group of the first tensile cell structure 1001 and each group of the second tensile cell structure 1002 include: a degree of freedom constraint component 100 and a four-bar tensile integral structure component 200; the degree of freedom constraint component 100 includes a square frame 101, a sliding component 102, a rod connector 103 and a second connecting shaft 104; the four-bar tensile integral structure component 200 includes a first tension elastic body 201, a second tension elastic body 202 and a connecting rod 203; there are two groups of square frames 101, which are respectively placed at the upper and lower ends of the entire structure, and hinge holes are arranged at the outer edge positions of the four corners of the square frame 101. Four regular quadrangular prism structures inside the structure are arranged in a 90° circular array, and an octagonal structure is arranged at the center of the structure and fixedly connected to the regular quadrangular prism structure. The function of the hinge hole position is to enable the cell structure to be hingedly connected through the hinge hole position, the regular quadrangular prism structure plays a guiding role, and the octagonal structure in the middle plays a limiting role.

[0034] See attached Figure 4 , Attachment Figure 5In the embodiment of the present invention, each group of the first tension cell structure 1001 includes: there are eight groups of sliding parts 102, which are respectively installed on the regular quadrangular prism structures of the two groups of square frames 101, and the lower end of the sliding parts 102 is designed with a short axis; there are eight groups of rod connectors 103, and the upper end surface of the structure is provided with a through hole, which cooperates with the short axis of the lower end of the sliding part 102 to achieve free rotation; the four groups of sliding parts 102 fixed on the regular quadrangular prism structure of the square frame 101 below and the four groups of sliding parts 102 fixed on the regular quadrangular prism structure of the square frame 101 above are arranged in opposite directions, and the four groups of rod connectors 103 rotatably connected to the four groups of sliding parts 102 below and the four groups of rod connectors 103 rotatably connected to the four groups of sliding parts 102 above are arranged in opposite directions; there are eight groups of the second connecting shafts 104.

[0035] See attached Figure 4 Each group of the first tension cell structures 1001 includes: there are eight groups of the first tension elastic bodies 201, and both ends of each group of the first tension elastic bodies 201 are respectively fixedly connected to the side surfaces of two adjacent groups of the sliding components 102 arranged on the same group of square frames 101.

[0036] See attached Figure 7 The four-rod and twelve-cable tensegrity structure has two different connection methods, which can achieve different deformation effects during compression. The first end of the rod of the four-rod and twelve-cable tensegrity structure is connected to a vertex of the bottom surface of the regular tetrahedron in space, and the second end is connected to the diagonal vertex of the side rectangle of the regular tetrahedron, and each rod is connected in sequence in a staggered manner in space.

[0037] In a preferred embodiment of the present invention, each group of the first tension cell structure 1001 includes: there are four groups of connecting rods 203, both ends of each group of connecting rods 203 are respectively hinged to the rod connector 103 through the second connecting axis 104, the spatial position of each group of connecting rods 203 is the same as the spatial position of the four-rod twelve-cable tensioned integral structure rods, and each group of connecting rods 203 are spatially staggered and connected in sequence.

[0038] Different deformation effects caused by different connection methods are: one is that the upper square frame 101 rotates clockwise relative to the lower square frame 101 in the top view direction after being loaded; the other is that the upper square frame 101 rotates counterclockwise relative to the lower square frame 101 in the top view direction after being loaded.

[0039] See attached Figure 5In the embodiments of the first tension cell structure 1001 and the second tension cell structure 1002 provided by the present invention, when working, the four groups of sliding components 102 fixed on the regular quadrangular prism structure of the square frame 101 below need to limit the sliding freedom. The rotation angle of the structure and the overall stiffness of the cell structure can be adjusted by adjusting the positions of the four groups of sliding components 102 on the regular quadrangular prism structure of the square frame 101 below. The connecting rod 203 is designed to be S-shaped in order to avoid interference and enable the cell structure to rotate at a larger angle.

[0040] In a preferred embodiment of the present invention, there are four groups of the second tension elastic bodies 202, and both ends of each group of the second tension elastic bodies 202 are fixedly connected to the lower end of one group of the connecting rods 203 and the upper end of another adjacent group of the connecting rods 203.

[0041] See attached Figure 1 and attached Figure 6 The working mode of the embodiment of the first tensioned cellular structure 1001 provided by the present invention is mainly that the cellular structure is under the action of the four-bar twelve-cable tensioned overall structure. When the structure is not subjected to external loads, the structure is subjected to the interaction of internal stresses and reaches equilibrium in a self-stable state; when subjected to external loads, the upper and lower surfaces will produce a torsional effect, and after the external loads are removed, the structure will return to its initial state.

[0042] See attached Figure 8 and attached Fig. 9 The working mode of the embodiment of the second tensioned cellular structure 1002 provided by the present invention is mainly that the cellular structure is under the action of the four-bar twelve-cable tensioned overall structure. When the structure is not subjected to external loads, the structure is subjected to the interaction of internal stresses and reaches equilibrium in a self-stable state; when subjected to external loads, the upper and lower surfaces will produce a torsional effect, and the torsional direction is opposite to that of the embodiment of the first tensioned cellular structure. After the external load is removed, the structure will return to its initial state.

[0043] See attached Figure 10-12 Each group of the first tension cell structures 1001 and each group of the second tension cell structures 1002 are hinged at the hinge holes at the four corners of the square frame 101 through the first connecting axis 300, and when the structure is subjected to load, the deformation of the entire structure will show a negative Poisson's ratio effect.

[0044] The present invention provides a square rotating rigid body structure with compression-torsion characteristics, which has the advantages of adaptability, self-recovery, indentation resistance, etc.; the present invention enriches the types of existing mechanical metamaterial cell structures by combining the tensegrity structure with the mechanical metamaterial structure, and opens up a new direction for the design, analysis and application of tensegrity mechanical metamaterial structures; the present invention has important academic significance. The square rotating rigid body structure with compression-torsion characteristics provided by the present invention has a simple structure, is expected to be vigorously developed, and can realize its application value in many fields.

[0045] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification.

[0046] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A square rotating rigid body structure with compression-torsion characteristics, characterized in that: The invention relates to a tensile cellular structure comprising a first connecting axis (300) and two different connection modes of a four-bar tensile structure: a first tensile cellular structure (1001) and a second tensile cellular structure (1002); the first tensile cellular structures (1001) have five groups in total, and the second tensile cellular structures (1002) have four groups in total; except for the different connection modes, the first tensile cellular structures (1001) and the second tensile cellular structures (1002) have the same components and connection modes of the components; each group of the first tensile cellular structures (1001) and each group of the second tensile cellular structures (1002) include: a degree of freedom constraint component (100) and a four-bar tensile integral structure component (200); The degree of freedom constraint assembly (100) comprises a square frame (101), a sliding component (102), a rod connecting component (103) and a second connecting shaft (104); the four-bar tensegrity structural assembly (200) comprises a first tension elastic body (201), a second tension elastic body (202) and a connecting rod (203); the square frame (101) has two groups, which are respectively arranged at the upper and lower ends of the entire structure; hinge holes are respectively arranged at the outer edge positions of the four corners of the square frame (101); four regular quadrangular prism structures are arranged in a 90° annular array inside the structure; an octagonal structure is arranged at the center of the structure and is fixedly connected to the regular quadrangular prism structure; the sliding component (102) has eight groups, which are respectively installed On the regular quadrangular prism structures of the two groups of square frames (101), short shafts are designed at the lower ends of the sliding components (102); there are eight groups of rod connectors (103), and through holes are provided on the upper end surfaces of the structures to cooperate with the short shafts at the lower ends of the sliding components (102) to achieve free rotation; the four groups of sliding components (102) fixed on the regular quadrangular prism structures of the lower square frames (101) and the four groups of sliding components (102) fixed on the regular quadrangular prism structures of the upper square frames (101) are arranged in opposite directions, and the four groups of rod connectors (103) rotatably connected to the four groups of sliding components (102) at the lower sides and the four groups of rod connectors (103) rotatably connected to the four groups of sliding components (102) at the upper sides are arranged in opposite directions. The connecting members (103) are arranged in opposite directions; there are eight groups of the second connecting shafts (104); there are eight groups of the first tension elastic bodies (201); the two ends of each group of the first tension elastic bodies (201) are respectively fixedly connected to the sides of two adjacent groups of sliding components (102) arranged on the same group of square frames (101); there are four groups of the connecting rods (203); the two ends of each group of the connecting rods (203) are respectively hinged to the rod connecting members (103) through the second connecting shafts (104); the spatial position of each group of the connecting rods (203) is the same as the spatial position of the rods of the four-rod twelve-cable tensioned integral structure; and each group of the connecting rods (203) are spatially staggered and connected in sequence;There are four groups of the second tension elastic bodies (202), and the two ends of each group of the second tension elastic bodies (202) are respectively fixedly connected to the lower end of one group of the connecting rods (203) and the upper end of another adjacent group of the connecting rods (203).

2. A square rotating rigid body structure with compression-torsion characteristics according to claim 1, characterized in that: Each group of the first tensioned cellular structures (1001) and each group of the second tensioned cellular structures (1002) are hinged at hinge holes at four corner positions of the square frame (101) via the first connecting axis (300), thereby forming a nine-cell structure of a square rotational rigid body structure with compression-torsion characteristics.

3. A square rotating rigid body structure with compression-torsion characteristics according to claim 2, characterized in that: Other multi-cellular structures and devices including a square rotating rigid body structure with compression-torsion characteristics, which is composed of the first tensile cellular structure (1001) and the second tensile cellular structure (1002) and is extended in the same connection mode as the first tensile cellular structure (1001) and the second tensile cellular structure (1002) in the nine-cell metamaterial structure.

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