Rigidity-variable chain type lattice structure

Abstract

The invention discloses a variable-stiffness chain type lattice structure. When the lattice structure is controlled in the first direction and the second direction, the multiple first unit cells are arranged at intervals in the first direction and the second direction respectively, the two ends of the multiple second unit cells are arranged between every two adjacent first unit cells in a sleeving mode respectively, and projection parts of the second unit cells and the two adjacent first unit cells on the horizontal plane coincide. When the lattice structure is controlled in the first direction, the second unit cells are arranged in the first direction and the second direction, the second unit cells arranged in the first direction are arranged on the adjacent second unit cells in a sleeving mode, and the fourth connecting rings of the second unit cells and the fourth connecting rings of the adjacent second unit cells are in a horizontal arrangement state and a vertical arrangement state correspondingly; the driving parts penetrate through the second connecting holes of the second unit cells in the first direction. The variable-stiffness chain type lattice structure has the advantages of excellent load capacity, high response speed, high stability and simple structure.

Description

Technical Field

[0001] The present application relates to the technical field of variable stiffness structures, and in particular to a variable stiffness chain lattice structure. Background Art

[0002] A variable stiffness structure is a structural system that can dynamically adjust its stiffness according to external conditions or control signals. Compared with traditional fixed stiffness structures, variable stiffness structures have the ability to flexibly switch between multiple stiffness states, so that they can better adapt to different working conditions or achieve specific functional requirements. Due to its high efficiency and wide adaptability, variable stiffness structures have shown great potential and value in modern robotics and other engineering applications.

[0003] Variable stiffness technology is mainly divided into two categories: material variable stiffness method and structural variable stiffness method. The material variable stiffness method achieves the change of stiffness by changing the physical properties of the material. Although it can produce a large change in elastic modulus, its response speed is relatively slow and the stiffness adjustment range is limited. In contrast, the structural variable stiffness method is more flexible and efficient, and can quickly adjust the stiffness of the structure in a wider range.

[0004] Among the methods of structural variable stiffness, particle blocking is a common technical means. However, this method faces some challenges in practical application: it requires a large number of particles to build the system, which not only increases the material cost, but also may increase the complexity of system design. In addition, the mobility of particles makes the particle arrangement uncertain, which may reduce the overall stiffness improvement effect of the system and affect the stability of the system. Summary of the invention

[0005] The embodiments of the present application overcome the defects of the above-mentioned background technology by providing a variable stiffness chain lattice structure.

[0006] In the first aspect, an embodiment of the present application provides a variable stiffness chain lattice structure, including multiple driving members, multiple first unit cells and multiple second unit cells; multiple first unit cells each include a first connecting ring, a second connecting ring and a third connecting ring; the first connecting ring is vertically connected to the second connecting ring and the third connecting ring, respectively, and the second connecting ring is vertically connected to the third connecting ring; when observed from the plane of the first connecting ring, the projections of the second connecting ring and the third connecting ring are both located in the middle of the first connecting ring; four first connecting holes are evenly arranged on the circumference of the first connecting ring; multiple second unit cells each include a fourth connecting ring, a fifth connecting ring and a sixth connecting ring; the fourth connecting ring is vertically connected to the fifth connecting ring and the third connecting ring, respectively. The sixth connecting ring, the fifth connecting ring is vertically connected to the sixth connecting ring; when observed from the plane of the fourth connecting ring, the projections of the fifth connecting ring and the sixth connecting ring are both located in the middle of the fourth connecting ring; the fourth connecting ring is circumferentially provided with two second connecting holes; when the lattice structure is controlled along the first direction and the second direction, a plurality of the first unit cells are respectively spaced along the first direction and the second direction, and the two ends of a plurality of the second unit cells are respectively sleeved between two adjacent first unit cells, so that the projections of the second unit cells and the two adjacent first unit cells in the horizontal plane partially overlap, in this state, the first connecting ring of the first unit cell is horizontally arranged, and the fourth connecting ring of the second unit cell is vertically arranged. Setting: the first connecting holes relatively arranged along the first direction and the second direction of the plurality of first connecting rings formed a straight line, and the second connecting holes relatively arranged along the second unit cell correspond to the first connecting holes respectively; the plurality of driving members pass through the first connecting holes of the first unit cell and the second connecting holes of the second unit cell in the first direction and the second direction respectively; the axial direction of the driving member in the first direction is perpendicular to the axial direction of the driving member in the second direction, and the driving member is configured to drive the lattice structure in the first direction and the second direction from loose to compact, so as to form a single-layer two-way lattice structure; when the lattice structure is controlled along the first direction alone, the plurality of second unit cells are arranged along the first direction The first direction and the second direction are set, wherein the second unit cell set along the first direction is sleeved on the adjacent second unit cell, the projections of the second unit cell and the adjacent second unit cell on the horizontal plane partially overlap, the fourth connecting ring of the second unit cell and the fourth connecting ring of the adjacent second unit cell are respectively in a horizontal setting state and a vertical setting state, and a plurality of second connecting holes relatively set in the second unit cells form a straight line; the outer wall of the second unit cell set along the second direction is connected to the outer wall of the adjacent second unit cell, and a plurality of the driving members respectively pass through the second connecting holes of the second unit cells in the first direction, and the driving members are configured to drive the lattice structure in the first direction from loose to compact to form a single-layer unidirectional lattice structure.

[0007] In a possible implementation manner, the first connecting ring, the second connecting ring, the third connecting ring, the fourth connecting ring, the fifth connecting ring, and the sixth connecting ring are all circular connecting rings having equal diameters.

[0008] In a possible implementation, the first connecting ring and the fourth connecting ring are both square connecting rings; the second connecting ring, the third connecting ring, the fifth connecting ring and the sixth connecting ring are all circular connecting rings, and their diameters are equal; the side length of the square connecting ring is equal to the diameter of the circular connecting ring; the four corners of the first connecting ring are all arc-shaped structures, and the four first connecting holes are all arranged at the vertices of the corresponding four arc-shaped structures; the two oppositely arranged corners of the fourth connecting ring are both arc-shaped structures, the two second connecting holes are both arranged at the vertices of the corresponding arc-shaped structures, and the remaining two oppositely arranged corners of the fourth connecting ring are both arranged as quarter circles equal to the side length of the fourth connecting ring.

[0009] In a possible implementation, the first unit cell and the second unit cell are both made of nylon.

[0010] In a possible implementation, the driving member includes a shape memory alloy wire and two clamps; when the lattice structure is controlled along a first direction and a second direction, a plurality of the shape memory alloy wires pass through a first connecting hole and a second connecting hole of the first unit cell and the second unit cell arranged along the first direction and the second direction, respectively, wherein the axial direction of the shape memory alloy wire in the first direction is perpendicular to the axial direction of the shape memory alloy wire in the second direction; when the lattice structure is controlled along the first direction alone, a plurality of the shape memory alloy wires pass through the second connecting holes of the second unit cell arranged along the first direction, respectively; the two clamps are used to fix the two ends of each of the shape memory alloy wires, respectively.

[0011] In a possible implementation, the variable stiffness chain lattice structure further includes a plurality of insulating sleeves; when the lattice structure is controlled along the first direction and the second direction, the plurality of insulating sleeves are respectively sleeved on the outer sides of the corresponding shape memory alloy wires.

[0012] In a possible implementation, the insulating sleeve includes a high temperature resistant glass fiber tube.

[0013] In a possible implementation, the single-layer unidirectional lattice structure and the single-layer bidirectional lattice structure are both arranged in multiple layers along their height direction, and the top walls of the single-layer unidirectional lattice structure and the single-layer bidirectional lattice structure of each layer are connected to the bottom walls of the single-layer unidirectional lattice structure and the single-layer bidirectional lattice structure of the adjacent layer.

[0014] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects:

[0015] The variable stiffness chain lattice structure provided in the embodiment of the present application includes multiple driving members, multiple first unit cells and multiple second unit cells. The embodiment of the present application realizes a variable stiffness characteristic from soft to rigid. Each first unit cell is composed of three mutually vertically connected connecting rings (first connecting ring, second connecting ring and third connecting ring) to form a hollow three-dimensional frame that is both stable and lightweight. Similarly, each second unit cell also adopts a similar hollow three-dimensional frame, but its unique connection method and layout are designed to meet specific interlocking and stiffness change requirements. The design of the hollow three-dimensional frame not only effectively maintains the strength of the structure, but also reduces the amount of material used, thereby reducing costs and reducing overall weight. This design also gives the structure a high degree of flexibility, enabling it to adapt to a variety of application scenarios and load conditions.

[0016] When the lattice structure is controlled along the first direction and the second direction, in the initial state, due to the loose relative position between the first unit cell and the second unit cell, the entire lattice structure exhibits soft characteristics and can bend and deform freely to adapt to various complex environments. However, when the driving parts start working, they will precisely control the lattice structure along the preset path (i.e., the first direction and the second direction).

[0017] When the lattice structure is controlled along the first direction alone, the driving member acts on the second unit cells arranged along the first direction. These second unit cells are mutually nested and tightly interlocked under the action of the driving force to form a rigid whole. At this time, the fourth connecting ring of the second unit cell and the fourth connecting ring of the adjacent second unit cell are respectively in a horizontal setting state and a vertical setting state. This unique layout further enhances the stability of the structure. At the same time, although the outer walls of the second unit cells arranged along the second direction are connected, they are not directly driven, so the degree of freedom in the second direction can be constrained while maintaining its original flexible state in the first direction. Due to the direct action of the driving member, the structure can respond quickly after receiving the control signal to achieve a rapid change in stiffness. This variable stiffness characteristic from soft to rigid makes the variable stiffness chain lattice structure provided in the embodiment of the present application have excellent load capacity, response speed and high stability, and the structure is simple, and its stiffness can be flexibly adjusted under different working conditions to meet actual needs. Therefore, the structure has broad application prospects in the fields of aerospace, automobiles, robots, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following is a brief introduction to the drawings required for use in the description of the embodiments of the present application. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 A schematic diagram of the structure of the first unit cell provided in an embodiment of the present application;

[0020] Figure 2 A top view of a first unit cell provided in an embodiment of the present application;

[0021] Figure 3 A schematic diagram of the structure of a second unit cell provided in an embodiment of the present application;

[0022] Figure 4 A left view of a second unit cell provided in an embodiment of the present application;

[0023] Figure 5 A schematic diagram of a control structure for realizing a lattice structure along a first direction and a second direction provided in an embodiment of the present application;

[0024] Figure 6 A schematic diagram of the structure of the first unit cell and the second unit cell provided in an embodiment of the present application;

[0025] Figure 7 A schematic diagram of the structure of the insulating sleeve provided in an embodiment of the present application;

[0026] Figure 8 A schematic diagram of a control structure for realizing a lattice structure along a first direction provided in an embodiment of the present application;

[0027] Fig. 9 for Figure 8 A top view of

[0028] Fig.10 A schematic structural diagram of a variable stiffness chain lattice structure provided in an embodiment of the present application.

[0029] Icons: 1-driving member; 11-shape memory alloy wire; 12-clamp; 2-first unit cell; 21-first connecting ring; 22-second connecting ring; 23-third connecting ring; 3-second unit cell; 31-fourth connecting ring; 32-fifth connecting ring; 33-sixth connecting ring; 4-insulating sleeve; 5-first connecting hole; 6-second connecting hole. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0031] In the description of the embodiments of the present application, it should be noted that the orientation or positional relationship indicated by the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the embodiments of the present application 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 cannot be understood as a limitation on the present application. The terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance. In addition, the terms "installed", "connected", and "connected" 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 it can be indirectly connected through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0032] The embodiment of the present application provides a variable stiffness chain lattice structure, such as Figures 1 to 10As shown. The variable stiffness chain lattice structure includes a plurality of driving members 1, a plurality of first unit cells 2 and a plurality of second unit cells 3. The plurality of first unit cells 2 each include a first connecting ring 21, a second connecting ring 22 and a third connecting ring 23. The first connecting ring 21 is vertically connected to the second connecting ring 22 and the third connecting ring 23, respectively, and the second connecting ring 22 is vertically connected to the third connecting ring 23. When observed from the plane of the first connecting ring 21, the projections of the second connecting ring 22 and the third connecting ring 23 are both located in the middle of the first connecting ring 21.

[0033] Four first connection holes 5 are evenly arranged around the circumference of the first connection ring 21. The plurality of second cells 3 each include a fourth connection ring 31, a fifth connection ring 32 and a sixth connection ring 33. The fourth connection ring 31 is vertically connected to the fifth connection ring 32 and the sixth connection ring 33, respectively, and the fifth connection ring 32 is vertically connected to the sixth connection ring 33. When the fourth connection ring 31 is observed from the plane, the projections of the fifth connection ring 32 and the sixth connection ring 33 are both located in the middle of the fourth connection ring 31. Two second connection holes 6 are relatively arranged around the circumference of the fourth connection ring 31.

[0034] When the lattice structure is controlled along the first direction and the second direction, the plurality of first cells 2 are spaced apart along the first direction and the second direction, and the two ends of the plurality of second cells 3 are respectively sleeved between two adjacent first cells 2, so that the projections of the second cells 3 and the two adjacent first cells 2 on the horizontal plane overlap. In this state, the first connecting ring 21 of the first cell 2 is horizontally arranged, and the fourth connecting ring 31 of the second cell 3 is vertically arranged. Figure 6 and Figure 7 As shown, the most basic form is composed of a first unit cell 2 and two second unit cells 3.

[0035] The first connection holes 5 of the plurality of first connection rings 21 arranged in the first direction and the second direction form a straight line, and the second connection holes 6 of the second unit cells 3 respectively correspond to the first connection holes 5. The plurality of driving members 1 respectively pass through the first connection holes 5 of the first unit cells 2 and the second connection holes 6 of the second unit cells 3 in the first direction and the second direction. The axial direction of the driving member 1 in the first direction is perpendicular to the axial direction of the driving member 1 in the second direction. The driving member 1 is configured to drive the lattice structure in the first direction and the second direction from loose (with gaps) to compact (close contact) to form a single-layer bidirectional lattice structure.

[0036] When the control of the lattice structure is realized along the first direction, a plurality of second cells 3 are arranged along the first direction and the second direction, wherein the second cells 3 arranged along the first direction are sleeved on the adjacent second cells 3, the projections of the second cells 3 and the adjacent second cells 3 on the horizontal plane partially overlap, and the fourth connecting ring 31 of the second cells 3 and the fourth connecting ring 31 of the adjacent second cells 3 are respectively in a horizontal setting state and a vertical setting state. The second connecting holes 6 arranged opposite to each other of the plurality of second cells 3 form a straight line. The outer wall of the second cells 3 arranged along the second direction is connected to the outer wall of the adjacent second cells 3, and the plurality of driving members 1 respectively pass through the second connecting holes 6 of the second cells 3 in the first direction. The driving member 1 is configured to drive the lattice structure in the first direction from loose to compact, so as to form a single-layer unidirectional lattice structure. Under the drive of the driving member 1, friction is generated at the boundary between the first cell 2 and the adjacent second cell 3, so as to realize the chain topological interlocking cells.

[0037] The single-layer bidirectional lattice structure has a higher degree of freedom and application space. The single-layer unidirectional lattice structure is simple to assemble and control, and the stiffness state of the structure after driving is more stable.

[0038] Furthermore, the second connecting ring 22 and the third connecting ring 23 are arranged in the middle of the first connecting ring 21, so that the first unit cell 2 in the first direction and the second direction can have the same interlocking effect. In addition, by adjusting the angle between the second connecting ring 22 and the third connecting ring 23, the present application can adjust the gap between the first unit cell 2 and the second unit cell 3 in the first direction and the second direction, as well as the contact position between the first unit cell 2 and the second unit cell 3.

[0039] It should be noted that the embodiment of the present application realizes a variable stiffness characteristic from soft to rigid. Each first unit cell 2 is composed of three mutually perpendicular connecting rings (a first connecting ring 21, a second connecting ring 22 and a third connecting ring 23), forming a hollow three-dimensional frame that is both stable and lightweight. Similarly, each second unit cell 3 also adopts a similar hollow three-dimensional frame, but its unique connection method and layout are designed to meet specific interlocking and stiffness change requirements. The design of the hollow three-dimensional frame not only effectively maintains the strength of the structure, but also reduces the amount of material used, thereby reducing costs and reducing overall weight. This design also gives the structure a high degree of flexibility, enabling it to adapt to a variety of application scenarios and load conditions.

[0040] The symmetry of each of the first unit cell 2 and the second unit cell 3 provides the basic condition for the lattice structure to be in an automatic flat state.

[0041] When the lattice structure is controlled along the first direction and the second direction, in the initial state, due to the loose relative position between the first unit cell 2 and the second unit cell 3, the entire lattice structure exhibits soft characteristics and can bend and deform freely to adapt to various complex environments. However, when the driving members 1 start working, they will precisely control the lattice structure along the preset path (i.e., the first direction and the second direction).

[0042] When the lattice structure is controlled along the first direction alone, the driving member 1 acts on the second cells 3 arranged along the first direction. These second cells 3 are mutually nested and tightly interlocked under the action of the driving force to form a rigid whole. At this time, the fourth connecting ring 31 of the second cell 3 and the fourth connecting ring 31 of the adjacent second cell 3 are respectively in a horizontal setting state and a vertical setting state. This unique layout further enhances the stability of the structure. At the same time, although the outer walls of the second cells 3 arranged along the second direction are connected, since they are not directly driven, the degree of freedom in the second direction can be constrained, and their original flexible state can be maintained in the first direction. Due to the direct action of the driving member 1, the structure can respond quickly after receiving the control signal to achieve a rapid change in stiffness. This variable stiffness characteristic from soft to rigid makes the variable stiffness chain lattice structure provided in the embodiment of the present application not only have excellent load capacity and response speed, but also can flexibly adjust its stiffness under different working conditions to meet actual needs. Therefore, the structure has broad application prospects in the fields of aerospace, automobiles, robots, etc.

[0043] Specifically, the present application is inspired by ancient chain mail and topological interlocking structures, and combines a loose chain structure with weaker stiffness with a truss unit cell of a lattice to design a variable stiffness chain lattice structure.

[0044] In the embodiment of the present application, the first connecting ring 21 , the second connecting ring 22 , the third connecting ring 23 , the fourth connecting ring 31 , the fifth connecting ring 32 and the sixth connecting ring 33 are all circular connecting rings with equal diameters.

[0045] It should be noted that the diameters of all circular connecting rings are equal, which ensures the geometric consistency of the first unit cell 2 and the second unit cell 3 and simplifies the design and manufacturing process.

[0046] In the embodiment of the present application, the first connecting ring 21 and the fourth connecting ring 31 are both square connecting rings. The second connecting ring 22, the third connecting ring 23, the fifth connecting ring 32 and the sixth connecting ring 33 are all circular connecting rings, and their diameters are equal. The side length of the square connecting ring is equal to the diameter of the circular connecting ring. The four corners of the first connecting ring 21 are all arc-shaped structures, and the four first connecting holes 5 are all arranged at the vertices of the corresponding four arc-shaped structures. The embodiment of the present application reduces stress concentration and also improves the strength and durability of the first connecting hole 5.

[0047] The two oppositely disposed corners of the fourth connecting ring 31 are both arc-shaped structures, the two second connecting holes 6 are both disposed at the vertices of the corresponding arc-shaped structures, and the remaining two oppositely disposed corners of the fourth connecting ring 31 are both configured as quarter circles with the same side length as the fourth connecting ring 31 .

[0048] Specifically, the design of the square connecting ring can guide the adjacent square connecting rings to ensure that they are aligned and move in the correct direction. This design is similar to the arc groove type in the chain, which to a certain extent limits the contact and rotation of the square connecting rings at the arc-shaped structure.

[0049] When the lattice structure is controlled along the first direction and the second direction, all fourth connecting rings 31 are arranged vertically, and their heights can be automatically kept consistent with the second connecting rings 22 or the third connecting rings 23, thereby further enhancing the integrity and stability of the structure. At the same time, when the lattice structure is controlled along the first direction alone, the heights of the fourth connecting rings 31 arranged vertically and the fifth connecting rings 32 or the sixth connecting rings 33 of the adjacent second unit cells 3 can also be kept consistent, thereby enhancing the integrity and stability of the structure.

[0050] The remaining two oppositely arranged corners of the fourth connecting ring 31 are both set to be a quarter circle with the same side length as the fourth connecting ring 31, so that the height of each first unit cell 2 and the second unit cell 3 in the lattice structure can be the same, so as to ensure that each first unit cell 2 and the second unit cell 3 in the lattice structure has the same height. When an object is placed on top of the lattice structure, this design can make the state of the object more stable, because the number of contact points between the object and the lattice structure is greater and the positions are evenly distributed. Therefore, the lattice structure can share the load more evenly, thereby improving its bearing capacity and impact resistance.

[0051] It should be noted that if Figure 5 As shown, all fourth connecting rings 31 are arranged vertically, and all first connecting rings 21 are arranged horizontally. This layout makes the first unit cell 2 and the second unit cell 3 consistent in height, greatly simplifying the control difficulty of the contact position. At the same time, due to the special design of the first connecting ring 21 and the fourth connecting ring 31, the range of movement between the first unit cell 2 and the adjacent unit cell is effectively expanded, thereby reducing the possibility of mutual interference during the working process and improving the overall performance and reliability of the structure.

[0052] In the embodiment of the present application, the first unit cell 2 and the second unit cell 3 are both made of nylon. As a common engineering plastic, nylon has good mechanical properties, wear resistance, chemical resistance and self-lubrication, and is therefore suitable for making structural parts that need to withstand certain loads and deformations.

[0053] In the embodiment of the present application, the driving member 1 includes a shape memory alloy wire 11 and two clamps 12. When the lattice structure is controlled along the first direction and the second direction, the plurality of shape memory alloy wires 11 pass through the first connection hole 5 and the second connection hole 6 of the first unit cell 2 and the second unit cell 3 arranged along the first direction and the second direction, respectively, wherein the axial direction of the shape memory alloy wire 11 in the first direction is perpendicular to the axial direction of the shape memory alloy wire 11 in the second direction. When the lattice structure is controlled along the first direction alone, the plurality of shape memory alloy wires 11 pass through the second connection hole 6 of the second unit cell 3 arranged along the first direction. The two clamps 12 are used to fix the two ends of each shape memory alloy wire 11, respectively.

[0054] It should be noted that the shape memory alloy wire 11 has obvious advantages such as simple structure, large output force, and light weight, which can make the entire structure smaller and lighter, because it does not require external control equipment and the control method is simple and direct. The deformation of the shape memory alloy wire 11 is mainly triggered by temperature changes and has stronger anti-interference ability. In the bending state under load, the unique design of the variable stiffness chain lattice structure allows the shape memory alloy wire 11 to be restored to a straight state without the need for an additional driving structure when it contracts. This self-recovery ability is usually not available in traditional variable stiffness structures.

[0055] Furthermore, the diameters of the first connecting hole 5 and the second connecting hole 6 are the same and are only slightly larger than the diameter of the shape memory alloy wire 11 (a suitable size relationship). When powered on, the shape memory alloy wire 11 guides and limits the movement of the first unit cell 2 and the second unit cell 3, causing the variable stiffness chain lattice structure to automatically return to a straight state.

[0056] The shape memory alloy wire 11 used in the present application is a spontaneous two-way shape memory alloy wire, which is trained by repeatedly completing the auxiliary two-way memory process to generate residual stress inside the material, showing a memory effect of two states. At high temperature and low temperature, it is respectively manifested as contraction and recovery along the axial direction, which can achieve reversible control of the variable stiffness chain lattice structure between high stiffness and flexibility.

[0057] Specifically, the clamp 12 of the embodiment of the present application may adopt a fixing block and a bolt, or may adopt other types of clamps 12 such as a brass drill clamp.

[0058] The present application is not limited to the above structure, and the driving member 1 can also be a variable stiffness chain lattice structure driven by a motor-controlled wire pull.

[0059] In the embodiment of the present application, the variable stiffness chain lattice structure further includes a plurality of insulating sleeves 4. When the lattice structure is controlled along the first direction and the second direction, the plurality of insulating sleeves 4 are respectively sleeved on the outer sides of the corresponding shape memory alloy wires 11.

[0060] It should be noted that the insulating sleeve 4 of the present application can prevent the shape memory alloy wire 11 from being electrically short-circuited with the surrounding environment when powered on for heating, ensuring that the current only passes through the shape memory alloy wire 11 itself, thereby ensuring heating efficiency and safety.

[0061] In the embodiment of the present application, the insulating sleeve 4 includes a high temperature resistant glass fiber tube.

[0062] It should be noted that the glass fiber material itself has extremely high insulation properties, which can effectively isolate current, prevent electrical short circuits or leakage, and ensure the safety of electrical equipment.

[0063] Furthermore, the single-layer unidirectional lattice structure and the single-layer bidirectional lattice structure are both arranged in multiple layers along their height direction, and the top wall of each layer of the single-layer unidirectional lattice structure and the single-layer bidirectional lattice structure is connected to the bottom wall of the single-layer unidirectional lattice structure and the single-layer bidirectional lattice structure of the adjacent layer.

[0064] It should be noted that this multi-layer arrangement improves the bending stiffness and torsional stiffness of the structure. Specifically, the number of shape memory alloy wires 11 increases, which improves the driving force. At the same time, the number of contacts between the first unit cell 2 and the second unit cell 3 increases, making the contact relationship inside the lattice structure more stable, and also expanding the overall structure from two dimensions to three dimensions, thereby achieving a significant improvement in structural stiffness and stability.

[0065] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other. Each embodiment focuses on the differences from other embodiments.

[0066] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit the present application. Although the present application has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some or all of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present application.

Claims

1. A variable stiffness chain lattice structure, characterized in that: It comprises a plurality of driving members (1), a plurality of first unit cells (2) and a plurality of second unit cells (3); Each of the plurality of first unit cells (2) comprises a first connecting ring (21), a second connecting ring (22) and a third connecting ring (23); The first connecting ring (21) is vertically connected to the second connecting ring (22) and the third connecting ring (23), respectively, and the second connecting ring (22) is vertically connected to the third connecting ring (23); When observing from a plane of the first connecting ring (21), the projections of the second connecting ring (22) and the third connecting ring (23) are both located in the middle of the first connecting ring (21); The first connecting ring (21) is evenly provided with four first connecting holes (5) in the circumferential direction; Each of the plurality of second unit cells (3) comprises a fourth connecting ring (31), a fifth connecting ring (32) and a sixth connecting ring (33); The fourth connecting ring (31) is vertically connected to the fifth connecting ring (32) and the sixth connecting ring (33), respectively, and the fifth connecting ring (32) is vertically connected to the sixth connecting ring (33); When observing from the plane of the fourth connecting ring (31), the projections of the fifth connecting ring (32) and the sixth connecting ring (33) are both located in the middle of the fourth connecting ring (31); The fourth connecting ring (31) is provided with two second connecting holes (6) in a circumferential direction thereof; When the lattice structure is controlled along the first direction and the second direction, a plurality of the first unit cells (2) are arranged at intervals along the first direction and the second direction respectively, and two ends of a plurality of the second unit cells (3) are respectively set between two adjacent first unit cells (2), so that the projections of the second unit cells (3) and the two adjacent first unit cells (2) on the horizontal plane partially overlap. In this state, the first connecting ring (21) of the first unit cell (2) is arranged horizontally, and the fourth connecting ring (31) of the second unit cell (3) is arranged vertically. The plurality of the first connecting rings (21) arranged along the first direction and the second direction are arranged relatively to each other. The first connection holes (5) form a straight line, and the second connection holes (6) of the second unit cell (3) are arranged opposite to each other and correspond to the first connection holes (5), respectively. The plurality of driving members (1) pass through the first connection holes (5) of the first unit cell (2) and the second connection holes (6) of the second unit cell (3) in the first direction and the second direction, respectively. The axial direction of the driving member (1) in the first direction is perpendicular to the axial direction of the driving member (1) in the second direction. The driving member (1) is configured to drive the lattice structures in the first direction and the second direction from loose to compact, so as to form a single-layer bidirectional lattice structure. When the lattice structure is controlled along the first direction alone, a plurality of the second single cells (3) are arranged along the first direction and the second direction, wherein the second single cell (3) arranged along the first direction is sleeved on the adjacent second single cell (3), the second single cell (3) and the adjacent second single cell (3) partially overlap in projection on the horizontal plane, the fourth connecting ring (31) of the second single cell (3) and the fourth connecting ring (31) of the adjacent second single cell (3) are respectively in a horizontal setting state and a vertical setting state, the second connecting holes (6) of the plurality of the second single cells (3) arranged opposite to each other form a straight line, the outer wall of the second single cell (3) arranged along the second direction is connected to the outer wall of the adjacent second single cell (3), and the plurality of the driving members (1) respectively pass through the second connecting holes (6) of the second single cells (3) in the first direction, and the driving members (1) are configured to drive the lattice structure in the first direction from loose to compact, so as to form a single-layer unidirectional lattice structure.

2. The variable stiffness chain lattice structure according to claim 1, characterized in that: The first connecting ring (21), the second connecting ring (22), the third connecting ring (23), the fourth connecting ring (31), the fifth connecting ring (32) and the sixth connecting ring (33) are all circular connecting rings with equal diameters.

3. The variable stiffness chain lattice structure according to claim 1, characterized in that: The first connecting ring (21) and the fourth connecting ring (31) are both square connecting rings; The second connecting ring (22), the third connecting ring (23), the fifth connecting ring (32) and the sixth connecting ring (33) are all circular connecting rings, and their diameters are equal; The side length of the square connecting ring is equal to the diameter of the circular connecting ring; The four corners of the first connecting ring (21) are all arc-shaped structures, and the four first connecting holes (5) are all arranged at the vertices of the corresponding four arc-shaped structures; The two oppositely disposed corners of the fourth connecting ring (31) are both arc-shaped structures, the two second connecting holes (6) are both arranged at the vertices of the corresponding arc-shaped structures, and the remaining two oppositely disposed corners of the fourth connecting ring (31) are both arranged as quarter circles with the same side length as the fourth connecting ring (31).

4. The variable stiffness chain lattice structure according to claim 1, characterized in that: The first unit cell (2) and the second unit cell (3) are both made of nylon.

5. The variable stiffness chain lattice structure according to claim 1, characterized in that: The driving member (1) comprises a shape memory alloy wire (11) and two clamps (12); When the lattice structure is controlled along the first direction and the second direction, the plurality of shape memory alloy wires (11) respectively pass through the first connection holes (5) and the second connection holes (6) of the first unit cells (2) and the second unit cells (3) arranged along the first direction and the second direction, wherein the axial direction of the shape memory alloy wires (11) in the first direction is perpendicular to the axial direction of the shape memory alloy wires (11) in the second direction; When the lattice structure is controlled along the first direction alone, a plurality of the shape memory alloy wires (11) respectively pass through the second connection holes (6) of the second unit cells (3) arranged along the first direction; The two clamps (12) are respectively used to fix the two ends of each shape memory alloy wire (11).

6. The variable stiffness chain lattice structure according to claim 5, characterized in that: Also includes a plurality of insulating sleeves (4); When the lattice structure is controlled along the first direction and the second direction, the plurality of insulating sleeves (4) are respectively sleeved on the outside of the corresponding shape memory alloy wires (11).

7. The variable stiffness chain lattice structure according to claim 6, characterized in that: The insulating sleeve (4) comprises a high temperature resistant glass fiber tube.

8. The variable stiffness chain lattice structure according to claim 1, characterized in that: The single-layer unidirectional lattice structure and the single-layer bidirectional lattice structure are both arranged in multiple layers along their height direction, and the top walls of the single-layer unidirectional lattice structure and the single-layer bidirectional lattice structure of each layer are connected to the bottom walls of the single-layer unidirectional lattice structure and the single-layer bidirectional lattice structure of the adjacent layer.

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