Pre-deformation zero-rigidity flexible hinge
By setting a pre -deformed ring reed on the outer ring of the flexible hinge, using negative rigidity and positive degree to offset the design, solving the problem of less flexible hinge, large stress, and large central drift, and realized the design of zero -stiffness flexible hinge. It is suitable for a variety of high -precision applications.
Patent Information
- Application Number
- CN202411659171.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-20
- Publication Date
- 2025-01-21
AI Technical Summary
The existing flexible hinges have problems such as small deformation, large stress and large center drift, while the zero-stiff flexible hinges have problems such as many components, large volume, and difficulty in processing and assembly.
It adopts a pre-deformed zero-stiffness flexible hinge design and sets multiple annular reeds on the outer ring. Each annular reed includes a first connecting part, a second connecting part and a deformation body. The annular reed is in a free state before assembly. After the inner ring is mounted, the annular reed is radially compressed, thereby generating negative stiffness in the hinge rotation direction. The positive and negative stiffness can be offset at the equilibrium position to achieve zero stiffness.
The flexible hinge design of large deformation, small stress, and small center drift has been realized. The overall stiffness is greatly reduced, the structure is compact, the volume is small, and the processing and assembly are easy. It is suitable for the fields of space, robotics, optics, biological engineering and other fields.
Smart Images
Figure CN119333521A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of flexible hinges, and in particular to a pre-deformed zero-rigidity flexible hinge. Background Art
[0002] A flexible hinge is an elastic support with a simple structure and a relatively regular shape. It has a rotation center that coincides with the geometric center axis and works by relying on the limited deformation of the elastic thin sheet uniformly distributed radially around the circumference. Under torsional load, it produces rotational motion within a limited angle range around its rotation center. Compared with traditional supports, elastic supports have many advantages such as no backlash, no friction, no gap, no noise, no wear, small space size, high motion sensitivity, easy control, and stable operation. They are widely used in many fields such as aerospace, robotics, optics, and bioengineering. They are important components in precision machinery, precision measuring instruments, and micro-nano devices. Such as attitude adjustment mechanisms in spacecraft, adaptive adjustment mechanisms on astronomical telescopes, alignment mechanisms of microwave antennas on spacecraft, solar panel folding mechanisms, robot wrist force sensors, and high-precision small-range torque sensors. The flexible hinge mechanism utilizes the characteristics of small deformation and self-recovery of elastic materials, eliminates the backlash and mechanical friction in the transmission process, and can obtain ultra-high displacement resolution. Flexible hinges are widely used in instruments such as gyroscopes, accelerometers, precision balances, and missile control, and have achieved unprecedented high precision and stability.
[0003] Existing flexible hinges have the problems of small deformation, large stress, and large center drift. The research on flexible hinges with large deformation, small stress, and small center drift has always been a difficult problem in the research of flexible hinges. It is difficult for known flexible hinges to take these three aspects into account. However, zero-stiffness flexible hinges have the problems of many components, large volume, and difficult processing and assembly. Zero-stiffness flexible hinges are generally composed of positive stiffness elements and several negative stiffness elements. Zero stiffness is achieved by matching positive and negative stiffness. The entire zero-stiffness flexible hinge consists of four or five parts, and the overall volume is relatively large, which greatly affects its application in aerospace, robotics, optics, bioengineering, etc. Summary of the invention
[0004] In view of the problems that the flexible hinges produced above have small deformation, large stress, large center drift, and the zero-rigidity flexible hinges have many parts, large volume, and are difficult to process and assemble, the purpose of the present invention is to provide a pre-deformed zero-rigidity flexible hinge.
[0005] In order to achieve the above object, the technical solution adopted by the present invention is:
[0006] A pre-deformed zero-rigidity flexible hinge, which includes: an outer ring and an inner ring, the outer ring is provided with a plurality of outer ring assembly through holes arranged at equal intervals along the circumference, and the inner ring is provided with a plurality of inner ring assembly through holes arranged at equal intervals along the circumference; the outer ring includes: an outer annular connecting portion, an annular spring leaf and a clamping portion, the plurality of annular spring leaves are arranged at equal intervals along the circumference, one end of each annular spring leaf is connected to the inner wall of the outer annular connecting portion, and the other end of each annular spring leaf is connected to a clamping portion, the outer wall of the inner ring is provided with a plurality of clamping grooves, each clamping portion is clamped in a clamping groove, and each annular spring leaf is in a compressed state along its own length direction.
[0007] The above-mentioned pre-deformed zero-rigidity flexible hinge, wherein each annular spring leaf comprises: a first connecting portion, a second connecting portion and a deformation body, an outer wall on one side of the deformation body and an inner wall of the outer annular connecting portion are connected via the first connecting portion, and an outer wall on the other side of the deformation body is connected to a clamping portion.
[0008] In the above-mentioned pre-deformed zero-rigidity flexible hinge, the first connecting portion and the second connecting portion of each annular spring leaf are located in the same plane.
[0009] In the above-mentioned pre-deformed zero-rigidity flexible hinge, each deformable body structure is symmetrically arranged, and the outer ring and the inner ring are coaxially arranged.
[0010] In the above-mentioned pre-deformed zero-rigidity flexible hinge, the deformable body is a square deformable body, the square deformable body is a rectangular cylindrical structure, and the first connecting portion and the second connecting portion are both connected to the outer wall of the square deformable body.
[0011] In the above-mentioned pre-deformed zero-rigidity flexible hinge, the deformation body is a circular deformation body, the circular deformation body is a circular cylindrical structure, and the first connecting part and the second connecting part are both connected to the outer wall of the square deformation body.
[0012] The above-mentioned pre-deformed zero-rigidity flexible hinge, wherein the deformable body is a series of multiple annular deformable bodies, each of which includes: an annular deformable body and a third connecting part, any two adjacent annular deformable bodies are connected by a third connecting part, and multiple annular deformable bodies are arranged in series, the outermost annular deformable body is connected to the first connecting part, and the innermost annular deformable body is connected to the second connecting part.
[0013] In the above-mentioned pre-deformed zero-rigidity flexible hinge, the multiple annular deformation bodies are all cylindrical structures, and the first connection part, the second connection part and any third connection part of each series-connected multiple annular deformation body are located in the same plane.
[0014] In the above-mentioned pre-deformed zero-rigidity flexible hinge, the multiple annular deformation bodies are all hollow structures in the shape of arc plates.
[0015] In the above-mentioned pre-deformed zero-rigidity flexible hinge, the dimensions of each of the multiple annular deformation bodies connected in series increase from the inside to the outside, thereby increasing the maximum compression amount of each annular spring leaf.
[0016] The above-mentioned pre-deformed zero-stiffness flexible hinge, in which a plurality of annular springs of the same structural size and arranged at equal intervals along the circumference are provided between the outer annular connecting portion and the inner ring. The annular springs are in a free state before assembly. After the inner ring is installed, the annular springs are radially compressed, thereby generating negative stiffness in the hinge rotation direction. The compression amount of each annular spring is the same. If the compression amount is appropriate, the positive stiffness and negative stiffness in the hinge rotation direction generated by the annular spring part can be just offset at the equilibrium position. Within the working stroke range, the residual positive stiffness is also very small, thereby realizing the zero-stiffness flexible hinge function.
[0017] Due to the adoption of the above technology, the present invention has the following positive effects compared with the prior art:
[0018] (1) In the present invention, the annular spring in the pre-deformed zero-stiffness flexible hinge provides elastic deformation in both radial and tangential directions. Before assembly, the annular spring is in a free state. After the inner ring is installed, the annular spring is radially compressed, thereby generating negative stiffness in the hinge rotation direction. The greater the compression, the greater the negative stiffness generated. If the compression is appropriate, the positive stiffness and negative stiffness generated by the annular spring in the hinge rotation direction can be exactly offset at the equilibrium position. Within the working stroke range, the residual positive stiffness is also very small, thereby realizing the zero-stiffness flexible hinge function;
[0019] (2) The pre-deformed zero-rigidity flexible hinge of the present invention adopts a method of offsetting positive and negative stiffnesses to achieve zero-rigidity design, which greatly reduces the overall stiffness of the flexible hinge, allowing for greater room for structural design of the flexible hinge. The elastic deformation part is allowed to be thicker, and the stiffness strength is better. The flexible hinge can be used to design large deformation, small stress, and small center drift.
[0020] (3) In the present invention, the components of the pre-deformed zero-stiffness flexible hinge are only the outer ring and the inner ring, and the positive stiffness element and the negative stiffness element are both arranged on the outer ring. The pre-deformation naturally formed during assembly causes the annular spring to generate negative stiffness in the rotation direction. The structure is compact, the volume is very small, and the processing and assembly are easy. It can be applied to many fields such as aerospace, robotics, optics, and bioengineering. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 This is a diagram showing an embodiment of a pre-deformed zero-rigidity flexible hinge of the present invention using multiple annular deformation bodies connected in series.
[0022] Figure 2 yes Figure 1 main view. Figure 3 yes Figure 2 Side section view of . Figure 4 yes Figure 1 Schematic diagram of the structure of the outer ring.
[0023] Figure 5 yes Figure 4 main view. Figure 6 yes Figure 4 An embodiment diagram in which multiple annular springs are in a compressed state.
[0024] Figure 7 yes Figure 6 main view.
[0025] Figure 8 This is a diagram showing an embodiment of a pre-deformed zero-rigidity flexible hinge using a square deformation body according to the present invention.
[0026] Fig. 9 yes Figure 8 main view. Fig.10 yes Fig. 9 Side section view of . Fig.11 yes Figure 8 Schematic diagram of the structure of the outer ring.
[0027] Fig.12 yes Fig.11 main view. Fig.13 yes Fig.11 An embodiment diagram in which multiple annular springs are in a compressed state.
[0028] Fig.14 yes Fig.13 main view.
[0029] Fig.15 This is a diagram showing an embodiment of a pre-deformed zero-rigidity flexible hinge of the present invention using a circular deformation body.
[0030] Fig.16 yes Fig.15 main view. Fig.17 yes Fig.16 Side section view of . Fig.18 yes Fig.15 Schematic diagram of the structure of the outer ring.
[0031] Fig.19 yes Fig.18 main view. Fig. 20 yes Fig.18 An embodiment diagram in which multiple annular springs are in a compressed state.
[0032] Fig.21 yes Fig. 20 main view.
[0033] Fig. 22 It is a structural schematic diagram of an inner ring of a pre-deformed zero-rigidity flexible hinge of the present invention.
[0034] In the accompanying drawings: 1, outer ring; 2, inner ring; 3, annular spring; 4, clamping part; 11, outer ring assembly through hole; 21, inner ring assembly part; 22, clamping groove; 23, inner ring assembly through hole; 31, first connecting part; 32, second connecting part; 33, square deformation body; 34, circular deformation body; 35, series-connected multiple annular deformation bodies; 351, annular deformation body; 352, third connecting part. DETAILED DESCRIPTION
[0035] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.
[0036] Please refer to Figures 1 to 22 As shown, a pre-deformed zero-rigidity flexible hinge is shown, which includes: an outer ring 1 and an inner ring 2, the outer ring 1 is provided with a plurality of outer ring assembly through holes 11 arranged at equal intervals along the circumference, and the inner ring 2 is provided with a plurality of inner ring assembly through holes 23 arranged at equal intervals along the circumference; the outer ring 1 includes: an outer annular connecting portion, an annular spring 3 and a clamping portion 4, a plurality of annular springs 3 are arranged at equal intervals along the circumference, one end of each annular spring 3 is connected to the inner wall of the outer annular connecting portion, and the other end of each annular spring 3 is connected to a clamping portion 4, the outer wall of the inner ring 2 is provided with a plurality of clamping grooves 22, each clamping portion 4 is clamped in a clamping groove 22, and each annular spring 3 is in a compressed state along its own length direction.
[0037] Furthermore, in a preferred embodiment, each annular spring leaf 3 includes: a first connecting portion 31, a second connecting portion 32 and a deformation body, an outer wall on one side of the deformation body and an inner wall of the outer annular connecting portion are connected through the first connecting portion 31, and an outer wall on the other side of the deformation body is connected to a clamping portion 4.
[0038] Furthermore, in a preferred embodiment, the first connecting portion 31 and the second connecting portion 32 of each annular spring leaf 3 are located in the same plane.
[0039] Furthermore, in a preferred embodiment, each deformation body structure is symmetrically arranged, and the outer ring 1 and the inner ring 2 are coaxially arranged.
[0040] Furthermore, in a preferred embodiment, the deformation body is a square deformation body 33 , the square deformation body 33 is a rectangular cylindrical structure, and the first connection portion 31 and the second connection portion 32 are both connected to the outer wall of the square deformation body 33 .
[0041] Furthermore, in a preferred embodiment, the deformation body is a circular deformation body 34 , which is a circular cylindrical structure, and the first connection portion 31 and the second connection portion 32 are both connected to the outer wall of the square deformation body 33 .
[0042] Furthermore, in a preferred embodiment, the deformation body is a series of multiple annular deformation bodies 35, each of which includes: an annular deformation body 351 and a third connecting part 352, any two adjacent annular deformation bodies 351 are connected by a third connecting part 352, and multiple annular deformation bodies 351 are arranged in series, the outermost annular deformation body 351 is connected to the first connecting part 31, and the innermost annular deformation body 351 is connected to the second connecting part 32.
[0043] Furthermore, in a preferred embodiment, the multiple annular deformation bodies 351 are all cylindrical structures, and the first connection part 31, the second connection part 32 and any third connection part 352 of each series-connected multiple annular deformation body 35 are located in the same plane.
[0044] Furthermore, in a preferred embodiment, grooves are provided at the connection between the two sides of each first connection portion 31 and the inner wall of the outer annular connection portion, and grooves are provided at the connection between the two sides of each second connection portion 32 and the clamping portion 4.
[0045] Furthermore, in a preferred embodiment, the plurality of outer ring assembly through holes 11 are all located on the outer annular connecting portion, the outer periphery of the inner ring 2 is provided with a plurality of inner ring assembly portions 21, the plurality of inner ring assembly portions 21 are arranged at equal intervals along the circumference, and each inner ring assembly portion 21 is provided with an inner ring assembly through hole 23.
[0046] The above are only preferred embodiments of the present invention, and are not intended to limit the implementation and protection scope of the present invention.
[0047] The present invention also has the following implementation modes on the basis of the above:
[0048] In a further embodiment of the present invention, Figure 4 The free state of the outer ring 1 of the serially connected multiple annular deformation body 35 is adopted. Fig.11 The free state of the outer ring 1 using the square deformation body 33, Fig.18 In order to adopt the free state of the outer ring 1 of the circular deformable body 34, the outer rings of various deformable body structures are processed by slow-feeding wire electrospark wire cutting. Figure 4 , Fig.11 and Fig.18This is an embodiment of a pre-deformed zero-rigidity flexible hinge using three different forms of deformable body structures. Other forms of deformable body structures can also be selected in production design. The number of deformable bodies can be three, four, five..., and the specific number can be designed based on the specific dimensions of the outer ring 1 and the inner ring 2. Three deformable bodies are preferred, which can achieve uniform deformation. The deformable body must have elastic deformation capabilities in both circumferential and radial directions, and have equivalent stiffness. After the inner ring 2 is assembled on the outer ring 1, the deformable body is radially compressed. After the deformable body is radially compressed by the inner ring 2, negative stiffness in the circumferential rotation direction will be generated. If the compression amount is appropriate, the positive and negative stiffness will just offset each other, thereby forming a zero-rigidity flexible hinge. That is, if the outer ring 1 is fixed, a very small torque is applied to the inner ring 2, and the inner ring 2 will produce a large rotation angle relative to the outer ring 1.
[0049] In a further embodiment of the present invention, Figure 4 , Fig.11 and Fig.18 This is an embodiment of a pre-deformed zero-rigidity flexible hinge using three different forms of deformation body structures. Three annular spring leaves 3 are evenly distributed along the circumference. The annular spring leaves 3 can undergo both flexural deformation along the rotation direction and telescopic deformation along the radial direction, which is equivalent to a two-degree-of-freedom spring.
[0050] In a further embodiment of the present invention, Figure 6 The outer ring 1 of the multiple annular deformation bodies 35 connected in series is in a pre-compressed state. Fig.13 The outer ring 1 of the square deformation body 33 is in a pre-compressed state. Fig. 20 In order to adopt the pre-compressed state of the outer ring 1 of the circular deformation body 34, the three annular springs 3 are all compressed in the radial direction, which will produce negative stiffness in the tangential direction. The flexural deformation of the annular spring 3 in the rotation direction has positive stiffness. Matching the positive and negative stiffness can reduce the stiffness of the flexible hinge to 3%-10% before the offset within the working stroke range, achieving the effect of a zero-stiffness flexible hinge.
[0051] In a further embodiment of the present invention, Fig. 22 It is a schematic diagram of the structure of the inner ring 2. An upwardly protruding mounting end is provided in the middle of the inner ring 2. The inner ring 2 is processed by slow-wire electrospark wire cutting, and finally the mounting end is chamfered for easy assembly.
[0052] In a further embodiment of the present invention, Figure 1 The inner ring 2 is assembled on the outer ring 1 of the series-connected multiple annular deformation body 35. Figure 8 The inner ring 2 is assembled on the outer ring 1 of the square deformation body 33. Fig.15It is a state where the inner ring 2 is assembled on the outer ring 1 of the circular deformation body 34. The three annular spring leaves 3 are compressed to produce pre-deformation and have negative stiffness along the tangential direction. The greater the pre-compression amount, the greater the negative stiffness. The annular spring leaves 3 themselves have positive stiffness along the rotation direction. Matching the positive and negative stiffness can achieve the effect of zero stiffness.
[0053] In a further embodiment of the present invention, the pre-deformed zero-stiffness flexible hinge of the present invention adopts a method of offsetting positive and negative stiffnesses to perform zero-stiffness design, so that the overall stiffness of the flexible hinge is greatly reduced. According to preliminary estimates, it is only 3% to 10% of the stiffness before the offset. This allows more room for structural design of the flexible hinge, and the elastic deformation part is allowed to be thicker, so the stiffness strength will be better. It can be used to design flexible hinges with large deformation, small stress, and small center drift.
[0054] In a further embodiment of the present invention, the components of the pre-deformed zero-rigidity flexible hinge are only the outer ring 1 and the inner ring 2, and the positive stiffness element and the negative stiffness element are both arranged on the outer ring 1. The annular spring 3 generates negative stiffness in the rotation direction by the pre-deformation naturally formed during assembly, and the structure is compact, the volume is very small, and the processing and assembly are easy. It can be applied to many fields such as aerospace, robotics, optics, and bioengineering.
[0055] In a further embodiment of the present invention, a pre-deformation method is used to realize the pre-tightening of the negative stiffness spring in the pre-deformed zero-stiffness flexible hinge. The annular spring leaf 3 in the pre-deformed zero-stiffness flexible hinge provides elastic deformation in both radial and tangential directions. The annular spring leaf 3 is in a free state before assembly. After the inner ring 2 is installed, the annular spring leaf 3 is radially compressed, thereby generating negative stiffness in the hinge rotation direction. The greater the compression, the greater the negative stiffness generated. If the compression is appropriate, the positive stiffness and negative stiffness generated by the annular spring leaf 3 in the hinge rotation direction can be exactly offset at the equilibrium position. Within the working stroke range, the residual positive stiffness is also very small, thereby realizing the zero-stiffness flexible hinge function.
[0056] In a further embodiment of the present invention, a general zero-stiffness spring system includes many parts, with a large overall volume, and is difficult to process and assemble, while the pre-deformed zero-stiffness flexible hinge spring (i.e., the annular spring leaf 3) and the outer ring 1 are integrated, and the actuators only include the outer ring 1 and the inner ring 2. After the product is finalized, the outer ring 1 and the inner ring 2 can also be programmed as one by laser welding or electron beam welding to avoid creeping of the inner ring 2 and the outer ring 1 during operation, with a small size, compact structure, and high precision.
[0057] In a further embodiment of the present invention, the principle of offsetting positive and negative stiffness is adopted to achieve zero stiffness of the flexible hinge. Due to the use of negative stiffness original components, the positive and negative stiffnesses of the annular spring 3 in the pre-deformed zero stiffness flexible hinge in the rotation direction offset each other, making the overall stiffness very small, and zero stiffness can be achieved at the equilibrium position, and it will also be about 5-10% before the offset at the maximum working stroke. Therefore, the use of the positive and negative stiffness offset method allows the elastic deformation part to be thicker in structure and the working stroke to be larger, making the pre-deformed zero stiffness flexible hinge easier to manufacture, more uniform deformation, and smaller center drift.
[0058] In a further embodiment of the present invention, Figures 1 to 21 As shown, each annular spring leaf 3 is a symmetrical structure, and multiple annular spring leaves 3 of the outer ring 1 are arranged at equal intervals along the circumference. After the outer ring 1 rotates around its axis by an angle of A×(360° / N), it completely overlaps with the outer ring 1 before rotation. A is any integer, and N is the number of annular spring leaves 3 of the outer ring 1.
[0059] In a further embodiment of the present invention, Figures 1 to 7 This is an embodiment of a pre-deformed zero-rigidity flexible hinge using multiple annular deformation bodies connected in series. In this embodiment, each annular deformation body 351 is a hollow arc-shaped plate structure, and the size of the annular deformation body 351 located on the inner side is smaller than the size of the annular deformation body 351 located on the outer side, thereby increasing the deformation amount of the multiple annular deformation bodies 35 connected in series. This structure can realize a flexible hinge with large deformation, small stress and small center drift.
[0060] In a further embodiment of the present invention, a pre-deformed zero-rigidity flexible hinge of multiple annular deformation bodies in series is used. The deformation amount of the multiple annular deformation bodies 35 in series can be increased by increasing the number of annular deformation bodies 351. This structure can realize a flexible hinge with large deformation, small stress and small center drift.
[0061] In a further embodiment of the present invention, a pre-deformed zero-rigidity flexible hinge with multiple annular deformation bodies connected in series is used, and the multiple annular deformation bodies 351 can also be of the same size to improve the rigidity of the outer ring 1.
[0062] In a further embodiment of the present invention, grooves are provided at the connections between the two sides of each first connection part 31 and the inner wall of the outer annular connection part, and grooves are provided at the connections between the two sides of each second connection part 32 and the clamping part 4. By providing a groove structure, the surface stretching area of the connection between the annular spring leaf 3 and the outer annular connection part and the clamping part 4 is increased. The arc surface with a groove design can effectively reduce the stress of the connection between the annular spring leaf 3 and the outer annular connection part and the clamping part 4 during the operation of the outer ring 1. The stress is dispersed on the entire arc surface to avoid stress concentration at the joint, which greatly improves the service life of the outer ring 1. At the same time, the groove structure is adopted to reduce the contact area between the annular spring leaf 3 and the outer annular connection part and the clamping part 4 after deformation, reduce friction, and avoid mutual interference.
[0063] In a further embodiment of the present invention, the outer ring 1 is provided with a plurality of outer ring assembly through holes 11 arranged at equal intervals along the circumference, and the inner ring 2 is provided with a plurality of inner ring assembly through holes 23 arranged at equal intervals along the circumference; so as to facilitate the assembly of the outer ring 1 and the inner ring 2.
[0064] The above are only preferred embodiments of the present invention, and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the description and illustrations of the present invention should be included in the protection scope of the present invention.
Claims
1. A pre-deformed zero-rigidity flexible hinge, characterized in that: include: An outer ring (1) and an inner ring (2), wherein the outer ring (1) is provided with a plurality of outer ring assembly through holes (11) arranged at equal intervals along the circumference, and the inner ring (2) is provided with a plurality of inner ring assembly through holes (23) arranged at equal intervals along the circumference; the outer ring (1) comprises: an outer annular connecting portion, an annular spring leaf (3) and a clamping portion (4); the plurality of annular spring leaves (3) are arranged at equal intervals along the circumference, one end of each annular spring leaf (3) is connected to the inner wall of the outer annular connecting portion, and the other end of each annular spring leaf (3) is connected to a clamping portion (4); the outer wall of the inner ring (2) is provided with a plurality of clamping grooves (22), each clamping portion (4) is clamped in a clamping groove (22), and each annular spring leaf (3) is in a compressed state along its own length direction.
2. The pre-deformed zero-rigidity flexible hinge according to claim 1, characterized in that: Each annular spring leaf (3) comprises a first connecting portion (31), a second connecting portion (32) and a deformable body, wherein an outer wall on one side of the deformable body and an inner wall of the outer annular connecting portion are connected via the first connecting portion (31), and an outer wall on the other side of the deformable body is connected to a clamping portion (4).
3. The pre-deformed zero-rigidity flexible hinge according to claim 2, characterized in that: The first connecting portion (31) and the second connecting portion (32) of each annular spring leaf (3) are located in the same plane.
4. The pre-deformed zero-rigidity flexible hinge according to claim 2, characterized in that: Each deformation body structure is symmetrically arranged, and the outer ring (1) and the inner ring (2) are coaxially arranged.
5. The pre-deformed zero-rigidity flexible hinge according to claim 2, characterized in that: The deformable body is a square deformable body (33), which is a rectangular cylindrical structure, and the first connecting portion (31) and the second connecting portion (32) are both connected to the outer wall of the square deformable body (33).
6. The pre-deformed zero-rigidity flexible hinge according to claim 2, characterized in that: The deformable body is a circular deformable body (34), which is a circular cylindrical structure, and the first connecting portion (31) and the second connecting portion (32) are both connected to the outer wall of the square deformable body (33).
7. The pre-deformed zero-rigidity flexible hinge according to claim 2, characterized in that: The deformation body is a series of multiple annular deformation bodies (35), each of which comprises an annular deformation body (351) and a third connecting portion (352), any two adjacent annular deformation bodies (351) are connected via a third connecting portion (352), and the multiple annular deformation bodies (351) are arranged in series, the outermost annular deformation body (351) is connected to the first connecting portion (31), and the innermost annular deformation body (351) is connected to the second connecting portion (32).
8. The pre-deformed zero-rigidity flexible hinge according to claim 7, characterized in that: The multiple annular deformation bodies (351) are all cylindrical structures, and the first connection part (31), the second connection part (32) and any third connection part (352) of each series-connected multiple annular deformation body (35) are located in the same plane.
9. The pre-deformed zero-rigidity flexible hinge according to claim 2, characterized in that: Grooves are provided at the connection points between the two sides of each first connection part (31) and the inner wall of the outer annular connection part, and grooves are provided at the connection points between the two sides of each second connection part (32) and the clamping part (4).
10. The pre-deformed zero-rigidity flexible hinge according to claim 1, characterized in that: The plurality of outer ring assembly through holes (11) are all located on the outer annular connecting portion, the outer circumference of the inner ring (2) is provided with a plurality of inner ring assembly portions (21), the plurality of inner ring assembly portions (21) are arranged at equal intervals along the circumference, and each inner ring assembly portion (21) is provided with an inner ring assembly through hole (23).