Self-adaptive spring type flexible hinge and design method thereof

Abstract

The invention relates to a self-adaptive spring type flexible hinge and a design method thereof, and belongs to the technical field of spacecraft structure and mechanism design. The self-adaptive spring type flexible hinge comprises a flexible hinge body with mounting interfaces symmetrically distributed at the two ends; the flexible hinge body is provided with a wave spring structure which advances along the axis of the flexible hinge body in the longitudinal direction and is arranged in the circumferential direction of the flexible hinge body in the transverse direction to form an annular hollow structure, and the wave crests and the wave troughs of two adjacent waveforms of the wave spring structure are arranged in a staggered mode and connected. The flexible hinge body can bear tension and compression loads and bending and torsion loads and can automatically return to the initial state within the linear elasticity range of the flexible hinge body, and the flexible hinge is simple in structure, good in torsional rigidity and axial rigidity and small in overall structural mass, has the characteristic of self-adaptability and can buffer and absorb energy to a certain extent.

Description

Technical Field

[0001] The present invention relates to the technical field of spacecraft structure and mechanism design, and in particular to an adaptive spring-type flexible hinge and a design method thereof. Background Art

[0002] Flexible hinge is a new type of mechanism for transmitting or converting motion, force or energy, which has the advantages of no friction, light weight, fatigue resistance, and can be processed in one piece. Flexible hinge plays an important role in the fields of precision instruments, aerospace, bionic machinery, robots, intelligent structures, etc.

[0003] Conventional rigid mechanical connections, such as hinges, sliders, universal joints and ball-and-socket joints, allow different degrees of freedom of movement between connected parts. However, the clearance between the mating parts of rigid joints can cause backlash in the mechanical assembly. In addition, there is relative motion in all the above joints, which leads to friction, resulting in wear and increased clearance. The kinematic chain of such joints compounds the individual errors from backlash and wear, resulting in poor accuracy and repeatability. The prospect of improving these two qualities is a key driving force in the research of new joints, which are large in size, relatively complex in structure, and have the problem of fatigue failure, which will bring incalculable losses.

[0004] Compared with traditional rigid mechanisms, flexible mechanisms have many advantages, including quality, production cost, service life, maintenance cost and buffering energy absorption.

[0005] Therefore, based on the above problems, it is necessary to design an adaptive spring-type flexible hinge and its design method. Summary of the invention

[0006] In order to solve the technical problems existing in the above-mentioned prior art, the purpose of the present invention is to provide an adaptive spring-type flexible hinge and its design method to solve the deficiencies in quality, production cost, service life, maintenance cost and buffering energy absorption of existing rigid mechanical connection devices.

[0007] To achieve the above-mentioned object of the invention, the present invention provides an adaptive spring type flexible hinge, comprising:

[0008] A flexible hinge body with mounting interfaces symmetrically arranged at both ends, the flexible hinge body having a wave spring structure which advances longitudinally along its axis and is arranged transversely along its circumference to form a ring-shaped hollow structure, the wave crests and wave troughs of two adjacent waves of the wave spring structure are staggered and connected, so that when bearing loads, the flexible hinge body can withstand tensile and compressive loads, bending and torsional loads, and can automatically return to its initial state within its linear elastic range.

[0009] Furthermore, the mounting virtual planes formed by the two mounting interfaces on the flexible hinge body are parallel to each other, the wave spring structure of the flexible hinge body includes a plurality of wave plate units having a width, and two adjacent wave plate units are staggered and connected to each other, so that the loads on both ends of the flexible hinge are distributed between the sinusoidal wave plates;

[0010] Furthermore, two of the wave plate units form a group, the two wave plate units in each group have the same function form, and the peaks and troughs of the waveforms of the two wave plate units are alternately arranged and connected.

[0011] Furthermore, the wave spring structure is located at the hollow cylinder wall portion of the closed annular structure formed after the crests and troughs of the two wave plate units are staggered and connected.

[0012] Furthermore, a plurality of the wave plate units are arranged and spliced ​​along a virtual circle to form a cylindrical structure.

[0013] Furthermore, the flexible hinge body is integrally formed, and the wave crests and troughs of the wave spring structure waveform are provided with wave transition fillets to achieve better buffering and energy absorption, reduce stress concentration, and increase service life.

[0014] Furthermore, the flexible hinge body is a nickel-titanium alloy tube. When the flexible hinge body is subjected to a load, the flexible hinge body can withstand a certain tensile and compressive load, a bending and torsional load, and can automatically return to an initial state within its linear elastic range. The flexible hinge has a simple structure, good torsional stiffness and axial stiffness, a small overall structural mass, and is adaptable, and can buffer and absorb energy to a certain extent.

[0015] The present invention is based on the above-mentioned design method of an adaptive spring-type flexible hinge, comprising:

[0016] The wave plate unit of the wave spring structure takes one of the mounting interfaces as a function starting point, and the mounting virtual plane where the mounting interface is located is arranged parallel to the wave oscillation direction of the wave spring structure.

[0017] Further, the basic parameters of the wave plate unit function include: the wave plate unit amplitude A, the frequency ω, and the axial length L of the wave plate unit from the starting point to the mounting interface plane; and

[0018] The initial phase θ of the waveform of the wave plate unit, and the waveform function value Y of the wave plate unit;

[0019] The functional relationship of the wave plate unit waveform is Y=Asin(ωL+θ);

[0020] Among them: A, ω, θ can all be flexibly designed according to the load conditions and the use environment. The design parameters of the wave plate unit are optimized to improve the buffering and energy absorption effects and have strong adaptability to the use environment. The shape of the wave plate unit, the wall thickness δ, diameter D, and axial length H of the hinge body can all be designed according to actual working conditions.

[0021] Furthermore, the wave plate unit is a sinusoidal wave plate unit or a waveform curve formed by a cubic spline curve.

[0022] The adaptive spring-type flexible hinge disclosed in the present invention has the following beneficial effects compared with the prior art:

[0023] The adaptive spring-type flexible hinge designed in the present invention has an integrally formed flexible hinge body. When subjected to load, it has good torsional stiffness and axial stiffness, small overall structural mass, can adaptively withstand tensile and compressive loads, bending and torsional loads, has low processing and manufacturing costs, high design freedom, simple structure, can buffer and absorb energy to a certain extent, and has high fatigue strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] 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 are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 It is a schematic diagram of the overall structure of the adaptive spring-type flexible hinge disclosed in the present invention;

[0026] Figure 2 It is a front view structural schematic diagram of the adaptive spring type flexible hinge disclosed in the present invention;

[0027] Figure 3 It is a structural parameter diagram of the adaptive spring-type flexible hinge disclosed in the present invention;

[0028] Figure 4 It is a top view of the adaptive spring-type flexible hinge disclosed in the present invention.

[0029] Description of reference numerals:

[0030] 1. Upper installation interface; 2. Flexible hinge body; 201. Wave plate unit I; 202. Wave plate unit I crest; 203. Wave plate unit I trough; 204. Wave plate unit II; 205. Sine wave plate unit II crest; 206. Wave plate unit II trough; 3. Lower installation interface. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the implementation of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the present invention.

[0032] Figure 1 The overall structure diagram of the adaptive spring flexible hinge is as follows:

[0033] like Figure 1 As shown, the present invention provides an adaptive spring type flexible hinge, which comprises: a flexible hinge body 2, and a mounting interface;

[0034] The mounting interfaces are symmetrically distributed at both ends of the flexible hinge body 2. The flexible hinge body 2 has a wave spring structure that advances longitudinally along its axis and is arranged transversely along its circumference to form a ring-shaped hollow structure. The wave crests and troughs of two adjacent waves of the wave spring structure are staggered and connected, so that in the working state, when subjected to loads from the mounting interface direction, the flexible hinge body 2 can withstand tensile and compressive loads, bending and torsion loads, and can automatically return to the initial state within its linear elastic range;

[0035] Specifically, the flexible hinge body 2 includes a plurality of wave plate units 201 and a wave plate unit 204, which are used to form a wave spring structure. The wave spring structure forms a hollow cylinder wall portion of a closed annular structure after the wave crests and wave troughs of two wave plate units are staggered and connected. A plurality of wave plate units with a certain width that advance along the axial direction are arranged in sequence along the circumferential direction. Adjacent wave plate units are staggered and connected to each other, and the loads on both ends of the flexible hinge will be distributed between the wave plate units.

[0036] The mounting interface includes an upper mounting interface 1 and a lower mounting interface 3, which are symmetrically distributed at both ends of the flexible hinge body 2 and are respectively used to connect with a connected member (not shown). The planes where the mounting interfaces are located are parallel to each other. The mounting interfaces can be freely designed according to specific installation conditions.

[0037] Figure 2 This is a schematic diagram of the front structure of the adaptive spring-type flexible hinge:

[0038] Figure 2The distribution and arrangement characteristics of the wave plate units are clearly given. The two wave plate units are symmetrically distributed with the connecting line as the symmetry axis. Preferably, each wave plate unit has a sine function as a trajectory characteristic, forming at least wave plate unit I 201, wave plate unit I peak 202, wave plate unit I trough 203, wave plate unit II 204, wave plate unit II peak 205, and wave plate unit II trough 206. The wave plate unit I peak 202 is connected to the wave plate unit II trough 205 between the wave plate unit I 201 and the wave plate unit II 204, and the wave plate unit I trough 203 is connected to the wave plate unit II peak 206, so that the load can be transmitted between the wave plate unit I 201 and the wave plate unit II 204, so that the load is evenly distributed, and the buffering, energy absorption and load-bearing functions of the adaptive spring-type flexible hinge are fully exerted.

[0039] Preferably, the flexible hinge body 2 is a nickel-titanium alloy tube, and a plurality of wave plate units are arranged and spliced ​​along a virtual circumference to form a cylindrical structure. The flexible hinge body 2 is integrally formed as a whole, and waveform transition fillets are set at the peaks and troughs of the waveform of the wave spring structure.

[0040] The present invention provides a design method for an adaptive spring-type flexible hinge:

[0041] Figure 3 It is the parameter diagram of the hinge main structure in the design method of the adaptive spring-type flexible hinge;

[0042] Figure 3 The adaptive spring-type flexible hinge body is unfolded along the normal straight line of a certain installation interface in the circumferential direction on the installation virtual plane;

[0043] In the method, the wave plate unit of the wave spring structure takes one of the mounting interfaces as the function starting point, and the mounting virtual plane where the mounting interface is located is set parallel to the wave oscillation direction of the wave spring structure.

[0044] For details, see Figure 3 As shown, the wave plate unit I 201 is installed below the surface with the interface 3 as the coordinate origin O to establish the following Figure 3 Coordinate system, the plane where the lower mounting interface 3 is located is parallel to the oscillation direction of the sinusoidal wave plate unit, and the basic parameters of the function include: the waveform amplitude A of the wave plate unit; the waveform frequency ω of the wave plate unit; the axial length L of the wave plate unit from the plane of the lower mounting interface 3; the initial waveform phase θ of the wave plate unit; the waveform function value Y of the wave plate unit; the waveform function relationship of the wave plate unit is Y=Asin(ωL+θ). Since the wave plate units 201 and 204 have the circumferential array combination characteristics, after obtaining the node coordinates of one group of units, the coordinates of each node can be obtained by directly translating other unit groups.

[0045] Preferably, the wave plate unit is a sinusoidal wave plate unit or a waveform curve formed by a cubic spline curve, and of course it can also be other forms of curves, as long as the flexible hinge body can be constructed according to the adaptive spring-type flexible hinge structure and design method.

[0046] Figure 4 The top view of the adaptive spring flexible hinge:

[0047] Figure 2 , 4 Some parameters of the adaptive spring-type flexible hinge and their meanings are given in , including the hinge wall thickness δ, hinge diameter D and hinge axial length H.

[0048] In the above embodiment, as long as it is determined Figure 3 , 4 The parameters in can be used to find the node coordinates and determine the structural parameters of the adaptive spring-type flexible hinge. Since multiple sinusoidal wave plate units are arranged along the circumferential direction, the wave plate shape, the wall thickness δ of the hinge body 2, the diameter D of the hinge body 2, and the axial length H of the hinge body 2 can all be designed according to the actual working conditions. By designing and optimizing parameters such as A, ω, θ, δ, D, and H, the geometric parameters of the flexible hinge are changed, so as to adjust the torsional stiffness, compressive stiffness and other properties of the flexible hinge. The adaptive spring-type flexible hinge is integrated as a whole, with a simple structure and high design freedom.

[0049] The adaptive spring-type flexible hinge of the present invention adopts a flexible hinge body. When subjected to load, the flexible hinge body can withstand certain tensile and compressive loads, bending and torsion loads, and can automatically return to the initial state within its linear elastic range. The flexible hinge has a simple structure, good torsional rigidity and axial rigidity, a small overall structural mass, and is adaptive, and can buffer and absorb energy to a certain extent. In addition, the shape of the connection between the sinusoidal wave plate units can adopt a waveform transition fillet to achieve better buffering and energy absorption, reduce stress concentration, and increase service life.

[0050] The adaptive spring-type flexible hinge designed in this application adopts a sinusoidal wave plate to wrap the curved array along the circumferential direction. The technical solution provided takes into account factors such as quality, production cost, service life, maintenance cost and buffering energy absorption, and effectively solves the problems existing in the existing rigid mechanical device connection load-bearing technology.

[0051] It should be understood that although this specification is described according to various embodiments, not every embodiment contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0052] The above description is only an illustrative embodiment of the present application and is not intended to limit the scope of the present application. Any equivalent changes, modifications and combinations made by any technician in the field without departing from the concept and principle of the present application shall fall within the scope of protection of the present application.

Claims

1. An adaptive spring-type flexible hinge, characterized in that: include: A flexible hinge body (2) is symmetrically provided with mounting interfaces at both ends, and the flexible hinge body (2) has a wave spring structure that advances longitudinally along its axis and is arranged transversely along its circumference to form a ring-shaped hollow structure. The wave crests and troughs of two adjacent waves of the wave spring structure are arranged alternately and connected, so that when subjected to load, the flexible hinge body (2) can withstand tensile and compressive loads, bending and torsion loads, and can automatically return to an initial state within its linear elastic range.

2. The adaptive spring-type flexible hinge according to claim 1, characterized in that ； The mounting virtual planes formed by the two mounting interfaces on the flexible hinge body (2) are parallel to each other, and the wave spring structure of the flexible hinge body (2) comprises a plurality of wave plate units having a width, and two adjacent wave plate units are arranged in a staggered manner and connected to each other.

3. The adaptive spring-type flexible hinge according to claim 2, characterized in that ； A plurality of the wave plate units are grouped into two, the two wave plate units in each group have the same function form, and the peaks and troughs of the waveforms of the two wave plate units are alternately arranged and connected.

4. The adaptive spring-type flexible hinge according to claim 3, characterized in that ； The wave spring structure is located at the hollow cylinder wall portion of the closed annular structure formed after the wave crests and wave troughs of the two wave plate units are staggered and connected.

5. The adaptive spring-type flexible hinge according to claim 4, characterized in that ； A plurality of the wave plate units are arranged and spliced ​​along a virtual circle to form a cylindrical structure.

6. The adaptive spring-type flexible hinge according to claim 1, characterized in that ； The flexible hinge body (2) is integrally formed, and wave transition fillets are arranged at the wave crests and wave troughs of the wave of the wave spring structure.

7. The adaptive spring-type flexible hinge according to claim 6, characterized in that ； The flexible hinge body (2) is a nickel-titanium alloy tube.

8. A method for designing an adaptive spring-type flexible hinge according to any one of claims 1 to 7, characterized in that ； The wave plate unit of the wave spring structure takes one of the mounting interfaces as a function starting point, and the mounting virtual plane where the mounting interface is located is arranged parallel to the wave oscillation direction of the wave spring structure.

9. The design method of a self-adaptive spring-type flexible hinge according to claim 8, It is characterized by: The basic parameters of the wave plate unit function include: the wave plate unit amplitude A, the frequency ω, and the axial length L of the wave plate unit from the starting point to the mounting interface plane; as well as The initial phase θ of the waveform of the wave plate unit, and the waveform function value Y of the wave plate unit; The functional relationship of the wave plate unit waveform is Y=Asin(ωL+θ).

10. The design method of a self-adaptive spring-type flexible hinge according to claim 9, characterized in that ； The wave plate unit is a sinusoidal wave plate unit or a waveform curve formed by a cubic spline curve.

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