High-bearing-capacity multidirectional chiral quasi-zero vibration isolator based on chiral distortion design

Abstract

The invention discloses a high-bearing-capacity multidirectional chiral quasi-zero vibration isolator based on chiral twisting design. The high-bearing-capacity multidirectional chiral quasi-zero vibration isolator comprises a base and a chiral twisting buckling unit. The chiral knob buckling unit comprises a mounting piece, a rotating piece and a plurality of elastic elements, the rotating piece is rotationally connected to the base, the mounting piece is coaxially arranged above the rotating piece, and the elastic elements are connected between the mounting piece and the rotating piece at intervals in the circumferential direction; and when the chiral knob buckling unit has no external load, each elastic element is in an inclined state. The chiral twisting buckling unit can generate chiral twisting deformation under the action of an external compression load to generate buckling platform stress, namely a quasi-zero stiffness stage in which the dynamic stiffness is close to 0. And a positive stiffness spring can be connected in parallel to chiral knob buckling to avoid instability caused by distortion and enhance the overall bearing capacity. In addition, the vibration isolator is low in tangential rigidity, multi-directional low-frequency quasi-zero vibration isolation is achieved, the structure is compact, and the problems that a quasi-zero rigidity vibration isolator is low in bearing capacity and can only act in one direction are effectively solved.

Description

Technical Field

[0001] The present invention relates to the fields of mechanical engineering, aerospace, shipbuilding and ocean, vibration and noise control, and metamaterial structure technology, and specifically to a high-load-bearing multi-directional chiral quasi-zero vibration isolator based on chiral twisting design, which is used to achieve multi-directional ultra-low frequency quasi-zero stiffness vibration isolation under heavy load, that is, to achieve high static stiffness, low dynamic stiffness, and high-load-bearing vibration isolation in the vertical direction and the shear direction at the same time. Background Art

[0002] The structural vibration of mechanical equipment can cause fatigue fracture of structural parts, reduce the control accuracy and stability of the system, and the noise radiated by vibration can also reduce the comfort of passengers in airplanes and high-speed trains. The vibration sound radiation can also restrict the acoustic stealth performance of the equipment. Vibration isolators are key components for solving the vibration of complex systems. According to the design theory of vibration isolators, the lower the dynamic stiffness (that is, the lower the installation natural frequency), the better the low-frequency broadband vibration isolation performance. Quasi-zero stiffness isolators with high static stiffness and low dynamic stiffness can make the natural frequency lower than 3Hz and have received widespread attention. Its realization requires nonlinear deformation of the overall structure.

[0003] Conventional quasi-zero stiffness isolators in the prior art are basically implemented using structures such as buckling springs, buckling beams / plates / shells, X-shaped folding structures, cams, and magnetic springs. The essence is to use the bending buckling of the structure to generate negative stiffness. The structure is complex, the load-bearing capacity is low, and the tangential stiffness is high. New methods are urgently needed to overcome the above technical difficulties. Summary of the invention

[0004] In view of the deficiencies in the above-mentioned prior art, the present invention provides a high-load-bearing multi-directional chiral quasi-zero vibration isolator based on chiral twisting design, which can achieve vertical and tangential vibration isolation frequencies below 3 Hz while greatly improving the load-bearing capacity per unit volume.

[0005] To achieve the above object, the present invention provides a high-load-bearing multi-directional chiral quasi-zero vibration isolator based on chiral twisting design, comprising a substrate and a chiral rotation-torsion buckling unit; The chiral rotation-torsion buckling unit comprises a mounting member, a rotating member and a plurality of elastic elements, wherein the rotating member is rotatably connected to the base, and a rotating shaft of the rotating member coincides with a central axis of the vibration isolator; The mounting member is coaxially arranged above the rotating member, and each of the elastic elements is connected between the mounting member and the rotating member at intervals along the annular direction; When the chiral rotation-torsion buckling unit has no external load, each of the elastic elements is in a tilted state, and the tilting direction and tilting angle of each of the elastic elements are the same.

[0006] In one embodiment, the high load-bearing multi-directional chiral quasi-zero vibration isolator based on chiral twist design further includes a balancing spring; One end of the balance spring is fixedly connected to the rotating member, and the other end is connected to the mounting member, and the axis of the balance spring coincides with the central axis of the vibration isolator.

[0007] In one embodiment, the first end of the elastic element is fixedly connected to the rotating member, and the distance between the center of the first end of the elastic element and the central axis of the vibration isolator is R1; The second end of the elastic element is fixedly connected to the mounting member, and the distance between the center of the second end of the elastic element and the central axis of the vibration isolator is R2; Wherein, R1=R2=R, and R is the installation pitch circle radius of the elastic element between the installation part and the rotating part.

[0008] In one embodiment, the distance between the mounting member and the rotating member is h0, and h0≈4R~5R.

[0009] In one embodiment, the elastic element is a cylindrical structure capable of withstanding bending and torsional deformation.

[0010] In one embodiment, the distance between two adjacent elastic elements is greater than or equal to the diameter of the elastic element.

[0011] In one embodiment, the base includes a bottom plate and a shell; The shell is detachably connected to the bottom plate, a placement cavity is formed between the shell and the bottom plate, and an opening communicating with the placement cavity is provided on the top of the shell; The rotating member is a rotating body structure with a convex cross-section, the bottom end of the rotating member is located in the placement cavity and is rotationally matched with the bottom plate and the shell, and the top end of the rotating member is located in the opening and is rotationally matched with the opening; The elastic element is connected to the top end of the rotating member.

[0012] In one embodiment, it also includes an end bearing; A sink groove is formed at the bottom end of the rotating member, the first end of the end bearing is fixedly embedded in the sink groove, and the second end of the end bearing is fixedly connected to the bottom plate.

[0013] In one embodiment, an annular groove is formed on the convex step surface of the rotating member, a plurality of balls are arranged in the annular groove, and the balls are in rolling engagement with the inner wall of the outer shell.

[0014] In one embodiment, the number of the chiral rotation-torsional buckling units is multiple, and the chiral rotation-torsional buckling units are distributed in an array on the substrate.

[0015] Compared with the prior art, the present invention has the following beneficial technical effects: 1. The high-load-bearing multi-directional chiral quasi-zero vibration isolator in the present invention corresponds to the lateral bending deformation of the elastic element when subjected to shear deformation, and its overall tangential stiffness is low, thus realizing multi-directional low-frequency quasi-zero vibration isolation, and having a compact structure, which effectively solves the problem that the quasi-zero stiffness vibration isolator has low load-bearing capacity and can only act in one direction; 2. The high-load multi-directional chiral quasi-zero vibration isolator in the present invention makes the vertical and 360-degree tangential vibration isolation frequencies lower than 3Hz, effectively achieving multi-directional quasi-zero performance, and its load-bearing capacity per unit volume is significantly better than the existing technology; 3. The high-load-bearing multi-directional chiral quasi-zero vibration isolator in the present invention can be made of all-metal materials and has high environmental adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0017] Figure 1 is an axonometric diagram of a chiral vibration isolator in an embodiment of the present invention; Figure 2 is a cross-sectional view of a chiral vibration isolator in an embodiment of the present invention; Figure 3 is an axonometric diagram of a chiral rotation-torsion buckling unit in an embodiment of the present invention; Figure 4 is a buckling deformation diagram of the chiral rotation-torsion buckling unit under the action of a compressive load in an embodiment of the present invention; Figure 5 is a compression displacement-load curve diagram of the chiral vibration isolator in an embodiment of the present invention; Figure 6 It is an axonometric view of a chiral rotation-torsion buckling unit with a balancing spring in an embodiment of the present invention; Figure 7 Schematic diagram of a large-scale quasi-zero stiffness vibration isolator in an embodiment of the present invention; Figure 8 This is a schematic diagram of an experiment in an embodiment of the present invention, wherein: Figure 8 (a) Schematic diagram of the chiral vibration isolator during the experiment; Figure 8 (b) is the vibration isolation curve of the chiral vibration isolator under different loads measured in the experiment; Fig. 9 Schematic diagram of comparison between the chiral vibration isolator in the embodiment of the present invention and the existing quasi-zero stiffness vibration isolator.

[0018] Reference numerals: mounting part 1, rotating part 2, elastic element 3, balancing spring 4, base plate 5, housing 6, end bearing 7, ball 8.

[0019] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0022] like Figure 1 Shown is a high-load-bearing multi-directional chiral quasi-zero vibration isolator (hereinafter referred to as “chiral vibration isolator”) based on chiral twisting design disclosed in this embodiment, which mainly includes a substrate and a chiral rotation-torsion buckling unit.

[0023] refer to Figure 2 , Figure 3 The chiral rotation-torsional buckling unit is cylindrical as a whole, and its axis coincides with the central axis of the chiral vibration isolator. Specifically, the chiral rotation-torsional buckling unit includes a mounting part 1, a rotating part 2 and a plurality of elastic elements 3. The rotating part 2 is rotatably connected to the base, and the rotating axis of the rotating part 2 coincides with the central axis of the chiral vibration isolator. The mounting part 1 is coaxially arranged above the rotating part 2, and each elastic element 3 is connected between the mounting part 1 and the rotating part 2 at intervals along the annular direction. When the chiral rotation-torsional buckling unit has no external load, there is an initial relative helical angle α0 that is not equal to 0, that is, each elastic element 3 is in a tilted state, and the tilt direction and tilt angle of each elastic element 3 are the same, thereby forming a chiral characteristic. Among them, In this embodiment, when the rotating member 2 has only rotational freedom, but the vertical deformation is limited, and the rotation of the mounting member 1 is limited, when the mounting member 1 is compressed, the entire chiral torsional buckling unit will gradually compress and rotate the rotating member 2 at the bottom. In addition, the elastic element 3 will produce structural buckling under the action of a large compressive load, forming Figure 4 The chiral torsional buckling deformation shown constitutes the plateau segment in the displacement-load curve, e.g. Figure 5As shown in Figure 2, the chiral torsional buckling deformation will produce negative stiffness and zero stiffness. When the load reaches the platform load, the dynamic stiffness will be close to 0, thus producing a quasi-zero stiffness characteristic of high static stiffness and low dynamic stiffness.

[0024] In order to avoid the instability caused by the negative stiffness of the chiral torsional buckling, in this embodiment, a balancing spring 4 is preferably embedded in the chiral torsional buckling unit. Figure 6 As shown, one end of the balance spring 4 is fixedly connected to the rotating member 2, and the other end is connected to the mounting member 1, and the axis of the balance spring 4 coincides with the central axis of the chiral vibration isolator, that is, the balance spring 4 is connected in parallel with the elastic element 3. The load-bearing capacity of the entire chiral vibration isolator can be increased by more than 20% by connecting the balance spring 4 in parallel. Further preferably, the compression buckling of the chiral vibration isolator can be close to horizontal by appropriately selecting the stiffness of the balance spring 4, reaching a state of zero dynamic stiffness.

[0025] In the specific implementation process, the first end of the elastic element 3 is fixedly connected to the rotating member 2 by means of gluing, snap connection, screw fixing, welding, etc., and the distance between the center of the first end of the elastic element 3 and the central axis of the chiral isolator is R1. The second end of the elastic element 3 is fixedly connected to the mounting member 1 by means of gluing, snap connection, screw fixing, welding, etc., and the distance between the center of the second end of the elastic element 3 and the central axis of the chiral isolator is R2. The performance of the chiral isolator with parameter R1≠R2 is lower than that of the chiral isolator with parameter R1=R2, so in this embodiment, R1=R2=R is preferred, and R is the installation pitch radius of the elastic element 3 between the mounting member 1 and the rotating member 2.

[0026] Assuming that the spacing between the mounting member 1 and the rotating member 2 is h0 when there is no external load on the chiral torsional buckling unit, for a given spacing h0 and overall buckling strain, reducing the mounting pitch radius R and the initial relative helical angle α0 can improve the bearing strength of the chiral torsional buckling unit, and the performance improvement effect brought by reducing R is more significant. Therefore, in order to ensure the overall structural stability, in this embodiment, the spacing between the mounting member 1 and the rotating member 2 is preferably set to h0≈4R~6R, for example, h0=40 mm, R=7.5 mm.

[0027] In this embodiment, the elastic element 3 is a cylindrical structure that can withstand buckling and torsion deformation, such as a rubber rod or a metal spring, etc. At the same time, in order to ensure that the elastic elements 3 after the chiral torsion buckling unit deformation do not contact each other before the structure collapses, the spacing between two adjacent elastic elements 3 is set to be greater than or equal to the diameter of the elastic element 3.

[0028] In the specific implementation process, the base includes a bottom plate 5 and a shell 6. Specifically, the shell 6 is detachably connected to the bottom plate 5 by bolt connection, snap connection, etc., and a placement cavity is formed between the shell 6 and the bottom plate 5, and an opening communicating with the placement cavity is provided at the top of the shell 6. The rotating member 2 is a rotating body structure with a convex cross-section as a whole, the bottom end of the rotating member 2 is located in the placement cavity and is rotatably matched with the bottom plate 5 and the shell 6 at the same time, the top end of the rotating member 2 is located in the opening and is rotatably matched with the opening, and the elastic element 3 is connected to the top end of the rotating member 2.

[0029] In order to make the rotating member 2 rotate frictionlessly in actual use, a circular groove is coaxially opened inside the rotating member 2, and an end bearing 7 is added, so that the first end of the end bearing 7 is embedded in the groove and fixedly connected to the groove wall by gluing, interference fit, etc., and the second end of the end bearing 7 is fixedly connected to the bottom plate 5 by gluing, etc. At the same time, a smooth annular groove is hollowed out in the circumferential direction along the edge of the convex step surface of the rotating member 2, and a number of balls 8 are placed inside the annular groove. When the housing 6 is installed on the bottom plate 5, the inner top wall of the housing 6 contacts the balls 8 to form a rolling fit, thereby preventing the chiral isolator from detaching under tension. External loads can be installed on the mounting member 1 through fasteners such as screws.

[0030] As a preferred embodiment, the number of chiral rotation-torsion buckling units can be multiple, and each chiral rotation-torsion buckling unit is distributed in an array on the substrate, or multiple chiral vibration isolators are directly arrayed to form a larger-scale quasi-zero stiffness vibration isolator to improve the overall bearing capacity, for example Figure 7 shown.

[0031] The following is a further description of the chiral vibration isolator in this embodiment in conjunction with specific experimental tests. In the test, the initial parameters of the chiral rotational-torsional buckling unit are h0=30mm, R=7.5mm, α0=5°, and the elastic element 3 is a steel spring with an outer diameter of 6mm and an inner diameter of 3.2mm. Figure 8 As shown, the cubic dimensions of a single chiral isolator are 25×25×38 mm. 3 .like Figure 5 As shown, a single chiral isolator enters a buckling state with a dynamic stiffness close to 0 at a compression load of 27 kg.

[0032] like Figure 8 As shown in the figure, loads of different weights were installed on the chiral vibration isolator and its vibration transmissibility was tested. The experimental results show that as the load increases, the resonance frequency of the chiral vibration isolator gradually decreases and reaches the lowest state when the load reaches around 27kg. The natural frequency obtained by the test is less than 2Hz.

[0033] like Fig. 9As shown, by comparing various quasi-zero stiffness isolators in existing public literature with the chiral vibration isolator in this embodiment, it can be seen that the chiral quasi-zero stiffness isolator in this embodiment may increase the load-bearing capacity per unit volume by more than 100 times compared with existing public solutions, and more than 1000 times compared with the current average level.

[0034] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A high-load-bearing multi-directional chiral quasi-zero vibration isolator based on chiral twist design, characterized in that: Includes base and chiral rotational-torsional buckling units; The chiral rotation-torsion buckling unit comprises a mounting member, a rotating member and a plurality of elastic elements, wherein the rotating member is rotatably connected to the base, and a rotating shaft of the rotating member coincides with a central axis of the vibration isolator; The mounting member is coaxially arranged above the rotating member, and each of the elastic elements is connected between the mounting member and the rotating member at intervals along the annular direction; When the chiral rotation-torsion buckling unit has no external load, each of the elastic elements is in a tilted state, and the tilting direction and tilting angle of each of the elastic elements are the same.

2. The high-load-bearing multi-directional chiral quasi-zero vibration isolator based on chiral twisting design according to claim 1 is characterized in that: Also included is a balance spring; One end of the balance spring is fixedly connected to the rotating member, and the other end is connected to the mounting member, and the axis of the balance spring coincides with the central axis of the vibration isolator.

3. The high-load-bearing multi-directional chiral quasi-zero vibration isolator based on chiral twisting design according to claim 1 or 2, characterized in that: The first end of the elastic element is fixedly connected to the rotating member, and the distance between the center of the first end of the elastic element and the central axis of the vibration isolator is R1; The second end of the elastic element is fixedly connected to the mounting member, and the distance between the center of the second end of the elastic element and the central axis of the vibration isolator is R2; Wherein, R1=R2=R, and R is the installation pitch circle radius of the elastic element between the installation part and the rotating part.

4. The high-load-bearing multi-directional chiral quasi-zero vibration isolator based on chiral twisting design according to claim 3 is characterized in that: The distance between the mounting member and the rotating member is h0, and h0≈4R~6R.

5. The high-load-bearing multi-directional chiral quasi-zero vibration isolator based on chiral twisting design according to claim 1 or 2, characterized in that: The elastic element is a cylindrical structure capable of bearing bending and torsional deformation.

6. The high-load-bearing multi-directional chiral quasi-zero vibration isolator based on chiral twisting design according to claim 5, characterized in that: The distance between two adjacent elastic elements is greater than or equal to the diameter of the elastic element.

7. The high-load-bearing multi-directional chiral quasi-zero vibration isolator based on chiral twisting design according to claim 1 or 2, characterized in that: The base comprises a bottom plate and a shell; The shell is detachably connected to the bottom plate, a placement cavity is formed between the shell and the bottom plate, and an opening communicating with the placement cavity is provided on the top of the shell; The rotating member is a rotating body structure with a convex cross-section, the bottom end of the rotating member is located in the placement cavity and is rotationally matched with the bottom plate and the shell, and the top end of the rotating member is located in the opening and is rotationally matched with the opening; The elastic element is connected to the top end of the rotating member.

8. The high-load-bearing multi-directional chiral quasi-zero vibration isolator based on chiral twisting design according to claim 7, characterized in that: Also includes end bearings; A sink groove is formed at the bottom end of the rotating member, the first end of the end bearing is fixedly embedded in the sink groove, and the second end of the end bearing is fixedly connected to the bottom plate.

9. The high-load-bearing multi-directional chiral quasi-zero vibration isolator based on chiral twisting design according to claim 7, characterized in that: An annular groove is provided on the convex step surface of the rotating member, a plurality of balls are arranged in the annular groove, and the balls are rollingly matched with the inner wall of the shell.

10. The high-load-bearing multi-directional chiral quasi-zero vibration isolator based on chiral twist design according to claim 1 or 2, characterized in that: The number of the chiral rotation-torsion buckling units is multiple, and the chiral rotation-torsion buckling units are distributed in an array on the substrate.

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