Quasi-zero stiffness vibration isolator

Abstract

The invention discloses a quasi-zero stiffness vibration isolator, and relates to the technical field of vibration isolation, the quasi-zero stiffness vibration isolator comprises a vibration isolation unit cell, the vibration isolation unit cell comprises a first fixer, a second fixer and a vibration isolation unit with an elastic self-recovery function, the vibration isolation unit comprises an X-shaped cross beam, and two sides of the X-shaped cross beam are respectively connected with the first fixer and the second fixer; the X-shaped cross beam has high bearing capacity in the initial state, the rigidity of the X-shaped cross beam is linear positive rigidity in the stage, after the borne load reaches the buckling limit, the X-shaped cross beam can be buckled, the buckling mode is that all sections of the cross beam are bent in the same direction, and in the stage, a load-displacement curve enters a platform area, so that the X-shaped cross beam is bent in the same direction. At the moment, the equivalent stiffness approaches to zero, namely, the X-shaped cross beam is designed and matched with the fixers on the two sides to serve as a fixing face and an equipment mounting face, and the vibration isolation unit cell of the quasi-zero stiffness vibration isolator with the efficient low-frequency vibration isolation performance and capable of effectively reducing the system mass and complexity is formed.

Description

Technical Field

[0001] The invention relates to the field of vibration isolation technology, in particular to a quasi-zero stiffness vibration isolator. Background Art

[0002] With the development of science and technology, the requirements of various disciplines for experimental detection accuracy are also increasing. Precision instruments are easily affected by vibration during operation, which affects the accuracy and even causes equipment damage. Taking into account the load-bearing performance and developing efficient vibration isolation for precision instruments has become an urgent problem to be solved. Due to the constraints of load-bearing performance, the stiffness of conventional vibration isolators cannot be reduced indefinitely. The quasi-zero stiffness vibration isolation technology, due to its "high static and low dynamic" characteristics, can well solve the contradiction between load-bearing and low-frequency vibration isolation. However, the quasi-zero stiffness vibration isolator structures currently known to the applicant are mostly composed of springs, cams and other components, and the overall structure is relatively complex and the overall weight is relatively high.

[0003] Therefore, people are in urgent need of a quasi-zero stiffness isolator that has both efficient low-frequency vibration isolation performance and can effectively reduce the mass and complexity of the system. Summary of the invention

[0004] The purpose of the present invention is to provide a quasi-zero stiffness vibration isolator to solve the problems existing in the above-mentioned prior art. By designing an X-shaped cross beam and cooperating with the fixers on both sides, a vibration isolation unit cell of a quasi-zero stiffness vibration isolator is formed which has both high-efficiency low-frequency vibration isolation performance and can effectively reduce the system mass and complexity.

[0005] To achieve the above-mentioned purpose, the present invention provides the following solution: The present invention provides a quasi-zero stiffness vibration isolator, including a vibration isolation unit cell, the vibration isolation unit cell includes a first fixer, a second fixer and a vibration isolation unit with elastic self-recovery function, the vibration isolation unit includes an X-shaped cross beam, and the two sides of the X-shaped cross beam are respectively connected to the first fixer and the second fixer.

[0006] Preferably, a plurality of the vibration isolation units are arranged between the first fixture and the second fixture.

[0007] Preferably, the quasi-zero stiffness vibration isolator includes a plurality of platform layers arranged in sequence from top to bottom, the platform layers include a plurality of vibration isolation cells arranged in the same plane, and the second fixer of the vibration isolation cell of the lower platform layer is fixedly connected or integrally arranged with the first fixer of the vibration isolation cell of the upper platform layer.

[0008] Preferably, the first fixer and the second fixer have the same structure.

[0009] Preferably, the first fixer and the second fixer both include a base plate and a plurality of limiting columns, the limiting columns are arranged on the base plate, and the limiting columns of the first fixer are opposite to and spaced from the limiting columns of the second fixer.

[0010] Preferably, the bottom plate is square, the four vibration isolation units are respectively arranged at the four edges of the bottom plate, and the limiting columns are arranged at the four corners of the bottom plate.

[0011] Preferably, two sides of the X-shaped cross beam are detachably connected to the first fixer and the second fixer respectively.

[0012] Preferably, the vibration isolation unit further includes an upper plate and a lower plate, the upper plate and the lower plate are respectively arranged on both sides of the X-shaped cross beam, the upper plate is parallel to the lower plate, and the upper plate and the lower plate are respectively plugged into the second fixture and the first fixture.

[0013] Preferably, tenons are arranged relatively on the opposite surfaces of the adjacent limiting columns of the first fixer and the second fixer, and the tenons are spaced apart from the bottom plate to form slots, and the slots match the corresponding upper plate or the lower plate, and the ends of the upper plate and the lower plate are inserted into the corresponding slots.

[0014] Preferably, the first fixer and the second fixer are both provided with a limiting wall for limiting the plug-in position of the upper plate or the lower plate, the limiting wall is located on the inner side of the limiting column, and the limiting wall is located on the movement path of the upper plate or the lower plate.

[0015] Compared with the prior art, the present invention mainly achieves the following technical effects:

[0016] The X-shaped cross beam has a high bearing capacity in the initial state. Its stiffness is linear positive stiffness at this stage. After the load reaches its buckling limit, the X-shaped cross beam will buckle. The buckling form is that each section of the cross beam bends in the same direction. At this stage, the load-displacement curve enters the platform area. At this time, the equivalent stiffness approaches zero. That is, the present application designs an X-shaped cross beam and cooperates with the two side fixtures as the fixing surface and the equipment installation surface to form a vibration isolation unit cell of a quasi-zero stiffness vibration isolator that takes into account efficient low-frequency vibration isolation performance and can effectively reduce the mass and complexity of the system.

[0017] Compared with the prior art, other solutions of the present invention have achieved the following technical effects:

[0018] As the load increases, multiple vertical platform layers will buckle in sequence. Each platform layer corresponds to a load mass. No human intervention is required and it develops completely spontaneously by the system, so that the vibration isolator has the function of load adaptive adjustment. In addition, multiple vibration isolation cells arranged in the platform layer can improve the bearing capacity of the overall vibration isolator. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] 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 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 these drawings without paying creative labor.

[0020] Figure 1 Schematic diagram of the structure of a quasi-zero stiffness vibration isolator in an embodiment of the present invention;

[0021] Figure 2 Schematic diagram of the structure of a vibration isolation unit cell in an embodiment of the present invention;

[0022] Figure 3 Schematic diagram of the structure of the vibration isolation unit in an embodiment of the present invention;

[0023] Figure 4 is a schematic structural diagram of a first fixer in an embodiment of the present invention;

[0024] Figure 5 is a quasi-zero stiffness characteristic curve of an X-shaped cross beam in an embodiment of the present invention;

[0025] Figure 6 is a load-displacement curve of a load-adaptive quasi-zero stiffness vibration isolator in an embodiment of the present invention;

[0026] Among them, 1. vibration isolation unit; 2. first fixer; 3. equipment installation surface; 4. fixing surface; 5. upper plate; 6. X-shaped cross beam; 7. lower plate; 8. limiting column; 9. bottom plate; 10. limiting wall; 11. tenon; 12. slot. DETAILED DESCRIPTION

[0027] 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.

[0028] The purpose of the present invention is to provide a quasi-zero stiffness vibration isolator to solve the problems existing in the prior art. By designing an X-shaped cross beam and cooperating with the fixers on both sides, a vibration isolation unit cell of the quasi-zero stiffness vibration isolator is formed which has both high-efficiency low-frequency vibration isolation performance and can effectively reduce the system mass and complexity.

[0029] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] Please refer to Figure 1 to Figure 6 As shown, a quasi-zero stiffness vibration isolator is provided, including a vibration isolation unit cell, the vibration isolation unit cell includes a first fixture 2, a second fixture and a vibration isolation unit 1 with elastic self-recovery function, the vibration isolation unit 1 includes an X-shaped cross beam 6, the two sides of the X-shaped cross beam 6 are respectively connected to the first fixture 2 and the second fixture, the X-shaped cross beam 6 has a high bearing capacity in the initial state, and its stiffness is a linear positive stiffness at this stage. After the load reaches its buckling limit, the X-shaped cross beam 6 will buckle, and the buckling form is that each section of the cross beam bends in the same direction. At this stage, the load-displacement curve enters the platform area, and the equivalent stiffness approaches zero at this time. That is, the present application designs the X-shaped cross beam 6, cooperates with the two side fixtures as the fixing surface 4 and the equipment installation surface 3, to form a vibration isolation unit cell of a quasi-zero stiffness vibration isolator that takes into account efficient low-frequency vibration isolation performance and can effectively reduce the system mass and complexity.

[0031] A plurality of vibration isolation units 1 are arranged between the first fixture 2 and the second fixture, which can correspondingly improve the bearing capacity of the vibration isolation unit cell.

[0032] In this embodiment, the quasi-zero stiffness vibration isolator includes multiple platform layers arranged in sequence from top to bottom, and the platform layers include multiple vibration isolation cells arranged in the same plane. The second fixer of the vibration isolation cell of the lower platform layer is fixedly connected or integrally arranged with the first fixer 2 of the vibration isolation cell of the upper platform layer. The fixed connection method can be welding or gluing. The spacing between adjacent vibration isolation cells in the same layer is zero. Adjacent vibration isolation cells in the same layer are welded or glued. The upper surface of the uppermost platform layer serves as the equipment installation surface 3, and the lower surface of the lowermost platform layer serves as the fixing surface 4. As the load increases, multiple vertical platform layers will buckle in sequence. Each platform layer corresponds to a load mass. No human intervention is required and it is completely developed spontaneously by the system, so that the vibration isolator has the function of load adaptive adjustment. Moreover, multiple vibration isolation cells arranged in the platform layer can improve the bearing capacity of the overall vibration isolator.

[0033] In this embodiment, the first fixture 2 has the same structure as the second fixture to facilitate production and processing.

[0034] The first fixer 2 and the second fixer both include a base plate 9 and a plurality of limit columns 8. The limit columns 8 are arranged on the base plate 9. The limit columns 8 of the first fixer 2 and the limit columns 8 of the second fixer are arranged opposite to and spaced apart from each other. The setting of the limit columns 8 can limit the maximum buckling deformation distance of the vibration isolation unit cell to ensure the normal use of the X-shaped cross beam 6. When the limit columns 8 of the first fixer 2 come into contact with the limit columns 8 of the second fixer, the equivalent stiffness of the vibration isolation unit cell will change from approaching zero to a linear positive stiffness again.

[0035] In this embodiment, the bottom plate 9 is square, and the four vibration isolation units 1 are respectively arranged at the four edges of the bottom plate 9, and the limiting columns 8 are arranged at the four corners of the bottom plate 9; in other embodiments, the bottom plate 9 of the first fixer 2 and the second fixer can also be designed to be a regular polygonal structure other than a square, and the multiple vibration isolation units 1 are respectively arranged at the multiple edges of the bottom plate 9, and the limiting columns 8 are arranged at the corners of the bottom plate 9.

[0036] The two sides of the X-shaped cross beam 6 are detachably connected to the first fixture 2 and the second fixture respectively, which facilitates the replacement of the X-shaped cross beam 6 and avoids the need to replace the entire vibration isolation unit cell after the X-shaped cross beam 6 in the vibration isolation unit cell is damaged, which is conducive to saving resources.

[0037] In the present embodiment, the structure of the detachable connection between the X-shaped cross beam 6 and the fixer is as follows: the vibration isolation unit 1 also includes an upper plate 5 and a lower plate 7, and the upper plate 5 and the lower plate 7 are respectively arranged on both sides of the X-shaped cross beam 6, the upper plate 5 is parallel to the lower plate 7, and the upper plate 5 and the lower plate 7 are respectively plugged into the second fixer and the first fixer 2; in other embodiments, the detachable connection between the two can also be achieved by connecting methods such as bolts or snaps.

[0038] On the basis of setting the limiting column 8, tenons 11 can be relatively set on the opposite surfaces of the first fixer 2 and the adjacent limiting columns 8 of the second fixer. The tenons 11 are spaced apart from the bottom plate 9 to form a slot 12. The slot 12 matches the corresponding upper plate 5 or lower plate 7. The ends of the upper plate 5 and the lower plate 7 are inserted into the corresponding slots 12 to complete the connection between the fixer and the vibration isolation unit 1.

[0039] In order to limit the X-shaped cross beam 6, a limiting wall 10 for limiting the plug-in position of the upper plate 5 or the lower plate 7 is provided on the first fixer 2 and the second fixer. The limiting wall 10 is located on the inner side of the limiting column 8. The limiting wall 10 is located on the movement path of the upper plate 5 or the lower plate 7. When the upper plate 5 and the lower plate 7 on both sides of the X-shaped cross beam 6 are inserted into the slot 12, when the upper plate 5 and the lower plate 7 abut against the limiting wall 10, it means that the upper plate 5 and the lower plate 7 are plugged in place. After being plugged in place, the outer edge of the X-shaped cross beam 6 is flush with the edge of the fixer.

[0040] The vibration isolation unit cell can be processed by 3D printing, wire cutting or milling.

[0041] When actually designing the vibration isolation unit cell, the design parameters of the vibration isolation unit 1 include the length l1, height h1, and beam thickness t1 of the X-shaped cross beam 6; the length l2 and thickness t2 of the upper and lower plates; the thickness b of the vibration isolation unit 1, and the design parameters of the first fixture 2 and the second fixture include the outer length a and outer height h2; the thickness t3 of the bottom plate 9, the height t2 and depth b of the slot 12, the height h3 and length l3 of the tenon 11; the height h4 and length l4 of the limit column 8; the height h5 and thickness t4 of the inner circle limit wall 10. Through parameter design, the equipment load can be adjusted to the platform area of ​​the quasi-zero stiffness metamaterial load-displacement curve. In this range, the system stiffness is extremely small (approaching zero), and its natural frequency will be greatly reduced. According to the vibration isolation principle, the effective vibration isolation range will be widened to the low frequency; taking the load mass m=4.7kg and the system stiffness k=16.67N / m as an example, its natural frequency ω=1.87Hz, and the lowest frequency of vibration isolation is 2.65Hz.

[0042] The material of the X-shaped cross beam 6 can be a polymer material such as nylon or resin, or a metal material such as aluminum alloy.

[0043] During actual use, the X-shaped cross beam 6 has a higher load-bearing capacity in the initial state. At this stage, its stiffness is a linear positive stiffness. After the load reaches its buckling limit, the X-shaped cross beam 6 will buckle. The buckling form is that each section of the X-shaped cross beam 6 bends in the same direction. At this stage, the load-displacement curve enters the platform area, and the equivalent stiffness approaches zero. As the load continues to increase, the upper plate 5 continues to move downward until the limit column 8 of the first fixer 2 contacts the limit column 8 of the second fixer. After the limit columns 8 of the two fixers contact, the equivalent stiffness will become a linear positive stiffness again.

[0044] Adaptive changes made according to actual needs are all within the protection scope of the present invention.

[0045] It should be noted that it is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-restrictive from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any reference numerals in the claims should not be regarded as limiting the claims involved.

[0046] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A quasi-zero stiffness vibration isolator, characterized in that: It includes a vibration isolation unit cell, which includes a first fixer, a second fixer and a vibration isolation unit with elastic self-recovery function. The vibration isolation unit includes an X-shaped cross beam, and the two sides of the X-shaped cross beam are respectively connected to the first fixer and the second fixer.

2. The quasi-zero stiffness isolator according to claim 1, characterized in that: A plurality of the vibration isolation units are arranged between the first fixture and the second fixture.

3. The quasi-zero stiffness isolator according to claim 1, characterized in that: The quasi-zero stiffness vibration isolator includes a plurality of platform layers arranged in sequence from top to bottom, the platform layers include a plurality of vibration isolation cells arranged in the same plane, the second fixer of the vibration isolation cell of the lower platform layer is fixedly connected or integrally arranged with the first fixer of the vibration isolation cell of the upper platform layer.

4. The quasi-zero stiffness isolator according to claim 1, characterized in that: The first fixture has the same structure as the second fixture.

5. The quasi-zero stiffness vibration isolator according to claim 4, characterized in that: The first fixer and the second fixer both include a bottom plate and a plurality of limiting columns. The limiting columns are arranged on the bottom plate. The limiting columns of the first fixer are opposite to and spaced from the limiting columns of the second fixer.

6. The quasi-zero stiffness vibration isolator according to claim 5, characterized in that: The bottom plate is square, the four vibration isolation units are respectively arranged at the four edges of the bottom plate, and the limiting columns are arranged at the four corners of the bottom plate.

7. The quasi-zero stiffness vibration isolator according to claim 5, characterized in that: Both sides of the X-shaped cross beam are detachably connected to the first fixer and the second fixer respectively.

8. The quasi-zero stiffness vibration isolator according to claim 7, characterized in that: The vibration isolation unit also includes an upper plate and a lower plate, the upper plate and the lower plate are respectively arranged on both sides of the X-shaped cross beam, the upper plate is parallel to the lower plate, and the upper plate and the lower plate are respectively plugged into the second fixer and the first fixer.

9. The quasi-zero stiffness vibration isolator according to claim 8, characterized in that: Tenons are arranged relatively on the opposite surfaces of the adjacent limiting columns of the first fixer and the second fixer, and the tenons are spaced apart from the bottom plate to form slots, and the slots match the corresponding upper plate or the lower plate, and the ends of the upper plate and the lower plate are inserted into the corresponding slots.

10. The quasi-zero stiffness vibration isolator according to claim 8, characterized in that: The first fixer and the second fixer are both provided with a limiting wall for limiting the insertion position of the upper plate or the lower plate, the limiting wall is located on the inner side of the limiting column, and the limiting wall is located on the movement path of the upper plate or the lower plate.

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