Quasi-zero stiffness vibration isolation device

Abstract

The utility model discloses a quasi-zero stiffness vibration isolation device which comprises a support, a positive stiffness vibration isolator and a negative stiffness mechanism. The positive stiffness vibration isolator comprises a first support and a second support, a first supporting column is arranged on the first support, and the second support is connected to the first supporting column in a sliding mode. The negative stiffness mechanism comprises an unsprung synchronization unit and a sprung synchronization unit, the unsprung synchronization unit is provided with a second supporting column, and the second supporting column is coaxially located above the first supporting column; an elastic damping structure is arranged between the first support and the second support, and a plurality of negative stiffness elements are arranged between the unsprung synchronization unit and the sprung synchronization unit to form vertical negative stiffness. The utility model relates to the field of vibration reduction and isolation, realizes that the dynamic rigidity is low or is close to zero in a static balance state, solves the difficult problem when a traditional linear vibration isolation system isolates low-frequency or ultralow-frequency vibration, reduces the initial vibration isolation frequency, enlarges the vibration isolation frequency range, and improves the vibration isolation efficiency of the system.

Description

Technical Field

[0001] The utility model relates to the technical field of vibration reduction and isolation of rail transit engineering and equipment, in particular to a quasi-zero stiffness vibration isolation device. Background Art

[0002] Vibration is everywhere in human living environment and engineering practice. Harmful vibration will affect the safety and reliability of the project, reduce the accuracy of precision instruments, and endanger human health, making human sense of security and comfort not guaranteed. The human body is very sensitive to vertical vibrations of 4-8HZ; and vehicles and other vehicles are prone to vibrations of 1-10HZ during movement; these vibrations may be periodic, random, and impact. At this time, traditional vibration isolators often have difficulty in achieving the desired vibration isolation goals because their natural frequencies cannot be reduced to a low enough level, which is mainly reflected in the poor vibration isolation performance against low-frequency disturbances. Therefore, it is very meaningful to study and design vibration isolators with low-frequency vibration isolation performance.

[0003] According to vibration isolation theory: the larger the parametric mass of the linear vibration isolation system and the smaller the support stiffness, the smaller the natural frequency of the system and the better the vibration isolation effect. The vibration isolation effect can only be achieved when the natural frequency of the vibration isolation system is greater than 100 times. However, in actual engineering design, due to the limitations of space, cost, and load-bearing capacity, the use of increasing mass and reducing stiffness to improve the vibration isolation effect of the vibration isolation system has considerable limitations. The quasi-zero stiffness vibration isolation technology obtains higher static stiffness and lower dynamic stiffness, thereby having good low-frequency vibration isolation performance on the basis of ensuring its load-bearing capacity. In recent years, quasi-zero stiffness vibration isolation technology has become a research hotspot for scholars at home and abroad. Therefore, the design and application of quasi-zero stiffness vibration isolation devices have become the goal pursued in the field of vibration reduction / isolation technology.

[0004] At present, the main method for real engineering application is to connect the negative stiffness mechanism in parallel to the positive stiffness system to achieve quasi-zero stiffness, and there have been many literature reports on the so-called "quasi-zero stiffness vibration isolation". However, most of the so-called "quasi-zero stiffness" vibration isolation devices currently launched are only theoretical research conducted by some schools, and there are not many "quasi-zero stiffness" vibration isolation devices that can be actually applied in engineering. Among them, the most relevant ones are as follows:

[0005] The invention patent with patent publication number CN108411713A discloses a quasi-zero stiffness isolator floating plate track bed and its design method, but in fact there is no feasible design scheme. The proposed scheme is only idealized or artificially functionalized and cannot be implemented in practice, so it has no practical application value.

[0006] The utility model patent with the patent publication number CN214938838U discloses a quasi-zero stiffness vibration isolator floating plate ballast and its design method, which uses disc springs as negative stiffness bearing components and installs them in parallel with positive stiffness rubber bearings to realize quasi-zero stiffness vibration isolators. This method theoretically utilizes the negative stiffness characteristics of disc springs, but in fact, disc springs do not have stable negative stiffness. They only have negative stiffness characteristics when the disc springs are deformed close to the horizontal position and flip over. In this case, the vibration isolator directly fails. Although the flipping of the disc spring is limited in structure, the generation of negative stiffness is also limited. Therefore, it is not advisable to use disc springs to achieve negative stiffness.

[0007] The invention patent with the patent publication number CN112963478A discloses a tunable buckling spring quasi-zero stiffness vibration isolation device, which realizes negative stiffness through the deformation of the buckling spring, but the technical solution proposed fixes the buckling spring on the fixed block and the slider of the bottom adjustment support device, and forms negative stiffness through the sliding of the buckling spring on the slider along the guide rail. Through careful analysis, it can be found that this is purely a test device and has no practical value, because it is rare to have such an environment that can slide on the guide rail in the actual field, so it is also a method with no practical value. Utility Model Content

[0008] In view of the problem that the existing linear spring isolators in the above-mentioned prior art are difficult to isolate low-frequency or ultra-low-frequency vibrations, the utility model provides a quasi-zero stiffness vibration isolation device, which can reduce the starting vibration isolation frequency, increase the vibration isolation frequency range, and improve the vibration isolation efficiency. It has the advantages of simple structure, high reliability, and long service life.

[0009] To achieve the above-mentioned purpose, the utility model provides a quasi-zero stiffness vibration isolation device, comprising a bracket, a positive stiffness vibration isolator and a negative stiffness mechanism;

[0010] The positive stiffness vibration isolator comprises a first support and a second support connected to the bracket, the first support is provided with a first vertical support column, and the second support is slidably connected to the first support column;

[0011] The negative stiffness mechanism comprises an unsprung synchronization unit and a sprung synchronization unit connected to the bracket, wherein the unsprung synchronization unit is provided with a second vertical support column, and the second support column is coaxially located above the first support column;

[0012] An elastic damping structure is provided between the first support and the second support, and a plurality of negative stiffness elements are provided between the unsprung synchronization unit and the sprung synchronization unit to form vertical negative stiffness when the sprung synchronization unit is vertically displaced under the action of vibration impact force.

[0013] In one embodiment, the sprung synchronization unit includes a first bearing portion of a tubular structure, and the unsprung synchronization unit includes a second bearing portion of a tubular structure;

[0014] The first bearing part is connected to the bracket, and the first bearing part is coaxially sleeved on the second bearing part, and an annular installation cavity is formed between the first bearing part and the second bearing part;

[0015] There are a plurality of negative stiffness elements, and each of the negative stiffness elements is arranged in the installation cavity at intervals along the circumferential direction.

[0016] In one embodiment, the negative stiffness element includes a first joint support block, a second joint support block and a plurality of bow-shaped tile springs;

[0017] The first joint support block is arranged on the inner wall of the first bearing portion, the second joint support block is arranged on the outer wall of the second bearing portion, and each of the bow-shaped tile-type springs is arranged vertically spaced between the first joint support block and the second joint support block;

[0018] The bow-shaped tile spring comprises a bow-shaped portion and arc portions arranged at both ends of the bow-shaped portion, a first groove is arranged on the first joint support block corresponding to the connection of each of the bow-shaped tile springs, and a second groove is arranged on the second joint support block corresponding to the connection of each of the bow-shaped tile springs;

[0019] The arc portion of the first end of the bow-shaped tile-type spring is arranged in the corresponding first groove and forms a rotational joint fitting relationship, the arc portion of the second end of the bow-shaped tile-type spring is arranged in the corresponding second groove and forms a rotational joint fitting relationship, and the first end of the bow-shaped tile-type spring is higher than the second end.

[0020] In one embodiment, the radius of the outer contour arc of the arc portion is 1 mm to 2 mm larger than the radius of the inner contour arc, and the position of the center of the inner contour arc of the arc portion is offset by 0.4 mm to 0.7 mm in the direction away from the arc portion compared to the center of the outer contour arc, so that the thickness of the arc portion forms a structure in which the thickness is the thickest at the top and gradually becomes thinner toward both ends;

[0021] The position of the line connecting the centers of the two arc portions is offset by 0.5mm to 1mm relative to the center of the inner contour arc of the bow portion in the direction away from the bow portion, the length of the line connecting the centers of the two arc portions is greater than twice the radius of the outer contour arc of the bow portion, and the radius of the arc portion is greater than the top thickness of the bow portion.

[0022] In one embodiment, the sprung synchronization unit further includes a cover plate, wherein the cover plate is threadedly connected to the top of the first bearing portion;

[0023] The outer wall of the first joint support block is slidably matched with the inner wall of the first bearing portion, and the first groove is provided on the inner wall of the first joint support block;

[0024] A first step structure is provided on the inner wall of the first bearing portion, the top end of the first joint supporting block abuts against the cover plate, and a gap is provided between the bottom end of the first joint supporting block and the first step structure.

[0025] In one of the embodiments, a stopper is provided between two adjacent negative stiffness elements, and the stopper is adapted to the triangular space between the two adjacent negative stiffness elements.

[0026] In one embodiment, the second support column is threadedly connected to the second bearing portion;

[0027] A sink groove and a spring washer are provided on the top of the second bearing portion, the bottom end of the spring washer is embedded in the sink groove, and the spring washer is sleeved on the second supporting column;

[0028] A locking nut is threadedly connected to the top of the second supporting column, and the locking nut abuts against the spring washer;

[0029] A disc spring is sleeved on the spring washer, and the concave surface of the disc spring faces upward.

[0030] In one embodiment, the top of the first bearing portion and the top of the second bearing portion are sealed by a first sealing structure;

[0031] A second step structure is provided on the inner wall of the first bearing portion, the bottom end of the second bearing portion is supported on the second step structure, and a second sealing structure is provided between the bottom end of the second bearing portion and the second step structure;

[0032] The gaps between the first bearing portion, the second bearing portion, the first sealing structure, the second sealing structure and the negative stiffness element are filled with lubricating grease.

[0033] In one embodiment, the first support is a cylindrical structure with an open top, one end of the first support column is coaxially arranged on the inner wall of the bottom of the first support, and the other end extends vertically upward;

[0034] The second support comprises a disc and a stepped shaft, the disc is connected to the support, and the stepped shaft is coaxially arranged at the bottom of the disc;

[0035] The elastic damping structure comprises a cylindrical coil spring, which is sleeved on the stepped shaft, and one end of the cylindrical coil spring abuts against the inner wall of the bottom of the first support, and the other end abuts against the bottom of the disc.

[0036] In one embodiment, the elastic damping structure further includes a damping disk and a liquid damping material;

[0037] The damping disc is sleeved on the outer wall of the bottom end of the stepped shaft, the liquid damping material is filled in the cylinder of the first support, and the damping disc is immersed in the liquid damping material.

[0038] Compared with the prior art, the utility model has the following beneficial technical effects:

[0039] The utility model adopts a negative stiffness mechanism with multiple negative stiffness elements and a positive stiffness isolator in parallel to form a quasi-zero stiffness vibration isolation device. Compared with a single linear spring isolator, it can achieve low or close to zero dynamic stiffness under static equilibrium state, solves the problem of traditional linear vibration isolation system in isolating low-frequency or ultra-low-frequency vibration, reduces the starting vibration isolation frequency, increases the vibration isolation frequency range, improves the vibration isolation efficiency of the system, and at the same time completely retains the load-bearing capacity and reliability of the existing linear spring isolator, and has the advantages of simple structure, high reliability, long service life, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the utility model 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 utility model. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0041] Figure 1 This is a cross-sectional view of the overall structure of the quasi-zero stiffness vibration isolation device in the embodiment of the utility model;

[0042] Figure 2 A cross-sectional view of a bracket in an embodiment of the utility model;

[0043] Figure 3 It is a cross-sectional view of a positive stiffness vibration isolator in an embodiment of the utility model;

[0044] Figure 4 An axial cross-sectional view of the negative stiffness mechanism in the embodiment of the utility model;

[0045] Figure 5 A radial cross-sectional view of the negative stiffness mechanism in the embodiment of the utility model;

[0046] Figure 6 is a cross-sectional view of a negative stiffness element in an embodiment of the utility model;

[0047] Figure 7 It is a front view of the bow-shaped tile spring in the embodiment of the utility model;

[0048] Figure 8 It is a schematic diagram of another implementation of the quasi-zero stiffness vibration isolation device in the embodiment of the utility model.

[0049] Figure numbers: bracket 1, annular steel plate 101, first load-bearing support ring 102, second load-bearing support ring 103, first support 2, second support 3, disc 301, stepped shaft 302, first support column 4, cylindrical helical spring 5, damping disc 6, second support column 7, first load-bearing part 8, disc-shaped load-bearing mounting plate 801, first step structure 802, second step structure 803, second load-bearing part 9, first joint support block 10, first groove 1001, second joint support block 11, second groove 1101, bow-shaped tile spring 12, bow-shaped part 1201, arc part 1202, cover plate 13, dust cover 14, block 15, spring washer 16, locking nut 17, disc spring 18, first sealing structure 19, second sealing structure 20.

[0050] The realization of the purpose, functional features and advantages of the utility model will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0051] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0052] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back...) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0053] In addition, in the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0054] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, a physical connection, or a wireless communication connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0055] 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.

[0056] like Figure 1 The quasi-zero stiffness vibration isolation device disclosed in this embodiment is shown, which is mainly composed of a bracket 1, a positive stiffness vibration isolator and a negative stiffness mechanism. Among them, the positive stiffness vibration isolator and the negative stiffness mechanism are installed in parallel on the bracket 1, and the three are assembled into a whole to achieve quasi-zero stiffness vibration isolation.

[0057] In this embodiment, the bracket 1 is not only the supporting part for the combined installation of the positive stiffness isolator and the negative stiffness mechanism, but also the installation or pre-embedded bearing part of the vibration isolation facility. Figure 2 The bracket 1 is a cylindrical steel cylinder structure as a whole, and a ring-shaped steel plate 101 with a square shape and a circular hole in the center is welded at the bottom of the cylinder, a first load-bearing support ring 102 is welded on the inner side of the cylinder of the bracket 1, and a second load-bearing support ring 103 is welded on the top of the cylinder of the bracket 1. In the specific implementation process, the bracket 1 as a whole can be set to a cylindrical shape, a rectangular shape, or other shapes.

[0058] refer to Figure 3The positive stiffness vibration isolator includes a first support 2, a second support 3, a first support column 4 and an elastic damping structure. The first support 2 is a cylindrical structure with an open top as a whole, and its top is located inside the bracket 1, and the bottom is located outside the bracket 1 after passing through the annular steel plate 101, so that the bottom of the first support 2 can be fixedly installed on the ground or other facility platforms. The second support 3 includes a disc 301 and a stepped shaft 302, and the stepped shaft 302 is coaxially arranged at the bottom of the disc 301, and the first bearing support ring 102 is supported, connected, welded, or fixedly connected to the top of the disc 301 by screws. The bottom end of the first support column 4 is coaxially welded to the inner wall of the bottom of the first support 2, and the other end extends vertically upward. The disc 301 and the stepped shaft 302 are sleeved on the first support column 4, and the disc 301, the stepped shaft 302 and the first support column 4 are all clearance-fitted, and the top plane of the first support column 4 is lower than the top plane of the disc 301.

[0059] In the specific implementation process, the elastic damping structure includes a cylindrical coil spring 5, which is sleeved on the stepped shaft 302, and one end of the cylindrical coil spring 5 abuts on the inner wall of the bottom of the first support 2, and the other end abuts on the bottom of the disc 301. When the bracket 1 undergoes vertical displacement under the action of the vibration impact force, the impact load is transmitted to the positive stiffness vibration isolator through the first bearing support ring 102 and the disc 301, so that the first support 2 and the second support 3 are relatively displaced, so that the cylindrical coil spring 5 absorbs the impact load as an elastic damping structure, and plays a vibration reduction and isolation effect. Preferably, the elastic damping structure also includes a damping disk 6 and a liquid damping material, the damping disk 6 is sleeved on the outer wall of the bottom end of the stepped shaft 302, the liquid damping material is filled in the cylinder of the first support 2, and the damping disk 6 is immersed in the liquid damping material to further enhance the vibration reduction and isolation effect of the positive stiffness vibration isolator.

[0060] The negative stiffness mechanism in this embodiment includes an unsprung synchronization unit and a sprung synchronization unit connected to the bracket 1. The unsprung synchronization unit is provided with a second vertical support column 7, the second support column 7 is coaxially located above the first support column 4, and there are multiple negative stiffness elements between the unsprung synchronization unit and the sprung synchronization unit to form vertical negative stiffness when the sprung synchronization unit undergoes vertical displacement under the action of vibration impact force.

[0061] refer to Figure 4 , Figure 5 The sprung synchronization unit includes a first bearing portion 8 of a tubular structure, and the unsprung synchronization unit includes a second bearing portion 9 of a tubular structure. The first bearing portion 8 is connected to the bracket 1, and the first bearing portion 8 is coaxially sleeved on the second bearing portion 9. An annular mounting cavity is formed between the first bearing portion 8 and the second bearing portion 9. There are multiple negative stiffness elements, and each negative stiffness element is arranged in the mounting cavity at intervals along the annular direction.

[0062] refer to Figure 6 , Figure 7 The negative stiffness element includes a first joint support block 10, a second joint support block 11 and a plurality of bow-shaped tile springs 12. The first joint support block 10 and the second joint support block 11 are both rectangular block structures, and their length direction is parallel to the axial direction of the first bearing part 8 and the second bearing part 9. The first joint support block 10 is arranged on the inner wall of the first bearing part 8, and the second joint support block 11 is arranged on the outer wall of the second bearing part 9. Each bow-shaped tile spring 12 is arranged between the first joint support block 10 and the second joint support block 11 at intervals in the vertical direction. The bow-shaped tile spring 12 includes an arched portion 1201 and arc portions 1202 arranged at both ends of the arched portion 1201. The arched portion 1201 is an arc plate-shaped structure, and the arc portion 1202 is a semi-cylindrical structure. A first groove 1001 is provided at the connection of the first joint support block 10 corresponding to each of the bow-shaped tile-type springs 12, that is, a plurality of first grooves 1001 corresponding to the bow-shaped tile-type springs 12 are vertically provided on the inner wall of the first joint support block 10. A second groove 1101 is provided at the connection of the second joint support block 11 corresponding to each of the bow-shaped tile-type springs 12, that is, a plurality of second grooves 1101 corresponding to the bow-shaped tile-type springs 12 are vertically provided on the outer wall of the second joint support block 11. The arc portion 1202 at the first end of the bow-shaped tile-type spring 12 is arranged in the corresponding first groove 1001 and forms a rotational joint fitting relationship. The arc portion 1202 at the second end of the bow-shaped tile-type spring 12 is arranged in the corresponding second groove 1101 and forms a rotational joint fitting relationship. Lubrication grooves are provided on the first groove 1001, the second groove 1101 and the arc portion 1202, and the first end of the bow-shaped tile-type spring 12 is higher than the second end, so that each bow-shaped tile-type spring 12 has a certain inclination angle in the same direction, so that the first joint support block 10 and the second joint support block 11 are installed in an upper and lower offset manner.

[0063] In this embodiment, the radius of the outer contour arc of the arc portion 1201 is 1mm to 2mm larger than the radius of the inner contour arc, and the position of the center of the inner contour arc of the arc portion 1201 is offset by 0.4mm to 0.7mm in the direction away from the arc portion 1201 compared to the center of the outer contour arc, so that the thickness of the arc portion 1201 forms a structure in which the thickness is thickest at the top and gradually thins toward the two ends. The position of the center line of the two arc portions 1202 is offset by 0.5mm to 1mm in the direction away from the arc portion 1201 relative to the center of the inner contour arc of the arc portion 1201, and the length of the center line of the two arc portions 1202 is slightly greater than twice the radius of the outer contour arc of the arc portion 1201, and the radius of the arc portion 1202 is slightly greater than the thickness of the top of the arc portion 1201. The connection relationship between the two arc portions 1202 and the outer contour arc and the inner contour arc on the bow portion 1201 is as follows: the arc portion 1202 is connected to the outer contour arc by an arc tangent to each other, and the arc portion 1202 and the inner contour arc are connected by two open secants tangent to the inner contour arc. The overall width dimension of the bow-shaped tile spring 12 is slightly larger than the length dimension of the line connecting the centers of the two arc portions 1202.

[0064] In the specific implementation process, a disc-shaped bearing mounting plate 801 is welded on the outer wall of the first bearing part 8, and the second bearing support ring 103 is supported, connected, welded, or fixedly connected to the top of the disc-shaped bearing mounting plate 801 by screws. The top inner wall of the first bearing part 8 has an internal thread, and the spring synchronization unit also includes a cover plate 13 and a dust cover 14. The cover plate 13 is a circular pancake structure, and its outer circumference is provided with an external thread and forms an assembly relationship with the internal thread on the top inner wall of the first bearing part 8. The center of the cover plate 13 is a stepped through hole or a hole groove, and the smallest through hole is processed into an inner hexagon to make way for the top of the second support column 7. The dust cover 14 is a cylindrical cover made of rubber material, and the dust cover 14 is sleeved on the top of the first bearing part 8 and the cover plate 13. The inner wall at the bottom of the first bearing part 8 is provided with a first step structure 802 and a second step structure 803. The outer wall of the first joint support block 10 is slidably matched with the inner wall of the first bearing part 8. At the same time, the top end of the first joint support block 10 abuts against the cover plate 13, and there is a gap between the bottom end of the first joint support block 10 and the first step structure 802. The bottom end of the second bearing part 9 is supported on the second step structure 803, and there is a clearance fit between the two. The outer wall of the second bearing part 9 along the axial middle is processed into a polygonal cylinder, and the two ends retain the cylindrical body, so that the outer wall of the second bearing part 9 forms a polygonal groove structure, and the second joint support block 11 is embedded in the groove on the outer wall of the second bearing part 9. Preferably, a plastic block 15 is installed in the triangular space between two adjacent negative stiffness elements, and the block 15 is adapted to the triangular space between the two adjacent negative stiffness elements, so as to prevent the negative stiffness element from moving in the installation cavity.

[0065] The second support column 7 includes a threaded rod at the top and an optical axis rod at the bottom. The threaded rod of the second support column 7 is threadedly connected to the inner wall of the second bearing part 9. The optical axis rod of the second support column 7 passes through the bottom of the first bearing part 8 and the second bearing part 9 and extends downward to the second support 3 of the positive stiffness isolator, and contacts and cooperates with the top of the first support column 4, wherein the optical axis rod of the second support column 7 and the first bearing part 8 and the second bearing part 9 are all clearance-matched. A recessed groove and a spring washer 16 are provided at the top of the second bearing part 9. The bottom end of the spring washer 16 is embedded in the recessed groove, and the spring washer 16 is sleeved on the second support column 7. A locking nut 17 is threadedly connected to the top of the second support column 7, and the locking nut 17 abuts against the spring washer 16. At the same time, a disc spring 18 is sleeved on the spring washer 16, and the concave surface of the disc spring 18 faces upward. Preferably, the mating surface between the bottom end of the second supporting column 7 and the top end of the first supporting column 4 is a curved surface structure or a tortuous surface structure to better transmit the vertical load; or a screw portion may be provided at the bottom end of the second supporting column 7, and a threaded hole may be provided at the top end of the first supporting column 4, so that the bottom end of the second supporting column 7 and the top end of the first supporting column 4 are fixedly connected by threads, that is, Figure 8 shown.

[0066] As a preferred embodiment, a first sealing structure 19 is provided between the top of the second bearing part 9 and the bottom of the cover plate 13, specifically, an annular rubber ring installed on the top of the second bearing part 9 by cold gluing and fitting the annular groove. A second sealing structure 20 is provided between the bottom end of the second bearing part 9 and the second step structure 803, and an annular rubber ring installed between the bottom end of the second bearing part 9 and the second step structure 803 by cold gluing and fitting the annular groove can also be used. Further preferably, the gaps between the first bearing part 8, the second bearing part 9, the first sealing structure 19, the second sealing structure 20 and the negative stiffness element are filled with lubricating grease, so that the negative stiffness mechanism can better transmit the impact load.

[0067] The working principle of the negative stiffness mechanism in this embodiment is as follows: the spring synchronization unit, the first joint support block 10 in the negative stiffness element and the second sealing structure 20 are relatively assembled and fixed together to form a first up-and-down motion synchronization mechanism. The unsprung synchronization unit, the spring washer 16, the locking nut 17, the disc spring 18, the first sealing structure 19, the second support column 7 and the second joint support block 11 in the negative stiffness element are relatively assembled and fixed together to form a second up-and-down motion synchronization mechanism. The first up-and-down motion synchronization mechanism is fixed together with the bracket 1 and bears the external loading force. The second up-and-down motion synchronization mechanism is connected and supported on the foundation ground or other facility platform through the second support column 7 and the first support column 4 on the positive stiffness vibration isolator. The bow-shaped tile spring 12 becomes an elastic support that can be compressed and deformed up and down between the first up-and-down motion synchronization mechanism and the second up-and-down motion synchronization mechanism. Tightening the cover plate 13 can pre-compress the bow-shaped tile spring 12 through the first joint support block 10, and at the same time eliminate the gap between the bottom end of the first joint support block 10 and the first step structure 802. When the first up-and-down motion synchronization mechanism is vertically displaced under the action of vibration impact force, vertical negative stiffness is formed by compression deformation and joint rotation of the bow-shaped tile spring 12. When the vertical relative displacement between the first up-and-down motion synchronization mechanism and the second up-and-down motion synchronization mechanism reaches the limit position, the disc spring 18 is responsible for limiting and buffering.

[0068] The above description is only a preferred embodiment of the utility model, and does not limit the patent scope of the utility model. All equivalent structural changes made by using the contents of the utility model specification and drawings under the utility model concept, or directly / indirectly used in other related technical fields are included in the patent protection scope of the utility model.

Claims

1. A quasi-zero stiffness vibration isolation device, characterized in that: It includes a bracket, a positive stiffness vibration isolator and a negative stiffness mechanism; The positive stiffness vibration isolator comprises a first support and a second support connected to the bracket, the first support is provided with a first vertical support column, and the second support is slidably connected to the first support column; The negative stiffness mechanism comprises an unsprung synchronization unit and a sprung synchronization unit connected to the bracket, wherein the unsprung synchronization unit is provided with a second vertical support column, and the second support column is coaxially located above the first support column; An elastic damping structure is provided between the first support and the second support, and a plurality of negative stiffness elements are provided between the unsprung synchronization unit and the sprung synchronization unit to form vertical negative stiffness when the sprung synchronization unit is vertically displaced under the action of vibration impact force.

2. The quasi-zero stiffness vibration isolation device according to claim 1, characterized in that: The sprung synchronization unit includes a first bearing portion of a tubular structure, and the unsprung synchronization unit includes a second bearing portion of a tubular structure; The first bearing part is connected to the bracket, and the first bearing part is coaxially sleeved on the second bearing part, and an annular installation cavity is formed between the first bearing part and the second bearing part; There are a plurality of negative stiffness elements, and each of the negative stiffness elements is arranged in the installation cavity at intervals along the circumferential direction.

3. The quasi-zero stiffness vibration isolation device according to claim 2, characterized in that: The negative stiffness element includes a first joint support block, a second joint support block and a plurality of bow-shaped tile springs; The first joint support block is arranged on the inner wall of the first bearing portion, the second joint support block is arranged on the outer wall of the second bearing portion, and each of the bow-shaped tile-type springs is arranged vertically spaced between the first joint support block and the second joint support block; The bow-shaped tile spring comprises a bow-shaped portion and arc portions arranged at both ends of the bow-shaped portion, a first groove is arranged on the first joint support block corresponding to the connection of each of the bow-shaped tile springs, and a second groove is arranged on the second joint support block corresponding to the connection of each of the bow-shaped tile springs; The arc portion of the first end of the bow-shaped tile-type spring is arranged in the corresponding first groove and forms a rotational joint fitting relationship, the arc portion of the second end of the bow-shaped tile-type spring is arranged in the corresponding second groove and forms a rotational joint fitting relationship, and the first end of the bow-shaped tile-type spring is higher than the second end.

4. The quasi-zero stiffness vibration isolation device according to claim 3, characterized in that: The radius of the outer contour arc of the arc portion is 1 mm to 2 mm larger than the radius of the inner contour arc, and the position of the center of the inner contour arc of the arc portion is offset by 0.4 mm to 0.7 mm in the direction away from the arc portion compared to the center of the outer contour arc, so that the thickness of the arc portion forms a structure in which the thickness is the thickest at the top and gradually becomes thinner towards both ends; The position of the line connecting the centers of the two arc portions is offset by 0.5mm to 1mm relative to the center of the inner contour arc of the bow portion in the direction away from the bow portion, the length of the line connecting the centers of the two arc portions is greater than twice the radius of the outer contour arc of the bow portion, and the radius of the arc portion is greater than the top thickness of the bow portion.

5. The quasi-zero stiffness vibration isolation device according to claim 3, characterized in that: The sprung synchronization unit further includes a cover plate, which is threadedly connected to the top of the first bearing portion; The outer wall of the first joint support block is slidably matched with the inner wall of the first bearing portion, and the first groove is provided on the inner wall of the first joint support block; A first step structure is provided on the inner wall of the first bearing portion, the top end of the first joint supporting block abuts against the cover plate, and a gap is provided between the bottom end of the first joint supporting block and the first step structure.

6. The quasi-zero stiffness vibration isolation device according to any one of claims 2 to 5, characterized in that: A stopper is provided between two adjacent negative stiffness elements, and the stopper is adapted to the triangular space between the two adjacent negative stiffness elements.

7. The quasi-zero stiffness vibration isolation device according to any one of claims 2 to 5, characterized in that: The second supporting column is threadedly connected to the second bearing portion; A sink groove and a spring washer are provided on the top of the second bearing portion, the bottom end of the spring washer is embedded in the sink groove, and the spring washer is sleeved on the second supporting column; A locking nut is threadedly connected to the top of the second supporting column, and the locking nut abuts against the spring washer; A disc spring is sleeved on the spring washer, and the concave surface of the disc spring faces upward.

8. The quasi-zero stiffness vibration isolation device according to any one of claims 2 to 5, characterized in that: The top of the first bearing portion and the top of the second bearing portion are sealed by a first sealing structure; A second step structure is provided on the inner wall of the first bearing portion, the bottom end of the second bearing portion is supported on the second step structure, and a second sealing structure is provided between the bottom end of the second bearing portion and the second step structure; The gaps between the first bearing portion, the second bearing portion, the first sealing structure, the second sealing structure and the negative stiffness element are filled with lubricating grease.

9. The quasi-zero stiffness vibration isolation device according to any one of claims 1 to 5, characterized in that: The first support is a cylindrical structure with an open top, one end of the first support column is coaxially arranged on the inner wall of the bottom of the first support, and the other end extends vertically upward; The second support comprises a disc and a stepped shaft, the disc is connected to the support, and the stepped shaft is coaxially arranged at the bottom of the disc; The elastic damping structure comprises a cylindrical coil spring, which is sleeved on the stepped shaft, and one end of the cylindrical coil spring abuts against the inner wall of the bottom of the first support, and the other end abuts against the bottom of the disc.

10. The quasi-zero stiffness vibration isolation device according to claim 9, characterized in that: The elastic damping structure also includes a damping disk and a liquid damping material; The damping disc is sleeved on the outer wall of the bottom end of the stepped shaft, the liquid damping material is filled in the cylinder of the first support, and the damping disc is immersed in the liquid damping material.

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