A negative stiffness adjustable vertical vibration isolation device based on quasi-zero stiffness characteristics

Abstract

The present invention proposes a negative stiffness adjustable vertical vibration isolation device based on quasi-zero stiffness characteristics, which relates to the technical field of vibration isolation devices. It includes a base plate, a positive stiffness unit and a negative stiffness unit. The positive stiffness unit includes a positive stiffness spring and a positive stiffness spring cover plate; the negative stiffness unit includes a first compression spring sheet, a second compression spring sheet, a third compression spring sheet, and a fourth compression spring sheet; a first center plate is provided between the first compression spring sheet and the second compression spring sheet; a second center plate is provided between the third compression spring sheet and the fourth compression spring sheet; the first compression spring sheet, the second compression spring sheet, the third compression spring sheet, the fourth compression spring sheet, the first center plate, the second center plate and the positive stiffness spring cover plate are stacked in the vertical direction. The present invention can effectively reduce the vibration transmission between the object and the base, reduce the size of the device without affecting the vibration isolation performance, achieve a compact design, and meet the requirements of some special vibration reduction systems.

Description

Technical Field

[0001] The present invention relates to the technical field of vibration isolation devices, and in particular to a negative stiffness adjustable vertical vibration isolation device based on quasi-zero stiffness characteristics. Background Art

[0002] In the engineering field, vibration affects user comfort, reduces the accuracy and stability of precision equipment, and can even cause structural fatigue failure. Previous research has extensively explored the problems caused by vibration in highly motion-sensitive equipment and devices, and proposed numerous measures to reduce vibration transmission. However, the natural frequency of vibration isolation systems based on traditional linear vibration isolation methods is relatively high, making them significantly limited in isolating low-frequency vibrations.

[0003] Unlike traditional linear vibration isolation methods, quasi-zero stiffness vibration isolation technology can significantly reduce dynamic stiffness without sacrificing static stiffness. This nonlinear characteristic of low dynamic stiffness and high static stiffness reduces the initial isolation frequency of the vibration isolation system while maintaining a high load-bearing capacity, thereby extending the isolation frequency band to the low-frequency region. By selecting appropriate system parameters and connecting positive and negative stiffness units in parallel, quasi-zero stiffness characteristics can be achieved. Currently, some quasi-zero stiffness isolators have been applied in engineering fields and have demonstrated their superiority over linear vibration isolation methods.

[0004] However, the quasi-zero stiffness isolators currently constructed based on geometric nonlinearity, magnetic nonlinearity and other elements are large in size, cannot meet the requirements of some vibration reduction systems, and have limited application scenarios. Summary of the Invention

[0005] The purpose of the present invention is to provide a negative stiffness adjustable vertical vibration isolation device based on quasi-zero stiffness characteristics, which can effectively reduce the vibration transmission between the object and the base, and has the nonlinear characteristics of low dynamic stiffness and high static stiffness. While ensuring a high load-bearing capacity, it greatly reduces the natural frequency of the vibration isolation system, thereby extending the vibration isolation frequency band to the low-frequency region; wherein, the stiffness of the negative stiffness unit can be adjusted by a cable to adapt to different loads; at the same time, the stacked arrangement of the compressed spring sheets can reduce the size of the device without affecting the vibration isolation performance, thereby achieving a compact design and meeting the requirements of some special vibration reduction systems.

[0006] The technical solution adopted in the present invention is:

[0007] The embodiment of the present application provides a negative stiffness adjustable vertical vibration isolation device based on quasi-zero stiffness characteristics, comprising a base plate, a positive stiffness unit, and a negative stiffness unit, wherein the positive stiffness unit comprises a plurality of positive stiffness springs vertically arranged on the top of the base plate and a positive stiffness spring cover plate arranged on the top of the positive stiffness springs;

[0008] The negative stiffness unit includes a first compression spring sheet, a second compression spring sheet, a third compression spring sheet, and a fourth compression spring sheet; a bottom rigid plate is provided on the top of the bottom plate, a top rigid plate is provided on the top of the bottom rigid plate, a flexible plate is provided opposite to the top rigid plate, and the negative stiffness unit is located between the top rigid plate and the flexible plate;

[0009] The first compression spring piece is located above the second compression spring piece, and a first center plate is provided between the first compression spring piece and the second compression spring piece; one end of the first compression spring piece is fixed to the top of the top rigid plate, and the other end of the first compression spring piece is fixed to the top of the first center plate; one end of the second compression spring piece is fixed to the bottom of the first center plate, and the other end of the second compression spring piece is fixed to the top of the flexible plate;

[0010] The third compression spring piece is located below the second compression spring piece and above the fourth compression spring piece, and a second center plate is provided between the third compression spring piece and the fourth compression spring piece; one end of the third compression spring piece is fixed to the bottom of the flexible plate, and the other end of the third compression spring piece is fixed to the top of the second center plate; one end of the fourth compression spring piece is fixed to the bottom of the second center plate, and the other end of the fourth compression spring piece is fixed between the bottom rigid plate and the top rigid plate;

[0011] The fourth compression spring sheet is located above the positive stiffness spring cover plate, and the first compression spring sheet, the second compression spring sheet, the third compression spring sheet, the fourth compression spring sheet, the first center plate, the second center plate and the positive stiffness spring cover plate are stacked in the vertical direction; the device also includes a side plate, and the first center plate, the second center plate and the positive stiffness spring cover plate are all fixed on the side plate.

[0012] Furthermore, in some embodiments of the present invention, the negative stiffness unit also includes a negative stiffness spring and a cable, a mounting sleeve is fixedly provided on one side of the flexible plate close to the top rigid plate, and a limiting slider is slidingly provided on the flexible plate, and one end of the limiting slider slides and is embedded in the mounting sleeve; the negative stiffness spring is located in the mounting sleeve, one end of the negative stiffness spring abuts against the limiting slider, and the other end of the negative stiffness spring abuts against the mounting sleeve; one end of the cable slides through the mounting sleeve and is connected to the limiting slider, and the other end of the cable is provided with an adjustment slider, and the adjustment slider is slidably arranged on the top rigid plate.

[0013] Furthermore, in some embodiments of the present invention, an adjusting bolt is provided on the outward side of the top rigid plate, and one end of the adjusting bolt passes through the top rigid plate and is threadedly connected to the adjusting slider.

[0014] Furthermore, in some embodiments of the present invention, a U-shaped limiting guide is provided on the inward side of the top rigid plate, the cross-section of the adjusting slider is polygonal, the adjusting slider is slidably arranged in the limiting guide, and the cable slides through the limiting guide.

[0015] Furthermore, in some embodiments of the present invention, gaskets are provided between the first compression spring piece and the first center plate, between the second compression spring piece and the first center plate, between the third compression spring piece and the second center plate, and between the fourth compression spring piece and the second center plate.

[0016] Furthermore, in some embodiments of the present invention, a rubber sheet is provided between the flexible plate and the bottom plate.

[0017] Furthermore, in some embodiments of the present invention, there are two side panels and they are arranged opposite to each other, the negative stiffness unit is located between the two side panels, and a top panel is provided on top of the side panels.

[0018] Furthermore, in some embodiments of the present invention, a shell is provided on the top of the base plate, and the positive stiffness unit and the negative stiffness unit are both provided in the shell.

[0019] Compared with the prior art, the embodiments of the present invention have at least the following advantages or beneficial effects:

[0020] An embodiment of the present invention provides a negative stiffness adjustable vertical vibration isolation device based on quasi-zero stiffness characteristics. The device can effectively reduce the vibration transmission between the object and the base, and has the nonlinear characteristics of low dynamic stiffness and high static stiffness. While ensuring a high load-bearing capacity, it greatly reduces the natural frequency of the vibration isolation system, thereby extending the vibration isolation frequency band to the low-frequency region. The stiffness of the negative stiffness unit can be adjusted by a cable to adapt to different loads. At the same time, the stacked arrangement of the compressed spring sheets can reduce the size of the device without affecting the vibration isolation performance, thereby achieving a compact design and meeting the requirements of some special vibration reduction systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 A schematic structural diagram of a vibration isolation device provided in an embodiment of the present invention;

[0023] Figure 2 A partial cross-sectional view of the vibration isolation device provided by an embodiment of the present invention with the side panels removed;

[0024] Figure 3 Schematic diagram of the internal structure of the vibration isolation device provided in an embodiment of the present invention Figure 1 ;

[0025] Figure 4Schematic diagram of the internal structure of the vibration isolation device provided in an embodiment of the present invention Figure 2 ;

[0026] Figure 5 A front view of the interior of a vibration isolation device provided by an embodiment of the present invention;

[0027] Figure 6 for Figure 4 Schematic diagram of the structure after removing the side panels;

[0028] Figure 7 A schematic diagram of the cable position provided in an embodiment of the present invention Figure 1 ;

[0029] Figure 8 A schematic diagram of the cable position provided in an embodiment of the present invention Figure 2 ;

[0030] Figure 9 This is a schematic diagram of the vibration isolation device provided in an embodiment of the present invention.

[0031] Icons: 1-base plate; 2-positive stiffness spring; 3-positive stiffness spring cover plate; 4-bottom rigid plate; 5-top rigid plate; 6-flexible plate; 7-side plate; 8-top plate; 9-housing; 10-rubber sheet; 11-gasket; 41-first compression spring sheet; 42-second compression spring sheet; 43-third compression spring sheet; 44-fourth compression spring sheet; 45-first center plate; 46-second center plate; 51-negative stiffness spring; 52-cable; 53-mounting sleeve; 54-limiting slider; 55-adjusting slider; 56-adjusting bolt; 57-limiting guide; 58-bolt washer. DETAILED DESCRIPTION

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of 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. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0033] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are intended to fall within the scope of protection of the present invention.

[0034] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0035] In the description of the embodiments of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the inventive product is typically placed when in use. These terms are intended only to facilitate the description of the present invention and to simplify the description, and are not intended to indicate or imply that the device or component referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting the present invention. Furthermore, the terms "first," "second," etc., etc., are intended only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0036] In addition, the use of terms such as "horizontal" and "vertical" does not mean that the component must be absolutely horizontal or vertical, but rather that it can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0037] In the description of the embodiments of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "disposed" and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0038] Example

[0039] Please refer to Figures 1-8 This embodiment provides a vertical vibration isolation device with adjustable negative stiffness based on quasi-zero stiffness characteristics. The device comprises a base plate 1, a positive stiffness unit, and a negative stiffness unit. The positive stiffness unit comprises multiple identical positive stiffness springs 2 vertically mounted on top of the base plate 1, and a positive stiffness spring cover 3 mounted on top of the positive stiffness springs 2. The positive stiffness springs 2 provide vertical support and positive stiffness. The number of positive stiffness springs 2 is adjustable, and a dispersed arrangement of multiple positive stiffness springs 2 increases the stability of the device, giving the structure a certain degree of anti-overturning capability.

[0040] This embodiment employs four positive springs 2, arranged in a dispersed arrangement, for a more stable structure. To facilitate connection, both ends of the positive springs 2 are flattened, with one end connected to the base plate 1 and the other to the positive spring cover 3. Both the base plate 1 and the positive spring cover 3, where they contact the positive springs 2, are provided with grooves, the number and location of which correspond to the number of positive springs 2, for accommodating them.

[0041] The negative stiffness unit includes a first compression spring piece 41, a second compression spring piece 42, a third compression spring piece 43, and a fourth compression spring piece 44, each of which is arranged horizontally. A bottom rigid plate 4 is provided on top of the bottom plate 1, a top rigid plate 5 is provided on top of the bottom rigid plate 4, and a flexible plate 6 is provided opposite the top rigid plate 5. The negative stiffness unit is located between the top rigid plate 5 and the flexible plate 6.

[0042] The first compression spring piece 41 is located above the second compression spring piece 42, and a first center plate 45 is provided between the first compression spring piece 41 and the second compression spring piece 42. One end of the first compression spring piece 41 is fixed to the top of the top rigid plate 5, and the other end of the first compression spring piece 41 is fixed to the top of the first center plate 45. One end of the second compression spring piece 42 is fixed to the bottom of the first center plate 45, and the other end of the second compression spring piece 42 is fixed to the top of the flexible plate 6.

[0043] The third compression spring piece 43 is located below the second compression spring piece 42 and above the fourth compression spring piece 44. A second center plate 46 is provided between the third compression spring piece 43 and the fourth compression spring piece 44. One end of the third compression spring piece 43 is fixed to the bottom of the flexible plate 6, and the other end of the third compression spring piece 43 is fixed to the top of the second center plate 46. One end of the fourth compression spring piece 44 is fixed to the bottom of the second center plate 46, and the other end of the fourth compression spring piece 44 is fixed between the bottom rigid plate 4 and the top rigid plate 5.

[0044] The fourth compression spring piece 44 is located above the positive stiffness spring cover plate 3, and the first compression spring piece 41, the second compression spring piece 42, the third compression spring piece 43, the fourth compression spring piece 44, the first center plate 45, the second center plate 46 and the positive stiffness spring cover plate 3 are stacked in the vertical direction; it also includes a side plate 7, and the first center plate 45, the second center plate 46 and the positive stiffness spring cover plate 3 are all fixed to the side plate 7. There are two side plates 7 and they are arranged opposite to each other. The negative stiffness unit is located between the two side plates 7, and a top plate 8 is provided on the top of the side plate 7. A shell 9 is provided on the top of the bottom plate 1, and bolt holes are provided on the bottom plate 1 for connecting to the shell 9. The positive stiffness unit and the negative stiffness unit are both provided in the shell 9. By connecting the bottom plate 1 and the shell 9 with bolts, the vibration isolation device can be closed to prevent dust and other impurities from entering the vibration isolation device.

[0045] In some embodiments of the present invention, the negative stiffness unit further comprises a negative stiffness spring 51 and a cable 52. A mounting sleeve 53 is fixedly provided on one side of the flexible plate 6 near the top rigid plate 5. A limit slider 54 is slidably provided on the flexible plate 6. One end of the limit slider 54 slides and fits into the mounting sleeve 53. The negative stiffness spring 51 is located within the mounting sleeve 53, and its two ends are also cut into flat surfaces. One end of the negative stiffness spring 51 abuts the limit slider 54, and the other end abuts the mounting sleeve 53. One end of the cable 52 slides through the mounting sleeve 53 and is connected to the limit slider 54. The other end of the cable 52 is provided with an adjustment slider 55, which is slidably mounted on the top rigid plate 5.

[0046] An adjusting bolt 56 is provided on the outward side of the top rigid plate 5. One end of the adjusting bolt 56 passes through the top rigid plate 5 and is threadedly connected to the adjusting slider 55. The side with the adjusting slider 55 is the adjusting end. When the adjusting bolt 56 at this end is turned, Figure 2 As shown, cable 52 pulls limit slider 54 to the right, compressing negative spring 51 and thereby changing the pressure applied to negative spring 51. Using cable 52 to adjust negative spring 51 does not introduce unknown stiffness to the structure. When the vibration isolation device moves vertically, the compressed spring leaves can bend in the vertical plane, imparting negative stiffness to the compressed spring leaves, thereby canceling the positive stiffness of positive spring 2 and achieving a quasi-zero stiffness characteristic.

[0047] In this embodiment, the vertical thickness of each compression spring leaf is typically much smaller than at least a portion of its length or width. Therefore, when the vibration isolation device moves vertically, the compression spring leaf can bend in the vertical plane. At least a portion of the compression spring leaves are stacked, thereby meeting the requirements of a compact design.

[0048] The negative stiffness adjustable vertical vibration isolation device based on quasi-zero stiffness characteristics provided in this application is used to reduce the propagation of axial or vertical vibrations between an object and a support. Top plate 8 is used to support the object being isolated. When pressure is applied to top plate 8, force is transmitted through side plates 7 to cause deformation of each compressed spring leaf. The deformation of both the compressed spring leaf and the negative stiffness spring 51 produces negative stiffness, which offsets the stiffness of the positive stiffness spring 2, thereby achieving a quasi-zero stiffness characteristic.

[0049] The principle of quasi-zero stiffness vibration isolation device is as follows Figure 9 As shown:

[0050] Among them, the total stiffness of the quasi-zero stiffness vibration isolation device is K = K p +K n . Where K p is the stiffness value of the positive stiffness element, K p >0;K n is the stiffness value of the negative stiffness element, Kn <0.

[0051] When the deformation of the positive stiffness unit is x0, a negative stiffness unit is connected in parallel in a certain neighborhood of x0 to adjust the K n Value | K p ∣≈∣K n ∣, then the total stiffness of the quasi-zero stiffness vibration isolation device approaches 0. The quasi-zero stiffness characteristic enables the vibration isolation device to achieve low dynamic stiffness while ensuring high static stiffness. The total load-deformation curve of the quasi-zero stiffness vibration isolation system is as follows: Figure 9 Shown as the solid line segment OABC.

[0052] The device can also be connected with vibration isolation devices in other directions to achieve multi-directional vibration isolation.

[0053] In this way, the vibration isolation device provided by the present application can effectively reduce the vibration transmission between the object and the base, and the device has the nonlinear characteristics of low dynamic stiffness and high static stiffness. While ensuring a high load-bearing capacity, it greatly reduces the natural frequency of the vibration isolation system, thereby expanding the vibration isolation frequency band to the low-frequency region; wherein, the stiffness of the negative stiffness unit can be adjusted by the cable to adapt to different loads; at the same time, through the stacking arrangement of the compressed spring sheets, the size of the device can be reduced without affecting the vibration isolation performance, thereby realizing a compact design and meeting the requirements of some special vibration reduction systems.

[0054] like Figures 1-8 As shown, in some embodiments of the present invention, a U-shaped limiting guide 57 is provided on the inward side of the top rigid plate 5, the cross-section of the adjusting slider 55 is polygonal, the adjusting slider 55 is slidably arranged in the limiting guide 57, and the cable 52 slides through the limiting guide 57.

[0055] The present invention provides a position-limiting guide 57, allowing the adjustment slider 55 to be in a rectangular parallelepiped shape. This prevents the adjustment slider 55 from rotating relative to the top rigid plate 5, thereby ensuring that the cable 52 is not subjected to torque during movement when the adjustment bolt 56 is rotated to adjust the cable 52. In this embodiment, the adjustment bolt 56 can be fitted with a plurality of bolt washers 58.

[0056] like Figures 1-8 As shown, in some embodiments of the present invention, a gasket 11 is provided between the first compression spring piece 41 and the first center plate 45, between the second compression spring piece 42 and the first center plate 45, between the third compression spring piece 43 and the second center plate 46, and between the fourth compression spring piece 44 and the second center plate 46. The gasket 11 can make the pressure distribution more uniform, thereby improving the fastening effect.

[0057] like Figures 1-8As shown, in some embodiments of the present invention, a rubber sheet 10 is provided between the flexible plate 6 and the bottom plate 1. The ends of the rubber sheet 10 are bonded to the flexible plate 6 and the bottom plate 1, respectively. When the compressed spring sheet slightly shortens or lengthens in the axial or compression direction, the rubber sheet 10 deforms. The rubber sheet 10 serves to block dust and is not subject to force.

[0058] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. It is obvious to those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, and that the present application can be implemented in other specific forms without departing from the spirit or basic features of the present application.

[0059] Therefore, no matter from which point of view, the embodiments should be regarded as illustrative rather than restrictive, and the scope of this application is limited by the appended claims rather than the above description, and it is intended that all changes that fall within the meaning and scope of the equivalent elements of the claims are included in this application. Any figure mark in the claims should not be regarded as limiting the claim involved. For those skilled in the art, various changes and variations of the present invention are possible. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A negative stiffness adjustable vertical vibration isolation device based on quasi-zero stiffness characteristics, characterized by: The positive stiffness unit comprises a bottom plate, a positive stiffness unit and a negative stiffness unit, wherein the positive stiffness unit comprises a plurality of positive stiffness springs vertically arranged on the top of the bottom plate and a positive stiffness spring cover plate arranged on the top of the positive stiffness springs; The negative stiffness unit includes a first compression spring sheet, a second compression spring sheet, a third compression spring sheet, and a fourth compression spring sheet; a bottom rigid plate is provided on the top of the bottom plate, a top rigid plate is provided on the top of the bottom rigid plate, a flexible plate is provided opposite to the top rigid plate, and the negative stiffness unit is located between the top rigid plate and the flexible plate; The first compression spring piece is located above the second compression spring piece, and a first center plate is provided between the first compression spring piece and the second compression spring piece; one end of the first compression spring piece is fixed to the top of the top rigid plate, and the other end of the first compression spring piece is fixed to the top of the first center plate; one end of the second compression spring piece is fixed to the bottom of the first center plate, and the other end of the second compression spring piece is fixed to the top of the flexible plate; The third compression spring piece is located below the second compression spring piece and above the fourth compression spring piece, and a second center plate is provided between the third compression spring piece and the fourth compression spring piece; one end of the third compression spring piece is fixed to the bottom of the flexible plate, and the other end of the third compression spring piece is fixed to the top of the second center plate; one end of the fourth compression spring piece is fixed to the bottom of the second center plate, and the other end of the fourth compression spring piece is fixed between the bottom rigid plate and the top rigid plate; The fourth compression spring piece is located above the positive stiffness spring cover plate, and the first compression spring piece, the second compression spring piece, the third compression spring piece, the fourth compression spring piece, the first center plate, the second center plate and the positive stiffness spring cover plate are stacked in a vertical direction; further comprising a side plate, the first center plate, the second center plate and the positive stiffness spring cover plate are all fixedly mounted on the side plate; The negative stiffness unit also includes a negative stiffness spring and a cable, a mounting sleeve is fixedly provided on one side of the flexible plate close to the top rigid plate, a limiting slider is slidably provided on the flexible plate, and one end of the limiting slider is slidably embedded in the mounting sleeve; the negative stiffness spring is located in the mounting sleeve, one end of the negative stiffness spring abuts against the limiting slider, and the other end of the negative stiffness spring abuts against the mounting sleeve; one end of the cable slides through the mounting sleeve and is connected to the limiting slider, and the other end of the cable is provided with an adjusting slider, and the adjusting slider is slidably provided on the top rigid plate; An adjusting bolt is provided on an outward side of the top rigid plate, and one end of the adjusting bolt passes through the top rigid plate and is threadedly connected to the adjusting slider.

2. The negative stiffness adjustable vertical vibration isolation device based on quasi-zero stiffness characteristics according to claim 1, characterized in that: A U-shaped limiting guide is provided on the inner side of the top rigid plate. The cross section of the adjusting slider is polygonal. The adjusting slider is slidably arranged in the limiting guide, and the cable slides through the limiting guide.

3. The negative stiffness adjustable vertical vibration isolation device based on quasi-zero stiffness characteristics according to claim 1 is characterized in that: Gaskets are provided between the first compression spring piece and the first center plate, between the second compression spring piece and the first center plate, between the third compression spring piece and the second center plate, and between the fourth compression spring piece and the second center plate.

4. The negative stiffness adjustable vertical vibration isolation device based on quasi-zero stiffness characteristics according to claim 1, characterized in that: A rubber sheet is provided between the flexible plate and the bottom plate.

5. The negative stiffness adjustable vertical vibration isolation device based on quasi-zero stiffness characteristics according to claim 1 is characterized in that: There are two side panels which are arranged opposite to each other, the negative stiffness unit is located between the two side panels, and a top panel is provided on the top of the side panels.

6. The negative stiffness adjustable vertical vibration isolation device based on quasi-zero stiffness characteristics according to claim 1, characterized in that: A shell is provided on the top of the bottom plate, and the positive stiffness unit and the negative stiffness unit are both provided in the shell.

Images