Negative stiffness adjustable damping device based on nonlinear vibration absorption of permanent magnet

Abstract

The invention relates to a negative stiffness adjustable vibration reduction device based on permanent magnet nonlinear vibration absorption, and belongs to the technical field of vibration reduction. The negative stiffness adjustable vibration reduction device comprises a base and a bearing platform located above the base and used for bearing equipment to be subjected to vibration reduction, and the bearing platform is connected with the base through a plurality of vibration isolation springs; an elastic damper, a vibrator and a magnetic vibration absorption device are sequentially arranged between the bearing platform and the base from top to bottom in the vertical direction, the periphery of the vibrator is connected with a plurality of adjustable negative stiffness mechanisms which are arranged in a central symmetry mode, and each adjustable negative stiffness mechanism comprises a negative stiffness fine adjustment device and a horizontal elastic element. And the horizontal elastic element is positioned between the negative stiffness fine adjustment device and the vibrator. The displacement change rate during vibration impact can be greatly reduced, and multi-frequency-band vibration reduction is achieved in a small space.

Description

Technical Field

[0001] The invention relates to the technical field of vibration reduction, and in particular to a negative stiffness adjustable vibration reduction device based on permanent magnet nonlinear vibration absorption. Background Art

[0002] With the continuous progress of my country's science and technology, key areas such as national defense security, energy development, shipbuilding, biomedical technology, automobile industry and robotics technology have put forward more stringent technical standards for vibration and noise control. Especially when dealing with low-frequency and even ultra-low-frequency vibration and resonance challenges, the demand for efficient vibration reduction technology has become particularly urgent. In specific application scenarios, such as working environments with limited space, traditional vibration isolation devices limit their application effectiveness due to their significant static deformation, which has become one of the technical bottlenecks. Moreover, in the current field of vibration isolation technology, in order to ensure the stability of the system, the design frequency threshold of the vibration isolation system is often difficult to set very low, which causes the frequency components of some excitation sources to fall outside the effective isolation frequency band of the vibration isolation system, that is, below its design vibration isolation frequency, and thus cannot exert the expected vibration isolation performance. In addition, in some cases, the transmission effect of the vibration isolation system on suppressing these specific line spectrum vibration components is extremely limited, and it is difficult to achieve the ideal vibration attenuation target.

[0003] At present, some advanced vibration reduction equipment has been used to solve the above problems, but most vibration reduction equipment still has the following shortcomings: first, the vibration reduction equipment occupies too much space and cannot function in a small working environment; second, traditional vibration isolators will resonate near the resonance frequency and will not have an effective vibration reduction effect; third, it is impossible to achieve vibration reduction of low-frequency and ultra-low-frequency vibrations; fourth, the existing negative stiffness system cannot adjust the stiffness. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides a negative stiffness adjustable vibration reduction device based on nonlinear vibration absorption of permanent magnets.

[0005] The technical solution adopted by the present invention to solve the above technical problems is: a negative stiffness adjustable vibration reduction device based on permanent magnet nonlinear vibration absorption, including a base and a bearing platform located above the base for bearing the equipment to be vibration reduced, the bearing platform is connected to the base through a plurality of vibration isolation springs, and elastic damping, a vibrator and a magnetic vibration absorption device are arranged in sequence from top to bottom in the vertical direction between the bearing platform and the base, the magnetic vibration absorption device is used to absorb vibration energy, and a plurality of adjustable negative stiffness mechanisms arranged symmetrically around the vibrator are connected, the adjustable negative stiffness mechanism includes a negative stiffness fine-tuning device and a horizontal elastic element, the horizontal elastic element is located between the negative stiffness fine-tuning device and the vibrator, and the negative stiffness fine-tuning device is used to adjust the compression amount of the horizontal elastic element.

[0006] As a preferred solution, the elastic damping is made of high-density rubber.

[0007] As a preferred solution, the vibrator includes a plurality of adjustment disks arranged in a stacked manner, and two adjacent adjustment disks are connected by a matching sleeve. The upper and lower end surfaces of the adjustment disks along the axial direction are respectively provided with connecting shaft portions, the outside of the connecting shaft portion is provided with an external thread, and the inside of the matching sleeve is provided with an internal thread matching the external thread.

[0008] As a preferred solution, the magnetic vibration absorption device includes a guide sleeve, in which a lower permanent magnet, a middle permanent magnet and an upper permanent magnet are arranged in sequence from bottom to top, the upper permanent magnet partially extends out of the guide sleeve, the lower permanent magnet and the middle permanent magnet magnetically repel each other, the middle permanent magnet and the upper permanent magnet magnetically repel each other, and the middle permanent magnet can move up and down in the guide sleeve.

[0009] As a preferred solution, a lower shell is provided on the outer side of the lower permanent magnet, a lower magnetic part facing the middle permanent magnet and protruding from the lower shell is provided on the lower permanent magnet, an upper shell is provided on the outer side of the upper permanent magnet, an upper magnetic part facing the middle permanent magnet and protruding from the upper shell is provided on the upper permanent magnet, the upper shell is located above the guide sleeve, the upper magnetic part partially extends into the guide sleeve, a fixed sleeve is provided on the outside of the middle permanent magnet, and the middle permanent magnet is provided with an upper magnetic surface that magnetically repels the upper magnetic part and a lower magnetic surface that magnetically repels the lower magnetic part.

[0010] As a preferred solution, the lower permanent magnet, the middle permanent magnet and the upper permanent magnet are all made of neodymium iron boron material.

[0011] As a preferred solution, the lower shell, the upper shell and the fixing sleeve are all made of silicon steel material.

[0012] As a preferred solution, the elastic element includes two Euler buckling beams symmetrically arranged up and down, and the concave surfaces of the two Euler buckling beams are arranged opposite to each other.

[0013] As a preferred scheme, the negative stiffness fine-tuning device includes a vertical plate, an outer shell arranged on the vertical plate and a top shell slidably inserted into the outer shell, one end of the top shell extends into the outer shell and the end is fixedly connected to the elastic element, an adjusting screw is arranged in the outer shell, the adjusting screw has a first threaded portion and a second threaded portion, the first threaded portion cooperates with the outer shell thread, the second threaded portion cooperates with the top shell thread, a large-pitch external thread is arranged on the outer side of the first threaded portion, a large-pitch internal thread that cooperates with the large-pitch external thread is arranged on the outer shell, a small-pitch external thread is arranged on the outer side of the second threaded portion, a small-pitch internal thread that cooperates with the small-pitch external thread is arranged on the top shell, and a mounting hole for the first threaded portion to pass through is arranged on the vertical plate.

[0014] The beneficial effects of the present application are as follows: 1. The elastic damping, vibrator and magnetic vibration absorption device of the present application form a vibration absorber system, which is a nonlinear system used to realize the vibration absorption function and can effectively eliminate resonance; multiple adjustable negative stiffness mechanisms are located around the vibration absorber system to realize negative stiffness balance and multi-band vibration reduction; the negative stiffness fine-tuning device is used to adjust the stiffness and maintain the negative stiffness balance; the vibration isolation spring is located between the bearing platform and the base to realize the vibration isolation function. While the present application has a vibration isolation spring to realize full-band vibration reduction, it also has a good vibration reduction effect of the vibration absorber system near the resonance frequency. Compared with the traditional vibration reduction device which requires a larger static deformation and has only a fixed stiffness in the face of different loads, the present invention can achieve negative stiffness balance by adopting an adjustable negative stiffness mechanism. When facing resonance frequency and low-frequency and ultra-low-frequency vibration, it can effectively achieve vibration reduction and reduce resonance and vibration static deformation displacement; and it has a negative stiffness fine-tuning device. When facing loads and vibrations under different working conditions, the stiffness of the adjustable negative stiffness mechanism can be adjusted to achieve vibration reduction in different working scenes. In addition, the present application occupies a small space and is suitable for vibration reduction needs under a variety of complex working conditions.

[0015] 2. The horizontal elastic element of the present application is symmetrically distributed by two upper and lower Euler buckled beams. The double-layer symmetrical Euler buckled beam structure can constrain each other when the vibrator is subjected to input loads and vibrations, thereby increasing the stability of the system. In addition, when facing large loads and large vibration displacements, the stiffness changes little, and it is more stable than traditional negative stiffness buckled beams. It fills the vibration reduction gap in the low-frequency band for the vibration reduction device, making the vibration reduction effect of the present application more comprehensive and effective.

[0016] 3. The magnetic vibration absorption device of the present application includes a lower permanent magnet, a middle permanent magnet and an upper permanent magnet. The magnetic vibration absorption system composed of three permanent magnets forms a nonlinear magnetic force due to the mutual repulsion between the magnets, and is a nonlinear system. Compared with the traditional magnet pair composed of two permanent magnets, the three permanent magnets interact with each other, and the middle permanent magnet is subjected to the vibration displacement caused by the upper permanent magnet due to vibration, which quickly consumes the energy of the system, and while playing a vibration absorption effect far exceeding that of the double magnets, it realizes the capture of the high-frequency resonance of the system; and the elastic damping of the present application is made of high-density rubber, which is a nonlinear material. While acting as an elastic damping, it also reduces the low-frequency resonance caused by the characteristics of the magnetic system itself and the outside. The two make the vibration absorber system have a strong vibration absorption effect for vibrations in multiple frequency bands, and it is a nonlinear system. While having a better vibration reduction effect, it also has the characteristics of high safety, high adaptability and high reliability; BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the present invention; Figure 2 is an axonometric view of the present invention; Figure 3It is a schematic structural diagram of the horizontal elastic element of the present invention; Figure 4 is a cross-sectional view of the negative stiffness fine-tuning device of the present invention; Figure 5 It is an axonometric diagram of the negative stiffness fine adjustment device of the present invention; Figure 6 It is a structural schematic diagram of the magnetic vibration absorption device of the present invention; Figure 7 It is a structural schematic diagram of the base and the bearing platform of the present invention; Figure 8 It is a schematic diagram of the structure of the vibrator of the present invention; Fig. 9 A comparison diagram of the force transmission rate between the present invention and the traditional vibration reduction structure; Fig.10 It is a comparison diagram of the displacement transfer function between the present invention and the traditional vibration reduction structure.

[0018] Markings in the figure: 1. base, 11. lower positioning countersunk hole, 12. lower positioning groove, 2. bearing platform, 21. upper positioning countersunk hole, 22. mounting protrusion, 221. upper positioning groove, 3. elastic damping, 31. positioning protrusion, 4. vibrator, 41. adjustment plate, 42. connecting shaft, 43. matching sleeve, 5. magnetic vibration absorbing device, 51. guide sleeve, 52. upper shell, 521. upper magnetic part, 53. fixing sleeve, 531. upper magnetic surface, 54. lower shell, 541. lower magnetic part, 6. vibration isolation spring, 7. negative stiffness fine-tuning device, 71. vertical plate, 72. outer shell, 73. adjusting screw, 731. first threaded part, 732. second threaded part, 74. top shell, 75. rotating disk, 8. horizontal elastic element, 81. Euler buckling beam, 82. first connecting frame, 83. second connecting frame. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solution and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that in the description of the present invention, unless otherwise specified, the meaning of "multiple" is two or more; the orientation or position relationship indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0020] See also Figure 1-10The embodiment of the present invention provides a negative stiffness adjustable vibration reduction device based on nonlinear vibration absorption of permanent magnets, comprising a base 1 and a bearing platform 2 located above the base 1 for bearing a device to be vibration reduced, the bearing platform 2 being connected to the base 1 via a plurality of vibration isolation springs 6, an elastic damper 3, a vibrator 4 and a magnetic vibration absorption device 5 being arranged in sequence from top to bottom along the vertical direction between the bearing platform 2 and the base 1, the magnetic vibration absorption device 5 being used to absorb vibration energy, a plurality of adjustable negative stiffness mechanisms being centrally symmetrically arranged are connected around the vibrator 4, the adjustable negative stiffness mechanisms comprising a negative stiffness fine-tuning device 7 and a horizontal elastic element 8, the horizontal elastic element 8 being located between the negative stiffness fine-tuning device 7 and the vibrator 4, the negative stiffness fine-tuning device 7 being used to adjust the compression amount of the horizontal elastic element 8.

[0021] Combination Figure 1 , Figure 2 and Figure 7 As shown, the elastic damper 3 is made of high-density rubber. The elastic damper 3 is shaft-shaped, and a positioning protrusion 31 is provided at the upper end of the elastic damper 3, and a mounting protrusion 22 is provided at the lower end of the bearing platform 2. An upper positioning groove 221 that cooperates with the positioning protrusion 31 is provided at the lower end of the mounting protrusion 22. There are four vibration isolation springs 6, and there are four adjustable negative stiffness mechanisms. The four vibration isolation springs 6 are arranged in a rectangular shape, and a horizontal elastic element 8 is provided between two adjacent vibration isolation springs 6. A lower positioning countersunk hole 11 is provided at the upper end of the base 1, and an upper positioning countersunk hole 21 is provided at the upper end of the bearing platform. The vibration isolation spring 6 is located between the lower positioning countersunk hole 11 and the upper positioning countersunk hole 21, and the two ends of the vibration isolation spring 6 are fixedly connected to the bottom of the upper positioning countersunk hole 21 and the bottom of the lower positioning countersunk hole 11, respectively.

[0022] Among them, combined Figure 1 , Figure 2 , Figure 7 and Figure 8 As shown, the vibrator 4 includes a plurality of adjustment disks 41 arranged in a stacked manner, and two adjacent adjustment disks 41 are connected by a matching sleeve 43. The upper and lower end surfaces of the adjustment disks 41 are respectively provided with connecting shafts 42 along the axial direction, and the outer surface of the connecting shaft 42 is provided with an external thread, and the matching sleeve 43 is provided with an internal thread matching the external thread. The connecting shaft 42 on the upper end surface of the adjustment disk 41 at the uppermost end is fixedly connected to the elastic damper 3, and the connecting shaft 42 on the lower end surface of the adjustment disk 41 at the lowermost end is fixedly connected to the magnetic vibration absorbing device 5. The number of adjustment disks 41 can be adjusted according to demand, so as to achieve the mass adjustment of the vibrator 3.

[0023] Combination Figure 1 , Figure 2 , Figure 6 and Figure 7As shown, the magnetic vibration absorbing device 5 is installed in the lower positioning groove 12 on the base 1, and the magnetic vibration absorbing device 5 includes a guide sleeve 51. A lower permanent magnet, a middle permanent magnet and an upper permanent magnet are arranged in sequence from bottom to top in the guide sleeve 51. The upper permanent magnet partially extends out of the guide sleeve 51. The lower permanent magnet and the middle permanent magnet magnetically repel each other, and the middle permanent magnet and the upper permanent magnet magnetically repel each other. The middle permanent magnet can move up and down in the guide sleeve 51.

[0024] Specifically, a lower shell 54 is provided on the outer side of the lower permanent magnet, and a lower magnetic portion 541 facing the middle permanent magnet and protruding from the lower shell 54 is provided on the upper end of the lower permanent magnet; an upper shell 52 is provided on the outer side of the upper permanent magnet, and an upper magnetic portion 521 facing the middle permanent magnet and protruding from the upper shell 52 is provided on the lower end of the upper permanent magnet; the upper shell 52 is located above the guide sleeve 51, and the upper magnetic portion 521 partially extends into the guide sleeve 51; a fixing sleeve 53 is provided on the outside of the middle permanent magnet, and an upper magnetic surface 531 that magnetically repels the upper magnetic portion 521 and a lower magnetic surface that magnetically repels the lower magnetic portion 541 are provided on the middle permanent magnet.

[0025] The lower permanent magnet, the middle permanent magnet and the upper permanent magnet of the present application are all made of neodymium iron boron material to provide strong magnetic force, and the lower shell 54, the upper shell 52 and the fixing sleeve 53 are all made of silicon steel material to prevent the permanent magnet 16 from leaking magnetism and protect the permanent magnet; the base 1 and the bearing platform 2 are both made of structural steel.

[0026] More specifically, the elastic damping 3, the vibrator 4 and the magnetic vibration absorbing device 2 form a vibration absorber system for realizing the vibration absorbing function. The vibration absorber system is a nonlinear system, which mainly solves the vibration reduction of low frequency, ultra-low frequency and resonant frequency. In the magnetic vibration absorbing device 5, the magnetic vibration absorbing system composed of three permanent magnets is a nonlinear system. The three permanent magnets interact with each other, which not only plays a vibration absorbing role, but also reduces the problem of easy jumping of magnetic vibration absorption. Rubber is a nonlinear material. While acting as an elastic damping 3, it also reduces the resonance caused by the characteristics of the magnetic vibration absorbing system itself and the outside. The two make the vibration absorber system have a strong vibration absorbing effect for vibrations in multiple frequency bands, and it is a nonlinear system. While having a better vibration reduction effect, it also has the characteristics of high safety, high adaptability and high reliability.

[0027] Combination Figure 1-3As shown, the elastic element includes two Euler buckling beams 81 symmetrically arranged in the upper and lower parts, and the concave surfaces of the two Euler buckling beams 81 are arranged opposite to each other. A first connecting frame 82 and a second connecting frame 83 are fixedly arranged at both ends of the elastic element, respectively. The first connecting frame 82 is connected to the vibrator 4 by fixing bolts, and a connecting plate for fixing bolt connection is provided on the adjustment plate 41 of the vibrator 4. The second connecting frame 83 is fixedly connected to the negative stiffness fine-tuning device 7 by mounting bolts. The two ends of the Euler buckling beam 81 are fixedly connected to the first connecting frame 82 and the second connecting frame 83, respectively, and the two ends of the Euler buckling beam 81 are welded to the first connecting frame 82 and the second connecting frame 83, respectively.

[0028] Combination Figure 1 , Figure 2 , Figure 4 and Figure 5 As shown, the negative stiffness fine-tuning device 7 includes a vertical plate 71, an outer shell 72 arranged on the vertical plate 71, and a top shell 74 slidably inserted into the outer shell 72. The top shell 74 is fixedly connected to the second connecting frame 83 by installing bolts. One end of the top shell 74 extends into the outer shell 72 and the end is fixedly connected to the elastic element. An adjusting screw 73 is provided in the outer shell 72. The adjusting screw 73 has a first threaded portion 731 and a second threaded portion 732 arranged in sequence along its axial direction. The end of the first threaded portion 731 away from the second threaded portion 732 is provided with an optical axis portion and a rotating disk 75 in sequence. The first threaded portion 731 is threadedly matched with the outer shell 72, and the second threaded portion 732 is threadedly matched with the top shell 74. A large-pitch external thread is provided on the outer side of the first threaded portion 731, and a large-pitch internal thread that matches the large-pitch external thread is provided on the outer shell 72. A small-pitch external thread is provided on the outer side of the second threaded portion 732, and a small-pitch internal thread that matches the small-pitch external thread is provided on the top shell 74. A mounting hole for the first threaded portion 731 to pass through is provided on the vertical plate 71.

[0029] The Euler buckling beam 81 of the present application uses beryllium bronze as its material, so that the vibration absorber system has a negative stiffness balance, which mainly solves the problem of reducing the displacement change rate when impacted and achieving the effect of vibration reduction in a small working space. The vibration isolation spring 6 is used to achieve the vibration isolation effect, which mainly solves the vibration reduction other than low frequency, ultra-low frequency and resonant frequency, and adopts active vibration isolation technology to improve the stability of the system. If the stiffness of the negative stiffness system needs to be adjusted, it is necessary to rotate the rotating disk 75 at the end of the adjusting screw 73, and under the action of the threaded fit, the top shell 74 is pushed forward, thereby pushing the Euler buckling beam 81 to bend, increasing the negative stiffness of the system, thereby generating a new negative stiffness balance, and achieving self-locking through threaded fit.

[0030] In addition, the vertical plate 71 is made of an integral body with the base 1, and the four vertical plates 71 and the base 1 form a accommodating cavity with an open upper end. The supporting platform 2 partially extends into the accommodating cavity, and the vibration isolation spring 6, vibrator 4, magnetic vibration absorption device 5 and horizontal elastic element 8 are all located in the accommodating cavity, so that the structure of the present application is compact and occupies a small area.

[0031] Combination Fig. 9 and Fig.10 As shown, the change curves of the force transfer rate and displacement transfer function of the present invention and the traditional vibration reduction structure are drawn using Matlab. It can be seen that the present invention has a good vibration reduction effect, the displacement attenuation can reach 94%, and the overall vibration reduction percentage can reach 80%.

[0032] Of course, the present invention is not limited to the above-described embodiments. Several other embodiments based on the design concept of the present invention are also provided below.

[0033] For example, in other embodiments, different from the above-described embodiments, Figure 1-2 As shown, in this embodiment, the number of the adjustment disk 41 is one.

[0034] It should be noted that the above embodiments are only used to illustrate the present invention, but the present invention is not limited to the above embodiments. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention fall within the protection scope of the present invention.

Claims

1. A negative stiffness adjustable vibration reduction device based on permanent magnet nonlinear vibration absorption, comprising a base (1) and a bearing platform (2) located above the base (1) for bearing a device to be vibration reduced, wherein the bearing platform (2) is connected to the base (1) via a plurality of vibration isolation springs (6), and is characterized in that: An elastic damper (3), a vibrator (4) and a magnetic vibration absorbing device (5) are arranged in sequence from top to bottom along the vertical direction between the bearing platform (2) and the base (1). The magnetic vibration absorbing device (5) is used to absorb vibration energy. The vibrator (4) is connected to a plurality of adjustable negative stiffness mechanisms arranged symmetrically around the vibrator. The adjustable negative stiffness mechanism comprises a negative stiffness fine-tuning device (7) and a horizontal elastic element (8). The horizontal elastic element (8) is located between the negative stiffness fine-tuning device (7) and the vibrator (4). The negative stiffness fine-tuning device (7) is used to adjust the compression amount of the horizontal elastic element (8).

2. The negative stiffness adjustable vibration reduction device based on permanent magnet nonlinear vibration absorption according to claim 1 is characterized in that: The elastic damper (3) is made of high-density rubber.

3. The negative stiffness adjustable vibration reduction device based on permanent magnet nonlinear vibration absorption according to claim 1, characterized in that: The vibrator (4) comprises a plurality of adjustment disks (41) arranged in a stacked manner, two adjacent adjustment disks (41) being connected via a matching sleeve (43), the upper and lower end surfaces of the adjustment disks (41) being respectively provided with connecting shaft portions (42), the connecting shaft portions (42) being provided with external threads on the outside, and the matching sleeve (43) being provided with internal threads matching the external threads.

4. The negative stiffness adjustable vibration reduction device based on permanent magnet nonlinear vibration absorption according to claim 1 is characterized in that: The magnetic vibration absorbing device (5) comprises a guide sleeve (51), a lower permanent magnet, a middle permanent magnet and an upper permanent magnet being arranged in sequence from bottom to top in the guide sleeve (51), the upper permanent magnet partially extending out of the guide sleeve (51), the lower permanent magnet and the middle permanent magnet magnetically repel each other, the middle permanent magnet and the upper permanent magnet magnetically repel each other, and the middle permanent magnet can move up and down in the guide sleeve (51).

5. The negative stiffness adjustable vibration reduction device based on permanent magnet nonlinear vibration absorption according to claim 4 is characterized in that: A lower shell (54) is provided on the outer side of the lower permanent magnet, a lower magnetic portion (541) facing the middle permanent magnet and protruding from the lower shell (54) is provided on the lower permanent magnet, an upper shell (52) is provided on the outer side of the upper permanent magnet, an upper magnetic portion (521) facing the middle permanent magnet and protruding from the upper shell (52) is provided on the upper permanent magnet, the upper shell (52) is located above the guide sleeve (51), the upper magnetic portion (521) partially extends into the guide sleeve (51), a fixing sleeve (53) is provided on the outer side of the middle permanent magnet, and an upper magnetic surface (531) that magnetically repels the upper magnetic portion (521) and a lower magnetic surface (541) that magnetically repels the lower magnetic portion (541) are provided on the middle permanent magnet.

6. The negative stiffness adjustable vibration reduction device based on permanent magnet nonlinear vibration absorption according to claim 5 is characterized in that: The lower permanent magnet, the middle permanent magnet and the upper permanent magnet are all made of neodymium iron boron material.

7. The negative stiffness adjustable vibration reduction device based on permanent magnet nonlinear vibration absorption according to claim 5, characterized in that: The lower housing (54), the upper housing (52) and the fixing sleeve (53) are all made of silicon steel material.

8. The negative stiffness adjustable vibration reduction device based on permanent magnet nonlinear vibration absorption according to claim 1 is characterized in that: The elastic element comprises two Euler buckling beams (81) which are symmetrically arranged up and down, and the concave surfaces of the two Euler buckling beams (81) are arranged opposite to each other.

9. The negative stiffness adjustable vibration reduction device based on permanent magnet nonlinear vibration absorption according to claim 1, characterized in that: The negative stiffness fine-adjusting device (7) comprises a vertical plate (71), an outer shell (72) arranged on the vertical plate (71), and a top shell (74) slidably inserted into the outer shell (72), one end of the top shell (74) extending into the outer shell (72) and the end thereof being fixedly connected to the elastic element, an adjusting screw (73) being arranged in the outer shell (72), the adjusting screw (73) having a first threaded portion (731) and a second threaded portion (732), the first threaded portion (731) being threadably matched with the outer shell (72), the second threaded portion (732) being threadably matched with the top shell (74), a large-pitch external thread being arranged on the outer shell (72), a large-pitch internal thread being matched with the large-pitch external thread being arranged on the outer shell (72), a small-pitch external thread being arranged on the outer shell (732), a small-pitch internal thread being matched with the small-pitch external thread being arranged on the top shell (74), and a mounting hole for the first threaded portion (731) to pass through being arranged on the vertical plate (71).

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