A vibration reduction device with adjustable dynamic characteristics

Abstract

The present invention discloses a vibration damping device with adjustable dynamic characteristics, comprising a load mass, the bottom of which is fixedly connected to a central shaft; a spring assembly, which is arranged on the central shaft and fixedly connected to the central shaft at one end, and can provide support stiffness; a base plate, on which a multi-layer plate extruded giant electrorheological fluid damper and an adjustable electromagnetic damper are sequentially arranged, and the bottom of the central shaft is connected to the multi-layer plate extruded giant electrorheological fluid damper; the multi-layer plate extruded giant electrorheological fluid damper and the adjustable electromagnetic damper can adjust the damping. The present invention has a wide adjustable damping range and nonlinear frequency-varying characteristics with high damping at low frequencies and low damping at high frequencies. It can effectively solve the contradiction between high and low frequency vibration attenuation and the problem of weak environmental adaptability, and achieve high-performance vibration reduction.

Description

Technical Field

[0001] The present invention relates to the technical field of vibration reduction, and in particular to a vibration reduction device with adjustable dynamic characteristics. Background Art

[0002] In the field of vibration reduction, the important indicators for measuring the performance of vibration reduction devices are the vibration reduction frequency band and the vibration attenuation rate. The linear two-parameter vibration reduction devices commonly used in engineering mainly use damping elements with fixed parameters to dissipate the vibration energy of the controlled object to achieve the purpose of vibration reduction. For example, publication number CN107606041B discloses a hybrid damper composed of a magnetorheological damper and an eddy current damper. This invention changes the stiffness of the magnetorheological damper under the same damping force by combining the magnetorheological damper and the eddy current damper. It is particularly suitable for application in semi-active vibration reduction systems using magnetorheological dampers. Publication number CN108571558A discloses a vibration reduction device that combines giant electrorheological fluid damping with metal rubber damping. The metal rubber of the vibration reduction device provided by this invention plays a damping role in passive vibration isolation, and the giant electrorheological fluid damper generates a damping force under the condition of power supply, playing a damping role in semi-active vibration isolation and active vibration isolation.

[0003] Due to structural limitations, linear two-parameter vibration damping devices face an inherent conflict in their damping requirements: high-frequency and low-frequency vibrations are mutually exclusive. Increasing damping can reduce the resonance peak near the natural frequency, but this also reduces the attenuation rate of high-frequency vibrations. Furthermore, once the dynamic characteristic parameters of a linear vibration damping device are determined, its applicable range is fixed, so it is only effective within a certain frequency range and has limited environmental adaptability.

[0004] With the continuous development of high-end IC chip manufacturing and ultra-precision testing, traditional vibration reduction devices can no longer meet the demand for environmental micro-vibration isolation. There is an urgent need to develop a new vibration reduction device with adjustable damping and frequency-dependent characteristics. This device should have nonlinear frequency-dependent characteristics (high damping at low frequencies and low damping at high frequencies) and be able to adapt to load changes. This can solve the contradiction between high- and low-frequency vibration attenuation and the problem of weak environmental adaptability, achieving high-performance vibration reduction.

[0005] Eddy current dampers provide nonlinear damping, suppressing resonance peaks while maintaining high attenuation rates at high frequencies. They offer advantages such as zero contact wear and ease of use. However, they typically use permanent magnets to generate magnetic fields, lacking controllability and limited environmental adaptability. Electrorheological fluid (ERF) dampers utilize fluid materials with electrorheological effects, offering advantages such as adjustable dynamic characteristics and fast response. However, ERFs have low yield stress, making them difficult to meet engineering requirements. Summary of the Invention

[0006] The purpose of the present invention is to provide a vibration reduction device with adjustable dynamic characteristics to solve the problems existing in the above-mentioned prior art. It has a large adjustable damping range and a nonlinear frequency-varying characteristic of large damping at low frequencies and small damping at high frequencies. It can well solve the contradiction between high and low frequency vibration attenuation and the problem of weak environmental adaptability, and achieve high-performance vibration reduction.

[0007] To achieve the above object, the present invention provides the following solutions:

[0008] The present invention provides a vibration damping device with adjustable dynamic characteristics, comprising a load mass, the bottom of which is fixedly connected to a central shaft; a spring assembly, which is inserted into the central shaft and fixedly connected to the central shaft at one end, capable of providing support stiffness; a base plate, on which a multi-layer plate extruded giant electrorheological fluid damper and an adjustable electromagnetic damper are sequentially arranged, the bottom of the central shaft being connected to the multi-layer plate extruded giant electrorheological fluid damper; the multi-layer plate extruded giant electrorheological fluid damper and the adjustable electromagnetic damper are capable of adjusting the damping. By rationally tuning various system parameters, the vibration damping device can reduce the peak value of the resonance while maintaining a high attenuation rate for high-frequency vibrations, thereby achieving high-performance vibration damping across the entire frequency band. The damping characteristics of the vibration damping device are jointly provided by the adjustable electromagnetic damper and the multi-layer plate extruded giant electrorheological fluid damper, which can achieve the purpose of wide-range adjustable system damping and increase the vibration damping device's adaptability to changes in environmental loads.

[0009] Optionally, the central axis includes a first central axis, and the bottom of the load mass block is fixedly connected to the first central axis; the multi-layer plate extruded giant electrorheological fluid damper includes a multi-layer plate extruded giant electrorheological fluid damper shell fixedly arranged on the base plate, and the adjustable electromagnetic damper includes a fixedly connected adjustable electromagnetic damper lower shell and an adjustable electromagnetic damper upper shell, the bottom of the adjustable electromagnetic damper lower shell is connected to the top of the multi-layer plate extruded giant electrorheological fluid damper shell, and a bearing seat is fixedly provided on the top of the adjustable electromagnetic damper upper shell, and a first linear bearing is installed on the bearing seat. The first central axis is positioned at the center of the vibration damping device through the first linear bearing and can move unidirectionally along the central axis.

[0010] Optionally, the spring assembly includes a first metal coil spring and a second metal coil spring which are sleeved on the first center shaft; the top of the first metal coil spring is fixedly connected to the first center shaft through an adjusting nut, and the connection position of the adjusting nut and the first center shaft can be adjusted, and the bottom of the first metal coil spring is arranged on the bearing seat; the second metal coil spring is located below the bearing seat, and its bottom is fixedly connected to the first center shaft through a fastening ring, and the connection position of the fastening ring and the first center shaft can be adjusted.

[0011] Optionally, the spring assembly further comprises a metal threaded tube spring, wherein the first central axis is a stepped axis, the lower end of which is connected to the metal threaded tube spring, and the bottom of the metal threaded tube spring is connected to the adjustable electromagnetic damper. The present invention combines adjustable electromagnetic damping, a multi-layer plate extrusion-type giant electrorheological fluid damper, and a metal threaded tube spring to form a multi-parameter system configuration, achieving adjustable dynamic characteristics of the vibration damping device, modular integrated design, and consistent structural coaxial characteristics. This reduces the peak-to-peak resonance of the system while ensuring high attenuation of high-frequency vibrations, achieving high-performance vibration damping across a wide operating frequency band. The metal threaded tube spring can conveniently adjust the secondary stiffness by adjusting the depth of the connecting shaft screwed into the threaded tube. It has a compact structure and can provide adjustable tensile and compressive stiffness. The adjustable electromagnetic damper adopts a Halbach magnetic array configuration, which greatly enhances the magnetic field and damping effects. The damping level can be adjusted by controlling the current in the coil. It is non-contact, has no mechanical losses, operates efficiently and stably, and is simple and easy to use. The multi-layer plate squeeze-type giant electrorheological fluid damper utilizes the greater yield stress of giant electrorheological fluid compared to traditional electrorheological fluids. By employing multiple electrode plates operating in squeeze mode, the effective area of ​​the electric field generated within a limited space is greatly increased, providing a wider range of damping force adjustment. It features a simple structure, a clear mechanism, and ease of adjustment. In practical engineering applications, the vibration reduction device provided by this invention can actively adjust its dynamic parameters based on real-time operating conditions, adapting to changes in environmental loads and achieving optimal vibration reduction.

[0012] Optionally, the adjustable electromagnetic damper further comprises a permanent magnet, a coil and a copper tube; the permanent magnet and the coil are both annular structures of the same specifications, the permanent magnet is a radially radiating magnetized magnet, and the magnetic field direction of the coil after charging is axial; the permanent magnet and the coil are alternately stacked along the axial direction, wherein the magnetic field directions of each adjacent permanent magnet are opposite, and the magnetic field directions of each adjacent energized coil are opposite; the copper tube is located at the center of the permanent magnet and the coil, and the lower end of the metal threaded tube spring passes through the center of the copper tube and is fixedly connected to the copper tube. The adjustable electromagnetic damper provided by the present invention adopts a Halbach magnetic array configuration, and by alternating the arrangement of axially magnetized coils and radially magnetized magnets, the magnetic field and damping effect of the electromagnetic damper are greatly enhanced. The adjustable electromagnetic damper is a non-contact damper that does not experience mechanical loss due to relative friction and can maintain efficient and stable operation for a long time. The adjustable electromagnetic damper does not contain oil during operation, is easy to clean and maintain, and does not have leakage problems, and is simple and easy to use. The adjustable electromagnetic damper has a high degree of linearity. By controlling the current in the coil, the magnetic field can be controlled, further adjusting the damping effect. The adjustable electromagnetic damper adopts a modular design and can be directly integrated into the existing system without affecting other dynamic characteristics of the system.

[0013] Optionally, the multi-layer plate extruded giant electrorheological fluid damper also includes a multi-layer plate extruded giant electrorheological fluid damper cover and a connector, and the bottom of the copper tube is fixedly connected to the connector; the central axis also includes a second central axis and a third central axis, the second central axis is positioned at the center of the vibration damping device through a second linear bearing and moves unidirectionally along the central axis, the upper end of the second central axis is engaged with the connector through a thread, and the second linear bearing is installed in the multi-layer plate extruded giant electrorheological fluid damper cover by bolts, and the multi-layer plate extruded giant electrorheological fluid damper cover is clamped with the giant electrorheological fluid damper shell through the adjustable electromagnetic damper lower shell; the multi-layer plate extruded giant electrorheological fluid damper is provided with a positive plate group and a negative plate group arranged alternately at intervals, the second central axis and the third central axis pass through the center hole of the positive plate group and are connected by threads, and are clamped to the positive plate group by a shoulder; the positive plate group and the negative plate group are both located between the bottom plate and the multi-layer plate extruded giant electrorheological fluid damper cover.

[0014] Optionally, sealing grooves are provided on the sides of the upper cover and the bottom plate of the multi-layer plate extruded giant electrorheological fluid damper, and sealing rings are placed in the sealing grooves to prevent leakage of the giant electrorheological fluid.

[0015] Optionally, the positive plate assembly includes three positive plates separated by positive plate spacer copper posts; the second and third central axes extend through the center holes of the three positive plates and are threadedly connected; and the negative plate assembly includes two negative plates separated by a negative plate spacer copper post, secured to the upper cover and base of the multi-layer plate extruded giant electrorheological fluid damper by negative plate positioning copper posts. The multi-layer plate extruded giant electrorheological fluid damper provided by the present invention leverages the rheological effect of giant electrorheological fluid (GERF) to provide active, adjustable fluid damping for the vibration reduction device. The fluid properties of GERF can be controlled by an externally applied electric field, and its yield stress is significantly greater than that of conventional ERF. The damper operates in extrusion mode, has a simple structure, and can provide greater damping force to the system compared to other operating modes. To further increase the adjustable damping range, the damper employs a multi-layer plate structure to increase the effective area of ​​the electrode plates that generate the electric field, thereby enhancing the damping effect of the damper. The multi-layer plate squeezed giant electrorheological fluid damper also adopts a modular design that is easy to integrate.

[0016] Compared with the prior art, the present invention has achieved the following technical effects:

[0017] The present invention has a nonlinear frequency-variable damping characteristic of high damping at low frequencies and low damping at high frequencies, and can actively adjust the dynamic characteristics of the vibration reduction device according to real-time working conditions to achieve high-performance vibration reduction. Specifically, the present invention has the following technical features:

[0018] (1) The present invention provides a novel modular multi-parameter vibration reduction device with adjustable dynamic characteristics, which modularizes a multi-plate extruded giant electrorheological fluid damper and an adjustable electromagnetic damper, and can be conveniently integrated and replaced; the combined vibration reduction device has a multi-parameter system configuration. Compared with the traditional two-parameter system, the multi-parameter system can reduce the peak-to-peak value of the system resonance while ensuring high attenuation of high-frequency vibrations, thereby achieving high-performance vibration reduction in a wider operating frequency band.

[0019] (2) The vibration reduction device provided by the present invention has a multi-parameter equivalent system configuration, which is composed of two vibration transmission paths, a primary path and a secondary path, connected in parallel. The primary path contains a primary stiffness element that supports the load; the secondary path is composed of a secondary stiffness element, an adjustable electromagnetic damper, and a multi-layer plate extrusion giant electrorheological fluid damper connected in series. The equivalent damping of the vibration reduction device of the present invention has the characteristic of following the frequency change, that is, the vibration reduction device of the present invention achieves the effect of frequency-variable damping from the system structure level, which can further improve the adjustable damping range of the vibration reduction device. By reasonably selecting the parameter values ​​of the dynamic elements, high-performance vibration reduction of the vibration reduction device can be achieved.

[0020] (3) The adjustable electromagnetic damper in the present invention is an adjustable eddy current damper based on the Halbach magnetic array. The Halbach magnetic array configuration greatly enhances the magnetic field of the electromagnetic damper by alternating the arrangement of axial magnetized coils and radial magnetized magnets, and its damping effect is the strongest among all configurations. Compared with traditional mechanical friction damping, viscous damping and eddy current damping, the adjustable electromagnetic damper of the present invention is a non-contact damper that does not have mechanical loss due to relative friction and can maintain efficient and stable operation for a long time. During the operation of the adjustable electromagnetic damper of the present invention, there is no oil present, it is easy to clean and maintain, there is no leakage problem, and it is simple and easy to use. The linearity of the adjustable electromagnetic damper of the present invention is very high, and the change of the magnetic field can be controlled by controlling the size of the current in the coil, and the size of the damping can be further adjusted. The adjustable electromagnetic damper of the present invention adopts a modular design and can be directly integrated into the original system without affecting other dynamic characteristics of the system.

[0021] (4) The multi-layer electrode plate extrusion type giant electrorheological fluid damper in the present invention uses a giant electrorheological fluid with a high yield stress to provide adjustable dynamic characteristics for the vibration reduction device. Compared with traditional electrorheological fluid, the giant electrorheological fluid has a larger yield stress and can provide a larger damping adjustment range. The damper works in an extrusion mode and has the characteristics of simple structure, clear mechanism, and easy adjustment. The damping size of the giant electrorheological fluid damper is related to the effective area of ​​the electrode plate that generates the electric field. In order to provide the device with greater system damping, the giant electrorheological fluid damper in the present invention uses a multi-layer electrode plate. In a limited space, the effective area of ​​the electric field is greatly increased.

[0022] (5) The vibration damping device provided by the present invention utilizes a metal threaded tube spring to connect the load to the adjustable electromagnetic damper and the multi-layer plate extrusion giant electrorheological fluid damper, providing secondary stiffness for the system. The threaded tube spring can conveniently adjust the secondary stiffness by adjusting the depth of the connecting shaft screwed into the threaded tube. It has a compact structure and can provide adjustable tensile and compressive stiffness.

[0023] (6) The vibration reduction device provided by the present invention realizes the characteristic of adjustable damping frequency. In practical applications, the vibration reduction device can actively adjust the damping parameters of the vibration reduction device according to the real-time working conditions, and achieve the best vibration reduction effect by reasonably selecting the damping parameter value.

[0024] (7) The vibration reduction device provided by the present invention adopts a coaxially symmetrical arrangement, with the primary and secondary vibration transmission paths concentrated on the central axis. The symmetry of the structure is conducive to ensuring the consistency of the vibration transmission characteristics of the device and achieving high-performance vibration reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 A half-section view of a new modular multi-parameter vibration reduction device with adjustable dynamic characteristics;

[0027] Figure 2 It is a half-section view of the three-dimensional structure of the adjustable electromagnetic damper;

[0028] Figure 3 Schematic diagram of the adjustable electromagnetic damper;

[0029] Figure 4 It is the three-dimensional structure diagram of the metal threaded tube spring;

[0030] Figure 5 A half-section view of the internal three-dimensional structure of a multi-layer plate squeezed giant electrorheological fluid damper;

[0031] Figure 6 This is a three-dimensional structural diagram of the central axis of the giant electrorheological fluid damper of the present invention;

[0032] Figure 7 This is a three-dimensional structural diagram of the positive electrode plate of the giant electrorheological fluid damper of the present invention;

[0033] Figure 8 This is a three-dimensional structural diagram of the negative electrode plate of the giant electrorheological fluid damper of the present invention;

[0034] Figure 9 The three-dimensional structure diagram of the upper shell of the adjustable electromagnetic damper;

[0035] Figure 10 The three-dimensional structure diagram of the lower shell of the adjustable electromagnetic damper;

[0036] Figure 11 This is a three-dimensional structural diagram of the upper cover of the giant electrorheological fluid damper of the present invention;

[0037] Figure 12 This is a three-dimensional structural diagram of the giant electrorheological fluid damper housing of the present invention;

[0038] Figure 13 This is a three-dimensional structural diagram of the base plate of the giant electrorheological fluid damper of the present invention;

[0039] Figure 14 Schematic diagram of the equivalent model of the traditional constant damping two-parameter vibration reduction device;

[0040] Figure 15 Provides a comparison chart of the vibration reduction effect of the vibration reduction device of the present invention and other vibration reduction means;

[0041] Figure 16 Schematic diagram of the equivalent model of the vibration reduction device of the present invention.

[0042] Explanation of the reference numerals: 1. load mass block; 2. adjusting nut; 3. first metal coil spring; 4. bearing seat; 5. fastening ring; 6. upper shell of adjustable electromagnetic damper; 7. lower shell of adjustable electromagnetic damper; 8. outer shell of multi-layer plate extruded giant electrorheological fluid damper; 9. bottom plate; 10. multi-layer plate extruded giant electrorheological fluid damper; 11. second linear bearing; 12. upper cover of multi-layer plate extruded giant electrorheological fluid damper; 13. connector; 14. metal thread Tube spring; 15. Adjustable electromagnetic damper; 16. Second metal coil spring; 17. First linear bearing; 18. Center axis; 10-1. Positive plate; 10-2. Negative plate; 10-3. Copper pillars spacing the positive plates; 10-4. Copper pillars spacing the negative plates; 10-5. Copper pillars positioning the negative plates; 15-1. Coil; 15-2. Permanent magnet; 15-3. Copper tube; 18-1. First center axis; 18-2. Second center axis; 18-3. Third center axis. DETAILED DESCRIPTION

[0043] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0044] The purpose of the present invention is to provide a vibration reduction device with adjustable dynamic characteristics to solve the problems existing in the above-mentioned prior art. It has a large adjustable damping range and a nonlinear frequency-varying characteristic of large damping at low frequencies and small damping at high frequencies. It can well solve the contradiction between high and low frequency vibration attenuation and the problem of weak environmental adaptability, and achieve high-performance vibration reduction.

[0045] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0046] like Figures 1 to 16 As shown, the present invention provides a vibration damping device with adjustable dynamic characteristics, which has a multi-parameter system equivalent model. The key adjustable damping component is provided by an adjustable electromagnetic damper 15 and a multi-layer plate extruded giant electrorheological fluid damper 10. The vibration damping device of the present invention has two vibration transmission paths, primary and secondary. The components in the device are arranged symmetrically, ensuring the consistency of the vibration transmission characteristics of the device structure in the vertical vibration damping direction. The primary path includes an adjustment nut 2, a first metal coil spring 3, a fastening ring 5, and a second metal coil spring 16. The secondary path includes an adjustable electromagnetic damper 15, a multi-layer plate extruded giant electrorheological fluid damper 10, a metal threaded tube spring 14, a connector 13, and a center shaft 18. The remaining components include a load mass 1, a bearing seat 4, a first linear bearing 17, and a second linear bearing 11. The adjustable electromagnetic damper 15 and the multi-layer plate extruded giant electrorheological fluid damper 10 both adopt a modular design, which can be easily integrated into the vibration damping device.

[0047] like Figure 1As shown, in the vibration damping device provided by the present invention, the load mass block 1 is fixedly mounted on the first central axis 18-1 through a threaded hole, the first central axis 18-1 is positioned at the center of the vibration damping device through a first linear bearing 17 and moves unidirectionally along the central axis, the first linear bearing 17 is mounted in the bearing seat 4 through bolts, the bearing seat 4 is fixed to the upper shell 6 of the adjustable electromagnetic damper through bolts, the upper shell 6 of the adjustable electromagnetic damper is fixed to the lower shell 7 of the adjustable electromagnetic damper through bolts, the lower shell 7 of the adjustable electromagnetic damper is fixed to the outer shell 8 of the multi-layer plate extruded giant electrorheological fluid damper through bolts, and the outer shell 8 of the multi-layer plate extruded giant electrorheological fluid damper is fixed to the base plate 9 through bolts. The first metal coil spring 3 is placed above the bearing seat 4, and is mounted on the first center shaft 18-1, supporting the load mass block 1 and the first center shaft 18-1 through the adjusting nut 2; the second metal coil spring 16 is located below the bearing seat 4, and is also mounted on the first center shaft 18-1, providing opposite forces to the load mass block 1 and the first center shaft 18-1 through the fastening ring 5, so as to limit the amplitude of the upward vibration of the load mass block 1. The first metal coil spring 3 and the second metal coil spring 16 jointly provide the main-stage stiffness, which is the supporting stiffness of the load mass block 1. By adjusting the position of the fastening ring 5 and the adjusting nut 2 on the first center shaft 18-1, the equilibrium position of the entire vibration damping device can be adjusted. Among them, the fastening ring 5 is used for coarse adjustment, and the adjusting nut 2 is used for fine adjustment. The first center shaft 18-1 is designed as a stepped shaft, and the lower end is also connected to the metal threaded tube spring 14 through a thread. By adjusting the depth of the first center shaft 18-1 screwed into the metal threaded tube spring 14, the stiffness of the metal threaded tube spring 14 can be adjusted. As Figure 4 As shown, the metal threaded tube spring 14 provides adjustable secondary stiffness for the vibration damping device, and has the advantages of compact structure and adjustable tension and compression stiffness.

[0048] like Figure 2 As shown, the adjustable electromagnetic damper 15 in the vibration reduction device provided by the present invention includes a permanent magnet 15-2, a coil 15-1 and a copper tube 15-3. The permanent magnet 15-2 and the wound coil 15-1 are both circular rings with the same specifications, wherein the permanent magnet 15-2 is a radially radiating magnetized magnet, and the magnetic field direction of the charged coil 15-1 is axial. The permanent magnets 15-2 and the coils 15-1 are stacked alternately along the axial direction, wherein the magnetic field directions of each adjacent permanent magnet 15-2 are opposite, and the magnetic field directions of each adjacent energized coil are opposite. For each permanent magnet 15-2, when the magnetic field directions of the energized coils on both sides point to it, the magnetic field direction of the permanent magnet 15-2 points to the central axis; when the magnetic field directions of the energized coils on both sides deviate from it, the magnetic field direction of the permanent magnet 15-2 deviates from the central axis, as shown in FIG. Figure 3As shown. Therefore, the magnetic mechanism of the adjustable electromagnetic damper 15 of the present invention adopts a Halbach magnetic array configuration, the magnetic field outside the magnetic mechanism is weakened, and the magnetic field inside the magnetic mechanism is greatly enhanced; and the magnetic field can be adjusted by adjusting the magnitude of the current in the energized coil, thereby achieving an adjustable damping effect. The magnetic mechanism stack is clamped and fixed by the adjustable electromagnetic damper upper shell 6 and the adjustable electromagnetic damper lower shell 7. The copper tube 15-3 located at the center of the magnetic mechanism is fixed to the lower end of the metal threaded tube spring 14 passing through the center of the copper tube 15-3 by bolts. During vibration, the copper tube 15-3 can move axially relative to the magnetic mechanism, generating a motional electromotive force in the copper tube 15-3, and then generating eddy current loss, thereby achieving the effect of dissipating vibration energy.

[0049] like Figures 5 to 8 As shown, the multi-layer plate squeezed giant electrorheological fluid damper 10 in the vibration damping device provided by the present invention includes a positive plate 10-1, a negative plate 10-2, a positive plate spacing copper post 10-3, a negative plate spacing copper post 10-4, a negative plate positioning copper post 10-5, a second central axis 18-2, and a third central axis 18-3. The second central axis 18-2 is positioned at the center of the vibration damping device by a second linear bearing 11 and moves unidirectionally along the central axis. The upper end of the second central axis 18-2 engages with a connector 13 via a threaded connection. The connector 13 is secured to the lower end of a metal threaded tube spring 14 and a copper tube 15-3 via bolts. The second linear bearing 11 is bolted to the upper cover 12 of the multi-layer plate squeezed giant electrorheological fluid damper. The upper cover 12 is clamped by the adjustable electromagnetic damper lower shell 7 and the multi-layer plate squeezed giant electrorheological fluid damper outer shell 8 and supported and fixed by the negative plate positioning copper post 10-5. The sides of the multi-layer plate extruded giant electrorheological fluid damper's upper cover 12 and base plate 9 are provided with sealing grooves for placement of sealing rings to prevent leakage of the giant electrorheological fluid. Inside the multi-layer plate extruded giant electrorheological fluid damper 10, three positive plates 10-1 are separated by positive plate spacer copper posts 10-3. The second and third central shafts 18-2 and 18-3 thread through the center holes of the positive plate assembly and are clamped to the positive plate assembly via a shoulder. Two negative plates 10-2 are separated by negative plate spacer copper posts 10-4. The negative plate assembly is positioned using negative plate locating copper posts 10-5. Bolts penetrate the negative plate spacer and locating copper posts to secure the negative plate assembly to the upper cover 12 and base plate 9 of the multi-layer plate extruded giant electrorheological fluid damper. The multi-layer plate squeeze-type giant electrorheological fluid damper 10 uses multi-layer plates, and the positive and negative plates are alternately and equidistantly arranged coaxially. In a limited space, the effective area for generating the electric field is greatly increased. At the same time, working in the squeeze mode, the output damping force range of the giant electrorheological fluid damper is greatly improved; by controlling the voltage between the positive and negative plates, active adjustment of the damping can be achieved.

[0050] The vibration reduction principle of the vibration reduction device of the present invention is described below:

[0051] like Figure 1 、 16 As shown, the present invention can be simplified into a multi-parameter system equivalent model, which has two vibration transmission paths, a primary and a secondary, wherein the support stiffness k in the primary path is provided by the first metal coil spring 3 and the second metal coil spring 16 on the upper and lower sides of the bearing seat 4 in the vibration reduction device; the secondary path is composed of a secondary stiffness k1, an intermediate equivalent mass m1 and an adjustable damping c connected in series, wherein the secondary stiffness k1 is provided by a metal threaded tube spring; the intermediate equivalent mass m1 is provided by the copper tube 15-3, the second central axis 18-2 and the third central axis 18-3 and the positive plate group in the secondary path; the adjustable damping c is provided by the adjustable electromagnetic damper 15 and the multi-layer plate squeezed giant electrorheological fluid damper 10, and its damping size is related to the current of the energized coil in the damper and the voltage between the positive and negative plate groups, respectively. The purpose of adjustable damping can be achieved by adjusting the current and voltage values.

[0052] according to Figure 16 The multi-parameter system equivalent model of the vibration reduction device of the present invention can be obtained according to Newton's second law:

[0053]

[0054] Where x, x1, and x0 correspond to the load mass m, the intermediate equivalent mass m1, and the displacement of the foundation vibration source, respectively.

[0055] Performing Laplace transform on the vibration differential equations (1) and rearranging them, we can obtain the algebraic equations:

[0056]

[0057] By combining the two equations in the analytical equation group (2), we can obtain the displacement vibration transmissibility expression of the system:

[0058]

[0059] In order to eliminate the influence of the dimension of system parameters and facilitate its mechanism research and parameter analysis, the system's transmissibility function is normalized and the following dimensionless parameters are defined: stiffness ratio N = k1 / k, mass ratio P = m1 / m, damping ratio ζ0 = c / 2mω0 and natural frequency The following system displacement vibration transmissibility function is obtained:

[0060]

[0061] Similarly, according to Figure 14 The equivalent model of the traditional constant damping two-parameter vibration reduction device can obtain the following system displacement vibration transmissibility function:

[0062]

[0063] like Figure 2 、 3 As shown, the adjustable electromagnetic damper in the present invention is an adjustable eddy current damper based on a Halbach magnetic array. Eddy current is a current loop induced inside a conductor due to changes in the magnetic field in the conductor. The damping force generated by the eddy current damper comes from the generation of electromotive force. This electromotive force is divided into two categories: induced electromotive force generated by a time-varying magnetic field and motional electromotive force generated by the movement of the conductor cutting the magnetic flux lines. Studies have shown that in actual situations, dampers designed based on motional electromotive force have higher damping efficiency than dampers designed based on induced electromotive force. Therefore, the adjustable electromagnetic damper 15 in the present invention adopts a design based on motional electromotive force to obtain greater damping. When the copper tube 15-3 in the adjustable electromagnetic damper 15 and the magnetic mechanism (coil, permanent magnet) move relative to each other due to vibration, the copper tube 15-3 cuts the magnetic flux lines and induces motional electromotive force in the copper tube 15-3, further generating induced eddy currents to dissipate vibration energy. The magnitude of eddy currents is directly proportional to the magnetic induction intensity, loop area, and rate of change of magnetic flux, and inversely proportional to the resistivity of the material. To achieve a wider adjustable range of electromagnetic damping, the electromagnetic damper in this invention employs a Halbach magnetic array configuration. By alternating axially magnetized coils and radially magnetized magnets, the electromagnetic damper's magnetic field is greatly enhanced, resulting in the strongest damping effect of all configurations. Furthermore, the magnetic field can be controlled by controlling the current in the coils, achieving adjustable damping.

[0064] Electrorheological fluid is an intelligent rheological material. When there is no electric field, the external characteristics of the material are liquid, and its properties are similar to silicone oil. When an electric field is applied on both sides of the material, the viscosity of the material changes accordingly. When the applied electric field continues to increase, the external characteristics of the material change to a solid-like state, and the viscosity properties of the material change in sequence to tofu, rubber, hard spring, and plastic. When the applied electric field decreases, the viscosity of the material decreases until it returns to a liquid state. The response time of the entire electrorheological effect process is very short (millisecond level). The rheological effect of electrorheological fluid has the characteristics of fast response speed and easy deployment and control of electric field, but at the same time there is a problem of insufficient yield stress strength and failure to meet the requirements of engineering applications. The multi-layer plate extruded giant electrorheological fluid damper 10 in the vibration reduction device of the present invention adopts an improved giant electrorheological fluid. Compared with traditional electrorheological fluid, the mechanical properties of the giant electrorheological fluid are greatly enhanced, and the yield strength reaches 130kPa, so it can provide a larger damping adjustment range. On the other hand, the yield strength of the giant electrorheological fluid is linearly related to the applied electric field, and has better control characteristics.

[0065] According to the working state, the multi-layer plate squeezed giant electrorheological fluid damper 10 can be specifically divided into three basic types: flow mode, shear mode and squeeze mode. The multi-layer plate squeezed giant electrorheological fluid damper 10 in the vibration reduction device of the present invention adopts the multi-layer plate squeeze mode, such as Figure 5 As shown. During operation, the positive and negative electrode plate groups of the multi-layer electrode plate squeeze type giant electrorheological fluid damper 10 undergo relative displacement due to vibration, the vertical distance between the parallel electrode plates changes, and then the electric field of the plates changes. The multi-layer electrode plate squeeze type giant electrorheological fluid damper 10 operates in a pure squeeze mode, and the friction and squeeze force between the electrode plates and the giant electrorheological fluid generate damping force. In order to ensure the adjustable range and stability of the output damping force, the multi-layer electrode plate squeeze type giant electrorheological fluid damper 10 in the vibration reduction device of the present invention is designed as a multi-layer electrode plate structure, with the positive and negative electrode plates arranged alternately, and the effective area for generating the electric field is greatly increased.

[0066] Both electromagnetic damping and giant electrorheological fluid damping have nonlinear characteristics and can be equivalent to viscous damping using the equivalent linearization method (equivalence principle: the energy consumed by equivalent viscous damping and inviscid damping in one vibration cycle is equal). When the relative motion between the adjustable electromagnetic damper 15 and the multi-layer plate squeezed giant electrorheological fluid damper 10 is simple harmonic vibration, the energy consumed by their damping force in one vibration cycle is The energy consumed by the equivalent damping force is Therefore, its equivalent viscous damping coefficient is:

[0067]

[0068] Where, F is the damping force output by the multi-layer plate squeezed giant electrorheological fluid damper 10 and the adjustable electromagnetic damper 15, and its magnitude is related to the voltage and current respectively; X r is the relative displacement amplitude between the working components, ω is the simple harmonic oscillation circular frequency, and c is the equivalent viscous damping coefficient of the multi-layer plate squeeze-type giant electrorheological fluid damper 10 and the adjustable electromagnetic damper 15. As can be seen from equation (6), the damping of the multi-layer plate squeeze-type giant electrorheological fluid damper 10 and the adjustable electromagnetic damper 15 in the vibration reduction device of the present invention can be adjusted by controlling the voltage and current, respectively.

[0069] Figure 15 This is a comparison chart of the vibration reduction effect of the vibration reduction device provided by the present invention and other vibration reduction means. Figure 15 The solid and dotted lines in the figure show that the traditional constant damping two-parameter vibration reduction has an inherent problem of high-low frequency contradiction in the system damping size. Its equivalent model and vibration transmissibility function are as follows: Figure 14As shown in Equation (5), the constant small damping vibration reduction method has good attenuation performance for high-frequency vibration, but the resonance peak cannot be suppressed. Increasing the damping and using the constant large damping vibration reduction method can effectively suppress the resonance peak amplitude, but the high-frequency attenuation performance is significantly deteriorated. Therefore, the traditional constant damping two-parameter vibration reduction method cannot simultaneously meet the high-performance broadband vibration reduction requirements of resonance suppression and high-frequency attenuation. Figure 15 The dotted line in the figure is the effect curve of ideal frequency-variable damping vibration reduction, which can perfectly solve the contradiction between high and low frequencies in the system damping requirements and is the ideal vibration reduction effect pursued by actual vibration reduction devices. Figure 15 It can be seen from the dotted line in the figure that the resonance peak of the vibration reduction device of the present invention is suppressed, while the high-frequency attenuation performance can be maintained, showing the characteristics of frequency-variable damping, with an effect close to the ideal frequency-variable damping vibration reduction, which greatly improves the vibration reduction performance of the device. Its equivalent model and vibration transmissibility function are as follows: Figure 16 As shown in formula (4).

[0070] In the description of the present invention, it should be noted that the terms "center," "top," "bottom," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0071] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A vibration damping device with adjustable dynamic characteristics, characterized in that: It includes a load mass block, the bottom of which is fixedly connected to a central shaft; A spring assembly, which is passed through the central shaft and fixedly connected to the central shaft at one end, and can provide support stiffness; A base plate, on which a multi-layer pole plate squeezed giant electrorheological fluid damper and an adjustable electromagnetic damper are arranged in sequence, the bottom of the central shaft is connected to the multi-layer pole plate squeezed giant electrorheological fluid damper; the multi-layer pole plate squeezed giant electrorheological fluid damper and the adjustable electromagnetic damper can adjust the damping; the central shaft includes a first central shaft, and the bottom of the load mass block is fixedly connected to the first central shaft; the multi-layer pole plate squeezed giant electrorheological fluid damper includes a multi-layer pole plate squeezed giant electrorheological fluid damper shell fixedly arranged on the base plate, the adjustable electromagnetic damper includes a fixedly connected adjustable electromagnetic damper lower shell and an adjustable electromagnetic damper upper shell, the bottom of the adjustable electromagnetic damper lower shell is connected to the top of the multi-layer pole plate squeezed giant electrorheological fluid damper shell, the top of the adjustable electromagnetic damper upper shell is fixedly provided with a bearing seat, and a first linear bearing is installed on the bearing seat, so The first central axis is positioned at the center of the vibration damping device through a first linear bearing and can move unidirectionally along the central axis; the spring assembly also includes a metal threaded tube spring, the first central axis is a stepped axis, the lower end of which is connected to the metal threaded tube spring, and the bottom of the metal threaded tube spring is connected to the adjustable electromagnetic damper; the adjustable electromagnetic damper also includes a permanent magnet, a coil and a copper tube; the permanent magnet and the coil are both annular structures with the same specifications, the permanent magnet is a radially radiating magnetized magnet, and the magnetic field direction of the coil after charging is axial; the permanent magnet and the coil are alternately stacked along the axial direction, wherein the magnetic field directions of each adjacent permanent magnet are opposite, and the magnetic field directions of each adjacent energized coil are opposite; the copper tube is located at the center of the permanent magnet and the coil, and the lower end of the metal threaded tube spring passes through the center of the copper tube and is fixedly connected to the copper tube.

2. The vibration damping device with adjustable dynamic characteristics according to claim 1, characterized in that: The spring assembly includes a first metal coil spring and a second metal coil spring sleeved on the first center shaft; the top of the first metal coil spring is fixedly connected to the first center shaft through an adjusting nut, and the connection position of the adjusting nut and the first center shaft can be adjusted, and the bottom of the first metal coil spring is arranged on the bearing seat; the second metal coil spring is located below the bearing seat, and its bottom is fixedly connected to the first center shaft through a fastening ring, and the connection position of the fastening ring and the first center shaft can be adjusted.

3. The vibration damping device with adjustable dynamic characteristics according to claim 1, characterized in that: The multi-layer plate extruded giant electrorheological fluid damper also includes a multi-layer plate extruded giant electrorheological fluid damper cover and a connector, and the bottom of the copper tube is fixedly connected to the connector; the central axis also includes a second central axis and a third central axis, the second central axis is positioned at the center of the vibration damping device through a second linear bearing and moves unidirectionally along the central axis, the upper end of the second central axis is engaged with the connector through a thread, and the second linear bearing is installed in the multi-layer plate extruded giant electrorheological fluid damper cover by bolts, and the multi-layer plate extruded giant electrorheological fluid damper cover is clamped to the giant electrorheological fluid damper shell through the adjustable electromagnetic damper lower shell; the multi-layer plate extruded giant electrorheological fluid damper is provided with a positive plate group and a negative plate group arranged alternately at intervals, the second central axis and the third central axis pass through the center hole of the positive plate group and are connected by threads, and are clamped to the positive plate group by a shaft shoulder; the positive plate group and the negative plate group are both located between the bottom plate and the multi-layer plate extruded giant electrorheological fluid damper cover.

4. The vibration damping device with adjustable dynamic characteristics according to claim 3, characterized in that: The sides of the upper cover and the bottom plate of the multi-layer plate extruded giant electrorheological fluid damper are provided with sealing grooves, and sealing rings are placed in the sealing grooves to prevent the giant electrorheological fluid from leaking.

5. The vibration damping device with adjustable dynamic characteristics according to claim 3, characterized in that: The positive plate group includes positive plates, and the three positive plates are separated by positive plate spacer copper pillars; the second center axis and the third center axis pass through the center holes of the three positive plates and are connected by threads; the negative plate group includes negative plates, and the two negative plates are separated by negative plate spacer copper pillars, which are respectively fixed to the upper cover and bottom plate of the multi-layer plate extruded giant electrorheological fluid damper through negative plate positioning copper pillars.

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