A three-dimensional vibration isolation device

Abstract

The three-dimensional vibration isolation device comprises a bottom plate, a top plate, a magnetic isolation sleeve, permanent magnets, springs, excitation coils, a control system and sensors, the top plate and the magnetic isolation sleeve are sequentially connected from the center of the bottom plate to the outer edge of the bottom plate, the magnetic isolation sleeve comprises a first magnetic isolation sleeve and a second magnetic isolation sleeve, the permanent magnets are arranged between the first magnetic isolation sleeve and the top plate, the springs are connected between the first magnetic isolation sleeve and the second magnetic isolation sleeve, the permanent magnets comprise first permanent magnets, second permanent magnets, third permanent magnets and fourth permanent magnets, and a plurality of groups are symmetrically arranged along the circumference of the bottom plate, and the excitation coils are wound on the third permanent magnets. The vibration isolation device can have low dynamic stiffness in three-dimensional directions, can realize quasi-zero stiffness in the horizontal direction, realizes quasi-zero stiffness in the horizontal direction through the parallel connection of magnetic negative stiffness and positive stiffness spring elements, and effectively isolates vibration in multiple directions.

Description

Technical Field

[0001] This invention relates to the field of vibration control technology, and specifically to a three-dimensional vibration isolation device. Background Technology

[0002] Blasting, construction, subway operation, and earthquakes often cause structural vibrations. These vibrations, transmitted through the soil, cause vibrations in building structures and indoor furniture, which not only damage the building structure but also seriously affect people's comfort. Magnetorheological elastomers are intelligent materials with special properties that can achieve adjustable stiffness and damping through an external magnetic field. By changing the strength of the magnetic field, their stiffness can be altered.

[0003] Traditional vibration isolation devices have limited effectiveness in the low-frequency range. Quasi-zero stiffness vibration isolation systems can effectively reduce the dynamic stiffness of structures, improve vibration isolation performance, and broaden the isolation frequency range. Currently, most quasi-zero stiffness vibration isolation structures can only achieve low dynamic stiffness in a single direction. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art. A three-dimensional vibration isolation device includes a base plate, a top plate, a permanent magnet, a spring, and a magnetic isolation sleeve. The base plate is provided with the top plate and the magnetic isolation sleeve sequentially from the center of the base plate to the outer edge of the base plate. The magnetic isolation sleeve includes a first magnetic isolation sleeve and a second magnetic isolation sleeve. The second magnetic isolation sleeve is slidably connected to the base plate. The permanent magnet is disposed between the first magnetic isolation sleeve and the top plate. The spring is connected between the first magnetic isolation sleeve and the second magnetic isolation sleeve.

[0005] Furthermore, the central column and the plate are integrally connected, the central column is located at the center of the plate, and the top plate can move up and down in the vertical direction.

[0006] Furthermore, a buffer pad is provided between the central column and the first magnetic shielding sleeve. The buffer pad is fixedly connected to the first magnetic shielding sleeve. The diameter of the central column is the same as the diameter of the through hole of the second magnetic shielding sleeve. The central column and the second magnetic shielding sleeve cannot move relative to each other in the horizontal direction, but can only move relative to each other in the vertical direction.

[0007] Furthermore, the permanent magnet includes a first permanent magnet, a second permanent magnet, a third permanent magnet, and a fourth permanent magnet, and multiple sets of the first permanent magnet, the second permanent magnet, the third permanent magnet, and the fourth permanent magnet are symmetrically arranged along the circumference of the base plate.

[0008] Furthermore, the first permanent magnet is fixed to the outer wall of the second magnetic shielding sleeve, the second permanent magnet is fixed to the inner wall of the first magnetic shielding sleeve, the vertical heights of the first permanent magnet and the second permanent magnet are the same, and the upper surfaces of the first permanent magnet and the second permanent magnet are located on the same plane.

[0009] Furthermore, the third permanent magnet is fixed to the inner wall of the second magnetic shielding sleeve, and the fourth permanent magnet is fixed to the outer wall of the central column. The upper surfaces of the third and fourth permanent magnets are located on the same plane.

[0010] Furthermore, a magnetorheological elastomer is provided between the third permanent magnet and the fourth permanent magnet. One end of the magnetorheological elastomer is fixedly connected to the third permanent magnet, and the other end is fixedly connected to the fourth permanent magnet. The magnetorheological elastomer is a shear-type magnetorheological elastomer, and an excitation coil is wound on the third permanent magnet.

[0011] Furthermore, a sensor is provided on the upper surface of the top plate to detect the vertical vibration of the upper structure. A control system is provided on the first magnetic shielding sleeve. The control system includes a controllable AC power supply, a vibration signal collector, and a controller. The controllable AC power supply is electrically connected to the excitation coil. The vibration signal collector collects the vibration signals detected by the sensor. The controller detects and controls the current input to the excitation coil based on the collected vibration signals.

[0012] Furthermore, multiple sets of springs are provided between the first magnetic shielding sleeve and the second magnetic shielding sleeve, and a viscous damper is also connected between the first magnetic shielding sleeve and the second magnetic shielding sleeve. The viscous damper is arranged parallel to the spring, and multiple sets of springs and viscous dampers are evenly arranged along the circumference of the base plate. The number of springs and viscous dampers is the same.

[0013] Furthermore, the first, second, third, and fourth permanent magnets are all neodymium magnets, samarium cobalt magnets, or other high-performance permanent magnets.

[0014] The magnetorheological elastomer is made by incorporating carbon black, carbonyl iron powder, or other materials that can improve the mechanical properties of the magnetorheological elastomer.

[0015] The first and second magnetic shielding sleeves are made of nickel-iron alloy, cobalt-iron alloy or other metal materials with good magnetic shielding properties.

[0016] The present invention has the following beneficial effects: the three-dimensional device of the present invention can have low dynamic stiffness in all three directions and can achieve quasi-zero stiffness in the horizontal direction.

[0017] (1) Traditional vibration isolation devices cannot simultaneously achieve high load-bearing capacity and low-frequency vibration isolation capacity. This device achieves both high load-bearing capacity and low-frequency vibration isolation capacity by introducing a magnetorheological elastomer.

[0018] (2) Previous quasi-zero stiffness vibration isolation devices could only achieve low dynamic stiffness in a single direction, while this device achieves low dynamic stiffness in three dimensions.

[0019] (3) By changing the current flowing into the excitation coil, the vertical stiffness of the magnetorheological elastomer can be adjusted according to the specific situation, which is suitable for a variety of working conditions and has good adaptability. Attached Figure Description

[0020] Figure 1 This is a vertical cross-sectional schematic diagram of the three-dimensional vibration isolation device of the present invention;

[0021] Figure 2 This is a schematic horizontal cross-sectional view of the three-dimensional vibration isolation device of the present invention.

[0022] Among them: top plate-1; bottom plate-2; first magnetic shielding sleeve-3; first permanent magnet-4; second permanent magnet-5; third permanent magnet-6; fourth permanent magnet-7; second magnetic shielding sleeve-8; magnetorheological elastomer-9; excitation coil-10; spring-11; control system-12; sensor-13; buffer pad-14; viscous damper-15. Detailed Implementation

[0023] The three-dimensional vibration isolation device of the present invention will be further described in detail below with reference to the accompanying drawings. The three-dimensional vibration isolation device provided by the present invention can not only have low dynamic stiffness in multiple directions and achieve good vibration isolation effect, but also can be adjusted according to different current magnitudes according to specific circumstances, thus having good adaptability.

[0024] According to the appendix Figure 1-2As shown in the figure and embodiments of the present invention, a three-dimensional vibration isolation device comprises a top plate 1, a bottom plate 2, a first magnetic isolation sleeve 3, a first permanent magnet 4, a second permanent magnet 5, a third permanent magnet 6, a fourth permanent magnet 7, a second magnetic isolation sleeve 8, a magnetorheological elastomer 9, an excitation coil 10, a spring 11, a sensor 13, and a control system 12. The bottom plate 2 is provided with the top plate 1, the second magnetic isolation sleeve 8, and the first magnetic isolation sleeve 3 sequentially arranged from the center of the bottom plate 2 to its outer edge. The second magnetic isolation sleeve 8 is slidably connected to the bottom plate 2. The permanent magnet is disposed between the first magnetic isolation sleeve 3 and the top plate 1. The two ends of the spring 11 are respectively connected between the second magnetic isolation sleeve 8 and the first magnetic isolation sleeve 3. The top plate 1 includes a flat plate and a central column, which are integrally connected. The central column is located at the center of the flat plate. The top plate 1 can move vertically because a magnetorheological elastomer 9 is provided between the third permanent magnet 6 and the fourth permanent magnet 7. One end of the magnetorheological elastomer 9 is fixedly connected to the third permanent magnet 6, and the other end is fixedly connected to the fourth permanent magnet 7. However, because the two sides of the magnetorheological elastomer 9 can deform relative to each other, the central column can move vertically relative to the magnetorheological elastomer 9.

[0025] According to an embodiment of the present invention, the permanent magnet includes a first permanent magnet 4, a second permanent magnet 5, a third permanent magnet 6, and a fourth permanent magnet 7, wherein multiple sets of the first permanent magnet 4, the second permanent magnet 5, the third permanent magnet 6, and the fourth permanent magnet 7 are symmetrically arranged circumferentially along the base plate 2. (The appendix of the present invention...) Figure 2 The illustration shows one embodiment of the present invention, wherein two sets of each of the first permanent magnet 4, second permanent magnet 5, third permanent magnet 6, and fourth permanent magnet 7 are provided, and the first permanent magnet 4, second permanent magnet 5, third permanent magnet 6, and fourth permanent magnet 7 located at one end of the central column and the first permanent magnet 4, second permanent magnet 5, third permanent magnet 6, and fourth permanent magnet 7 at the symmetrical end are all on the same straight line. The first permanent magnet 4 is disposed on the outer wall surface of the second magnetic shielding sleeve 8, and the second permanent magnet 5 is disposed on the inner wall surface of the first magnetic shielding sleeve 8. The vertical heights of the first permanent magnet 4 and the second permanent magnet 5 are the same, and the upper surfaces of the first permanent magnet 4 and the second permanent magnet 5 are located on the same plane. The third permanent magnet 6 is fixedly welded to the inner wall surface of the second magnetic shielding sleeve 8, and the fourth permanent magnet 7 is fixedly welded to the outer wall surface of the central column. The upper surfaces of the third permanent magnet 6 and the fourth permanent magnet 7 are located on the same plane. To ensure the uniformity of the magnetic field strength, the first permanent magnet 4 and the second permanent magnet 5 have the same length, width and height, and the third permanent magnet 6 and the fourth permanent magnet 7 have the same length, width and height. The first permanent magnet 4, the second permanent magnet 5, the third permanent magnet 6, the fourth permanent magnet 7 and the spring 11 are all arranged symmetrically.

[0026] According to an embodiment of the present invention, a magnetorheological elastomer 9 is further disposed between the third permanent magnet 6 and the fourth permanent magnet 7. The magnetorheological elastomer 9 is a smart material with special properties; it is a shear-type magnetorheological elastomer, and its stiffness and damping can be adjusted by an external magnetic field. Changing the magnitude of the magnetic field alters its stiffness. A buffer pad 14 is disposed between the central column and the first magnetic shielding sleeve 3, and the buffer pad 14 is fixedly connected to the inner wall surface of the upper plate of the first magnetic shielding sleeve 3.

[0027] According to an embodiment of the present invention, a sensor 13 is provided on the upper surface of the top plate 1 to detect the vertical vibration of the upper structure. A control system 12 is provided on the first magnetic shielding sleeve 3. The control system 12 includes a controllable AC power supply, a vibration signal collector, and a controller. The controllable AC power supply is electrically connected to the excitation coil 10. The vibration signal collector collects the vibration signals detected by the sensor 13. The controller detects and controls the current input to the excitation coil 10 according to the collected vibration signals.

[0028] According to an embodiment of the present invention, multiple sets of springs 11 are arranged between the second magnetic shielding sleeve 8 and the first magnetic shielding sleeve 3, and are symmetrically arranged in pairs with the center of the central column as the symmetrical point, that is, the number of springs 11 is even. A viscous damper 15 is also fixedly connected between the first magnetic shielding sleeve 3 and the second magnetic shielding sleeve 8. The viscous damper 15 is arranged parallel to the springs 11, and the number of viscous dampers 15 is the same as the number of springs 11.

[0029] The working principle of the three-dimensional vibration isolation device of the present invention is as follows: The magnetorheological elastomer is a shear-type magnetorheological elastomer. The left and right sides of the magnetorheological elastomer can undergo relative shear deformation in the vertical direction. In the initial state, the spring 11 is in its original length state. The main magnetic field direction generated by the third permanent magnet 6 and the fourth permanent magnet 7 is perpendicular to the shear deformation direction. At this time, the vertical shear stiffness of the magnetorheological elastomer 9 is large, and it mainly bears the self-weight of the upper structure. When the upper structure vibrates in multiple directions, in the vertical direction, the vibration signal collector receives the vibration signal detected by the sensor 13. The controller determines the magnitude of the current input to the excitation coil 10 based on the collected vibration signal. The controllable AC power supply flows current into the excitation coil 10, so that the direction of the magnetic field generated by the excitation coil 10 is opposite to the direction of the main magnetic field generated by the third permanent magnet 6 and the fourth permanent magnet 7, thereby reducing the magnitude of the magnetic field at the magnetorheological elastomer 9 and greatly reducing the vertical shear stiffness of the magnetorheological elastomer 9. When the vertical amplitude is too large, the direction of the current is changed so that the direction of the magnetic field generated by the excitation coil 10 is the same as the direction of the main magnetic field generated by the third permanent magnet 6 and the fourth permanent magnet 7, thereby increasing the magnitude of the magnetic field at the magnetorheological elastomer 9 and greatly increasing the vertical shear stiffness of the magnetorheological elastomer 9, which can prevent the device from being damaged. In the horizontal direction, since the diameter of the central column of the top plate 1 is the same as the diameter of the through hole of the second magnetic sleeve 8, the top plate 1 and the second magnetic sleeve 8 move together in the horizontal plane. The spring 11 deforms to provide positive stiffness. At the same time, the distance between the first permanent magnet 4 and the second permanent magnet 5 changes, and the force between the first permanent magnet 4 and the second permanent magnet 5 provides negative stiffness. Quasi-zero stiffness vibration isolation is achieved by connecting positive and negative stiffness in parallel. Meanwhile, the viscous damper 15 can consume energy. When the amplitude is too large, the upper end plate of the first magnetic sleeve 3 can play a limiting role. The buffer pad 14 can prevent the top plate 1 from generating a huge impact force when it collides with the first magnetic sleeve 3.

[0030] According to an embodiment of the present invention, the first permanent magnet 4, the second permanent magnet 5, the third permanent magnet 6, the fourth permanent magnet 7, and the spring 11 can be arranged symmetrically along the circumferential direction of the base plate 2.

[0031] According to an embodiment of the present invention, the magnetorheological elastomer 9 has the same size as the connecting surface of the third permanent magnet 6 and the fourth permanent magnet 7, and the spring 11 is initially in its original length state.

[0032] The installation method of the three-dimensional vibration isolation device of the present invention is as follows: the first magnetic isolation sleeve 3 is divided into an upper plate and a vertical plate and welded together; the second magnetic isolation sleeve 8 is divided into an upper plate, a lower plate, and a vertical plate and welded together; the top plate 1 is divided into a central column and a flat plate and welded together. Holes are pre-drilled in the upper plates of both the first magnetic isolation sleeve 3 and the second magnetic isolation sleeve 8 to connect the excitation coil 10 and the controllable AC power supply. First, the upper plate and the vertical plate of the second magnetic isolation sleeve 8 are welded together. Then, the first permanent magnet 4 and the third permanent magnet 6 are welded to the outer wall and inner wall of the vertical plate of the second magnetic isolation sleeve 8, respectively. The excitation coil 10 is wound around the third permanent magnet 6. Next, the magnetorheological elastomer 9 is welded to the third permanent magnet 6. The fourth permanent magnet 7 and the magnetorheological elastomer 9 are welded together. Finally, the lower end of the central column of the upper plate 1 is connected to the fourth permanent magnet 6. The permanent magnet 7 is welded, then the bottom plate of the second magnetic shielding sleeve 8 is welded to the vertical plate, and then the welded whole is placed on the bottom plate 2. Next, one end of the spring 11 and the viscous damper 15 is welded to the second magnetic shielding sleeve 8, the vertical plate of the first magnetic shielding sleeve 3 is welded to the bottom plate 2, the second permanent magnet 5 is welded to the vertical plate of the first magnetic shielding sleeve 3, and the other end of the spring 11 and the viscous damper 15 is welded to the vertical plate of the first magnetic shielding sleeve 3. Then, the horizontal plate of the first magnetic shielding sleeve 3 is welded to the buffer pad 14, and then the horizontal plate and the vertical plate of the first magnetic shielding sleeve 3 are welded. Next, the flat plate of the top plate 1 and the center column are welded. Finally, the control system 13 and the sensor 12 are installed, and the excitation coil 10 is connected to the control system 13.

[0033] According to an embodiment of the present invention, the first permanent magnet 4, the second permanent magnet 5, the third permanent magnet 6 and the fourth permanent magnet 7 are all neodymium magnets, samarium cobalt magnets or other high-performance permanent magnets, the magnetorheological elastomer 9 is doped with carbon black, carbonyl iron powder or other materials that can improve the mechanical properties of the magnetorheological elastomer, and the first magnetic shielding sleeve 3 and the second magnetic shielding sleeve 8 are made of nickel-iron alloy, cobalt-iron alloy or other metal materials with good magnetic shielding properties.

[0034] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0035] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0036] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

Claims

1. A three-dimensional vibration isolation device, characterized in that, The device includes a base plate, a top plate, a permanent magnet, a spring, and a magnetic shielding sleeve. The base plate is provided with the top plate and the magnetic shielding sleeve in sequence from the center of the base plate to the outer edge of the base plate. The magnetic shielding sleeve includes a first magnetic shielding sleeve and a second magnetic shielding sleeve. The second magnetic shielding sleeve is slidably connected to the base plate. The permanent magnet is disposed between the first magnetic shielding sleeve and the top plate. The spring is connected between the first magnetic shielding sleeve and the second magnetic shielding sleeve. The top plate includes a flat plate and a central column, which are integrally connected. The central column is located at the center of the flat plate, and the top plate can move vertically up and down. The permanent magnet includes a first permanent magnet, a second permanent magnet, a third permanent magnet, and a fourth permanent magnet, with multiple sets of each type symmetrically arranged around the bottom plate. The first permanent magnet is fixed to the outer wall of the second magnetic shielding sleeve, and the second permanent magnet is fixed to the inner wall of the first magnetic shielding sleeve. The first and second permanent magnets have the same vertical height, and their upper surfaces are on the same plane. The third permanent magnet is fixed to the inner wall of the second magnetic shielding sleeve, and the fourth permanent magnet is fixed to the outer wall of the central column. The upper surfaces of the magnet and the fourth permanent magnet are located on the same plane; a magnetorheological elastomer is also provided between the third and fourth permanent magnets, one end of which is fixedly connected to the third permanent magnet and the other end is fixedly connected to the fourth permanent magnet. The magnetorheological elastomer is a shear-type magnetorheological elastomer. An excitation coil is wound on the third permanent magnet; a sensor is provided on the upper surface of the top plate to detect the vertical vibration of the upper structure; a control system is provided on the first magnetic shielding sleeve, the control system includes a controllable AC power supply, a vibration signal collector, and a controller. The controllable AC power supply is electrically connected to the excitation coil, the vibration signal collector collects the vibration signals detected by the sensor, and the controller detects and controls the current input to the excitation coil based on the collected vibration signals.

2. The three-dimensional vibration isolation device according to claim 1, characterized in that, A buffer pad is provided between the central column and the first magnetic shielding sleeve, and the buffer pad is fixedly connected to the first magnetic shielding sleeve.

3. The three-dimensional vibration isolation device according to claim 1, characterized in that, Multiple sets of springs are provided between the first and second magnetic shielding sleeves. A viscous damper is also connected between the first and second magnetic shielding sleeves, and the viscous damper is arranged parallel to the spring.

4. The three-dimensional vibration isolation device according to claim 1, characterized in that, The first, second, third, and fourth permanent magnets are all neodymium magnets or samarium cobalt magnets. The magnetorheological elastomer is a material doped with carbon black or carbonyl iron powder. The first and second magnetic shielding sleeves are made of nickel-iron alloy or cobalt-iron alloy materials.

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