A desktop quasi-zero stiffness three-degree-of-freedom vibration isolator

Abstract

The application provides a desktop quasi-zero stiffness three-degree-of-freedom vibration isolator, which comprises a table top, a vibration isolator and a bottom plate, the table top comprises an upper panel and a lower panel, a rubber plate is arranged between the upper panel and the lower panel, four corners of the top of the bottom plate are respectively provided with the vibration isolators, the top of the vibration isolator is connected with the bottom of the four corners of the lower panel, the bottom of the lower panel is provided with a support frame body, the middle top of the bottom plate is provided with a negative stiffness device in the middle bottom of the support frame body, the bottom of the upper panel is further provided with a vertical acceleration sensor, a vertical position sensor, a lateral acceleration sensor and a lateral position sensor, and the bottom plate is further provided with a controller. The application has the adjustment ability of stiffness, can meet the vibration reduction demand of super-low frequency equipment through multi-stage vibration reduction, can realize three-degree-of-freedom vibration reduction ability, can be suitable for different types of precision instruments, has wide application range and strong universality.

Description

Technical Field

[0001] This invention relates to the field of vibration isolation device technology, specifically a desktop quasi-zero stiffness three-degree-of-freedom vibration isolator. Background Technology

[0002] Vibration, especially low-frequency vibration, significantly interferes with experimental equipment such as electron microscopes and laser interferometers. In the use of electron microscopes, due to their high resolution and image processing capabilities, they are easily affected by environmental factors, and beam control is a key component affecting resolution and image quality. Low-frequency ground vibrations can affect image quality, thus limiting their magnification efficiency. These environmental problems can lead to periods when microscopes cannot be used.

[0003] Currently, desktop vibration isolation platforms are mainly used to achieve vibration reduction. However, traditional desktop vibration isolation platforms usually use air springs or air-bearing vibration isolation methods to achieve vibration reduction. Although they have a certain vibration reduction effect, they require an external air source, have a narrow range of applications, and cannot meet the requirements for vibration reduction of ultra-low frequency vibrations. They also have a narrow vibration isolation band and poor positioning effect. Summary of the Invention

[0004] The purpose of this invention is to provide a desktop quasi-zero stiffness three-degree-of-freedom vibration isolator to solve the problems existing in the background art.

[0005] The technical solution of this invention is implemented as follows: A desktop quasi-zero stiffness three-degree-of-freedom vibration isolator includes a tabletop, vibration isolators, and a base plate. The tabletop includes an upper panel and a lower panel, with a rubber plate between the upper and lower panels. Vibration isolators are installed at the four corners of the top of the base plate, and the tops of the vibration isolators are connected to the bottoms of the four corners of the lower panel. A support frame is installed at the bottom of the lower panel. A negative stiffness device is installed between the top of the base plate and the bottom of the support frame. The vibration isolator includes a top plate, a base, a partition plate, and a first spring. An opening is formed in the middle of the partition plate, and the first spring passes through the opening and is perpendicularly connected to the middle of the bottom of the top plate and the middle of the top of the base. A second spring is installed on both sides of the first spring and between the partition plate and the base. Two springs are installed on both sides of the first spring and between the partition and the top plate. Connecting plates are installed on both sides of the bottom of the top plate. A vertical voice coil motor is installed between the bottom of the connecting plate and the base. A horizontal voice coil motor is installed on the other two sides of the bottom of the top plate. The horizontal voice coil motors are connected and fixed to the base by vertical plates. A vertical acceleration sensor, a vertical position sensor, a horizontal acceleration sensor, and a horizontal position sensor are also installed on the bottom of the top plate. The negative stiffness device includes an upper pad, a lower pad, and a negative stiffness voice coil motor. Connecting blocks are installed on the left and right sides of the bottom of the upper pad. A negative stiffness voice coil motor is installed between the bottom of the connecting blocks and the lower pad. A controller is also installed on the base plate.

[0006] Furthermore, both the tabletop and the base plate are rectangular in structure.

[0007] Furthermore, a rectangular hole is provided in the center of the platform.

[0008] Furthermore, the support frame includes a support plate, and four rectangular frames are installed around the support plate, so that the support frame as a whole has a "cross" shaped structure.

[0009] Furthermore, the vibration isolator is installed on the same diagonal of the base plate, and the driving direction of the transverse voice coil motor is the front-to-back direction, while the driving direction of the transverse voice coil motor on the other diagonal is the left-to-right direction.

[0010] Furthermore, the vibration isolator is fixed to the lower panel and the base plate by bolts.

[0011] Furthermore, the negative stiffness device is fixed to the support plate and the base plate by bolts.

[0012] Furthermore, both the support frame and the lower panel are magnetic shielding plates.

[0013] Furthermore, the first spring, the second spring, and the third spring are all metal springs.

[0014] Furthermore, the controller is connected to the vertical acceleration sensor, the vertical position sensor, the lateral acceleration sensor, the lateral position sensor, the vertical voice coil motor, the lateral voice coil motor, and the negative stiffness voice coil motor via cables.

[0015] This invention achieves load-bearing through four metal springs and stiffness adjustment through two parallel negative stiffness voice coil motors, so that the system reaches static near-zero stiffness at the initial equilibrium position.

[0016] This invention achieves first vibration reduction for vertical high-frequency vibration sources through a rubber plate and second vibration reduction through a series structure of a second and third spring, enabling the system to reduce vibration at higher vertical frequencies. For vertical low-frequency vibration sources and horizontal vibration sources, vibration reduction is achieved through a voice coil motor. The system has a wide vibration isolation band and precise positioning, and can achieve vibration control from 0.1Hz to 200Hz.

[0017] This invention has the ability to adjust stiffness, and the multi-stage vibration reduction can meet the vibration reduction requirements of ultra-low frequency equipment. It can achieve three-degree-of-freedom vibration reduction capability, and can be adapted to different types of precision instruments. It has a wide range of applications and strong versatility. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the present invention.

[0019] Figure 2 This is an exploded view of the structure of the present invention.

[0020] Figure 3 This is a schematic diagram of the vibration isolator structure of the present invention.

[0021] Figure 4 This is a schematic diagram of the negative stiffness device of the present invention.

[0022] In the diagram, 1-tabletop, 101-upper panel, 102-rubber plate, 103-lower panel, 104-rectangular hole, 2-vibration isolator, 201-top plate, 202-base, 203-partition, 204-first spring, 205-opening, 206-second spring, 207-third spring, 208-connecting plate, 209-vertical voice coil motor, 210-vertical plate, 211-horizontal voice coil motor, 212-vertical acceleration sensor, 213-vertical position sensor, 214-horizontal acceleration sensor, 215-horizontal position sensor, 3-base plate, 4-support frame, 401-support plate, 402-rectangular frame, 5-controller, 6-negative stiffness device, 601-upper pad, 602-lower pad, 603-connecting block, 604-negative stiffness voice coil motor. Detailed Implementation

[0023] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0024] like Figure 1-4As shown, a desktop quasi-zero stiffness three-degree-of-freedom vibration isolator includes a tabletop 1, vibration isolators 2, and a base plate 3. The tabletop 1 includes an upper panel 101 and a lower panel 103, with a rubber plate 102 between the upper panel 101 and the lower panel 103. Vibration isolators 2 are installed at the four corners of the top of the base plate 3, and the top of each vibration isolator 2 is connected to the bottom of the four corners of the lower panel 103. A support frame 4 is installed at the bottom of the lower panel 103. A negative stiffness device 6 is installed between the top of the base plate 3 and the bottom of the support frame 4. The vibration isolator 2 includes a top plate 201, a base 202, a partition 203, and a first spring 204. An opening 205 is provided in the middle of the partition 203. The first spring 204 passes through the opening 205 and is perpendicularly connected to the middle of the bottom of the top plate 201 and the middle of the top of the base 202. Second springs 206 are installed on both sides of the first spring 204 and between the partition 203 and the base 202. A third spring 207 is installed on both sides of the top plate 201 and between the partition plate 203 and the top plate 201. A connecting plate 208 is installed on both sides of the bottom of the top plate 201. A vertical voice coil motor 209 is installed between the bottom of the connecting plate 208 and the base 202. A horizontal voice coil motor 211 is installed on the other two sides of the bottom of the top plate 201. The horizontal voice coil motor 211 is connected and fixed to the base 202 by a vertical plate 210. A vertical acceleration sensor 212, a vertical position sensor 213, a horizontal acceleration sensor 214, and a horizontal position sensor 215 are also installed on the bottom of the top plate 201. The negative stiffness device 6 includes an upper pad 601, a lower pad 602, and a negative stiffness voice coil motor 604. A connecting block 603 is installed on the left and right sides of the bottom of the upper pad 601. A negative stiffness voice coil motor 604 is installed between the bottom of the connecting block 603 and the lower pad 602. A controller 5 is also installed on the bottom plate 3.

[0025] Both the tabletop 1 and the base plate 3 are rectangular in shape.

[0026] A rectangular hole 104 is provided in the middle of the tabletop 1.

[0027] The support frame 4 includes a support plate 401, and four rectangular frames 402 are installed around the support plate 401. The support frame 4 has an overall "cross" shaped structure.

[0028] The vibration isolator 2 is installed on the base plate 3. The horizontal voice coil motor 211 on the same diagonal is driven in the front-to-back direction, and the horizontal voice coil motor 211 on the other diagonal is driven in the left-to-right direction.

[0029] The vibration isolator 2 is bolted to the lower panel 103 and the base plate 3, which facilitates disassembly, maintenance and repair.

[0030] The negative stiffness device 6 is bolted to the support plate 401 and the base plate 3, which facilitates disassembly, maintenance and repair.

[0031] Both the support frame 4 and the lower panel 103 are magnetic shielding plates.

[0032] The first spring 204, the second spring 206, and the third spring 207 are all metal springs.

[0033] The controller 5 is connected to the vertical acceleration sensor 212, the vertical position sensor 213, the lateral acceleration sensor 214, the lateral position sensor 215, the vertical voice coil motor 209, the lateral voice coil motor 211, and the negative stiffness voice coil motor 604 via cables.

[0034] During installation, the precision instrument is placed on the table 1, and the weight is borne by the four first springs 204 of the vibration isolator 2. Then, the controller 5 controls the two negative stiffness voice coil motors 604 of the negative stiffness device 6 to drive in different directions, such as up and down, to adjust the positive and negative stiffness of the system, so that the system reaches static quasi-zero stiffness in the initial equilibrium position.

[0035] During operation, vibration signals are collected by the vertical acceleration sensor 212, vertical position sensor 213, lateral acceleration sensor 214, and lateral position sensor 215, and then transmitted to the controller 5. For vertical high-frequency vibration sources, the rubber plate 102 first reduces vibration, and then the series structure of the second spring 206 and the third spring 207 reduces vibration a second time. For vertical low-frequency vibration sources, the controller 5 controls the vertical voice coil motor 209 of the vibration isolator 2 to reduce vibration. For horizontal left-right vibration sources, the controller 5 controls the diagonally driven horizontal voice coil motor 211 of the vibration isolator 2 to reduce vibration. For horizontal front-back vibration sources, the controller 5 controls the diagonally driven front-back horizontal voice coil motor 211 of the vibration isolator 2 to reduce vibration.

[0036] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A desktop quasi-zero stiffness three-degree-of-freedom vibration isolator, comprising a tabletop, the isolator, and a base plate, characterized in that, The platform includes a top panel and a bottom panel, with a rubber sheet between them. Vibration isolators are installed at the four corners of the top of the bottom panel, with the top of each isolator connected to the bottom of the four corners of the bottom panel. A support frame is installed at the bottom of the bottom panel. A negative stiffness device is installed between the top of the bottom panel and the bottom of the support frame. Each vibration isolator includes a top plate, a base, a partition plate, and a first spring. An opening is formed in the center of the partition plate, through which the first spring passes perpendicularly to the center of the bottom of the top plate and the center of the top of the base. Second springs are installed on both sides of the first spring and between the partition plate and the base. A third spring is installed. Connecting plates are installed on both sides of the bottom of the top plate. A vertical voice coil motor is installed between the bottom of the connecting plate and the base. A horizontal voice coil motor is installed on the other two sides of the bottom of the top plate. The horizontal voice coil motor is connected and fixed to the base by a vertical plate. A vertical acceleration sensor, a vertical position sensor, a horizontal acceleration sensor, and a horizontal position sensor are also installed on the bottom of the top plate. The negative stiffness device includes an upper pad, a lower pad, and a negative stiffness voice coil motor. Connecting blocks are installed on the left and right sides of the bottom of the upper pad. A negative stiffness voice coil motor is installed between the bottom of the connecting blocks and the lower pad. A controller is also installed on the base plate. The vibration isolator is installed on the same diagonal of the base plate. The driving direction of the horizontal voice coil motor is the front-to-back direction, and the driving direction of the horizontal voice coil motor on the other diagonal is the left-to-right direction. During installation, the precision instrument is placed on the table. The four first springs of the vibration isolator provide positive stiffness by bearing the weight. Then, the controller controls the two negative stiffness voice coil motors of the negative stiffness device to drive in different directions (up and down) to provide negative stiffness, thereby adjusting the positive and negative stiffness of the system so that the system reaches static quasi-zero stiffness at the initial equilibrium position. At this time, the second and third springs are in a natural extension and contraction state and are not under force. During operation, vibration signals are collected by a vertical acceleration sensor, a vertical position sensor, a lateral acceleration sensor, and a lateral position sensor, and then the signals are transmitted to the controller. When there is a vertical vibration source, the first vibration reduction is achieved through the rubber plate, and the second vibration reduction is achieved through the series structure composed of the second and third springs, thus achieving high-frequency vibration reduction; the vertical voice coil motor of the vibration isolator is controlled by the controller to achieve low-frequency vibration reduction; When there is a horizontal vibration source, the transverse voice coil motor of the vibration isolator is controlled by the controller to achieve horizontal vibration reduction in the forward, backward, left and right directions.

2. The desktop quasi-zero stiffness three-degree-of-freedom vibration isolator according to claim 1, characterized in that, Both the tabletop and the base plate are rectangular in shape.

3. A desktop quasi-zero stiffness three-degree-of-freedom vibration isolator according to claim 1, characterized in that, A rectangular hole is provided in the center of the platform.

4. A desktop quasi-zero stiffness three-degree-of-freedom vibration isolator according to claim 1, characterized in that, The support frame includes a support plate, and four rectangular frames are installed around the support plate. The support frame has an overall "cross" shaped structure.

5. A desktop quasi-zero stiffness three-degree-of-freedom vibration isolator according to claim 1, characterized in that, The vibration isolator is fixed to the lower panel and the base plate by bolts.

6. A desktop quasi-zero stiffness three-degree-of-freedom vibration isolator according to claim 1, characterized in that, The negative stiffness device is fixed to the support plate and the base plate by bolts.

7. A desktop quasi-zero stiffness three-degree-of-freedom vibration isolator according to claim 1, characterized in that, Both the support frame and the lower panel are magnetic shielding plates.

8. A desktop quasi-zero stiffness three-degree-of-freedom vibration isolator according to claim 1, characterized in that, The first spring, the second spring, and the third spring are all metal springs.

9. A desktop quasi-zero stiffness three-degree-of-freedom vibration isolator according to claim 1, characterized in that, The controller is connected to the vertical acceleration sensor, vertical position sensor, lateral acceleration sensor, lateral position sensor, vertical voice coil motor, lateral voice coil motor, and negative stiffness voice coil motor via cables.

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