A three-degree-of-freedom quasi-zero stiffness ultra-low frequency vibration isolator based on magnetic-spring

Abstract

The present invention provides a three-degree-of-freedom quasi-zero stiffness ultra-low frequency vibration isolator based on a magnetic spring, comprising a top plate, a base, a vertical rod and an air spring, wherein the air spring is installed in the middle of the top of the base, and the vertical rods are four and respectively installed in the middle of the four sides of the top of the base, a support rod A is vertically installed in the middle of the bottom of the top plate, a ball joint A is installed at the bottom of the support rod A, a guide rod is installed at the bottom of the ball joint A, the top of the piston is vertically connected to the bottom of the guide rod, a metal spring A connected to the base is sleeved on the lower part of the vertical rod, a slider is installed on the top of the metal spring A and the vertical rod, a metal spring B is installed between the slider and the side of the air spring, and a metal spring C is respectively installed between the four side surfaces of the upper part of the guide rod and the vertical rod. The present invention can achieve quasi-zero stiffness in the three degrees of freedom in the vertical and horizontal directions, the system vibration isolation band is wide, vibration control of 0.1Hz~200Hz can be achieved, and the load-bearing requirement of 5000kg can be met.

Description

Technical Field

[0001] The invention relates to the technical field of vibration isolation devices, in particular to a quasi-zero stiffness ultra-low frequency vibration isolator based on a magnet-spring three-degree-of-freedom. Background Art

[0002] At present, the semiconductor industry is developing rapidly. The precision requirements of semiconductor production equipment are getting higher and higher, and the equipment is becoming more and more sensitive to environmental requirements such as micro-vibration. A small amount of micro-vibration will reduce the output yield of the equipment or even make the equipment unable to work normally. Therefore, the isolation of micro-vibration is becoming more and more important.

[0003] Quasi-zero stiffness isolator is a combination isolator that connects positive and negative stiffness elastic components in parallel at a static equilibrium position to obtain zero stiffness. This type of isolator has a large static stiffness and can bear the weight of the isolated equipment. When the equipment vibrates at a static equilibrium position, the stiffness is very low, or even approaches zero, which is conducive to low-frequency vibration isolation. Most quasi-zero stiffness isolators are designed for a single vibration isolation object. Once the isolator is manufactured, the structural parameters cannot be changed. Therefore, when the vibration isolation mass changes, such as overload or underload, the isolator no longer has the quasi-zero stiffness characteristic, the vibration isolation performance decreases, and the effect is even worse than that of the linear vibration isolation system, which greatly limits its application range. A small number of isolators can still have quasi-zero stiffness characteristics under variable loads, but the vibration isolation mass cannot change continuously. The isolator can only maintain quasi-zero stiffness at several specific masses, with a small scope of application, and generally cannot meet the vibration isolation requirements of large loads. In addition, at present, most quasi-zero stiffness isolators can achieve quasi-zero stiffness for a single vertical degree of freedom, and cannot achieve quasi-zero stiffness for multiple degrees of freedom. Summary of the invention

[0004] The object of the present invention is to provide a three-degree-of-freedom quasi-zero stiffness ultra-low frequency vibration isolator based on a magnet-spring to solve the problems existing in the above-mentioned background technology.

[0005] The technical solution of the present invention is achieved as follows: a three-degree-of-freedom quasi-zero stiffness ultra-low frequency vibration isolator based on a magnetic-spring, comprising a top plate, a base, a vertical rod and an air spring, wherein the air spring is installed in the middle of the top of the base, and the vertical rods are four and respectively installed in the middle of the four sides of the top of the base, a support rod A is vertically installed in the middle of the bottom of the top plate, a ball joint A is installed at the bottom of the support rod A, a guide rod is installed at the bottom of the ball joint A, the guide rod vertically penetrates into the interior of the air spring, a piston is installed inside the air spring, the top of the piston is vertically connected to the bottom of the guide rod, a metal spring A connected to the base is sleeved on the lower part of the vertical rod, a slider is installed on the top of the metal spring A and on the vertical rod, a metal spring B is installed between the slider and the side of the air spring, a metal spring C is respectively installed between the four side surfaces of the upper part of the guide rod and the vertical rod, a telescopic rod is also installed between the metal spring C and the vertical rod, and a metal spring C is installed below the metal spring C and on the four guide rods. Leaf springs A are respectively installed between the periphery and the vertical rod, a support rod is vertically installed on the inner side of the upper part of the vertical rod, an electromagnet is installed on the top of the support rod, a permanent magnet is installed at the lower part of the support rod A horizontally opposite to the electromagnet, a leaf spring B is vertically installed between the top plate and the slider, a support rod B is also vertically installed between the outer side of the top of the slider and the top plate, a ball joint B is also installed between the support rod B and the top plate, a vertical voice coil motor is installed between the top of the vertical rod and the top plate, a support block is installed on the top of the support rod, and a horizontal voice coil motor is installed between the support block and the support rod A, a vertical acceleration sensor, a horizontal left and right acceleration sensor, a horizontal front and back acceleration sensor, a vertical position sensor, a horizontal left and right position sensor, and a horizontal front and back position sensor are also installed at the bottom of the top plate, a controller is installed on the top of the base, an air intake pipe is opened on one side of the air spring, and a servo valve is installed on the air intake pipe.

[0006] Furthermore, a linear bearing is installed at the connection portion between the guide rod and the air spring, and the guide rod vertically passes through the linear bearing.

[0007] Furthermore, hinges A are respectively installed at the connection parts between the metal spring B and the slider and the air spring.

[0008] Furthermore, hinges B are respectively installed at the connection positions between the metal spring C and the guide rod and the telescopic rod.

[0009] Furthermore, a locking device is installed on the telescopic rod.

[0010] Furthermore, a limiting device A is installed above the slider and on the vertical rod.

[0011] Furthermore, a limiting device B is installed at the bottom of the support block.

[0012] Furthermore, the controller is connected to the electromagnet, the vertical voice coil motor, the horizontal voice coil motor, the vertical acceleration sensor, the horizontal left and right acceleration sensor, the horizontal front and back acceleration sensor, the vertical position sensor, the horizontal left and right position sensor, and the horizontal front and back position sensor through cables.

[0013] The beneficial effects of the present invention are: The present invention provides vertical positive stiffness through air springs in the vertical direction, provides vertical negative stiffness through four metal springs C, and realizes negative stiffness adjustment through four groups of magnetic devices in the horizontal direction, so that the system can realize quasi-zero stiffness in three degrees of freedom in the vertical and horizontal directions when in static balance.

[0014] When the present invention uses a vertical high-frequency vibration source, firstly, an air spring is passed to realize the first vertical high-frequency vibration reduction, and then the second vertical high-frequency vibration reduction is realized by metal spring A, the third vertical high-frequency vibration reduction is realized by metal spring B, and the fourth vibration reduction is realized by leaf spring A; when the present invention uses a horizontal high-frequency vibration source, high-frequency vibration reduction is realized by leaf spring B; when the present invention uses a vertical low-frequency vibration source, vertical low-frequency vibration reduction is realized by controlling four vertical voice coil motors through a controller; when the present invention uses a horizontal low-frequency vibration source, horizontal low-frequency vibration reduction is realized by controlling four horizontal voice coil motors through a controller.

[0015] The present invention can achieve quasi-zero stiffness in three degrees of freedom in the vertical and horizontal directions. The system has a wide vibration isolation band and can achieve vibration control of 0.1Hz~200Hz. The system has large static stiffness and bearing capacity, which can meet the load-bearing requirements of 5000kg precision instruments. It also has high positioning accuracy and the ability to adjust bearing capacity and stiffness. It can be adapted to precision instruments of different models, has a wide range of applications, and is highly versatile. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the structure of the present invention.

[0017] In the figure, 1-top plate, 2-base, 3-vertical rod, 4-air spring, 401-piston, 402-linear bearing, 403-intake pipe, 404-servo valve, 5-support rod A, 6-ball joint A, 7-guide rod, 8-metal spring A, 9-slider, 10-metal spring B, 11-metal spring C, 12-telescopic rod, 13-leaf spring A, 14-support rod, 15-electromagnet, 16-permanent magnet, 17-leaf spring B, 18-support rod B, 19-ball Hinge B, 20-vertical voice coil motor, 21-support block, 22-horizontal voice coil motor, 23-hinge A, 24-locking device, 25-hinge B, 26-vertical acceleration sensor, 27-horizontal left and right acceleration sensor, 28-horizontal front and back acceleration sensor, 29-vertical position sensor, 30-horizontal left and right position sensor, 31-horizontal front and back position sensor, 32-controller, 33-limit device A, 34-limit device B. DETAILED DESCRIPTION

[0018] The technical solution of the present invention will be described clearly and completely in conjunction with the embodiments below. Obviously, the embodiments described 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 creative work are within the scope of protection of the present invention.

[0019] like Figure 1As shown, a three-degree-of-freedom quasi-zero stiffness ultra-low frequency vibration isolator based on a magnetic-spring comprises a top plate 1, a base 2, a vertical rod 3 and an air spring 4, wherein the air spring 4 is installed in the middle of the top of the base 2, and the vertical rods 3 are four and are respectively installed in the middle of the four sides of the top of the base 2, a support rod A5 is vertically installed in the middle of the bottom of the top plate 1, a ball joint A6 is installed at the bottom of the support rod A5, a guide rod 7 is installed at the bottom of the ball joint A6, and the guide rod 7 vertically penetrates into the interior of the air spring 4, and a piston 401 is installed in the interior of the air spring 4. The top of the plug 401 is vertically connected to the bottom of the guide rod 7. The lower part of the vertical rod 3 is covered with a metal spring A8 connected to the base 3. A slider 9 is installed on the top of the metal spring A8 and the vertical rod 3. A metal spring B10 is installed between the slider 9 and the side of the air spring 4. Metal springs C11 are installed between the four sides of the upper part of the guide rod 7 and the vertical rod 3. A telescopic rod 12 is also installed between the metal spring C11 and the vertical rod 3. Leaf springs A are installed below the metal spring C11 and around the guide rod 7 and the vertical rod 3. 13, a support rod 14 is vertically installed on the inner side of the upper part of the vertical rod 3, an electromagnet 15 is installed on the top of the support rod 14, a permanent magnet 46 is installed at the lower part of the support rod A5 and the electromagnet 15, a leaf spring B17 is vertically installed between the top plate 1 and the slider 9, a support rod B18 is also vertically installed between the top outer side of the slider 9 and the top plate 1, a ball joint B19 is also installed between the support rod B18 and the top plate 1, a vertical voice coil motor 20 is installed between the top of the vertical rod 3 and the top plate 1, and the top of the support rod 14 is installed. A support block 21 is installed, and a horizontal voice coil motor 22 is installed between the support block 21 and the support rod A5. A vertical acceleration sensor 26, a horizontal left and right acceleration sensor 27, a horizontal front and back acceleration sensor 28, a vertical position sensor 29, a horizontal left and right position sensor 30, and a horizontal front and back position sensor 31 are also installed at the bottom of the top plate 1. A controller 32 is installed on the top of the base 2. An air intake pipe 103 is opened on one side of the air spring 4, and a servo valve 404 is installed on the air intake pipe 403.

[0020] A linear bearing 402 is installed at the connection portion between the guide rod 7 and the air spring 4 , and the guide rod 7 vertically passes through the linear bearing 402 .

[0021] Hinges A23 are installed at the connection positions between the metal spring B10 and the slider 9 and the air spring 4 respectively.

[0022] Hinges B25 are installed at the connection positions between the metal spring C11 and the guide rod 7 and the telescopic rod 12 respectively.

[0023] The telescopic rod 12 is provided with a locking device 25 .

[0024] A limiting device A33 is installed above the sliding block 9 and on the vertical rod 3 .

[0025] A limiting device B34 is installed at the bottom of the support block 21.

[0026] The controller 32 is connected to the electromagnet 15, the vertical voice coil motor 20, the horizontal voice coil motor 22, the vertical acceleration sensor 26, the horizontal left and right acceleration sensor 27, the horizontal front and back acceleration sensor 28, the vertical position sensor 29, the horizontal left and right position sensor 30, and the horizontal front and back position sensor 31 through cables.

[0027] During installation, the precision instrument is placed on the top plate 1, and then the air pressure of the air spring 4 is controlled by adjusting the servo valve 404 according to the weight of the precision instrument to ensure that the load-bearing requirements can be met and the system can be provided with positive stiffness in the vertical direction. By adjusting the air pressure of the air spring 4, the vertical positive stiffness of the system is adjusted. The metal spring C11 around the guide rod 7 provides the system with vertical negative stiffness, and the length of the telescopic rod 12 is adjusted through the locking device 24 to adjust the compression of the metal spring C11, thereby adjusting the vertical negative stiffness of the system. At the same time, the controller 32 The current of the electromagnet 15 is controlled, thereby controlling the strength of the electromagnetic field it generates, and then controlling the attraction between the electromagnet 15 and the permanent magnet 16, and then controlling the negative stiffness of the system in the horizontal left-right direction and the horizontal front-back direction. At this time, it is ensured that the metal spring B10 and the metal spring C11 are in a horizontal position without tilt when the system is in initial static equilibrium. The metal spring A8, the metal spring B10, and the metal spring C11 are all in a natural expansion and contraction state. At this time, when the system is in the initial static equilibrium position, the static quasi-zero stiffness is achieved in the three degrees of freedom in the vertical and horizontal directions.

[0028] During operation, vibration signals are collected through the vertical acceleration sensor 26, the horizontal left and right acceleration sensor 27, the horizontal front and back acceleration sensor 28, the vertical position sensor 29, the horizontal left and right position sensor 30, and the horizontal front and back position sensor 31, and then the signals are transmitted to the controller 32; when it is a vertical high-frequency vibration source, firstly, the air spring 4 is passed to realize the first vertical high-frequency vibration reduction, and then the second vertical high-frequency vibration reduction is realized by the metal spring A8, the third vertical high-frequency vibration reduction is realized by the metal spring B10, and the fourth vibration reduction is realized by the leaf spring A13; when it is a horizontal high-frequency vibration source, high-frequency vibration reduction is realized by the leaf spring B17; when it is a vertical low-frequency vibration source, the four vertical voice coil motors 20 are controlled by the controller 32 to realize vertical low-frequency vibration reduction; when it is a horizontal low-frequency vibration source, the four horizontal voice coil motors 22 are controlled by the controller 32 to realize horizontal low-frequency vibration reduction.

[0029] 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 principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A three-degree-of-freedom quasi-zero stiffness ultra-low frequency vibration isolator based on a magnetic-spring, comprising a top plate, a base, a vertical rod and an air spring, characterized in that: The air spring is installed in the middle of the top of the base, and the four vertical rods are respectively installed in the middle of the four sides of the top of the base, a support rod A is vertically installed in the middle of the bottom of the top plate, a ball joint A is installed at the bottom of the support rod A, and a guide rod is installed at the bottom of the ball joint A, and the guide rod vertically penetrates into the air spring, and a piston is installed inside the air spring, and the top of the piston is vertically connected to the bottom of the guide rod, and a metal spring A connected to the base is sleeved on the lower part of the vertical rod, a slider is installed on the top of the metal spring A and the vertical rod, and a metal spring B is installed between the slider and the side of the air spring, and metal springs C are respectively installed between the four side surfaces of the upper part of the guide rod and the vertical rod, and a telescopic rod is also installed between the metal spring C and the vertical rod, and a leaf spring A is respectively installed below the metal spring C and between the four sides of the guide rod and the vertical rod. A support rod is installed, an electromagnet is installed on the top of the support rod, a permanent magnet is installed at the lower part of the support rod A at a position horizontally opposite to the electromagnet, a leaf spring B is vertically installed between the top plate and the slider, a support rod B is also vertically installed between the outer side of the top of the slider and the top plate, a ball joint B is also installed between the support rod B and the top plate, a vertical voice coil motor is installed between the top of the vertical rod and the top plate, a support block is installed on the top of the support rod, a horizontal voice coil motor is installed between the support block and the support rod A, a vertical acceleration sensor, a horizontal left and right acceleration sensor, a horizontal front and back acceleration sensor, a vertical position sensor, a horizontal left and right position sensor, and a horizontal front and back position sensor are also installed at the bottom of the top plate, a controller is installed on the top of the base, an air intake pipe is opened on one side of the air spring, and a servo valve is installed on the air intake pipe.

2. According to claim 1, a three-degree-of-freedom quasi-zero stiffness ultra-low frequency vibration isolator based on a magnetic-spring is characterized in that: A linear bearing is installed at the connection position between the guide rod and the air spring, and the guide rod vertically passes through the linear bearing.

3. The three-degree-of-freedom quasi-zero stiffness ultra-low frequency vibration isolator based on a magnet-spring according to claim 1, characterized in that: Hinges A are respectively installed at the connection positions between the metal spring B, the slider and the air spring.

4. The three-degree-of-freedom quasi-zero stiffness ultra-low frequency vibration isolator based on a magnet-spring according to claim 1, characterized in that: Hinges B are respectively installed at the connection positions between the metal spring C and the guide rod and the telescopic rod.

5. The three-degree-of-freedom quasi-zero stiffness ultra-low frequency vibration isolator based on a magnet-spring according to claim 1, characterized in that: A locking device is installed on the telescopic rod.

6. The three-degree-of-freedom quasi-zero stiffness ultra-low frequency vibration isolator based on a magnet-spring according to claim 1, characterized in that: A limiting device A is installed above the sliding block and on the vertical rod.

7. The three-degree-of-freedom quasi-zero stiffness ultra-low frequency vibration isolator based on a magnet-spring according to claim 1, characterized in that: A limiting device B is installed at the bottom of the support block.

8. The three-degree-of-freedom quasi-zero stiffness ultra-low frequency vibration isolator based on magnet-spring according to claim 1, characterized in that: The controller is connected to the electromagnet, the vertical voice coil motor, the horizontal voice coil motor, the vertical acceleration sensor, the horizontal left and right acceleration sensor, the horizontal front and back acceleration sensor, the vertical position sensor, the horizontal left and right position sensor, and the horizontal front and back position sensor through cables.

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