A variable stiffness anti-vibration device based on magnetofluid.

Abstract

This invention provides a variable stiffness anti-vibration device based on magnetofluid, comprising a shell, a support rod, a top plate, a first magnetofluid, and a first electromagnetic coil. The support rod is vertically and movably connected to the middle of the top of the shell. The top of the support rod is vertically connected to the middle of the bottom of the top plate. A metal spring is installed on the outer side of the support rod, between the bottom of the top plate and the top of the shell. A piston is vertically connected to the bottom of the support rod. A partition is horizontally installed on the lower inner side of the shell. The piston and the partition form a first chamber, the partition and the bottom inner side of the shell form a second chamber, and a third chamber is installed around the perimeter of the shell. This system can achieve vibration control from 0.2Hz to 250Hz, with high positioning accuracy and high load-bearing capacity, meeting the load requirements of 3000kg precision instruments. It also has stiffness adjustment capabilities, making it adaptable to different types of precision instruments, with a wide range of applications and strong versatility.

Description

Technical Field

[0001] This invention relates to the field of semiconductor-specific devices technology, specifically a variable stiffness anti-vibration device based on magnetic fluid. Background Technology

[0002] The semiconductor industry is developing rapidly, and the precision requirements of semiconductor production equipment are getting higher and higher. The equipment is also becoming more and more sensitive to environmental conditions such as micro-vibration. Even a small amount of micro-vibration can reduce the output yield of the equipment or even cause the equipment to malfunction. Therefore, the isolation of micro-vibration is becoming increasingly important.

[0003] Magnetofluids possess both the fluidity of liquids and the magnetic properties of solid magnetic materials. They are stable colloidal liquids composed of magnetic solid particles with diameters on the nanometer scale (below 10 nanometers), a carrier liquid (also called a medium), and surfactants. This fluid exhibits no magnetic attraction when static, but displays magnetism when an external magnetic field is applied, making it widely applicable in practical applications.

[0004] Currently, the application of magnetofluids in vibration reduction is mainly based on the viscoelasticity of the magnetofluid itself, or by driving the movement of the magnetofluid through changes in heat flow. Regardless of the method, the positioning accuracy of the system is poor, making it unsuitable for low-frequency or ultra-low-frequency vibrations. Furthermore, the stiffness of the system is generally difficult to change, limiting its applicability. Summary of the Invention

[0005] The purpose of this invention is to provide a variable stiffness anti-vibration device based on magnetofluid to solve the problems existing in the background art.

[0006] The technical solution of this invention is implemented as follows: A variable stiffness anti-vibration device based on magnetofluid includes a shell, a support rod, a top plate, a first magnetofluid, and a first electromagnetic coil. The support rod is vertically and movably connected to the middle of the top of the shell. The top of the support rod is vertically connected to the middle of the bottom of the top plate. A metal spring is installed between the outer side of the support rod, the bottom of the top plate, and the top of the shell. A piston is vertically connected to the bottom of the support rod. A partition is horizontally installed on the lower inner side of the shell. The piston and the partition form a first chamber. The partition and the bottom inner side of the shell form a second chamber. A third chamber is installed around the perimeter of the shell. The first chamber is filled with the first magnetofluid, and the second chamber is filled with a second magnetofluid. The system contains a fluid, with the third chamber filled with a third magnetorheological fluid. A first electromagnetic coil is installed inside the wall of the outer shell and around the first chamber. A second electromagnetic coil is installed inside the wall of the outer shell and around the second chamber. An electromagnet is embedded in the center of the bottom of the piston. A magnetorheological elastomer is also installed at the connection between the bottom of the support rod and the piston. A third electromagnetic coil is installed around the magnetorheological elastomer and on the top of the piston. A fourth electromagnetic coil is installed on the top of the inner side of the outer shell and on the left and right sides of the support rod. A permanent magnet is installed vertically below the fourth electromagnetic coil and on the top of the piston. A first through hole is opened in the center of the partition, and second through holes are provided on the left and right sides below the outer shell to connect the second and third chambers.

[0007] Furthermore, a linear bearing is installed between the outer casing and the support rod.

[0008] Furthermore, the magnetic fields of the first, second, and third electromagnetic coils are all directed with the N pole facing upwards, and the fourth electromagnetic coil exhibits an attractive force with the permanent magnet.

[0009] Furthermore, the outer casing has a cylindrical structure with a bottom cover and a base.

[0010] Furthermore, a first magnetic shielding plate is installed on the outer side of the outer shell, a second magnetic shielding plate is installed inside the partition plate, a third magnetic shielding plate is installed on the outer side of the third electromagnetic coil, and a fourth magnetic shielding plate is installed between the top of the piston and the third electromagnetic coil and the permanent magnet. The first, second, third, and fourth magnetic shielding plates are all made of aluminum alloy plates.

[0011] Furthermore, a one-way valve is installed on the top of the third chamber.

[0012] Furthermore, the piston is surrounded by two layers of sealing rings, upper and lower.

[0013] Furthermore, an acceleration sensor and a position sensor are also installed at the bottom of the top plate.

[0014] Furthermore, a controller is mounted on the top of the housing.

[0015] Furthermore, the controller is connected via cables to a first electromagnetic coil, a second electromagnetic coil, an electromagnet, a third electromagnetic coil, a fourth electromagnetic coil, an acceleration sensor, and a position sensor.

[0016] The beneficial effects of this invention are as follows:

[0017] This invention expands the volume of the magnetofluid holding cavity and reduces the system's natural frequency by using a series of three-stage magnetofluid configurations. Furthermore, it improves the positioning accuracy of the magnetofluid drive through a two-stage magnetofluid drive and achieves adjustable system stiffness through a magnetorheological elastomer, thus meeting the stiffness and load-bearing requirements of different precision instruments.

[0018] This invention achieves high-frequency vibration reduction by connecting a metal spring in parallel with a three-stage series magnetofluid structure and a magnetorheological elastomer, thus expanding the vibration isolation bandwidth. The parallel connection of a two-stage magnetofluid drive and a magnetic drive improves the system's positioning accuracy. This system can achieve vibration control from 0.2Hz to 250Hz, with high positioning accuracy and high load-bearing capacity, meeting the load requirements of 3000kg precision instruments. It also has adjustable stiffness, making it suitable for different types of precision instruments, with a wide range of applications and strong versatility. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the present invention.

[0020] In the diagram, 1-outer shell, 2-support rod, 3-top plate, 4-metal spring, 5-piston, 6-partition, 7-first chamber, 8-second chamber, 9-third chamber, 10-first magnetorheological fluid, 11-second fluid, 12-third magnetorheological fluid, 13-first electromagnetic coil, 14-second electromagnetic coil, 15-electromagnet, 16-magnetorheological elastomer, 17-third electromagnetic coil, 18-fourth electromagnetic coil, 19-permanent magnet, 20-first through hole, 21-second through hole, 22-linear bearing, 23-first magnetic shielding plate, 24-second magnetic shielding plate, 25-third magnetic shielding plate, 26-fourth magnetic shielding plate, 27-one-way valve, 28-sealing ring, 29-accelerometer, 30-position sensor, 31-controller. Implementation

[0021] 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.

[0022] like Figure 1As shown, a variable stiffness anti-vibration device based on magnetofluid includes a shell 1, a support rod 2, a top plate 3, a first magnetofluid 10, and a first electromagnetic coil 13. The support rod 2 is vertically and movably connected to the middle of the top of the shell 1. The top of the support rod 2 is vertically connected to the middle of the bottom of the top plate 3. A metal spring 4 is installed between the outer side of the support rod 2, the bottom of the top plate 1, and the top of the shell 1. A piston 5 is vertically connected to the bottom of the support rod 2. A partition 6 is horizontally installed on the lower inner side of the shell 1. The piston 5 and the partition 6 form a first chamber 7. The partition 6 and the bottom inner side of the shell 1 form a second chamber 8. A third chamber 9 is installed around the shell 1. The first chamber 7 is filled with the first magnetofluid 10, the second chamber 8 is filled with a second magnetofluid 11, and the third chamber... The third magnetorheological fluid 12 is filled inside the shell 1. A first electromagnetic coil 13 is installed inside the wall of the outer shell 1 and around the first chamber 7. A second electromagnetic coil 14 is installed inside the wall of the outer shell 1 and around the second chamber 8. An electromagnet 15 is embedded in the middle of the bottom of the piston 5. A magnetorheological elastomer 16 is also installed at the connection between the bottom of the support rod 2 and the piston 5. A third electromagnetic coil 17 is installed around the magnetorheological elastomer 17 and on the top of the piston 5. A fourth electromagnetic coil 18 is installed on the top of the inner side of the outer shell 1 and on the left and right sides of the support rod 2. A permanent magnet 19 is installed at the vertical position below the fourth electromagnetic coil 18 and on the top of the piston 5. A first through hole 20 is opened in the middle of the partition 6. A second through hole 21 is provided on the left and right sides below the outer shell 1 to connect the second chamber 8 and the third chamber 9.

[0023] A linear bearing 22 is installed between the outer shell 1 and the support rod 2.

[0024] The magnetic field directions of the first electromagnetic coil 13, the second electromagnetic coil 14, and the third electromagnetic coil 17 are all N-pole upwards, and the fourth electromagnetic coil 18 and the permanent magnet 19 exhibit an attractive force relationship.

[0025] The outer shell 1 has a cylindrical structure and includes a bottom cover and a base.

[0026] A first magnetic shielding plate 23 is installed on the outer side of the outer shell 1, a second magnetic shielding plate 24 is installed inside the partition plate 6, a third magnetic shielding plate 25 is installed on the outer side of the third electromagnetic coil 17, and a fourth magnetic shielding plate 26 is installed between the top of the piston 5 and the third electromagnetic coil 17 and the permanent magnet 19. The first magnetic shielding plate 23, the second magnetic shielding plate 24, the third magnetic shielding plate 25 and the fourth magnetic shielding plate 26 are all made of aluminum alloy plate.

[0027] A one-way valve 27 is installed on the top of the third chamber 9.

[0028] The piston 5 is surrounded by two layers of sealing rings 28.

[0029] An acceleration sensor 29 and a position sensor 30 are also installed at the bottom of the top plate 3.

[0030] A controller 31 is mounted on the top of the outer casing 1.

[0031] The controller 31 is connected to the first electromagnetic coil 13, the second electromagnetic coil 14, the electromagnet 15, the third electromagnetic coil 17, the fourth electromagnetic coil 18, the acceleration sensor 29, and the position sensor 30 via cables.

[0032] During installation, the precision instrument is mounted on the top plate 1. According to the load-bearing and stiffness requirements of the precision instrument, the strength of the magnetic field of the third electromagnetic coil 17 is controlled by the controller 31, thereby adjusting the stiffness of the magnetorheological elastomer 16 to meet the requirements.

[0033] During operation, the precision instrument generates vibrations. Vibration signals are collected by the position sensor 30 and the acceleration sensor 29 and transmitted to the controller 31. For high-frequency vibration sources, high-frequency damping is achieved through a parallel mechanism consisting of a metal spring 4, a first magnetic fluid, a second magnetic fluid, a third magnetic fluid, and a magnetorheological elastic body. For low-frequency vibration sources, the controller 31 controls the magnetic field strength of the first electromagnetic coil 13, causing the first magnetic fluid 10 to flow towards a region with higher magnetic field strength. The controller 31 then controls the magnetic field strength of the electromagnet 15, causing the first fluid 10 to flow towards the piston 5, applying a force to the piston 5. Simultaneously, as the piston 5 moves, the first chamber 7 generates… Under negative pressure, the controller 31 controls the magnetic field strength of the second electromagnetic coil 14, causing the second magnetic fluid 11 to flow towards the area with higher magnetic field strength in the middle, and then flow through the first through hole 20 to the first chamber 7. At the same time, the third magnetic fluid 12 flows to the second chamber 8 under the negative pressure. Under the negative pressure, the one-way valve 27 opens to allow air to enter. At this time, the first magnetic fluid 10, the second magnetic fluid 11, and the third magnetic fluid 12 form a series structure to apply a reaction force to the piston 5 for vibration reduction. Meanwhile, the controller 31 controls the magnetic field strength of the parallel fourth electromagnetic coil 18 and the permanent magnet 19 to drive the piston 5 to move through magnetic force, further realizing vibration reduction and improving the system's positioning accuracy and vibration reduction capability.

[0034] 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 variable stiffness anti-chatter device based on magnetic fluid, comprising a housing, a support rod, a top plate, a first magnetic fluid and a first electromagnetic coil, characterized in that, The middle of the top of the shell is vertically connected with a support rod, the top of the support rod is vertically connected with the middle of the bottom of the top plate, metal springs are installed between the outside of the support rod, the bottom of the top plate and the top of the shell, the bottom of the support rod is vertically connected with a piston, a partition plate is transversely installed in the lower part of the inner side of the shell, the first chamber is composed between the piston and the partition plate, the second chamber is composed between the partition plate and the bottom of the inner side of the shell, the third chamber is installed around the shell, the first magnetic fluid is filled in the first chamber, the second fluid is filled in the second chamber, the third magnetic fluid is filled in the third chamber, the first electromagnetic coil is installed around the inside of the wall of the shell and the first chamber, the second electromagnetic coil is installed around the inside of the wall of the shell and the second chamber, the electromagnet is embedded in the middle of the bottom of the piston, the magnetorheological elastomer is also installed at the connection between the bottom of the support rod and the piston, the third electromagnetic coil is installed around the magnetorheological elastomer and the top of the piston, the fourth electromagnetic coil is installed on the left and right sides of the top of the inner side of the shell, the permanent magnet is installed on the top of the piston below the vertically corresponding position of the fourth electromagnetic coil, the first through hole is arranged in the middle of the partition plate, the second through hole is arranged on the left and right sides below the shell to communicate the second chamber with the third chamber.

2. A variable stiffness anti-chatter device based on magnetic fluid according to claim 1, characterized in that, Linear bearings are installed between the shell and the support rod.

3. A variable stiffness anti-chatter device based on magnetic fluid as claimed in claim 1, wherein, The magnetic field directions of the first electromagnetic coil, the second electromagnetic coil and the third electromagnetic coil are all N-pole upward, and the fourth electromagnetic coil and the permanent magnet exhibit attractive force.

4. A magnetofluid-based anti-chatter device of claim 1, wherein, The shell is in cylindrical structure with a bottom cover and a base.

5. A magnetofluid-based anti-chatter device of claim 1, wherein, The first magnetic shield plate is installed on the outer side of the shell, the second magnetic shield plate is installed inside the partition plate, the third magnetic shield plate is installed outside the third electromagnetic coil, the fourth magnetic shield plate is installed between the top of the piston and the third electromagnetic coil and the permanent magnet, and the first magnetic shield plate, the second magnetic shield plate, the third magnetic shield plate and the fourth magnetic shield plate are all made of aluminum alloy plate.

6. A magnetofluid-based anti-chatter device of claim 1, wherein, A one-way valve is installed on the top of the third chamber.

7. A magnetofluid-based anti-chatter device of claim 1, wherein, Two layers of sealing rings are installed around the piston.

8. A magnetofluid-based anti-chatter device of claim 1, wherein, An acceleration sensor and a position sensor are also installed on the bottom of the top plate, a controller is installed on the top of the shell, and the controller is connected with the first electromagnetic coil, the second electromagnetic coil, the electromagnet, the third electromagnetic coil, the fourth electromagnetic coil, the acceleration sensor and the position sensor through cables.

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