CN103062306B - Eddy current damping vibration isolator of double-layer air-flotation orthogonal decoupling and two-dimensional flexible hinge angle decoupling - Google Patents

Abstract

The eddy current damping vibration isolator with double-layer air bearing orthogonal decoupling and two-dimensional flexible hinge angle decoupling belongs to the field of precision vibration isolation technology. The sleeve and air bearing plate of the main body of the vibration isolator are lubricated and supported by the air bearing surface, The eddy current damper attenuates the vibration energy and improves the stability. The air bearing plate and the lower mounting plate, the piston cylinder and the sleeve are lubricated and supported by the air bearing surface, and the freedom of horizontal linear motion between the upper mounting plate and the lower mounting plate is passed through the double positive The decoupling of the cross-air bearing guide rail, the degree of freedom of angular motion is decoupled through the two-dimensional flexible hinge, the voice coil motor, displacement sensor, limit switch and controller, and the driver constitute a position closed-loop feedback control system, which controls the relative position of the upper and lower mounting plates Precise control; the invention has the characteristics of three-dimensional zero stiffness, high positioning accuracy, decoupling of linear motion freedom and angular motion freedom, and can effectively solve the problem of ultra-precision measuring instruments and processing equipment, especially step-scanning lithography machines. performance isolator needs.

Description

Eddy current damping vibration isolator with double-layer air bearing orthogonal decoupling and two-dimensional flexible hinge angle decoupling

technical field

The invention belongs to the technical field of precision vibration isolation, and mainly relates to an electric eddy current damping vibration isolator with double-layer air flotation orthogonal decoupling and two-dimensional flexible hinge angle decoupling.

Background technique

With the continuous improvement of ultra-precision machining and measurement accuracy, environmental vibration has become an important factor restricting the improvement of the accuracy and performance of ultra-precision machining equipment and measuring instruments. In particular, the ultra-large-scale integrated circuit processing equipment represented by the step-scan lithography machine is extremely technically intensive and complex, and the key technical indicators have reached the limit of the existing technology, representing the highest level of ultra-precision processing equipment. Precision vibration isolation has become the core key technology in this type of equipment; the line width of the step-and-scan lithography machine has reached 22nm and below, the positioning accuracy and overlay accuracy of silicon wafers have reached several nanometers, and the movement speed of the workpiece table has reached 1m/s Above, the acceleration of the workpiece table reaches dozens of times of the acceleration of gravity, which poses a new challenge to the existing vibration isolation technology. First of all, the lithography machine needs to provide an "ultra-quiet" working environment for the metrology system and the lithography objective lens, and at the same time needs to drive the workpiece table to move at high speed and high acceleration, which poses extremely strict requirements on the vibration isolation performance of the vibration isolation system. It is required that the natural frequencies in the three directions must be below 1Hz; secondly, the relative position between the various components of the lithography machine, such as the distance between the lithography objective lens and the surface of the silicon wafer, has very strict requirements and is in a position closed loop Under the control of the feedback control system, the relative position accuracy between the upper and lower mounting plates of the vibration isolator is required to reach the order of 10 μm, and the positioning accuracy of the traditional vibration isolator is far from meeting the requirements.

According to the vibration isolation theory, the natural frequency of a passive vibration isolator is proportional to the stiffness and inversely proportional to the load mass. Therefore, under the premise of a certain load mass, reducing the stiffness of the vibration isolator is to reduce the natural frequency and improve low frequency and ultra-low frequency vibration isolation. efficient way to perform. Vibration isolators in the form of traditional air springs have an inherent contradiction between static load capacity and stiffness. At the same time, they are constrained by factors such as material properties and structural stiffness. It is very difficult to further reduce their stiffness, especially the horizontal stiffness. In response to this problem, the researchers introduced the "pendulum" structure into the air spring vibration isolator to achieve the purpose of reducing the horizontal stiffness of the vibration isolator (1. Nikon Corporation. Vibration Isolator With Low Lateral Stiffness. US Patent Publication No.: US20040065517A1 ; 2. U.S.Philips Corporation. Positioning Device with a Force Actuator System for Compensating Center-of-gravity Displacements, and Lithographic Device Provided with Such APositioning Device. U.S. Patent No.: US005844664A). This method can reduce the horizontal stiffness of the air spring isolator to a certain extent and improve its low-frequency vibration isolation performance. The problems of this method are as follows: 1) Due to the constraints of material properties and structural stiffness, the amplitude of vertical and horizontal stiffness reduction of the vibration isolator is limited; 2) The vertical and horizontal positioning accuracy of the air spring vibration isolator is very poor, It cannot meet the requirements of the photolithography process; 3) To achieve a lower horizontal stiffness requires a larger pendulum length, resulting in excessive height of the vibration isolator, prone to string-membrane resonance, and poor stability.

Through the analysis of the technical scheme of the existing air spring isolator, it can be seen that the existing air spring isolator is difficult to meet the requirements of ultra-low stiffness and high positioning accuracy of the lithography machine. The German IDE company proposed a vibration isolator technology solution that abandons the traditional rubber air spring (1. Integrated Dynamics Engineering GmbH. Isolatorgeometrie Eines Schwingungsisolationssystem. European Patent No.: EP1803965A2; 2. Integrated Dynamics Engineering GmbH. Schwingungsisolationssystem Mit Pneumatischemil. European Patent No.: filter Tiefpass EP1803970A2; 3. Integrated Dynamics Engineering GmbH. Air Bearing with Consideration of High-Frequency Resonances. US Patent Publication No.: US20080193061A1). The solution uses vertical and horizontal air bearings to decouple and isolate vibrations in all directions, which can achieve extremely low stiffness and natural frequency. The problems of this solution are: 1) In the disclosed technical solution, the vibration isolator cannot achieve precise positioning; 2) In the patent EP1803965A2, there is no degree of freedom of angular movement around the horizontal axis between the upper and lower mounting plates. The angular stiffness and natural frequency are very high; patents EP1803970A2 and US20080193061A1 use rubber blocks to provide angular freedom of rotation around the horizontal axis for the upper and lower mounting plates, but due to the high angular stiffness of the rubber blocks, the angular freedom of motion cannot be effectively achieved Degree of freedom decoupling, the friction between the components of the angular motion degree of freedom decoupling mechanism introduces additional stiffness, which restricts the vibration isolation performance.

Netherlands ASML company also proposed a similar vibration isolator technical scheme (1. U.S.Philips Corp, ASM Lithography B.V. Pneumatic Support Device with A Controlled Gas Supply, and Lithographic Device Provided with Such A Support Device. U.S. Patent No.: US006144442A; 2 .Koninklijke Philips ElectronicsN.V.，ASM Lithography B.V.Lithographic Pneumatic Support Device with Controlled Gas Supply.国际专利公开号：WO99/22272；3.ASML Netherlands B.V.Support Device，LithographicApparatus，and Device Manufacturing Method Employing A Supporting Device，and A PositionControl System Arranged for Use in A Supporting Device.美国专利号：US007084956B2；4.ASML Netherlands B.V.Support Device，Lithographic Apparatus，and Device ManufacturingMethod Employing A Supporting Device and A Position Control System Arranged for Use in ASupporting Device.欧洲专利号： EP1486825A1). In patent US006144442A and WO99/22272, closed-loop feedback control is performed on the air source pressure to achieve the purpose of improving the stability and performance of the vibration isolator; in patent US007084956B2 and EP1486825A1, a vibration sensor is installed on the upper mounting plate, and a reference vibration system is introduced at the same time. The vibration isolation performance of the vibration isolator is improved through the control algorithm. However, the proposed technical solution still does not solve the problem of decoupling the precise positioning of the vibration isolator and the angular motion degrees of freedom of the upper and lower mounting plates.

Contents of the invention

The purpose of the present invention is to provide a double-layer gas isolator for the urgent requirements of ultra-precision measuring instruments and processing equipment, especially ultra-large-scale integrated circuit processing equipment such as step-scan lithography machines, for vibration isolators with low natural frequency and high positioning accuracy. An eddy current damping vibration isolator with floating orthogonal decoupling and two-dimensional flexible hinge angle decoupling. The vibration isolator has approximately zero stiffness and extremely low natural frequency in three dimensions. The degree of freedom of three-dimensional linear motion and the degree of freedom of angular motion are decoupled, so as to effectively solve the problem of precision vibration isolation in ultra-precision measuring instruments and processing equipment, especially in step-and-scan lithography machines.

Technical solution of the present invention is:

An electric eddy current damping vibration isolator with double-layer air flotation orthogonal decoupling and two-dimensional flexible hinge angle decoupling. The main body of the isolator is installed between the upper mounting plate and the lower mounting plate. The clean compressed air source communicates with the main body of the vibration isolator through the air pipe. In the structure of the main body of the vibration isolator, the lower surface of the sleeve and the air floating plate are axially loaded The plane air-bearing surface is lubricated and supported, the piston cylinder is installed in the sleeve under the buckle, and the sleeve is lubricated and supported by the radial bearing cylinder air-bearing surface, the two-dimensional flexible hinge is installed between the piston cylinder and the upper mounting plate, and the X-direction air The lower surface of the floating guide rail is rigidly connected with the air bearing plate, the sleeve and the X-direction air bearing guide rail are lubricated and guided by the air bearing surface of the X-direction guide rail, the lower surface of the Y-direction air bearing guide rail is rigidly connected with the lower mounting plate, and the air bearing plate is connected to the lower mounting plate. The mounting plate is lubricated and supported by the bearing air bearing surface in the Z direction, the air bearing plate and the Y direction air bearing guide rail are lubricated and guided by the air bearing surface of the Y direction guide rail; the Z direction voice coil motor, the Z direction displacement sensor, the Z direction limit switch, the Z direction The eddy current damper is installed between the piston barrel and the sleeve, the X-direction voice coil motor, the X-direction displacement sensor, the X-direction limit switch, the X-direction eddy current damper, and the Y-direction eddy current damper are installed between the sleeve and the air Between the floating boards, the voice coil motor in the Y direction, the displacement sensor in the Y direction, and the limit switch in the Y direction are installed between the air floating board and the lower mounting plate. The direction of the driving force of the coil motor and the Y-direction voice coil motor is in the horizontal plane and perpendicular to each other. The driving force direction of the motor is consistent, and the damping force direction of the X, Y, Z direction eddy current damper is respectively consistent with the driving force direction of the X, Y, Z direction voice coil motor; the X, Y, Z direction displacement sensor and the X, Y direction The , Z direction limit switches are respectively connected to the signal input terminals of the controller, the signal output terminals of the controller are connected to the signal input terminals of the driver, and the signal output terminals of the driver are respectively connected to the X, Y and Z direction voice coil motors.

The X-direction eddy current damper is composed of an X-direction permanent magnet installed on the side wall of the lower surface of the sleeve along the direction of the driving force of the X-direction voice coil motor, and the Y-direction eddy current damper is formed by the side wall of the lower surface of the sleeve along the direction of the Y-direction voice coil. The Y-direction permanent magnet installed in the driving force direction of the motor is composed of the Z-direction permanent magnet installed in the cylindrical side wall of the sleeve along the Z-direction voice coil motor driving force direction, and the X, Y and Z directions are permanent magnets. The magnetic pole direction of the magnet is perpendicular to the surface of the sleeve, and the N and S poles are arranged alternately. The sleeve is made of ferromagnetic material, and the piston cylinder and the air floating plate are made of non-magnetic and good conductor material.

A gas pressure sensor is arranged in the piston barrel, an air inlet and a solenoid valve are arranged on the piston barrel, the gas pressure sensor is connected to the signal input end of the controller, the signal output end of the controller is connected to the signal input end of the driver, and the driver The signal output terminal is connected with the solenoid valve.

The voice coil motors in the X, Y and Z directions are cylindrical voice coil motors or flat voice coil motors.

The X-direction air-floating guide rail and the Y-direction air-floating guide rail have a single guide rail structure or a double guide rail structure.

The X, Y, and Z direction displacement sensors are grating scales, magnetic scales, capacitive scales or linear potentiometers.

The X-, Y-, and Z-direction limit switches are mechanical limit switches, Hall-type limit switches or photoelectric limit switches.

The gas pressure in the piston barrel is 0.1MPa-0.8MPa.

The air film thickness of the axial bearing plane air bearing surface, the radial bearing cylindrical air bearing surface, the X guiding guide air bearing surface, the Y guiding guide air bearing surface and the Z bearing air bearing surface is 10 μm to 20 μm.

The diameter of the orifice on the cylindrical air-floating surface on the piston barrel and the orifice on the plane air-floating surface on the sleeve is φ0.1mm˜φ1mm.

The technical innovation of the present invention and the good effect that produce are:

(1) The present invention abandons the traditional vibration isolator technical scheme based on elastic elements/mechanisms, and adopts the axial bearing flat air bearing surface and the radial bearing cylindrical air bearing surface to decouple and isolate the horizontal and vertical vibrations respectively. There is no friction on the floating surface, and the stiffness is approximately zero, so that the vibration isolator can obtain approximately zero stiffness characteristics and outstanding ultra-low frequency vibration isolation performance, which solves the problem that the existing technology is limited by structural stiffness and material properties, and the stiffness is difficult to further reduce. Stiffness and stability Sexual incompatibility. This is one of the innovative points that the present invention is different from the prior art.

(2) The present invention adopts displacement sensors, limit switches, controllers, drivers, and voice coil motors to form a closed-loop feedback control system for vertical and horizontal positions to precisely control the relative position between the upper and lower mounting plates , the positioning accuracy can reach 10 μm level and above, which can effectively solve the problems of low positioning accuracy, positioning accuracy, stiffness, and vibration isolation performance of existing technical solutions. This is the second innovative point that the present invention is different from the prior art.

(3) The present invention uses double-layer orthogonal air-floating guide rails and two-dimensional flexible hinges to decouple the degrees of freedom of linear motion and angular motion between the upper and lower mounting plates of the vibration isolator. Friction, no wear, and the introduction of additional stiffness can be ignored, which can effectively solve the problems of friction and wear and the introduction of additional stiffness in the existing technical solutions using elastic body decoupling. This is the third innovative point that the present invention is different from the prior art.

(4) The present invention adopts a gas pressure sensor, a solenoid valve, a controller, a driver, etc. to form a pressure closed-loop feedback control system to precisely control the gas pressure in the sleeve to keep it constant, and to balance the gravity and balance the axial load of the vibration isolator. Compensation, under the action of the air bearing surface of the radial bearing cylinder, the piston cylinder carrying the load gravity can slide up and down freely along the sleeve with zero stiffness, so as to achieve the ideal gravity balance and zero stiffness vibration isolation effect. This is the fourth innovative point that the present invention is different from the prior art.

(5) The present invention uses an active actuator to actively control the relative position between the upper and lower mounting plates, and the parameters of the vibration isolator can be adjusted in real time according to the characteristics of the vibration-isolated object and the change of the working environment, so as to adapt to different working conditions and have the advantages of Better flexibility, adaptability and stability. This is the fifth innovative point that the present invention is different from the prior art.

(6) The present invention uses an eddy current damper based on an alternating magnetic pole permanent magnet array, which can be well integrated with a vibration isolator. The eddy current damper has a relatively ideal linear damping characteristic, which can effectively attenuate vibration energy and reduce The overshoot of the motor drive positioning provides the stability of the vibration isolator. This is the sixth innovation point that the present invention is different from the prior art.

Description of drawings

Figure 1 is a schematic diagram of the structure of the eddy current damping vibration isolator with double-layer air bearing orthogonal decoupling and two-dimensional flexible hinge angle decoupling after the upper mounting plate is removed;

Fig. 2 is a schematic cross-sectional structure diagram of an eddy current damping vibration isolator with double-layer air bearing orthogonal decoupling and two-dimensional flexible hinge angle decoupling;

Fig. 3 is a schematic diagram of an axial bearing plane air bearing surface, a radial bearing cylindrical air bearing surface and an X-guided guide air bearing surface;

Fig. 4 is a schematic diagram of the bearing air bearing surface in the Z direction and the air bearing surface of the Y guide rail;

Fig. 5 is a schematic diagram of the sleeve structure;

Fig. 6 is a schematic structural diagram of two one-dimensional flexible hinges being orthogonally superimposed to form a two-dimensional flexible hinge;

Fig. 7 is a structural schematic diagram of a cylindrical two-dimensional flexible hinge;

Figure 8 is a block diagram of the control structure of the eddy current damping vibration isolator with double-layer air bearing orthogonal decoupling and two-dimensional flexible hinge angle decoupling;

Fig. 9 is a schematic diagram of an orifice on the plane air bearing surface on the sleeve;

Fig. 10 is the schematic diagram of the orifice on the cylindrical air bearing surface on the piston barrel;

Fig. 11 is a schematic cross-sectional structure diagram of an eddy current damper;

Fig. 12 is an A-A sectional view of an installation method of the Z-direction permanent magnet on the inner cylindrical side wall of the sleeve;

Figure 13 is an A-A cross-sectional view of another installation method of the Z-direction permanent magnet on the inner cylindrical side wall of the sleeve;

Fig. 14 is a schematic diagram of an installation method of X and Y direction permanent magnets on the side wall of the lower surface of the sleeve;

Fig. 15 is a schematic diagram of another installation method of the permanent magnets in the X and Y directions on the side wall of the lower surface of the sleeve.

Part number description in the picture: 1 upper mounting plate, 2 lower mounting plate, 3 clean compressed air source, 4 main body of vibration isolator, 5 piston cylinder, 6 sleeve, 7 two-dimensional flexible hinge, 8 X direction voice coil motor, 8a X Direction motor iron yoke, 8b X direction motor magnet, 8c X direction motor coil bobbin, 8d X direction motor coil, 9Y direction voice coil motor, 10Z direction voice coil motor, 10a Z direction motor iron yoke, 10b Z direction motor magnet , 10c Z-direction motor coil skeleton, 10d Z-direction motor coil, 10e Z-direction motor transition piece, 11X-direction displacement sensor, 11a X-direction grating reading head transition piece, 11b X-direction grating reading head, 11c X-direction glass scale, 12Y Direction displacement sensor, 13Z direction displacement sensor, 13a Z direction grating reading head transition piece, 13b Z direction grating reading head, 13c Z direction glass grating scale, 14X direction limit switch, 14a X direction limit block, 14b X direction Hall Switch, 14c X-direction limit switch transition piece, 14d X-direction limit block transition piece, 15Y-direction limit switch, 16Z-direction limit switch, 16a Z-direction limit block, 16b Z-direction Hall switch, 16c Z-direction limit switch Position switch transition piece, 17 gas pressure sensor, 18 solenoid valve, 19 controller, 20 driver, 21 axial bearing plane air bearing surface, 22 radial bearing cylindrical air bearing surface, 23 air inlet, 24 plane air bearing surface throttle hole, 25 cylinder air bearing surface throttle hole, 26 air pipes, 29X air bearing guide rail, 30Y air bearing guide rail, 31X guide air bearing surface, 32Y guide rail air bearing surface, 33Z bearing air bearing surface, 34 air bearing plate, 35 cylindrical two Dimensional flexible hinge, 40X direction eddy current damper, 40A X direction permanent magnet, 41Y direction eddy current damper, 41A Y direction permanent magnet, 42Z direction eddy current damper, 42AZ direction permanent magnet.

Detailed ways

Specific embodiments of the present invention are given below in conjunction with the accompanying drawings.

An eddy current damping vibration isolator with double-layer air flotation orthogonal decoupling and two-dimensional flexible hinge angle decoupling, consisting of an upper mounting plate 1, a lower mounting plate 2, a clean compressed air source 3, an air pipe 26 and a vibration isolator main body 4, the main body of the vibration isolator 4 is installed between the upper mounting plate 1 and the lower mounting plate 2, and the clean compressed air source 3 communicates with the main body of the vibration isolator 4 through the air pipe 26. In the structure of the main body of the vibration isolator 4, the sleeve The lower surface of the cylinder 6 and the air bearing plate 34 are lubricated and supported by the axial bearing plane air bearing surface 21, the piston cylinder 5 is installed undercut in the sleeve 6, and the sleeve 6 is lubricated and supported by the radial bearing cylindrical air bearing surface 22 , the two-dimensional flexible hinge 7 is installed between the piston cylinder 5 and the upper mounting plate 1, the lower surface of the X-direction air bearing guide rail 29 is rigidly connected with the air bearing plate 34, and the sleeve 6 and the X-direction air bearing guide rail 29 pass through the X guide rail The air bearing surface 31 is lubricated and guided, the lower surface of the Y-direction air bearing guide rail 30 is rigidly connected to the lower mounting plate 2, the air bearing plate 33 and the lower mounting plate 2 are lubricated and supported by the Z-direction bearing air bearing surface 33, and the air bearing plate 34 is connected to the Y The air bearing guide rail 30 is lubricated and guided by the air bearing surface 32 of the Y guide rail; the Z direction voice coil motor 10, the Z direction displacement sensor 13, the Z direction limit switch 16, and the Z direction eddy current damper 42 are installed on the piston barrel 5 and the sleeve Between the barrels 6, the X-direction voice coil motor 8, the X-direction displacement sensor 11, the X-direction limit switch 14, the X-direction eddy current damper 40, and the Y-direction eddy current damper 41 are installed on the sleeve 6 and the air bearing plate 34 Between, the Y direction voice coil motor 9, the Y direction displacement sensor 12, and the Y direction limit switch 15 are installed between the air bearing plate 34 and the lower mounting plate 2; the driving force direction of the Z direction voice coil motor 10 is the vertical direction , the driving force directions of X-direction voice coil motor 8 and Y-direction voice coil motor 9 are in the horizontal plane and are perpendicular to each other, X, Y, Z direction displacement sensors 11, 12, 13 and X, Y, Z direction limit switches 14, The directions of the action lines of 15 and 16 are consistent with the directions of the driving forces of the voice coil motors 8, 9 and 10 in the X, Y and Z directions, and the directions of the damping forces of the eddy current dampers 40, 41 and 42 in the X, Y and Z directions are respectively in line with the X , Y, and Z direction voice coil motors 8, 9, and 10 have the same driving force direction; X, Y, and Z direction displacement sensors 11, 12, and 13 and X, Y, and Z direction limit switches 14, 15, and 16 are respectively connected with the control The signal input end of controller 19 is connected, the signal output end of controller 19 is connected with the signal input end of driver 20, and the signal output end of driver 20 is connected with X, Y, Z direction voice coil motors 8, 9, 10 respectively.

X, Y, and Z direction displacement sensors 11, 12, and 13 measure the displacement output by X, Y, and Z direction voice coil motors 8, 9, and 10, and X, Y, and Z direction limit switches 14, 15, and 16 are for X , Y, and Z direction voice coil motors 8,9,10 movement stroke limit; 16 feedback signals to control the X, Y, Z direction voice coil motors 8, 9, 10 to accurately control the relative position between the upper and lower mounting plates 1, 2.

The X-direction eddy current damper 40 is composed of an X-direction permanent magnet 40A installed on the side wall of the lower surface of the sleeve 6 along the direction of the driving force of the X-direction voice coil motor 8, and the Y-direction eddy current damper 41 is formed by the lower surface side of the sleeve 6. The wall is composed of a Y-direction permanent magnet 41A installed along the Y-direction of the driving force of the voice coil motor 9, and the Z-direction eddy current damper 42 is installed along the Z-direction of the Z-direction of the driving force of the voice coil motor 10 on the side wall of the sleeve 6. Composed of permanent magnets 41A, the X, Y, and Z directions of the magnetic poles of the permanent magnets 40A, 41A, and 42A are perpendicular to the surface of the sleeve 6, and the N and S poles are alternately arranged. The sleeve 6 is made of ferromagnetic material, and the piston barrel 5 and the gas Floating plate 2 adopts non-magnetic good conductor material.

Gas pressure sensor 17 is provided in described piston barrel 5, and air inlet 23 and solenoid valve 18 are provided on piston barrel 5, and gas pressure sensor 17 is connected with the signal input end of controller 19, and the signal output end of controller 19 is connected with The signal input end of the driver 20 is connected, and the signal output end of the driver 20 is connected with the solenoid valve 18 .

The voice coil motors 8, 9 and 10 in the X, Y and Z directions are cylindrical voice coil motors or flat voice coil motors.

The X-direction air-floating guide rail 29 and the Y-direction air-floating guide rail 30 have a single guide rail structure or a double guide rail structure.

The X, Y, Z direction displacement sensors 11, 12, 13 are grating scales, magnetic scales, capacitive scales or linear potentiometers.

The X, Y, and Z limit switches 14, 15, and 16 are mechanical limit switches, Hall-type limit switches or photoelectric limit switches.

The gas pressure in the piston barrel 5 is 0.1MPa-0.8MPa.

The air film thickness of the axial bearing plane air bearing surface 21 , the radial bearing cylindrical air bearing surface 22 , the X guide rail air bearing surface 31 , the Y guide guide air bearing surface 32 and the Z bearing air bearing surface 33 is 10 μm to 20 μm.

The diameters of the cylindrical air bearing surface throttle hole 25 on the piston barrel 5 and the plane air bearing surface throttle hole 24 on the sleeve 6 are φ0.1mm˜φ1mm.

An embodiment of the present invention is given below in conjunction with FIG. 1 to FIG. 5 and FIG. 8 . In this embodiment, when the vibration isolator is in operation, the lower mounting plate 2 is installed on the foundation, the base of the instrument or the foundation frame, and the upper mounting plate 1 is connected to the load to be vibration-isolated. Voice coil motors 8, 9, and 10 in X, Y, and Z directions all adopt cylindrical voice coil motors. Taking the X-direction voice coil motor 8 as an example, it mainly includes an X-direction motor iron yoke 8a, an X-direction motor magnet 8b, an X-direction motor coil skeleton 8c, and an X-direction motor coil 8d. The X-direction motor iron yoke 8a and the X-direction motor bobbin 8c are cylindrical, the X-direction motor magnet 8b is cylindrical, and the X-direction motor coil 8d is wound on the X-direction motor coil bobbin 8c. The X-direction motor iron yoke 8a and the X-direction motor magnetic steel 8b constitute the stator of the motor, and the X-direction motor coil skeleton 8c and the X-direction motor coil 8d constitute the mover of the motor. In the Z-direction voice coil motor 10, the Z-direction motor transition piece 10e provides the installation structure of the Z-direction motor coil skeleton 10c. When the motor is working, a current is passed through the coil. According to the electromagnetic theory, the energized coil will be affected by the Lorentz force in the magnetic field. By controlling the magnitude and direction of the current, the magnitude and direction of the motor output driving force can be controlled.

X, Y, and Z direction displacement sensors 11, 12, 13 adopt grating rulers. Taking the Z-direction displacement sensor 13 as an example, it mainly includes the Z-direction grating reading head transition piece 13a, the Z-direction grating reading head 13b, and the Z-direction glass grating scale 13c. The Z-direction grating reading head transition piece 13a provides Z-direction grating reading Mounting structure of the head 13b. When the grating ruler is working, the Z-direction grating reading head 13b can detect the relative displacement between it and the Z-direction glass grating ruler 13c, and send it to the controller 19 through the signal wire.

X, Y, Z direction limit switches 14, 15, 16 adopt Hall type limit switches. Taking the Z-direction limit switch 16 as an example, it mainly includes components such as a Z-direction limit block 16a, a Z-direction Hall switch 16b, and a Z-direction limit switch transition piece 16c. The two Z-direction Hall switches 16b are installed back to back, and the two Z-direction limit blocks 16a are made of metal materials, and are installed opposite to the sensitive end of the Z-direction Hall switch 16b. The Z-direction limit switch transition piece 16c provides a mounting structure for the Z-direction Hall switch 16b. When the limit switch is working, when the Z-direction Hall switch 16b is close to the Z-direction limit block 16a, the Z-direction Hall switch 16b gives a limit signal and sends it to the controller 19 through the signal wire.

In this embodiment, the Z-direction voice coil motor 10 , the Z-direction displacement sensor 13 and the Z-direction limit switch 16 are installed between the piston cylinder 5 and the sleeve 6 and inside the piston cylinder 5 .

The load bearing of the vibration isolator is realized in the following manner: the clean compressed air source 3 delivers clean compressed air to the piston cylinder 5 through the air pipe 26 , the electromagnetic valve 18 and the air inlet 23 . The controller 19 controls the opening of the solenoid valve 18 according to the feedback signal from the gas pressure sensor 17, and adjusts the gas flow rate input into the piston cylinder 5, thereby adjusting the pressure of the clean compressed air in the piston cylinder 5, so that the clean compressed air acts on the piston cylinder. The upward force of 5 is balanced with the gravity of the load, the piston cylinder 5 and other parts loaded on the piston cylinder 5, so as to realize the ideal gravity compensation and zero-stiffness vibration isolation effect.

In this embodiment, the pressure of the clean compressed air in the piston cylinder 5 is 0.4MPa, and the effective radius of the lower surface of the piston cylinder 5 is 100mm, so the mass carried by a single vibration isolator is: m=p×πr ² /g≈1282kg, Where p is the gas pressure, p=0.4MPa, r is the effective radius of the lower surface of the piston cylinder 5, r=100mm, g is the acceleration of gravity, g=9.8m/s ² .

Figure 6 shows an embodiment of a two-dimensional flexible hinge. In this embodiment, the two-dimensional flexible hinge 7 is composed of two one-dimensional flexible hinges that are orthogonally superimposed.

Fig. 7 shows another embodiment of the two-dimensional flexible hinge. In this embodiment, the cylindrical two-dimensional flexible hinge 35 has a cylindrical shape and is processed into a form that is thin in the middle and thick at both ends.

Figure 9 shows an embodiment of the orifice on the plane air bearing surface of the sleeve. In this embodiment, eight orifice holes 24 on the plane air-floating surface are uniformly distributed around the center of the circle on the lower surface of the sleeve 6 along the circumferential direction, with a diameter of φ0.2mm.

Figure 10 shows an embodiment of the orifice on the cylindrical air bearing surface on the piston cylinder. In this embodiment, two rows of orifice holes 25 on the cylindrical air-floating surface are evenly distributed along the circumferential direction on the side wall of the piston cylinder 5, and the number of orifice holes 25 on each row of cylindrical air-floating surface is 8, with a diameter of φ0.2mm.

An embodiment of the Z-direction eddy current damper is given below in conjunction with Fig. 11 and Fig. 12 . In this embodiment, the vibration isolator has two Z-direction eddy current dampers 42, which are composed of a Z-direction permanent magnet 42A array installed on the inner cylindrical side wall of the sleeve 6. The sleeve 6 is made of No. 45 steel material, which has a relatively high High magnetic permeability, the piston cylinder 5 is made of red copper material, which is non-magnetic and has high electrical conductivity. The Z-direction permanent magnet 42A is bar-shaped, arranged along the driving force direction of the Z-direction voice coil motor 10 , that is, the axis direction of the sleeve 6 , the magnetic pole direction is perpendicular to the inner cylindrical surface of the sleeve 6 , and N and S poles are alternately arranged. When the sleeve 6 and the piston barrel 5 move relative to each other in the Z direction, the piston barrel 5 cuts the lines of magnetic force to generate eddy currents and damping forces, and the Z-direction damping force is proportional to the relative movement speed of the sleeve 6 and the piston barrel 5 in the Z direction. It is consistent with the direction of the driving force of the Z-direction voice coil motor 10 , that is, the axis direction of the sleeve 6 , so as to consume vibration energy and improve positioning stability.

Fig. 11 and Fig. 13 show another embodiment of the Z eddy current damper. In this embodiment, the vibration isolator has four Z-direction eddy current dampers 42 , which are composed of a Z-direction permanent magnet 42A array installed on the inner cylindrical side wall of the sleeve 6 . The Z-direction permanent magnet 42A is bar-shaped, arranged along the driving force direction of the Z-direction voice coil motor 10 , that is, the axis direction of the sleeve 6 , the magnetic pole direction is perpendicular to the inner cylindrical surface of the sleeve 6 , and N and S poles are alternately arranged.

An embodiment of the X, Y direction eddy current damper is given below in conjunction with Fig. 11 and Fig. 14 . In this embodiment, the vibration isolator has two X-direction eddy current dampers 40 and two Y-direction eddy current dampers 41, respectively composed of X and Y direction permanent magnets 40A and 41A installed on the side wall of the lower surface of the sleeve 6. Composed of an array, the sleeve 6 is made of No. 45 steel material with high magnetic permeability, and the air floating plate 34 is made of red copper material, which is non-magnetic and has high electrical conductivity. The permanent magnets 40A and 41A in the X and Y directions are elongated, arranged along the driving force directions of the voice coil motors 8 and 9 in the X and Y directions respectively, the direction of the magnetic poles is perpendicular to the lower surface of the sleeve 6, and the N and S poles are arranged alternately . When the sleeve 6 and the air-floating plate 34 move relative to each other, the air-floating plate 34 cuts the lines of magnetic force to generate eddy currents and damping forces. The movement speed is directly proportional, and the direction is consistent with the driving force directions of the X and Y direction voice coil motors 8 and 9, so as to consume vibration energy and improve positioning stability.

Figure 11 and Figure 15 show another embodiment of the X, Y direction eddy current damper. In this embodiment, the vibration isolator has an X-direction eddy current damper 40 and a Y-direction eddy current damper 41, which are respectively composed of arrays of X- and Y-direction permanent magnets 40A and 41A installed on the side wall of the lower surface of the sleeve 6 . The permanent magnets 40A and 41A in the X and Y directions are elongated, arranged along the driving force directions of the voice coil motors 8 and 9 in the X and Y directions respectively, the direction of the magnetic poles is perpendicular to the lower surface of the sleeve 6, and the N and S poles are arranged alternately .

Claims (10)

1. An eddy current damping vibration isolator with double-layer air flotation orthogonal decoupling and two-dimensional flexible hinge angle decoupling, consisting of an upper mounting plate (1), a lower mounting plate (2), and a clean compressed air source (3) , air pipe (26) and vibration isolator main body (4), the vibration isolator main body (4) is installed between the upper mounting plate (1) and the lower mounting plate (2), and the clean compressed air source (3) passes through the air pipe ( 26) Connected with the vibration isolator main body (4), it is characterized in that: in the structure of the vibration isolator main body (4), the lower surface of the sleeve (6) and the air floating plate (34) pass through the axial bearing plane air The floating surface (21) is lubricated and supported, the piston cylinder (5) is installed in the sleeve (6) undercut, and is lubricated and supported with the sleeve (6) through the radial bearing cylindrical air bearing surface (22), and the two-dimensional flexible hinge ( 7) Installed between the piston cylinder (5) and the upper mounting plate (1), the lower surface of the X-direction air bearing guide rail (29) is rigidly connected to the air bearing plate (34), and the sleeve (6) is connected to the X-direction air bearing The guide rail (29) is lubricated and guided by the air bearing surface (31) of the X guide rail, the lower surface of the Y direction air bearing guide rail (30) is rigidly connected with the lower mounting plate (2), and the air bearing plate (34) is connected with the lower mounting plate (2). ) is lubricated and supported by the bearing air bearing surface (33) in the Z direction, and the air bearing plate (34) and the air bearing guide rail (30) in the Y direction are lubricated and guided by the air bearing surface (32) of the Y direction guide rail; the voice coil motor (10) in the Z direction , Z direction displacement sensor (13), Z direction limit switch (16), Z direction eddy current damper (42) are installed between piston cylinder (5) and sleeve (6), X direction voice coil motor (8 ), X-direction displacement sensor (11), X-direction limit switch (14), X-direction eddy current damper (40), Y-direction eddy current damper (41) are installed on sleeve (6) and air bearing plate ( 34), the Y direction voice coil motor (9), the Y direction displacement sensor (12), and the Y direction limit switch (15) are installed between the air floating plate (34) and the lower mounting plate (2); the Z direction The direction of the driving force of the voice coil motor (10) is the vertical direction, the directions of the driving force of the X-direction voice coil motor (8) and the Y-direction voice coil motor (9) are in the horizontal plane and perpendicular to each other, and the X, Y and Z directions are displaced The direction of the action line of the sensor (11, 12, 13) and the X, Y, Z direction limit switch (14, 15, 16) and the direction of the driving force of the X, Y, Z direction voice coil motor (8, 9, 10) Consistent, the damping force directions of the X, Y, Z direction eddy current dampers (40, 41, 42) are respectively consistent with the driving force directions of the X, Y, Z direction voice coil motors (8, 9, 10); X, Y , Z direction displacement sensor (11,12,13) and X, Y, Z direction limit switch (14,15,16) is connected with the signal input terminal of controller (19) respectively, the signal output of controller (19) The end is connected with the signal input end of the driver (20), and the signal output end of the driver (20) is respectively connected with the X, Y, and Z direction voice coil motors (8, 9, 10). 2. The eddy current damping vibration isolator with double-layer air bearing orthogonal decoupling and two-dimensional flexible hinge angle decoupling according to claim 1, characterized in that: the X-direction eddy current damper (40) consists of a sleeve The side wall of the lower surface of the cylinder (6) is composed of an X-direction permanent magnet (40A) installed along the direction of the driving force of the X-direction voice coil motor (8), and the Y-direction eddy current damper (41) is formed by the side wall of the lower surface of the sleeve (6). The Y-direction permanent magnet (41A) installed along the driving force direction of the Y-direction voice coil motor (9) is formed, and the Z-direction eddy current damper (42) is formed by the inner cylinder side wall of the sleeve (6) along the Z-direction voice coil motor ( 10) Z-direction permanent magnets (42A) installed in the driving force direction, the magnetic pole directions of X, Y, and Z-direction permanent magnets (40A, 41A, 42A) are perpendicular to the surface of the sleeve (6), and the N and S poles alternate Arrangement, sleeve (6) adopts ferromagnetic material, and piston barrel (5) and air-floating plate (34) adopt nonmagnetic good conductor material. 3. The eddy current damping vibration isolator with double-layer air bearing orthogonal decoupling and two-dimensional flexible hinge angle decoupling according to claim 1, characterized in that: the piston cylinder (5) is provided with a gas pressure sensor (17), the piston cylinder (5) is provided with an air inlet (23) and a solenoid valve (18), and the gas pressure sensor (17) is connected with the signal input end of the controller (19), and the signal of the controller (19) The output end is connected with the signal input end of the driver (20), and the signal output end of the driver (20) is connected with the electromagnetic valve (18). 4. The eddy current damping vibration isolator with double-layer air bearing orthogonal decoupling and two-dimensional flexible hinge angle decoupling according to claim 1, characterized in that: the X, Y, Z direction voice coil motors (8 , 9, 10) are cylindrical voice coil motors or flat voice coil motors. 5. The eddy current damping vibration isolator with double-layer air bearing orthogonal decoupling and two-dimensional flexible hinge angle decoupling according to claim 1, characterized in that: the X-direction air bearing guide rail (29) and the Y-direction The air bearing guide rail (30) is a single guide rail structure or a double guide rail structure. 6. The eddy current damping vibration isolator with double-layer air bearing orthogonal decoupling and two-dimensional flexible hinge angle decoupling according to claim 1, characterized in that: said X, Y, Z direction displacement sensors (11, 12, 13) are grating scale, magnetic scale, capacitive scale or linear potentiometer. 7. The eddy current damping vibration isolator with double-layer air bearing orthogonal decoupling and two-dimensional flexible hinge angle decoupling according to claim 1, characterized in that: the X, Y, Z direction limit switches (14 , 15, 16) are mechanical limit switches, Hall-type limit switches or photoelectric limit switches. 8. The eddy current damping vibration isolator with double-layer air bearing orthogonal decoupling and two-dimensional flexible hinge angle decoupling according to claim 1, characterized in that: the gas pressure in the piston cylinder (5) is 0.1MPa ~0.8MPa. 9. The eddy current damping vibration isolator with double-layer air bearing orthogonal decoupling and two-dimensional flexible hinge angle decoupling according to claim 1, characterized in that: the axial bearing plane air bearing surface (21), diameter The thickness of the air film on the bearing cylindrical air bearing surface (22), the X guiding guide air bearing surface (31), the Y guiding guide air bearing surface (32) and the Z bearing air bearing surface (33) is 10 μm to 20 μm. 10. The electric eddy current damping vibration isolator with double-layer air bearing orthogonal decoupling and two-dimensional flexible hinge angle decoupling according to claim 1, characterized in that: the cylindrical air bearing surface section on the piston barrel (5) The diameter of the flow hole (25) and the plane air bearing surface throttle hole (24) on the sleeve (6) is φ0.1mm～φ1mm.