Six-degree-of-freedom active vibration isolation system for precision equipment with moving sliding table

Abstract

The six-degree-of-freedom active vibration isolation system comprises a panel and four vibration isolators, the four vibration isolators are installed at the four corners of the bottom of the panel, the bottoms of the vibration isolators are installed at the top of a concrete base, the sliding table is installed at the top of the panel, a guide rail is installed at the top of the sliding table, and the movable sliding table is installed on the guide rail. A sliding block is installed on the guide rail, damping alloy is installed on the left side and the right side of the sliding table, rubber is installed between the four corners of the bottom of the sliding table and the panel, copper foil is further installed between the top of the rubber and the bottom of the sliding table, and the position between the bottom of the sliding table and the panel is coated with a copper-nickel composite coating. The six-degree-of-freedom vibration control and precise positioning can be achieved, the vibration isolation belt is wider, vibration isolation of a 0.1-300 Hz vibration source can be achieved, the positioning precision can reach 0.5 micrometer, the bearing capacity is large, the 7000 kg bearing requirement can be met, the six-degree-of-freedom vibration isolation device can adapt to precise instruments of different models, the application range is wide, and the universality is high.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vibration control, and particularly relates to a six-degree-of-freedom active isolation system for a precision device with a moving slide table. BACKGROUND

[0002] At present, the semiconductor industry is developing rapidly, and the precision requirements of semiconductor production equipment are higher and higher. The equipment is more and more sensitive to the environment such as micro-vibration. A little micro-vibration will reduce the yield of the equipment, and even the equipment cannot work normally. Especially for the equipment with a slide table, such as a semiconductor detection device, it may face the problems of high speed, high load or frequent start-stop working conditions, and the influence of "dynamic change of center of gravity" caused by the movement of the slide table on the stability of the isolation system. The existing isolation technology (such as spring and air bag) has limitations in dynamic response and durability, and cannot meet the isolation requirements of the equipment with a slide table. SUMMARY

[0003] The present application aims to provide a six-degree-of-freedom active isolation system for a precision device with a moving slide table, so as to solve the problems in the background art.

[0004] The technical scheme of the present application is implemented as follows: a six-degree-of-freedom active vibration isolation system for a precision device with a moving slide table, comprising a panel and a vibration isolator, the vibration isolator is installed at four corners of the bottom of the panel, the bottom of the vibration isolator is installed on the top of a concrete base, the top of the panel is provided with a slide table, the top of the slide table is provided with a guide rail, a sliding block is installed on the guide rail, damping alloy is installed on the left and right sides of the slide table, rubber is installed between the four corners of the bottom of the slide table and the panel, copper foil is further installed between the top of the rubber and the bottom of the slide table, a copper-nickel composite coating is coated between the bottom of the slide table and the panel, the vibration isolator comprises a top plate and an air chamber, a piston is installed in the air chamber, the top of the piston is connected with the top of the air chamber through an air film, a guide rod is vertically installed in the piston, the bottom of the piston is in a convex structure, four support rods are vertically installed around the bottom of the air chamber and below the piston, an upper plate spring is installed in parallel between the upper part of the support rod and the convex bottom of the piston, a lower plate spring is installed below the upper plate spring between the middle of the support rod and the convex bottom of the piston, a magnetorheological elastomer is installed at the four corners of the bottom of the air chamber, a coil is installed outside the magnetorheological elastomer, a vertical voice coil motor is installed on the top of the right side and the back side of the air chamber, a vertical piezoelectric driver is installed on the top of the left side and the front side of the air chamber, a baffle is vertically installed around the bottom of the top plate, a horizontal voice coil motor is installed below the vertical voice coil motor between the top of the right side and the back side of the air chamber and the baffle, a horizontal piezoelectric driver is installed below the vertical piezoelectric driver between the top of the left side and the front side of the air chamber and the baffle, a flexible ball hinge A is further installed between the vertical piezoelectric driver and the top plate, a flexible ball hinge B is further installed between the horizontal piezoelectric driver and the baffle, an air inlet pipe is formed on one side of the bottom of the air chamber, a servo valve is further installed on the air inlet pipe, a vertical position sensor, a vertical acceleration sensor, a horizontal left-right position sensor, a horizontal left-right acceleration sensor, a horizontal front-back position sensor and a horizontal front-back acceleration sensor are embedded in the bottom of the top plate, and a controller is installed on the top of the concrete base.

[0005] The top of the support rod has a gap with the piston, and the support rod also has a limiting function to avoid damage to the air chamber caused by overload of the top equipment.

[0006] The upper plate spring is three pieces, and the lower plate spring is two pieces.

[0007] The vertical voice coil motor and the vertical piezoelectric driver are fixedly installed on the air chamber through a support.

[0008] The horizontal voice coil motor and the horizontal piezoelectric driver are fixedly installed on the air chamber through a connecting plate.

[0009] The magnetorheological elastomer and the coil are further provided with a pad between the bottom and the concrete base.

[0010] The controller is connected via cables to a vertical position sensor, a vertical acceleration sensor, a horizontal left-right position sensor, a horizontal left-right acceleration sensor, a horizontal forward-backward position sensor, a horizontal forward-backward acceleration sensor, a coil, a servo valve, a vertical voice coil motor, a vertical piezoelectric actuator, a horizontal voice coil motor, and a horizontal piezoelectric actuator. Furthermore, the aforementioned The beneficial effects of this invention are as follows: This invention achieves load bearing through an air chamber and a magnetorheological elastomer, and adjusts the system stiffness through the series interaction of the two.

[0011] This invention addresses the high-frequency vibrations generated by the movement of a sliding table by: first, absorbing the vibrations with a damping alloy; then, absorbing the vibrations with damping sand; next, further absorbing and reducing vibrations through the damping effect of rubber, and increasing the shear strain of the rubber with copper foil to maximize shear strain and enhance vibration reduction; second, further enhancing the vibration reduction effect by strengthening contact damping with a copper-nickel composite coating; further reducing vibrations by adjusting the air pressure in the air chamber; then, performing two rounds of vibration reduction through the parallel action of the upper and lower leaf springs; and finally, further reducing vibrations through the damping effect of a magnetorheological elastomer. Through these eight combined vibration reduction actions, the high-frequency vibrations generated by the movement of the sliding table are suppressed.

[0012] When suppressing low-frequency vibrations, the present invention first performs feedforward control vibration reduction through a vertical piezoelectric actuator, and then performs compensation vibration reduction through a vertical voice coil motor; in the horizontal direction, it first performs feedforward control vibration reduction through a transverse piezoelectric actuator, and then performs compensation vibration reduction through a transverse voice coil motor.

[0013] In this invention, the upper and lower leaf springs work in parallel, resulting in high stiffness and rapid deformation recovery. As passive components, they enable rapid response and positioning of the slide table. Furthermore, the controller controls the current in the coil, thereby controlling the magnetic field strength and the stiffness of the magnetorheological elastomer, achieving dynamic and rapid response. Vertically, the vertical piezoelectric actuator achieves rapid positioning via feedforward control, followed by compensation positioning via a vertical voice coil motor. Horizontally, the transverse piezoelectric actuator achieves rapid positioning via feedforward control, followed by compensation positioning via a transverse voice coil motor. The combined action of the piezoelectric actuator and the voice coil motor enables rapid and precise positioning of the slide table.

[0014] This invention can achieve vibration control and precise positioning with six degrees of freedom. It has a wider vibration isolation band, can isolate vibration sources from 0.1 to 300 Hz, and has a positioning accuracy of up to 0.5 μm. It has a large load capacity, can meet the load requirement of 7000 kg, and can be adapted to different types of precision instruments. It has a wide range of applications and strong versatility. Attached Figure Description

[0015] Fig. 1 This is a schematic diagram of the structure of the present invention.

[0016] Fig. 2 This is a schematic diagram of an active vibration isolator.

[0017] In the diagram: 1-Panel, 2-Isolator, 201-Top plate, 202-Air chamber, 203-Piston, 204-Air film, 205-Guide rod, 206-Support rod, 207-Upper leaf spring, 208-Lower leaf spring, 209-Magnetorheological elastomer, 210-Coil, 211-Vertical voice coil motor, 212-Vertical piezoelectric actuator, 213-Baffle, 214-Transverse voice coil motor, 215-Transverse piezoelectric actuator, 216-Flexible ball joint A, 217-Flexible ball joint B, 218-Inlet pipe, 219-Servo valve, 220 - Vertical position sensor, 221 - Vertical acceleration sensor, 222 - Horizontal left-right position sensor, 223 - Horizontal left-right acceleration sensor, 224 - Horizontal forward-backward position sensor, 225 - Horizontal forward-backward acceleration sensor, 226 - Bracket, 227 - Connecting plate, 228 - Pad, 3 - Concrete base, 4 - Slide table, 401 - Slider, 402 - Guide rail, 403 - Cast iron, 404 - Damping sand, 5 - Controller, 6 - Damping alloy, 7 - Copper-nickel composite coating, 8 - Copper foil, 9 - Rubber. Detailed Implementation

[0018] 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.

[0019] like Figs. 1-2As shown, a six-degree-of-freedom active vibration isolation system for precision equipment with a moving slide table includes a panel 1 and a vibration isolator 2, the vibration isolator 2 is installed at the four corners of the bottom of the panel 1, the bottom of the vibration isolator 2 is installed on the top of the concrete base 3, the top of the panel 1 is installed with a slide table 4, the top of the slide table 4 is installed with a guide rail 402, the guide rail 402 is installed with a sliding block 401, the left and right sides of the slide table 4 are installed with damping alloy 6, the bottom of the slide table 4 is installed with rubber 9 between the four corners and the panel 1, the top of the rubber 9 is installed with copper foil 8 between the bottom of the slide table 4, the bottom of the slide table 4 is coated with copper-nickel composite coating 7 between the panel 1, the vibration isolator 2 includes a top plate 201 and an air chamber 202, the air chamber 202 is installed with a piston 203, the top of the piston 203 is connected with the top of the air chamber 202 through the air film 204, the inside of the piston 203 is vertically installed with a guide rod 205, the bottom of the piston 204 is in convex structure, the bottom of the inside of the air chamber 202 and the four around below the piston 203 are vertically installed with four support rods 206, the upper part of the support rod 206 is parallelly installed with the upper plate spring 204 between the bottom convex of the piston 203, the lower part of the support rod 206 is installed with the lower plate spring 208 between the bottom convex of the piston 203 and below the upper plate spring 207, the four corners of the bottom of the air chamber 202 are respectively installed with magnetorheological elastomers 209, the outside of the magnetorheological elastomers 209 is installed with coils 210, the right side and the back side top of the air chamber 202 are installed with vertical voice coil motors 211, the left side and the front side top of the air chamber 202 are respectively installed with vertical piezoelectric actuators 212, the bottom of the top plate 201 is vertically installed with baffles 213, the right side and the back side top of the air chamber 202 are respectively installed with horizontal voice coil motors 214 below the vertical voice coil motors 211 between the baffles, the left side and the front side top of the air chamber 202 are respectively installed with horizontal piezoelectric actuators 215 below the vertical piezoelectric actuators 212 between the baffles 213, the vertical piezoelectric actuators 212 and the top plate 201 are further installed with flexible ball hinges A 216, the horizontal piezoelectric actuators 217 and the baffles 213 are further installed with flexible ball hinges B 217, one side of the bottom of the air chamber 202 is provided with an air inlet pipe 218, the air inlet pipe 218 is further installed with a servo valve 219, the bottom of the top plate 201 is further embedded with a vertical position sensor 220, a vertical acceleration sensor 221, a horizontal left-right position sensor 222, a horizontal left-right acceleration sensor 223, a horizontal front-back position sensor 224, and a horizontal front-back acceleration sensor 225, the top of the concrete base 3 is further installed with a controller.

[0020] The top of the support rod 206 has a gap with the piston 203, and the support rod 206 also has a limiting function to avoid damage to the air chamber 202 caused by overload of the top equipment.

[0021] The upper plate spring 207 is three pieces, and the lower plate spring 208 is two pieces.

[0022] The vertical voice coil motor 211 and the vertical piezoelectric driver 212 are fixedly installed with the air chamber 202 through the support 226.

[0023] The horizontal voice coil motor 214 and the horizontal piezoelectric driver 215 are fixedly installed with the air chamber through the connecting plate 227.

[0024] The cushion plate 228 is further installed between the magnetorheological elastomer 209, the bottom of the coil 210 and the concrete base 3.

[0025] The controller 5 is connected with the vertical position sensor 220, the vertical acceleration sensor 221, the horizontal left-right position sensor 222, the horizontal left-right acceleration sensor 223, the horizontal front-back position sensor 224, the horizontal front-back acceleration sensor 225, the coil 210, the servo valve 219, the vertical voice coil motor 211, the vertical piezoelectric driver 212, the horizontal voice coil motor 214 and the horizontal piezoelectric driver 215 through the cable.

[0026] During installation, the precision instrument is installed on the sliding block 401, and according to the requirements of the precision instrument, the controller 5 controls the servo valve 219 to control the air pressure of the air chamber 202, so as to realize the bearing requirement of the top precision instrument, and at the same time, the positive stiffness of the system can be adjusted, in addition, the controller 5 controls the current size of the coil 210 to control the magnetic field strength, so as to control the stiffness of the magnetorheological elastomer 209, and then form a series structure with the air chamber 202, and together realize the adjustment of the stiffness of the system.

[0027] During work, the vibration signals are collected through the vertical position sensor 220, the vertical acceleration sensor 221, the horizontal left-right position sensor 222, the horizontal left-right acceleration sensor 223, the horizontal front-back position sensor 224 and the horizontal front-back acceleration sensor 225, and then the vibration signals are transmitted to the controller 5. The high-frequency vibration generated by the movement of the sliding table 401 is firstly absorbed by the damping alloy 6; then, the vibration is absorbed by the damping sand 404; then, the vibration is further absorbed by the damping effect of the rubber 9, and the shear strain of the rubber 9 is increased by the copper foil 8, so that the maximum shear strain is generated, and the damping effect is improved; secondly, the contact damping is further improved by the copper-nickel composite coating 7; in addition, the damping effect is further realized by the air pressure of the air chamber 2; then, the vibration is damped twice by the parallel action of the upper plate spring 207 and the lower plate spring 208; finally, the vibration is further damped by the damping effect of the magnetorheological elastomer 209; the high-frequency vibration generated by the movement of the sliding table 401 is suppressed by eight times of combined damping effect.

[0028] When low-frequency vibration occurs, in the vertical direction, the vertical piezoelectric driver 212 is used for feedforward control to reduce vibration, and then the vertical voice coil motor 211 is used for compensation to reduce vibration; in the horizontal direction, the horizontal piezoelectric driver 215 is used for feedforward control to reduce vibration, and then the horizontal voice coil motor 214 is used for compensation to reduce vibration.

[0029] In addition, the upper leaf spring 207 and the lower leaf spring 208 act in parallel, have large rigidity, and have fast recovery of deformation, as passive elements, can quickly respond to positioning of the slide table 401, and secondly, the current of the coil 210 is controlled by the controller 5 to control the magnetic field strength, so as to control the rigidity of the magneto-rheological elastomer 209, and dynamic fast response can be realized. In the vertical direction, the vertical piezoelectric driver 212 can be quickly positioned through feedforward control, and then the vertical voice coil motor 211 is used for compensation positioning; in the horizontal direction, the horizontal piezoelectric driver 215 can be quickly positioned through feedforward control, and then the horizontal voice coil motor 214 is used for compensation positioning; through the combined action of the piezoelectric driver and the voice coil motor, the slide table 401 can be quickly and accurately positioned.

[0030] The above only describes the preferred embodiments of the present application and is not used to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A six-degree-of-freedom active isolation system for precision equipment with a moving slide table, comprising a panel and an isolator, characterized in that, The vibration isolator is installed at four corners of the bottom of the panel, the bottom of the vibration isolator is installed on the top of the concrete base, the top of the panel is installed with a sliding table, the top of the sliding table is installed with a guide rail, the guide rail is installed with a sliding block, the left and right sides of the sliding table are installed with damping alloy, the bottom of the sliding table is installed with rubber between the four corners and the panel, the top of the rubber is installed with copper foil between the bottom of the sliding table, the bottom of the sliding table is coated with copper-nickel composite coating between the panel, the vibration isolator comprises a top plate and a gas chamber, the gas chamber is installed with a piston, the top of the piston is connected with the top of the gas chamber through a gas film, the inside of the piston is vertically installed with a guide rod, the bottom of the piston is in convex structure, the bottom of the inside of the gas chamber and the four around the bottom of the piston are vertically installed with four supporting rods, the upper part of the supporting rod is parallelly installed with an upper plate spring between the convex bottom of the piston, the middle of the supporting rod is installed with a lower plate spring below the upper plate spring between the convex bottom of the piston, the four corners of the bottom of the gas chamber are respectively installed with a magnetorheological elastomer, the outside of the magnetorheological elastomer is installed with a coil, the right side and the back side of the top of the gas chamber are installed with a vertical voice coil motor, the left side and the front side of the top of the gas chamber are respectively installed with a vertical piezoelectric driver, the bottom of the top plate is vertically installed with a baffle, the right side and the back side of the top of the gas chamber are respectively installed with a horizontal voice coil motor below the vertical voice coil motor between the baffle, the left side and the front side of the top of the gas chamber are respectively installed with a horizontal piezoelectric driver below the vertical piezoelectric driver between the baffle, the vertical piezoelectric driver and the top plate are further installed with a flexible ball hinge A, the horizontal piezoelectric driver and the baffle are further installed with a flexible ball hinge B, one side of the bottom of the gas chamber is provided with an air inlet pipe, the air inlet pipe is further installed with a servo valve, the bottom of the top plate is further embedded with a vertical position sensor, a vertical acceleration sensor, a horizontal left-right position sensor, a horizontal left-right acceleration sensor, a horizontal front-back position sensor, a horizontal front-back acceleration sensor, the top of the concrete base is further installed with a controller.

2. The six-degree-of-freedom active vibration isolation system for precision equipment with a moving slide table according to claim 1, characterized in that, The top of the supporting rod has a gap with the piston, and the supporting rod also has a limiting function to avoid damage to the gas chamber caused by overload of the top equipment.

3. The six-degree-of-freedom active vibration isolation system for precision equipment with a moving slide table according to claim 1, wherein, The upper plate spring is three pieces, and the lower plate spring is two pieces.

4. The six-degree-of-freedom active vibration isolation system for precision equipment with a moving slide table according to claim 1, wherein, The vertical voice coil motor and the vertical piezoelectric driver are fixedly installed with the gas chamber through a support.

5. The six-degree-of-freedom active vibration isolation system for precision equipment with a moving slide table according to claim 1, wherein, The horizontal voice coil motor and the horizontal piezoelectric driver are fixedly installed with the gas chamber through a connecting plate.

6. The six-degree-of-freedom active vibration isolation system for precision equipment with a moving slide table according to claim 1, wherein, The bottom of the magnetorheological elastomer and the coil is further installed with a pad between the concrete base.

7. The six-degree-of-freedom active vibration isolation system for precision equipment with a moving slide table according to claim 1, wherein, The controller is connected with the vertical position sensor, the vertical acceleration sensor, the horizontal left-right position sensor, the horizontal left-right acceleration sensor, the horizontal front-back position sensor, the horizontal front-back acceleration sensor, the coil, the servo valve, the vertical voice coil motor, the vertical piezoelectric driver, the horizontal voice coil motor and the horizontal piezoelectric driver through a cable.

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