JPH0545284U - Actuator for vibration isolation table - Google Patents

Abstract

(57) [Summary] [Purpose] To provide an actuator for an anti-vibration table capable of promptly switching between active anti-vibration and passive anti-vibration. [Structure] An air spring 1a for supporting a surface plate 2, a spring portion 1 fixed to the air spring and provided with magnets 1b, 1c, 1d, and a pedestal portion 4 provided with coils 4b, 4c, 4d at positions facing the magnets. Consists of. [Effect] By switching the energization of the coil of the gantry,
The excitation of the coil is turned on / off, the reaction between the coil and the magnet of the spring portion is switched, and active vibration isolation and passive vibration isolation can be quickly selected.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a vibration isolation table actuator, and more particularly to a vibration isolation table actuator including an air spring, a magnet, and a coil.

[0002]

[Prior Art]

 Electron microscopes that apply electron beams, precision equipment such as holography equipment, and LSI manufacturing equipment such as steppers are used by being mounted on a vibration isolation device to prevent optical path obstruction, alignment, and shorten processing time. .. The anti-vibration device includes a passive anti-vibration device that damps vibrations by vibration absorbing means such as air springs, coil springs, and anti-vibration rubber, as well as self-excitation of the precision equipment itself and the natural frequency of the anti-vibration device surface plate. On the other hand, each motion component in the X-axis, Y-axis, and Z-axis directions of the surface plate is detected, and the active damper is activated in the opposite phase corresponding to the motion component in each direction to actively perform vibration isolation. Active vibration isolation devices are used.

In this active vibration isolator, as shown in FIG. 5, a surface plate 2 on which a precision instrument 9 is mounted is supported by a passive brake 50 from a pedestal 40 fixed to a floor 30, and a surface plate is also provided. The vibration of the surface plate 2 is detected by the sensor 60 attached to 2, and the signal of the sensor 60 is amplified by the preamplifier 70, processed by the detection signal control unit 80, amplified by the power amplifier 90, and then the surface plate 2 is processed. The active brake element 10 is actuated so as to excite the vibration in the opposite phase of the generated vibration, and quick vibration isolation is performed. Although FIG. 5 illustrates the vibration isolation of one motion component, it is general to perform the vibration isolation in at least three directions.

An electromagnetic actuator, in particular, a linear motor such as a voice coil motor (VCM) is used as the active brake element 10 of such an active vibration isolator, and the precision vibration isolator (VCM) suppresses the leakage magnetic flux of the VCM ( The applicant of the present invention has proposed, for example, Japanese Unexamined Patent Publication No. 2-190640 and Japanese Unexamined Patent Publication No. 2-228712), or a precision vibration isolator (Japanese Unexamined Patent Publication No. 3-84235) that introduces a servo by liquid operation. ..

[0005]

[Problems to be solved by the device]

 In the conventional precision vibration isolator described above, the performance of the active brake element, which is the actuator for the vibration isolation table, was improved, but it is easy to switch to passive braking without active braking, and only passive braking. There has been a demand for the development of a precision vibration isolator that can be easily switched to active braking again.

[0006]

【Purpose】

 The present invention has been made to solve the above-mentioned conventional problems, and it is an object of the present invention to provide an actuator for an anti-vibration table that can quickly switch between active anti-vibration and passive anti-vibration as needed. To aim.

[0007]

[Means for Solving the Problems]

 In order to achieve the above object, an actuator for an anti-vibration table according to the present invention includes a spring portion having an air spring supporting a surface plate and a magnet fixed to the air spring, and a coil at a position facing the magnet. And a pedestal part provided with.

[0008]

[Action]

 By energizing the coil, the coil of the gantry and the magnet at the opposite position function to perform active vibration isolation. By de-energizing the coil, it is possible to easily switch to passive vibration isolation using only the air spring.

[0009]

【Example】

 Hereinafter, embodiments of an actuator for a vibration isolation table according to the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, an anti-vibration table actuator according to the present invention includes a spring portion 1 (FIG. 1A) that supports a surface plate 2 and a pedestal portion 4 (FIG. 1) that supports or floats the spring portion 1. (B)). The spring portion 1 is composed of an air spring 1a for supporting the surface plate 2, and a casing 1m provided with permanent magnets 1b, 1c, 1d in a plurality of directions thereunder, and the gantry portion 4 includes a horizontal coil 4b, It is composed of a plurality of side wall portions 4q and 4q having 4c and a bottom surface portion 4p having a vertical coil 4d.

The gantry unit 4 is installed on the floor 3 (FIG. 2), and the vertical coil 4d of the gantry unit 4 corresponds to the permanent magnet 1d on the bottom surface of the casing 1m among the permanent magnets of the spring unit 1. The horizontal coils 4b, 4c are provided at positions corresponding to the permanent magnets 1b, 1c on the side surface of the permanent magnet of the spring portion 1, respectively, and the coils 4b, 4c, 4d are the permanent magnets of the spring portion 1. It is arranged so as to cover 1b, 1c, and 1d.

As shown in FIG. 3, the anti-vibration table actuator according to the present invention is usually installed on the lower four sides of the surface plate with the coils 4b and 4c oriented in the optimum directions. The number of coils 4 of each gantry unit 4 is not limited to three. The anti-vibration table to which the actuator for the anti-vibration table according to the present invention is applied has a structure as shown in FIG. 2 when viewed from the side, and the frame 1m of the spring part 1 (air band 1a and case 1m) is attached to the frame part 4. Is covered.

When performing active vibration isolation, the signal detected by the sensor 6 installed on the surface plate 2 is amplified by the preamplifier 7, processed by the control unit 8, amplified by the power amplifier 9, and then the surface plate. The vibration isolation table actuator according to the present invention is operated as an active brake element composed of the spring portion 1 and the pedestal portion 4 so as to excite the vibration of the opposite phase to that generated in the vibration 2 (FIG. 4).

That is, the coils 4b, 4c, and 4d of the gantry unit 4 are excited by the signal from the control unit 8 for exciting the vibration having the opposite phase to the vibration generated on the surface plate 2, and the respective coils are excited. The spring portion 1 including the air spring 1a and the permanent magnets 1b, 1c, 1d that react with the permanent magnets 1b, 1c, 1d of the spring portion 1 at corresponding positions and support the surface plate 2 depending on the magnitude of the repulsive force. Is levitated or tilted to perform quick vibration isolation.

When only passive vibration isolation is required, when the feedback cycle of the surface plate 2-sensor 6-preamplifier 7-control unit 8-power amplifier 9-actuator-surface plate 2 is cut off, the magnet 1d of the spring unit 1 , The bottom part 4p (coil 4d) of the gantry part 4 is contacted, and only the spring part 1 functions. If the output part for levitation of the spring part 1 is provided in addition to the actuator output for canceling the vibration, the spring part 1 can be always levitated.

When superconducting wires are used for the windings of the coils 4b, 4c, and 4d of the above-mentioned embodiment and a refrigerating device is mounted around the coils, a superconducting actuator is obtained, a larger output is obtained, and heat generation of the coils is prevented. To be done.

[0016]

[Effect of the device]

 As is clear from the above embodiments, the vibration isolation table actuator according to the present invention includes a spring portion having an air spring supporting the surface plate and a magnet fixed to the air spring, and a coil at a position facing the magnet. Since it consists of the pedestal part provided, it is possible to quickly switch between active vibration isolation and passive vibration isolation as needed by switching the power supply to the coil.

[Brief description of drawings]

FIG. 1 is a view showing a structure of an anti-vibration table actuator according to the present invention, in which (a) is a perspective view illustrating a spring portion thereof;
(B) is a perspective view explaining the gantry part provided with the coil.

FIG. 2 is a diagram illustrating a vibration isolation table to which the vibration isolation actuator according to the present invention is applied.

FIG. 3 is a plan view illustrating an arrangement of a gantry unit including coils of the vibration isolation actuator according to the present invention.

FIG. 4 is a diagram illustrating control of an active vibration isolation table.

FIG. 5 is a diagram illustrating a conventional vibration isolation table.

[Explanation of Codes] 1 ... Spring part 1a ... Air spring 1b, 1c, 1d ... Magnet 1m ... Casing 2, 20 ... Surface plate 3, 30 ... Floor 4 ... Frame part 4b, 4c ... Horizontal coil 4d ... Vertical use Coil 4p ... Bottom part 4q ... Side wall part 6, 60 ... Sensor 10 ... Actuator 40 ... Stand 7, 70 ... Preamplifier 8, 80 ... Control part 9, 90 ... Power amplifier

Claims (1)

[Scope of utility model registration request] 1. A remover comprising a spring portion having an air spring for supporting a surface plate and a magnet fixed to the air spring, and a pedestal portion provided with a coil at a position facing the magnet. Shaking table actuator.