JP2000002289A - Vibration eliminating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration eliminating device which can simply apply proper pre-load to a vibration controlling actuator. SOLUTION: A clearance adjusting member 12 is arranged between a lamination rubber 28 and a piezoelectric element 26. The clearance adjusting member is prepared by screwing a nut member 48 with a rod 44 formed with a left threaded screw and a rod 46 formed with a right threaded screw. The clearance adjusting member 12 is extended or contracted by turning the nut member 48, for adjusting pre-load to be applied to a vibration controlling actuator 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-vibration apparatus, and more particularly to an anti-vibration apparatus for actively controlling the vibration of a table on which anti-vibration equipment such as a semiconductor manufacturing facility is mounted.

[0002]

2. Description of the Related Art Generally, an anti-vibration apparatus is constructed by supporting an anti-vibration table on which anti-vibration equipment such as a semiconductor manufacturing facility is mounted in a vertical direction and a horizontal direction by a plurality of vibration control actuators. This vibration control actuator supports a vibration isolation table via an elastic body and a piezoelectric element, and reduces the vibration of the vibration isolation table by increasing or decreasing the voltage applied to the piezoelectric element.

By the way, in such a vibration control actuator using an elastic body and a piezoelectric element, the controllability of the piezoelectric element is required unless a predetermined load (hereinafter referred to as a preload) is applied in advance in the driving direction. And has a drawback that good vibration isolation effect cannot be obtained. In particular, when a plurality of vibration control actuators that perform horizontal vibration isolation are installed, an optimal vibration isolation effect cannot be obtained unless substantially equal preloads are applied to all the vibration control actuators.

Therefore, in the conventional vibration isolator, the bolts fixing the vibration control actuator to the floor or the like are once removed, and the vibration control actuator is tightened again while applying an external force in the driving direction by some method. By raising, a preload was given.

[0005]

However, the reason for fixing the vibration control actuator while applying an external force is as follows.
Not only is it a complicated operation, but it is difficult to apply an appropriate preload. In addition, if the preload is not appropriate, the bolt must be removed again, which has a problem that the preload of another vibration control actuator already fixed is affected. For this reason, it takes skill and time to apply an appropriate preload to all the vibration control actuators.

The present invention has been made in view of such circumstances, and has as its object to provide an anti-vibration apparatus that can easily apply an appropriate preload to a vibration control actuator.

[0007]

In order to achieve the above object, the present invention provides a vibration control actuator comprising an elastic body and a piezoelectric element arranged in series, comprising: In a vibration isolator interposed between a mounting part such as a floor surface and the like, a predetermined preload is applied in a driving direction of the piezoelectric element by a reaction force that compresses the elastic body, An interval adjusting means for adjusting an interval between the elastic body and the piezoelectric element is provided therebetween.

According to the present invention, the distance adjusting means is provided between the elastic body and the piezoelectric element, thereby adjusting the distance between the elastic body and the piezoelectric element. That is, when the distance between the elastic body and the piezoelectric element is increased, the amount of compression of the elastic body increases, and the load applied to the piezoelectric element increases. Conversely, when the distance between the elastic body and the piezoelectric element is reduced, the amount of compression of the elastic body increases. And the load applied to the piezoelectric element is reduced. Accordingly, the adjustment of the preload applied to the piezoelectric element can be performed in the vibration control actuator, so that the bolts fixing the vibration control actuator to the installation portion are once removed as in the related art, and the amount of compression of the elastic body is reduced. It is not necessary to perform a complicated operation of adjusting the temperature and fixing it to the installation portion again.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a vibration isolator according to the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 is a top view of a vibration isolation device 10 of the present invention, and shows an arrangement of vibration control actuators 24 and 30 interposed between a vibration isolation table 22 and a base 20 (see FIG. 2). still,
The arrow in the figure indicates the horizontal vibration control actuator 30.
Are shown.

As shown in FIG. 1, a vertical vibration control actuator 24 is provided below each of four corners of a rectangular vibration isolating table 22 on which anti-vibration equipment such as a semiconductor device is mounted.
Is provided. The vertical vibration control actuator 24 drives the anti-vibration table 22 in the vertical direction (the Z direction in FIG. 1) to vibrate the vertical vibration. The horizontal vibration control actuators 3 are provided below the vibration isolation table 22 near the vertical vibration control actuators 24, respectively.
0 is provided. By arranging the horizontal vibration control actuator 30 as shown in FIG.
The anti-vibration table 22 is driven in the horizontal direction to eliminate horizontal vibrations. That is, a pair of vibration control actuators 30 and 30 arranged at substantially one diagonal position of the four corners
1 (in the X direction in FIG. 1) and outward with respect to the vibration isolation table 22, and a pair of vibration control actuators 30 and 30 arranged in the other diagonal position are moved in the horizontal Y direction (Y in FIG. 1). Direction) and inward with respect to the vibration isolation table 22.

A plurality of vertical vibration detectors 32 for detecting vertical vibrations and a plurality of horizontal X-direction vibration detectors for detecting horizontal X-direction vibration are provided at four corners of the lower surface of the vibration isolation table 22. 34 and a plurality of horizontal Y sensors for detecting vibration in the horizontal Y direction.
A direction vibration detector 36 is attached. And
The vibration signals obtained by these detectors 32, 34, 36 are sent to a controller (not shown). The controller applies a drive voltage to each of the vibration control actuators 24 and 30 based on a preset program to drive the anti-vibration table 22, thereby isolating the vibration.

The above-described vibration control actuator 24,
30 has the same configuration except that the driving direction is different. Hereinafter, an example of the horizontal vibration control actuator 30 will be described. FIG. 2 is a longitudinal sectional view showing the state of attachment of the actuator 30 for vibration control.

As shown in FIG. 1, the vibration control actuator 30 mainly includes a piezoelectric element 26, a laminated rubber 28,
It is composed of the interval adjusting member 12 and the actuator body 14. The actuator body 14 is mounted on the base 20 with bolts 4.
The piezoelectric element 26 is fixed at 0 and 40 and is provided inside. The piezoelectric element 26 is supported by the actuator body 14 by the element enclosing elastic body 42 so as to be driven in the horizontal X direction (see FIG. 1). The element enclosing elastic body 42 may be anything as long as it is an elastic body, for example, a leaf spring or the like.
The laminated rubber 28 is supported on the piezoelectric element 26 via the gap adjusting member 12.

The laminated rubber 28 abuts or is connected to the vertical surface 54A of the mounting jig 54 on the lower surface of the vibration isolation table 22, and the shearing direction applied to the piezoelectric element 26 (the direction orthogonal to the driving direction of the piezoelectric element 26). ) Is absorbed to prevent the piezoelectric element 26 from being broken. Note that a rubber column or the like may be provided instead of the laminated rubber 28. The interval adjusting member 12 is mainly composed of a rod 44, a rod 46, and a nut member 48. One end of the rod 44 is supported by the piezoelectric element 26 via the flange 50, and a left-hand thread is provided on the other end. One end of the rod 46 is supported by the laminated rubber 28 via the flange 52, and a right-hand thread is provided at the other end. The directions of the threads of the rod 44 and the rod 46 may be reversed. The nut member 48 is, for example, a turnbuckle, and is configured to be coaxial with the rods 44 and 46 and screwed to the opposite side. Thus, when the nut member 48 is rotated in one direction, the screws of the rods 44 and 46 can be simultaneously tightened without rotating the laminated rubber 28 and the piezoelectric element 26.
That is, since the interval between the laminated rubber 28 and the piezoelectric element 26 is reduced, the reaction force of the laminated rubber 28 can be reduced, and the preload applied to the piezoelectric element 26 can be reduced. Similarly, when the nut member 48 is rotated in the opposite direction, the interval between the laminated rubber 28 and the piezoelectric element 26 can be increased.
The preload applied to 6 can be increased. Nuts 56, 56 are provided on both sides of the nut member 48,
When the piezoelectric element 26 is driven, the screws are prevented from loosening.

Next, regarding the operation of the vibration isolator configured as described above, the horizontal vibration control actuator 30 will be described.
An example will be described. First, the vibration control actuator 30
Are arranged as shown in FIG. 1, and the actuator body 14 is fixed to the base 20 with bolts 40. At this time, if the actuator main body 14 is fixed in a state where the screws of the rods 44 and 46 are tightened, there is no need to fix the actuator main body 14 while pushing it in the driving direction as in the related art.

Next, the nut member 48 of the gap adjusting member 12 is rotated in the direction in which the gap adjusting member 12 extends. As a result, the laminated rubber 28 is compressed, and a preload is applied to the vibration control actuator by the reaction force of the compressed laminated rubber 28. Then, the preload is finely adjusted by rotating the nut member 48, and an appropriate preload is applied to each of the vibration control actuators 30. At this time, there is no need to remove the bolt 40 to release the fixing of the actuator body 14, so that the preload can be easily and accurately adjusted without affecting the preload of the other actuators for vibration control. As described above, in each vibration control actuator 30, an appropriate preload can be easily applied, so that
The horizontal vibration of the vibration isolation table 22 can be efficiently removed. Note that the preload can be accurately measured by measuring the electromotive force of the piezoelectric element 26.

The same operation as described above is performed in the vertical vibration control actuator 24. That is, the preload applied by the anti-vibration table 22 and the anti-vibration device mounted on the anti-vibration table 22 is adjusted by rotating the nut member 48. Thereby, the vibration in the vertical direction of the vibration isolation table 22 can be reliably removed. In addition, since the preload is adjusted in each of the vibration control actuators 24, it is possible to cope with a case where the center of gravity is deviated by installing anti-vibration devices.

As described above, in the vibration isolator 10 according to the present invention, the laminated rubber 2 of the vibration control actuators 24 and 30 is used.
Since the expandable and contractible interval adjusting member 12 is provided between the piezoelectric element 8 and the piezoelectric element 26, the preload can be easily adjusted in the vibration control actuators 24 and 30. Therefore, the preload can be adjusted without releasing the fixing of the actuator body 14, so that an appropriate preload can be applied to all the vibration control actuators without affecting other vibration control actuators. .

Further, according to the present invention, when the gap adjusting member 12 is contracted by rotating the nut member 48, the piezoelectric element 26 and the like can be removed while the actuator main body 14 is fixed to the base 20. Therefore, it is possible to easily replace the piezoelectric element 26 and the like. Further, the vibration isolator 10 of the present invention
In this case, the interval between the laminated rubber 28 and the piezoelectric element 26 can be adjusted while the actuator body 14 is fixed to the base 20, so that a plurality of vibration control actuators that are driven in different directions can be integrated. For example, FIG. 3 shows an integrated structure of two vibration control actuators that are driven in a vertical direction and a horizontal direction, respectively.
In the vibration control actuator shown in the figure, a piezoelectric element 26 and a laminated rubber 28 are arranged in series in a vertical direction and a horizontal direction, respectively. 12 are provided respectively. Thus, the vertical and horizontal preloads can be adjusted by expanding and contracting the gap adjusting members 12, 12, respectively. As described above, by integrating the plurality of vibration control actuators driven in different directions into an integral structure, the time and space required for installing the vibration control actuator can be greatly reduced.

The spacing adjusting member 12 is not limited to the embodiment described above. For example, a nut member having a female screw is connected to the laminated rubber 28, a nut member having an opposite female screw is connected to the piezoelectric element 26, and a rod is screwed to the two nut members. The interval may be adjusted by rotating. Further, the distance may be adjusted using a drive device such as a hydraulic cylinder.

[0021]

As described above, in the vibration damping device according to the present invention, an appropriate preload can be easily and accurately applied to the piezoelectric element by the gap adjusting means disposed between the piezoelectric element and the elastic body. Can be. As a result, the vibration isolation effect can be improved, and the time for adjusting the preload can be significantly reduced as compared with the conventional case.

[Brief description of the drawings]

FIG. 1 is a top view of a vibration isolator according to the present invention.

FIG. 2 is a longitudinal sectional view of the vibration control actuator of FIG. 1;

FIG. 3 is a longitudinal sectional view in a case where an actuator for vibration control that is driven in a horizontal direction and a vertical direction is integrated.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Vibration isolator 12 ... Interval adjustment member 14 ... Actuator main body 24 ... Vertical vibration control actuator 26 ... Piezoelectric element 28 ... Laminated rubber 30 ... Horizontal vibration control actuator 44 ... (Piezoelectric element side) rod 46 ... (Laminated rubber side) Rod 48 Nut member

Claims (3)

[Claims] A vibration control actuator comprising an elastic body and a piezoelectric element arranged in series is interposed between an anti-vibration table on which an object to be anti-vibrated is mounted and an installation portion such as a floor surface. In a vibration isolator that applies a predetermined preload in a driving direction of the piezoelectric element by a reaction force that compresses a body, an interval between the elastic body and the piezoelectric element is adjusted between the elastic body and the piezoelectric element. An anti-vibration device characterized by comprising an interval adjusting means for performing the operation. 2. A vibration control actuator for performing horizontal vibration isolation and a vibration control actuator for performing vertical vibration isolation are integrally provided between the vibration isolation table and the installation portion. The vibration isolator according to claim 1, wherein: 3. An elastic body-side rod having one end fixed to the elastic body and a screw provided at the other end, and one end fixed to the piezoelectric element and the other end of the elastic body rod at the other end. The piezoelectric element-side rod provided with a screw in a direction opposite to the screw, and a nut member screwed to the screw of the elastic body-side rod and the screw of the piezoelectric element-side rod, respectively. Anti-vibration device.