JPH04307140A - Vibration isolator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a vibration isolator, and in particular, a vibration isolator used to prevent vibrations such as those caused by earthquakes and traffic vibrations from propagating to anti-vibration equipment such as precision equipment. Regarding.

0002

[Background Art] Conventionally, when installing anti-vibration equipment such as precision equipment on the floor of a factory, vibration isolation was used to prevent vibrations such as earthquake shaking and traffic vibration from propagating to the anti-vibration equipment. The device is in use. As shown in FIG. 4, this type of vibration isolator has a bottom pedestal 12 fixed on a factory floor 10 with bolts (not shown), and a vibration absorbing unit 1 mounted on the bottom pedestal 12.
A pedestal 16 is attached via 4 and 14. The vibration absorption unit 14 includes a plurality of laminated rubber (or springs)
18, 18... and stabilizers 20, 20... are stacked alternately and in a row, and four of them are arranged at the corners of the base 12 and the pedestal 16, and have a low natural frequency (about 1Hz). degree)
is configured to achieve this.

[0003] On the pedestal 16 is placed a precision instrument 22 indicated by a two-dot chain line in the figure. As a result, the floor surface 10
The vibrations propagated to the base 12 are isolated by passing through the vibration absorption units 14, 14, .

0004

[Problems to be Solved by the Invention] However, with conventional vibration isolators, vibrations from the floor 10 are difficult to propagate to the pedestal 16 and a sufficient vibration isolating effect is maintained. When placed, the X
- Excessive self-vibration generated when the Y stage 24 (in FIG. 4) moves propagates to the pedestal 16 as shown in FIG. be.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vibration isolator that can absorb and isolate excessive self-vibration when it occurs in anti-vibration equipment. shall be.

[0006]

[Means for Solving the Problem] In order to achieve the above object, the present invention provides a vibration isolator constructed by interposing a plurality of vibration absorbing units between a bottom stand and a pedestal on which an anti-vibration device is mounted. In the apparatus, a vibration sensor is attached to the pedestal and detects the amount of displacement or acceleration of the pedestal due to vibration; a lock means that can freely restrain the pedestal from the vibration absorption unit; a control device that transmits a signal to the locking means to restrain the pedestal for a predetermined period of time when detecting that the mount exceeds a predetermined value, and transmits a signal to release the restraint after the elapse of the predetermined period of time. shall be.

[0007]

[Operation] According to the present invention, when a signal is input from the vibration sensor to the control device due to excessive self-vibration of the anti-vibration equipment, the amount of displacement or acceleration of the pedestal exceeds a value that adversely affects the performance of the anti-vibration equipment. , the control device transmits a signal to the locking means to lock the pedestal for a predetermined period of time, that is, for a period longer than the time until the device for generating self-vibration of the anti-vibration device stops. Thereby, the locking means restrains the pedestal from the vibration absorbing unit for a predetermined period of time, so that the excessive vibration can be prevented from being absorbed by the locking means and propagated to the vibration isolator. Furthermore, after the predetermined time described above has elapsed, the control device releases the restraint of the locking means, returns the vibration isolator to its normal function as a vibration isolator, and isolates the remaining vibrations with the vibration absorbing unit.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the vibration isolator according to the present invention will be described in detail below with reference to the accompanying drawings. 1 and 2 show an embodiment to which the vibration isolator according to the present invention is applied, and FIG.
The same or similar members as those in the conventional example shown in FIG.

As shown in FIGS. 1 and 2, a factory floor 10
A rectangular base 12 is fixed onto the top with bolts (not shown). This bottom stand 12 has four vibration absorption units 14.
, 14 . . . The vibration absorption units 14, 14, . . . are arranged at the corners of the bottom 12 and the pedestal 16. Further, four side plates 26, 26... are fixed to the periphery of the base 12 so as to stand up on the floor 10, and pneumatic cylinders 2 are attached to the inner surfaces of the side plates 26, 26...
8, 28... are attached. Said pneumatic cylinder 28, 2
The rod parts 30, 30... of 8... are attached to the frame 16 when extended.
It is attached so that it can be retracted by pressing the side of it. The rod portions 30, 30... are expanded and contracted by pneumatic cylinders 28, 28...
It is controlled by a controller 32 connected to via a cable.

An X-Y stage 24 is mounted on the pedestal 16.
A reduction exposure device 22, which is shown by a two-dot chain line in the figure and has a built-in device, is placed therein. Further, a vibration sensor 34 is fixed on the pedestal 16 and connected to the controller 32 via a cable. The vibration sensor 34 detects the amount of displacement of the pedestal 16 due to vibration, and outputs this detection signal to the controller 32.

Next, the control of the controller 32 of the vibration isolator constructed as described above will be explained with reference to FIG. The vertical axis of FIG. 3 shows the displacement amount of the gantry vibration, and the horizontal axis shows the elapsed time. First, when the X-Y stage 24 of the reduction exposure device 22 placed on the pedestal 16 is moved with the rod portion 30 of the pneumatic cylinder 28 contracted, the pedestal 16 moves as shown in (A) in FIG. Start vibrating. The amount of displacement of the vibration is constantly input to the controller 32 by the vibration sensor 34.

Next, from the vibration sensor 34 to the controller 3
2, an upper limit value at which the amount of displacement of the vibration is determined to be excessive vibration;
That is, when a signal exceeding a value that adversely affects the performance of the reduction exposure device 22 is input, as shown in (B), the rod portions 30, 3 are sent from the controller 32 to the pneumatic cylinders 28, 28...
Outputs a signal (lock-on signal) that extends 0... As a result, the pedestal 16 is pressed by the rod portions 30, 30... and restrained from the vibration absorbing units 14, 14..., so that excessive vibration of the pedestal 16 is transferred to the vibration absorbing units 14.
, 14 . . . and is absorbed by the rod portions 30 , 30 . . . . In addition, in the state of (B), the floor surface 10 and the rod part 30
Since there is no vibration isolation effect against the vibrations from , 30...
6, these vibrations are propagated.

Next, when the X-Y stage 24 moves and preparation for exposure is completed, the controller 32 causes the rod portions 30,
Outputs a signal (lock-off signal) for contracting 30. As a result, the pressure of the rod portions 30, 30, . Therefore, the vibration propagating to the pedestal 16 in (B) is isolated and attenuated by the vibration absorption units 14, 14, . . . . Note that the controller 32 includes
- Since the time from when the Y stage 24 moves until the exposure preparation is completed is stored in advance, the series of operations described above can be performed automatically.

As described above, in this embodiment, when excessive self-vibration occurs in the reduction exposure device 22 placed on the pedestal 16, the excessive vibration is immediately absorbed and vibration-isolated, so that the reduction exposure device 22 can be prevented from deteriorating in function. In this embodiment, the pneumatic cylinder 28 is used as the locking mechanism of the gantry, but the present invention is not limited to this, and an electromagnetic cylinder may also be used.

Furthermore, the vibration sensor 34 may be configured to detect acceleration due to vibration of the pedestal 16.

[0016]

[Effects of the Invention] As explained above, according to the vibration isolator according to the present invention, the amount of displacement or acceleration of the pedestal can be reduced to a value that adversely affects the performance of the vibration-absorbing equipment due to excessive self-vibration of the vibration-absorbing equipment. When an exceeding signal is input from the vibration sensor to the control device, the control device activates the locking means to restrain the pedestal for a predetermined period of time, so that the excessive vibration of the anti-vibration equipment can be absorbed by the locking means. . Furthermore, the control device releases the restraint of the locking means after the predetermined time described above and returns the vibration isolator to its normal function as a vibration isolator, so that the remaining vibrations can be isolated by the vibration absorbing unit. can.

[Brief explanation of drawings]

[Fig. 1] A side view showing an embodiment of a vibration isolator according to the present invention.

[
Figure 2: Top view in Figure 1

[Fig. 3] An explanatory diagram showing a transient response vibration waveform when a vibration-resistant device generates self-vibration using the vibration isolator according to the present invention.

[
Figure 4: An explanatory diagram showing an example of a conventional vibration isolator

[Fig. 5] An explanatory diagram showing a transient response vibration waveform when vibration-absorbing equipment generates self-vibration using a conventional vibration isolator.

[Explanation of symbols]

12...Bottom stand 16... mount 24...X-Y stage 28...Pneumatic cylinder 30...Rod part 32...Controller 34...Vibration sensor

Claims (1)

[Claims] 1. In a vibration isolating device configured by interposing a plurality of vibration absorbing units between a bottom stand and a stand on which vibration-absorbing equipment is mounted, the vibration isolator is attached to the stand and prevents the stand from being damaged by vibration. a vibration sensor that detects displacement or acceleration; a locking means that can freely restrain the pedestal from a vibration absorption unit; 1. A vibration isolator comprising: a control device that transmits a signal to restrain a frame for a predetermined period of time, and transmits a signal to release the restraint after a predetermined period of time has elapsed.