JP2003074620A - Vibration isolator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control pressure in pressure chambers without response delay, in a vibration isolator: formed with a pressure chamber expandable/contractable in the vertical direction and a pressure chamber expandable/contractable in the horizontal direction between a fixed base and a movable base via a flexible airtight member respectively; feeding back the pressure in the vertical pressure chamber and the horizontal pressure chamber; and controlling the pressure in the both pressure chamber. SOLUTION: Pressure sensors detecting the pressures of the vertical pressure chamber and the horizontal pressure chamber are provided in the vertical pressure chamber and the horizontal pressure chamber respectively.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an anti-vibration device for preventing the propagation of vibration from a fixed base to a movable base.

[0002]

2. Description of the Related Art Conventionally, as a type of such a vibration isolation device, a pressure chamber that can be expanded and contracted in a vertical direction and a horizontal chamber between a fixed base and a movable base via flexible airtight members, respectively. There is known a vibration isolation device based on the principle of forming pressure chambers capable of expanding and contracting in the direction and controlling the suction and discharge of pressurized air in these pressure chambers to keep the movable table in a floating state and prevent the propagation of vibrations. There is.

In such a vibration isolator, based on the position of the movable table and the pressures in the vertical pressure chamber and the horizontal pressure chamber,
A pressure control mechanism that controls the compressed air pressure in both pressure chambers is essential. That is, the position and acceleration of the movable table are detected, the pressure in both pressure chambers is controlled by the electropneumatic conversion mechanism and the servo valve to eliminate the resonance region, and at the same time, the pressures in both pressure chambers are detected and fed back. The servo valve controls the compressed air pressure in the same pressure chamber.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to make it possible to control the pressure of a pressure chamber in a vibration isolator that feeds back and controls the pressure of the pressure chamber as described above without delay in response.

[0005]

SUMMARY OF THE INVENTION A vibration isolation device according to the present invention includes a pressure chamber capable of expanding and contracting in a vertical direction and a pressure chamber capable of expanding and contracting in a horizontal direction between a fixed base and a movable base via flexible airtight members. A pressure sensor that detects the pressure in the vertical pressure chamber and the horizontal pressure chamber in a vibration isolation device that forms a chamber and controls the pressure in both the pressure chambers by feeding back the pressures in the vertical pressure chamber and the horizontal pressure chamber. Are provided in the vertical pressure chamber and the horizontal pressure chamber, respectively. As described above, when the pressure sensor is directly provided in the pressure chamber, the pressure in the pressure chamber can be detected in real time, and feedback control of the pressure in the pressure chamber can be performed without delay in response.

It is preferable that the pressure sensor is fixed to a part of a fixing base which constitutes a part of the wall surface of the pressure chamber. Further, the lead wire of the pressure sensor can be guided to the outside through a compressed air passage to the vertical pressure chamber and the horizontal pressure chamber.

[0007]

1 and 2 show an embodiment of a vibration isolation device according to the present invention. The fixed base 20 fixed on the base 10 has a central column 21 and a fixed horizontal substrate portion 22 at the upper end thereof. A movable table 30 is located outside the fixed table 20. The movable base 30 has a tubular portion 31 located on the outer periphery of the center column 21, and a movable horizontal substrate portion 32 corresponding to the fixed horizontal substrate portion 22 and continuous with the upper end portion of the tubular portion 31. . In the illustrated example, the tubular portion 31 of the movable table 30 has a quadrangular planar shape, as is apparent from FIG.

Upper and lower ends of a vertical bellows (flexible airtight member) 41 are airtightly fixed between the fixed horizontal substrate portion 22 of the fixed base 20 and the movable horizontal substrate portion 32 of the movable base 30. Thus, a vertical pressure chamber 40 in the vertical direction is formed between the fixed horizontal substrate portion 22 and the movable horizontal substrate portion 32. Macroscopically, the vertical bellows 41 has a cylindrical shape as a whole, and has a plurality of (three in the illustrated example) semicircular cross-section portions 41a on its peripheral wall surface.

In the vertical pressure chamber 40, a pressure sensor 42 is fixed on the upper surface of the fixed horizontal substrate portion 22. The lead wire 43 of the pressure sensor 42 is guided to the outside via the compressed air passage 23 to the vertical pressure chamber 40 formed in the central column 21 of the fixed base 20.

Between the central column 21 of the fixed base 20 and the tubular portion 31 of the movable base 30, a pair of horizontal bellows (flexible airtight member) is formed at a pair of opposing positions in two orthogonal directions in the horizontal direction.
Both ends of 51 are airtightly fixed. Two pairs of horizontal pressure chambers 5 that can be expanded and contracted in the horizontal direction are provided between the fixed base 20 and the movable base 30 by the two pairs of horizontal bellows 51.
0 is formed. The horizontal bellows 51 has a smaller diameter than the vertical bellows 41. A fixed chamber 52 that forms a horizontal pressure chamber 50 together with a horizontal bellows 51 is formed in the center column 21 of the fixed base 20.

A fixed chamber 52 is provided in each horizontal pressure chamber 50.
The pressure sensor 53 is fixed by being positioned inside. The lead wire 54 of the pressure sensor 53 is connected to the compressed air passage 2 to the horizontal pressure chamber 50 formed in the central column 21 of the fixed base 20.
It is led to the outside through 4.

The vertical pressure chamber 40 and the pair of horizontal pressure chambers 50 are connected to a vertical pressure control servo valve 61 and a horizontal pressure control servo valve 62, respectively. Pressure control servo valve 62
Is connected to a compressed air source 64 via a regulator 63. In addition, the compressed air passages 23, 2 of the fixed base 20
Lead wire 4 of the pressure sensor 42 guided to the outside through
3 and the lead wire 54 of the pressure sensor 53 are led to a control circuit (CPU) 65. The control circuit 65
Vertical pressure chamber 40 detected by pressure sensor 42
The vertical pressure control servo valve 61 is controlled by the internal pressure,
The horizontal pressure control servo valve 62 is controlled by the pressure in the pair of horizontal pressure chambers 50 detected by each pressure sensor 53.
To control. The horizontal pressure control servo valve 62 is a differential pressure type that controls the pressure of the pair of horizontal pressure chambers 50 by one.
Although only a pair of horizontal pressure chambers 50 and corresponding pressure sensors 53 and horizontal pressure control servo valves 62 are shown in FIG. 1, these are a pair of horizontal pressure chambers existing in two orthogonal directions. Two pairs are provided corresponding to 50.

In the vibration isolator having the above structure, the pressurized air from the compressed air source 64 is supplied to the regulator 63 and the vertical pressure control servo valve 61 according to the weight of the movable table 30 and the object placed on the movable table 30.
The movable table 30 and the mounted object can be held in a floating state by adjusting the pressure via the movable table 3 and introducing it into the vertical direction pressure chamber 40, and the vertical vibration applied to the fixed table 20 causes the movable table 3 to move.
It can be prevented from being transmitted to 0. At the same time, the pressurized air from the compressed air source 64 is similarly pressure-adjusted and introduced into each horizontal pressure chamber 50 in the horizontal direction via the regulator 63 and the horizontal pressure control servo valve 62. The vibration of 30 can also be prevented.

At this time, the pressure in the vertical pressure chamber 40 is detected by the pressure sensor 42, and the pressure in each horizontal pressure chamber 50 is detected by the pressure sensor 53 in real time (without time delay), and the detected pressure is controlled by the control circuit. 65 is input. Since the control circuit 65 controls the vertical pressure control servo valve 61 and the horizontal pressure control servo valve 62 to open and close according to the detected pressure, it is possible to perform control with a minimum response delay.

FIG. 3 is a schematic diagram in which the pressure fluctuations (compensation) to be changed via the servo valves 61 and 62 are drawn by broken lines when the pressure fluctuations in the pressure chambers 40 and 50 occur as shown by the solid lines. The ideal control is that the solid line and the broken line are symmetrical, but in reality there is a time delay from the detection of the pressure to the operation of the servo valve, and this response delay reduces the vibration isolation performance. . According to this embodiment, the pressure chambers 40, 50
A pressure sensor 42 in which the internal pressure is directly arranged in the pressure chamber,
Since it is detected by 53, response delay can be minimized and more ideal control can be performed. In the conventional device, the pressure in the pressure chambers 40, 50 is controlled by the compressed air passages 23, 2
Since it is detected by a sensor provided outside the apparatus via 4, it is not only time-consuming to detect the pressure fluctuation of the pressure chambers 40 and 50, but also the detected pressure itself becomes inaccurate. The pressure control was also inaccurate.

In the above embodiment, a pair of horizontal pressure chambers 50 in the horizontal direction are provided in two orthogonal directions, but a mode in which only one pair is provided is also possible.

[0017]

According to the present invention, between the fixed base and the movable base, a pressure chamber capable of expanding / contracting in the vertical direction and a pressure chamber capable of expanding / contracting in the horizontal direction are respectively provided via a flexible airtight member. It is possible to control the pressure in the pressure chambers without a response delay in a vibration isolation device that controls the pressures in both the pressure chambers by feeding back the pressures in the vertical pressure chambers and the horizontal pressure chambers. Vibration isolation performance can be obtained.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of a vibration isolation device according to the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a graph showing a pressure fluctuation in the pressure chamber and a compensation model thereof.

[Explanation of symbols]

10 basics 20 fixed base 21 central pillar 22 Fixed horizontal board 23 24 Compressed air passage 30 movable platform 31 tubular part 32 Movable horizontal board 40 Vertical pressure chamber 41 Vertical Bellows (Flexible Airtight Member) 42 53 Pressure sensor 43 54 Lead wire 50 Horizontal pressure chamber 51 Horizontal Bellows (Flexible Airtight Member) 52 Fixed chamber 61 Vertical pressure control servo valve 62 Horizontal pressure control servo valve 64 compressed air source 65 Control circuit (CPU)

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Keiji Tamaki             1840 Mitsuhashi, Saitama City, Saitama Prefecture Fujikurago             Mu Industry Co., Ltd. Omiya factory (72) Inventor Tomomasa Fujita             1840 Mitsuhashi, Saitama City, Saitama Prefecture Fujikurago             Mu Industry Co., Ltd. Omiya factory (72) Inventor Hiroshi Kinda             1840 Mitsuhashi, Saitama City, Saitama Prefecture Fujikurago             Mu Industry Co., Ltd. Omiya factory F term (reference) 3J048 AB12 AD03 BE02 CB09 DA05                       EA13                 3J069 AA20 AA24 AA32 EE70

Claims (3)

[Claims] 1. A pressure chamber which is vertically expandable and contractable between a fixed base and a movable base via a flexible airtight member, and
A vibration isolator that forms a pressure chamber capable of expanding and contracting in the horizontal direction and controls the pressure in both the pressure chambers by feeding back the pressures in the pressure chambers in the vertical direction and the pressure chambers in the horizontal direction. An anti-vibration device, wherein pressure sensors for detecting the pressure in the pressure chamber are provided in the vertical pressure chamber and the horizontal pressure chamber, respectively. 2. The vibration isolator according to claim 1, wherein the pressure sensor is fixed to a part of a fixed base forming part of wall surfaces of the vertical pressure chamber and the horizontal pressure chamber. 3. The vibration isolator according to claim 1, wherein the lead wire of the pressure sensor is guided to the outside through a compressed air passage to the vertical pressure chamber and the horizontal pressure chamber. apparatus.