JP2005069303A - Pneumatic control type vibration isolator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pneumatic control type vibration isolator, easily providing large force or large displacement output, with reduced consumption of compressed air, and having a vibration isolating function also provided on a direction orthogonal to an output shaft. <P>SOLUTION: The pneumatic control type vibration isolator 1 incorporates an air spring 11 for active vibration isolation connected to a compressed air source 14 through a vacuum servo valve 13, and a valve element operating to correspond to vertical motions of an input ends 16. The pneumatic control type vibration isolator comprises: air springs 12 for passive vibration isolation which are connected with the compressed air source 14 through leveling valves 15 increasing/decreasing an air flow rate in proportion to distances of the vertical motions, and arranged in parallel with the air spring 11; a surface plate 17 vertically moving integrally with the input ends 16; and a calculation control means 19 which receives electric signals of detected vibration states from a vibration sensor 18 detecting the vibration states in the vertical directions, and outputs control signals to servo valve 13 to adjust a compressed air amount for the air spring 11. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a pneumatically controlled vibration isolator using an air spring.

2. Description of the Related Art Conventionally, an active vibration isolator that combines active vibration isolation means and passive vibration isolation means is known (see, for example, Patent Documents 1 to 4).
In these Patent Documents 1 to 4, for example, an active vibration isolation means using an actuator that is electrically operated such as a laminated piezoelectric element or an electromagnetically operated actuator such as a magnetostrictive element, and a passive that uses a spring member. An active vibration isolator having a vibration isolation unit arranged in parallel is disclosed.

On the other hand, an active vibration isolator using an air spring connected to a compressed air source via a servo valve is also known (see, for example, Patent Document 5).
JP-A-8-128498 JP-A-8-32274 Japanese Patent Laid-Open No. 10-318324 JP 2002-181123 A JP-A-6-159433

Among the active vibration isolation devices disclosed in Patent Documents 1 to 4, when the active vibration isolation means uses an actuator that operates electrically like a laminated piezoelectric element, only displacement output in units of microns can be obtained. There is a problem that it is not suitable for vibration control in a low frequency region where the frequency is large. On the other hand, among the active vibration isolation devices disclosed in Patent Documents 1 to 4, in the case of using an electromagnetically actuated actuator for the active vibration isolation means, there is a problem that a large output cannot be obtained and the heating value of the coil portion is large. There is. In the case of a laminated piezoelectric element, the spring constant in the direction perpendicular to the output axis is almost a rigid body, and there is a problem that there is almost no vibration isolation in this direction.
Furthermore, the passive vibration isolator in the active vibration isolators disclosed in Patent Documents 1 to 4 has a problem that position control cannot be performed because it simply uses an elastic spring.

In the case of the active vibration isolator disclosed in Patent Document 5, an air spring that supports the total weight of the device to be vibration-isolated and the surface plate on which the device is mounted, and simultaneously performs both the position control and the control for reducing vibrations. This air spring needs to have a large capacity in order to perform these functions. Also, the servo valve must be used in a state where compressed air is always released due to its structure, and the discharge amount is proportional to the pressure of the air spring. For this reason, in the case of this active vibration isolator, there is a problem that the amount of compressed air consumed is very large.
The present invention has been made in order to eliminate such a conventional problem. A large force and a large displacement output can be easily obtained, the amount of compressed air consumption is small, and vibration isolation is performed in a direction perpendicular to the output shaft. An object of the present invention is to provide a pneumatically controlled vibration isolator having a function.

  The pneumatic control type vibration isolator according to the first aspect of the present invention includes an active vibration isolation air spring connected to a compressed air source via an electropneumatic servo valve, and a valve element that operates in accordance with the vertical movement of the input end. Passive vibration isolation air spring connected to the compressed air source via a leveling valve that increases or decreases the air flow rate in proportion to the vertical movement distance and is arranged in parallel with the active vibration isolation air spring A surface plate that is horizontally supported by the active vibration isolating air spring and the passive vibration isolating air spring and that moves up and down integrally with the input end; The active vibration isolating air is received so that the height of the active vibration isolating air spring changes in a direction to cancel the detected vibration state upon receipt of an electric signal indicating the detected vibration state from a vibration sensor that detects the vibration state. To spring A control signal for adjusting the compressed air quantity was configured with an arithmetic control means for outputting to the electro-pneumatic servovalve.

  The pneumatic control type vibration isolator according to the second aspect of the present invention includes an active vibration isolation air spring connected to a compressed air source via an electropneumatic servo valve, and a valve element that operates in accordance with the vertical movement of the input end. Is connected to a compressed air source via a leveling valve that increases or decreases the air flow rate in proportion to the vertical movement distance, and is disposed in series above the active vibration damping air spring. With a vibration damping air spring, a mechanical spring arranged in series below and in parallel with the active vibration damping air spring below the passive vibration damping air spring, and the passive vibration damping air spring, An electric signal indicating a detected vibration state from a surface plate supported horizontally at the top and moving up and down integrally with the input end and a vibration sensor for detecting a vibration state in the vertical direction of the surface plate is received. Cancel detection vibration state Arithmetic control means for outputting a control signal for adjusting the amount of compressed air to the active vibration isolating air spring to the electropneumatic servo valve so that the height of the active vibration isolating air spring changes in the direction It was set as the structure provided with.

  According to the first and second inventions, since only an air spring is used, a large force and a large displacement output can be easily obtained, and a vibration isolating function is also provided in a direction perpendicular to the output shaft. Position control, that is, control for maintaining a constant height, is performed by a passive vibration isolating air spring through which compressed air flows in and out through a leveling valve, and vibration control of the surface plate is controlled through an electropneumatic servo valve. The active vibration isolation air spring is used to flow in and out, reducing the capacity of the active vibration isolation air spring, reducing the amount of compressed air released from the electro-pneumatic servo valve, and consuming compressed air. The effect of reducing the amount is achieved.

FIG. 1 shows an air pressure controlled vibration isolator 1 according to the first aspect of the present invention. The air pressure controlled vibration isolator 1 includes an active vibration isolation air spring 11 and a passive vibration isolation air spring 12 arranged in parallel. It has.
The active vibration isolation air spring 11 is connected to the compressed air source 14 via the electropneumatic servo valve 13, and the passive vibration isolation air spring 12 is connected to the compressed air source 14 via the leveling valve 15. The leveling valve 15 is a mechanical type that incorporates a valve body (not shown) that operates in response to the vertical movement of the input end 16 and increases or decreases the air flow rate in proportion to the vertical movement distance of the input end 16.

  A surface plate 17 is supported horizontally on the active vibration isolation air spring 11 and the passive vibration isolation air spring 12 so that the input end 16 moves up and down integrally with the surface plate 17. Is provided. Note that the surface plate 17 is equipped with a device O to be subjected to vibration isolation, for example, a precision device such as a scanning electron microscope or an atomic force microscope.

The surface plate 17 is provided with a vibration sensor 18 for detecting the vibration state of the surface plate 17 in the vertical direction. An electric signal indicating the detected vibration state from the vibration sensor 18 is input to the arithmetic control means 19. The Then, a control signal for canceling the detected vibration state is output from the arithmetic control means 19 to the electropneumatic servo valve 13. That is, the flow rate of the compressed air passing through the electropneumatic servo valve 13 is adjusted so that the height of the active vibration isolation air spring 11 changes in the direction to cancel the detected vibration state by this control signal.
In FIG. 1, alphabets “A” and “B” indicate that they are continuous.

  In the pneumatic control type vibration damping device 1 having the above-described configuration, the force that supports the mass of the device O on the surface plate 17 is the compressed air supplied to the passive vibration damping air spring 12 via the leveling valve 15. In addition to being generated by pressure, the air flow rate is increased / decreased in proportion to the fluctuation amount of the input end 16 of the leveling valve 15, and the height of the surface plate 17 is kept constant by the passive vibration damping air spring 12, that is, position control I am letting. On the other hand, the fluctuation of the force that supports the device O due to the vibration disturbance transmitted to the device O is very small, and the force opposite to the force, that is, the control pressure necessary to cancel the vibration disturbance is electropneumatic. The vibration control for canceling the vibration of the surface plate 17 is performed by the compressed air supplied to the active vibration isolating air spring 11 via the servo valve 13. For this reason, in the pneumatic control type vibration isolator 1, a large force and a large displacement output can be easily obtained, and the air spring is advantageous in that it has a vibration isolation function in a direction orthogonal to the output shaft. The electropneumatic servo valve 13 that discharges suffices to have a small standard, and the consumption of compressed air is very small.

  FIG. 1 is an example, and the number of active vibration isolation air springs 11 and passive vibration isolation air springs 12 is not limited in any way. For example, passive vibration isolation air springs 12 and leveling valves are not limited. Fifteen pairs may be arranged at the four corners of the surface plate 17, and the pair of the active vibration isolation air spring 11 and the vibration sensor 18 may be arranged at the center of the surface plate 17. A plurality of pairs of air springs 12 and leveling valves 15 may be arranged, and a pair of active vibration isolation air springs 11 and vibration sensors 18 may be arranged at the center of the surface plate.

FIG. 2 shows an air pressure controlled vibration isolator 2 according to the second aspect of the present invention. The air pressure controlled vibration isolator 2 is composed of an active vibration isolating air spring 11 and a passive vibration isolating device disposed in series above the air vibration removing air spring 11. Parts that are provided with the air spring 12 and are common to the pneumatic control type vibration isolator 1 shown in FIG.
In this pneumatic control type vibration isolator 2, in order to reduce the force acting on the active vibration isolating air spring 11 below the passive vibration isolating air spring 12, it is connected in series with the passive vibration isolating air spring 12. A mechanical spring 21 is provided in the active vibration isolation air spring 11. Similarly to the above, the position control and vibration control of the surface plate 17 are shared by the passive vibration isolation air spring 12 and the active vibration isolation air spring 11, that is, the position control of the surface plate 17 is passive vibration isolation air spring. 12, the vibration control of the surface plate 17 is performed by the active vibration isolating air spring 11, and the vertical static force acting on the active vibration isolating air spring 11 is supported by the mechanical spring 21. Yes.
For this reason, also in the case of this pneumatic control type vibration isolator 2, the electropneumatic servo valve 13 that constantly discharges air while taking advantage of the above-described air spring is sufficient, so that compressed air is sufficient. The consumption of is very low.

  The present invention is, for example, as a device equipped with precision equipment such as a scanning electron microscope and an atomic force microscope with relatively small load fluctuations, or in an environment where a large compressor cannot be installed and active vibration isolation is necessary. Although it is particularly suitable as a vibration isolator to be used, application of the present invention is not limited to these.

It is a figure which shows the pneumatic control type vibration isolator which concerns on 1st invention. It is a figure which shows the pneumatic control type vibration isolator which concerns on 2nd invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pneumatically controlled vibration isolator 2 Pneumatically controlled vibration isolator 11 Active vibration isolating air spring 12 Passive vibration isolating air spring 13 Electropneumatic servo valve 14 Compressed air source 15 Leveling valve 16 Input end 17 Surface plate 18 Vibration sensor 19 Calculation control means 21 Mechanical spring O Equipment

Claims (2)

An active anti-vibration air spring connected to a compressed air source via an electropneumatic servo valve;
Built-in valve element that operates in response to the vertical movement of the input end, is connected to a compressed air source via a leveling valve that increases or decreases the air flow rate in proportion to the vertical movement distance, and the active vibration isolation air An air spring for passive vibration isolation arranged in parallel with the spring;
A surface plate that is horizontally supported by these active vibration isolating air springs and passive vibration isolating air springs and that moves up and down integrally with the input end;
An electric signal indicating a detected vibration state is received from a vibration sensor that detects a vertical vibration state of the surface plate, and the height of the active vibration isolation air spring changes in a direction to cancel the detected vibration state. An air pressure control type vibration isolator comprising: an operation control means for outputting a control signal for adjusting a compressed air amount to the active vibration isolating air spring to the electropneumatic servo valve. An active anti-vibration air spring connected to a compressed air source via an electropneumatic servo valve;
Built-in valve element that operates in response to the vertical movement of the input end, is connected to a compressed air source via a leveling valve that increases or decreases the air flow rate in proportion to the vertical movement distance, and the active vibration isolation air An air spring for passive vibration isolation arranged in series above the spring;
A mechanical spring disposed below the passive vibration damping air spring, in series with the passive vibration damping air spring, and in parallel with the active vibration damping air spring;
A surface plate that is supported horizontally by the passive vibration damping air spring and moves up and down integrally with the input end;
An electric signal indicating a detected vibration state is received from a vibration sensor that detects a vertical vibration state of the surface plate, and the height of the active vibration isolation air spring changes in a direction to cancel the detected vibration state. An air pressure control type vibration isolator comprising: an operation control means for outputting a control signal for adjusting a compressed air amount to the active vibration isolating air spring to the electropneumatic servo valve.

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