JPH03219141A - Active damping base - Google Patents

Abstract

PURPOSE:To isolate any vibration transmitted from a floor surface by one device by forming an active damping base with vertically active damping bodies disposed between a fixed base and a damping base body through vertical supporting bodies, and horizontally active damping bodies disposed between the fixed base and damping base body. CONSTITUTION:An active damping base is formed of a fixed base 25; a damping base body 2 disposed above the fixed base 25; horizontally deflectable vertical supporting bodies B2, disposed between the fixed base 25 and damping base body 2, for supporting the damping base body 2; vertically active damping bodies disposed between the fixed base 25 and damping base body 2 through the vertical supporting bodies B2; and horizontally active damping bodies A1 disposed between the fixed base 25 and damping base body 2. Since a vertical air spring 3e is supported by the vertically supporting bodies B2 movable by deflecting almost freely, in the horizontal direction, the vertically active damping bodies and horizontally active damping bodies A1 can be integrated with little interference between them.

Description

[Detailed Description of the Invention] <Industrial Application Fields> The present invention is mainly applicable to precision vibration isolation of various precision instruments such as holography centers, electron microscopes, semiconductor manufacturing equipment, laser length measuring machines, and ultra-precision measuring devices. The present invention relates to an active vibration isolation device.

(Conventional technology and its circuit problems) A variety of miscellaneous vibrations are transmitted to the floor surface, including strong vibrations, weak vibrations, vibrations of various frequencies from high to low frequencies, horizontal vibrations, and vertical vibrations. The miscellaneous vibrations mentioned above are also transmitted from the floor to the installed equipment. In addition, when the equipment itself is driven or when a workpiece moves, it generates vibrations, tilts, etc. If the accuracy of the equipment is comparable to that of an ordinary machine tool, these vibrations will affect the accuracy of the equipment. Although the effect is slight, these vibrations have a fatal effect on equipment accuracy in ultra-high performance machine tools such as JigPolar, ultra-super LSI manufacturing equipment, laser length measuring machines, etc.

Therefore, vibration isolation for these ultra-precision devices is an important element to ensure accuracy, but as mentioned above, the vibrations transmitted to ultra-precision devices from the floor are of various types, and depending on the frequency, resonance may exist. Something like a spring couldn't handle it. Therefore, instead of the conventional vibration isolation concept, an active vibration isolation concept was introduced, which converts the vibration input from the floor into an electrical signal and controls the vibration isolator to cancel this vibration, but the system is complicated and Isolation of vertical vibration due to
Level maintenance, horizontal vibration isolation, etc. are performed separately, which not only makes the device large-scale, but also prevents it from being freely installed.

In addition, if the connection between the active vibration isolator and the vibration isolator is made by a rigid arm, or if they are integrated with bolts, it may be possible to cancel the desired vibration, but the There was also the problem that vibration in the direction was transmitted from the connecting member to the vibration isolating table main body, making complete vibration isolation impossible.

(Object of the invention) The present invention was made in view of the drawbacks of the conventional example, and
The purpose is to provide an active vibration isolator that is capable of blocking all vibrations transmitted from the floor surface, including high and low vibration frequencies, strength and direction of vibration, with one device.

(Means for Solving the Problems) The present invention aims to solve the problems of the prior art, and the active vibration isolation table of claim (1) includes: ■ a fixed base (25), and ■ a fixed base. (25) The main body of the vibration isolation table (2
) and ■ Disposed between the fixed base (25) and the vibration isolator main body (2), and can be freely bent in the horizontal direction and the vibration isolator main body (2)
A vertical support (B2.) for supporting the vibration isolating table body (2) and a fixed base (25) via the vertical support (B2).
) A vertical active vibration damper (^2) installed between the fixed base (25) and the vibration isolator main body (2). It is composed of (^1) and
In claim (2), the active vibration isolator of claim (1) is provided with: ■ a horizontal active vibration damper via a horizontal support (B1) that can be freely bent in directions other than the axial direction; (^1) is connected between the fixed base (25) and the vibration isolator main body (2), and claim (3) is limited to the active vibration damper, ■The vertical active damper (^2) and the horizontal active damper (^1) are replaced by air springs (3) or piezo elements (3p).
Alternatively, it is characterized by being configured with a linear motor (3Q).

Furthermore, in claim (4), limitations are attached to the support, such that the horizontal and vertical supports (Bl, 2) are a laminate of a rubber plate 31) and a metal plate <32). (7), and in claim (5), the horizontal support (B1) of claim (2) is
(1) The horizontal support (B1) is a wire rod (8).

(Function) ■When precision equipment operates or a workpiece moves, the vibration isolation table main body (2) on which the precision equipment is placed will tilt as the center of gravity moves; If removed, the vibration isolator body (2) will sink or rise from the reference level. On the other hand, miscellaneous vibrations of different strengths, such as horizontal, vertical, high frequency, and low frequency, are transmitted from the floor to the vibration isolation table main body (2).

■The level sensor (9) measures the inclination and ups and downs of the vibration isolation table
) and immediately detected by the vertical active damper (^2
) is sent a command to expand, and is immediately raised to the reference level (H,), returning to the level.

■Also, vertical vibration is detected by vertical acceleration sensor (10)
is detected, and the vertical active vibration damper (^2) is controlled to expand and contract minutely and quickly to cancel the vertical vibration.

■Similarly, the position sensor (1
) immediately detects this, and the control side or control horizontal active vibration damper (^1) expands and contracts, and the vibration isolation table main body (2) is pushed back to the reference position (So).

■Also, horizontal vibration is detected by horizontal acceleration sensor (11)
is detected, and the horizontal active vibration damper (^1) is controlled to expand and contract minutely and quickly to cancel the horizontal vibration.

■The above vertical active damping body (^2) is a vertical support (B1) that can bend almost freely in the horizontal direction.
It is supported so that there is almost no interference with the horizontal active damper (^1).

■Also, the horizontal active vibration damper (Δ1) and the vibration isolation table body (2)
are connected by a horizontal support (B1), which is, for example, a wire (8)r or a laminate (7) of a metal plate (32) and a rubber plate (31), so the horizontal support (B1) Vibration in a direction that is not parallel to the axis of the horizontal support (B1)
Since the vibration is deflected and absorbed, it is not transmitted to the vibration isolating table main body (2). Therefore, the horizontal active damper (^1
), horizontal vibrations are almost completely canceled. (The following is a blank space) (Examples) The present invention will be described below with reference to illustrated examples.

The vibration isolation table consists of a vibration isolation table main body (2), which is a surface plate part for mounting manufacturing equipment such as holography sets, electron microscopes, and ultra-precision measurement equipment such as semiconductor manufacturing equipment, and a vibration isolation table main body (2).
2) 3 to 4 active vibration isolators (^) to support
It also consists of an active vibration isolator control circuit for actively controlling the active vibration isolator (^). This active vibration isolator (＾
) is a block-shaped device that incorporates a vertical active vibration damping mechanism and a horizontal active vibration damping mechanism, and when using four sets of active vibration damping devices (8) as shown in Figure 1, Adjacent active damping devices (^) are arranged so that their horizontal control directions are perpendicular to each other, and although not shown, three sets of active damping devices (8) are used. In this case, the horizontal control direction is perpendicular to the center of gravity and at an angle of 120° to each other, or the horizontal control direction is directed toward the center of gravity and at an angle of 120° to each other. It is something that

The active vibration isolator (8) according to the present invention includes one using an air spring, one using a piezo element, and one using a linear motor. Below, we will mainly explain the case where the air spring (3) is used as the vertical active damper (^2) and the horizontal active damper (^1). Also, the vertical support (B2) is a laminated As the support (7), the horizontal support (B1) will be mainly explained using a wire rod (8).

In Figure 2.3.6.7, the active vibration isolator (^) has two-way control, vertical and horizontal. (Of course, it is also possible to perform three-axis control in the vertical direction and the horizontal direction, as shown in FIG. 8.

) Here, the explanation will be centered on FIGS. 1 to 4. The active vibration isolator (^) consists of a vertical air spring (3e), a vertical support (B
2) In this embodiment, a laminate (7), a pair of horizontal air springs (3a) (3b), a level sensor (9), a vertical acceleration sensor (10), a horizontal position sensor (1), and a horizontal acceleration It is composed of a sensor (11).

Vertical air spring (3e) and horizontal air spring (3m) (
3b) are each composed of a rubber spring part (5) and an air tank (4) that communicates with the spring part (5). The entire circumference of the rubber spring part (5) is a ring-shaped fixed seat (24) that is bolted airtight to the fixed base (25) to the partition plate (26) to which the air tank (4) is attached. , a circular washer (27a) (27b) with a trapezoidal cross section is attached to the central movable part.
), (27e) are inserted. Horizontal air spring (3
a) The air tanks (4) in (3b) are arranged independently on the left and right through a central partition plate (26').

In this embodiment, the horizontal air spring (3aH3b) has a control side and a reference side, and the reference side horizontal air spring (3a) is connected to a constant pressure air source (16) via a precision regulator (19) It is connected to. On the other hand, the control side air spring (3b
) is connected to the air pressure source (16) via a control valve (6a), and this control valve (6a) is controlled by an active vibration isolating circuit to be described later. As can be seen in Figure 2, the horizontal air springs (3a) (3b) are surrounded by a casing (30), and the centrifugal washers (27a, b) are connected to the gauging (3).
0) is fixed to the inner surface.

In this example, the casing (30) and the vibration isolating table main body (2) are made of a thin wire rod (8) or a vertical support (B) which will be described later.
2) are connected by a laminated structure similar to that of 2). The connection method is to protrude the arm (29) from the outer surface of the casing (30) as shown by the solid line in Fig.
) to the wire rod (8) stretched between the side walls (2a) of the arm (2).
9) may be fixed, or a wire rod (8) protruding from the center of the casing (30) may be fixed to the side wall (2a) of the vibration isolation table main body (2) as shown by the imaginary line. good.

The vertical air spring (3e) is mounted on a vertical support (B2), which is mounted on a fixed base (25). In this embodiment, the vertical support (B2) is, for example, a rubber plate (3).
1) and a metal plate (32) in many layers (7)
), and has the property of moving almost freely in the horizontal direction but being hardly compressed in the vertical direction.

In this embodiment, vertical supports (B2) are used in two stages.

The active vibration isolator (^) assembled in this way is
It is used by being attached to the four corners of the base (28) as shown in the figure. The mounting direction is as shown by the arrows in FIG. 1, and the horizontal air springs (3a) and (3b) are arranged so that their expansion and contraction directions are orthogonal to each other.

Next, the active vibration isolation circuit will be explained.

A horizontal position sensor (1) and a horizontal acceleration sensor (11) are attached to the arm (29) of the active vibration isolator (^), which moves back and forth, left and right, and rotationally, together with the vibration isolator main body (2). (Of course, the installation position may be other than this.) As shown in Figure 4, the horizontal position sensor (1)
is adapted to instantly detect the amount of deviation of the vibration isolation table main body (2) from the horizontal reference position (So) and input it to one end of the position differential amplifier (12a). For example, a non-contact analog output type proximity sensor is used as the horizontal position sensor (1).

A horizontal reference position voltage corresponding to the reference horizontal position (S,) of the vibration isolation table main body (2) is input to the other end input of the position differential amplifier (12a). The horizontal position integral amplifier (13) is connected to the output end of this horizontal position differential amplifier (12a).
a) only, or horizontal position integrating amplifier (13a) and feedback compensation circuit (XFb) to speed up level setting
, or a feed forward control circuit (XFf) based on prior data for adding to the feedback compensation value to enhance the damping effect at the initial motion, and this is further connected to the drive circuit (17). and an adder (
The air spring (3b) on the control side is controlled by this drive circuit (17) via the drive circuit (17) so as to correspond to the horizontal position control value that is its output.

In the above case, if only the horizontal position integrating amplifier (13a) is used, the return to the reference horizontal position (So) is performed according to the time constant of the integrating amplifier (13a), and the return speed cannot be said to be very quick. However, the horizontal position integrating amplifier (13a) and the feedback compensation circuit (XFb)
This is improved when using .

As shown in Figure 4, the feedback compensation circuit (XFb)
In the first example, the horizontal position proportional amplifier (14a) and/or the horizontal position differential amplifier (15a) are configured, and in the second example, the horizontal position proportional amplifier (14a) and the phase compensation circuit (15a) are configured. ).

In the case of the first example, ■Horizontal position integral amplifier (13a), ten horizontal position proportional amplifiers (14a), ■horizontal position integral amplifier (13a), ten horizontal position differential amplifiers (15a), ■horizontal position integral amplifier (13a).
The combination is: 10 horizontal position proportional amplifiers (14a) + horizontal position differential amplifiers (15a), and in the case of the second example: 10 horizontal position integral amplifiers (13a), 10 horizontal position proportional amplifiers (14a), and 10 phase compensation circuits ( 15a'), the combination is as follows.

In order to speed up the above-mentioned horizontal position settling, the time constant of integration can be made faster by adding proportional, differential or phase compensation in addition to analog integration of relative displacement.

In addition, the time constant of the air spring (3) is higher than the frequency range (for example, 0
．． Effective relative displacement control is possible by feeding back the differential component in the frequency range (1 Hz or higher) and, conversely, feeding back the proportional component in the low frequency range. This eliminates the displacement vibration in the low frequency band, which is difficult to achieve by feeding back information from the horizontal acceleration sensor (11), which will be described later.
! (The main body of the vibration isolation table when returning to the horizontal position centered on So>
2) It is possible to control the gentle horizontal sway.

Furthermore, there is a limit to reducing the initial response to disturbance using only the feedback control described above, and it is effective to add feedforward control to improve this. The case where the feedforward control circuit (XFf) is used will be explained below.

The first method of the feedforward control circuit (XFf) is to pattern the horizontal position fluctuation caused by the drive of the equipment or device to be controlled in advance and store it in, for example, a CPU.
The system captures the initial signal that the horizontal position fluctuation has occurred, instantly selects the most optimal pattern, and operates the control valve (6a) according to the pattern in accordance with the input of the horizontal position fluctuation to the vibration isolation table main body (2). It is a method of controlling, and 4
For L East, instead of making the above pattern in advance,
Measures the magnitude of the horizontal position fluctuation that is to be input to the vibration isolation table main body (2) immediately before inputting it to the vibration isolation table main body (2), and calculates this to control the control valve (6a) in real time. It is. This improves the problem that feedback control alone was not sufficient to control the horizontal position during initial movement.

The control valve (6a) is connected to the air tank (4) of the control side air spring (3b), and the reference side air spring (3a) is connected to the air pressure source (16) via the regulator (19). There is. The control valve (6a) is a servo valve, for example, which has the ability to accurately control the valve opening degree by an input current and accurately control the pressure in the air tank (4) of the control side air spring (3b). It is. Next, an analog horizontal position integral amplifier (13a) and a horizontal position proportional amplifier (
The functions of 14a) and horizontal position differential amplifier <15a) will be explained.

The analog horizontal position integrating amplifier (13a) multiplies the difference, integrates it, and outputs it as an analog output (Kl/gate), and returns the vibration isolation table main body (2) to the reference horizontal position according to its time constant. The drive circuit (17) controls the control valve (6a) (i.e., the horizontal position sensor (1)
The control valve (6a) is actuated by the drive circuit (17) so that the output potential of the horizontal position differential amplifier (12a) becomes equal to the potential of the reference horizontal position, and the output of the horizontal position differential amplifier (12a) becomes zero. Hold. ) is shown.

As mentioned above, the horizontal position proportional amplifier (14a) doubles the output of the horizontal position differential amplifier (12a) to speed up the rise of the horizontal position return, and also to reduce the horizontal vibration caused by the horizontal position return. The drive circuit (17) controls the control valve (
6a).

The horizontal position differential amplifier (15a) converts the output of the horizontal position differential amplifier (12a) into K. It is multiplied and differentiated (K, -S>), which works to stiffen the air spring and reduce the responsiveness of horizontal position displacement. It has a control effect on fluctuations (horizontal shaking).

The phase compensation circuit (15a') functions similarly to the horizontal position differential amplifier (15a).

The feedback compensation circuit (XFb) includes the horizontal position proportional amplifier (14a) and/or the horizontal position differential amplifier (14a).
5a), a horizontal position proportional amplifier (14a), and a phase compensation circuit (15a'), and has various filter functions such as a bypass filter, low-pass filter, and notch filter, and performs phase compensation with frequency weighting. It is something to do.

The function of the feedforward control circuit (XFf) is as described above.

However, if a device operates on the vibration isolation table body (2) or a large external force is applied, the vibration isolation table body (2) may move to the reference horizontal position (S).
o), this movement amount (9) is detected by the analog horizontal position sensor (1), outputted as an analog horizontal position voltage, and sent to the horizontal position differential amplifier (1).
2a), and is compared with the reference horizontal position voltage, and the amount of deviation is output as a positive voltage difference. The reference horizontal position voltage becomes higher than the horizontal position voltage, and the positive difference is detected by the analog horizontal position 1 integrating amplifier (13a) or the analog horizontal position integrating amplifier (13a) and the feedback compensation circuit (
XFb) and analog horizontal position integrating amplifier (13
In the case of only a), the analog integral value is
In case b), the sum of the analog integral value and the feedback compensation value is output, and is sent to the drive circuit (17) via the integrator (Ka).
). Furthermore, in order to enhance the control effect at the time of initial operation, a feedforward control circuit (XFf) is added, and the feedforward control value in either of the two cases described above is added to the feedback compensation value. As a result, the control valve (8a) is controlled by the drive circuit (17), supplies compressed air to the air tank (4) of the air spring (3b), and moves the vibration isolation table main body (2) to the reference side air spring (3a). An attempt is made to push the vibration isolator main body (2) back to the reference horizontal position (So) against the reference pressure.
>, the output voltage of the horizontal position sensor (1) gradually increases, approaches the reference horizontal position voltage, and finally becomes equal, and the output of the horizontal position differential amplifier (12a) becomes zero. The input value to the drive circuit (17) is stable at this point, and the vibration isolation table body (2) is at the reference horizontal position! (SO).

Here, as shown in Fig. 15, a coil spring (3f
), it reacts quickly to the control side air spring (3b) and the control speed is fast.

When the vibration isolation table main body (2) is moving in the opposite direction from the reference horizontal position (So), the output of the horizontal position differential amplifier (12a) becomes negative. Then, as mentioned above, the vibration isolation table main body (
2) moves in the direction of returning to the standard horizontal position (So),
When the reference horizontal position (So) is reached, the output of the horizontal position differential amplifier (12a) becomes zero, and the output of the horizontal position proportional amplifier (
14a), etc., it is fixed at the reference horizontal position (So) without any shaking.

Next, we will discuss isolation of minute vibrations in air spring type vibration isolation tables. This vibration isolating table main body (2) is subjected to the horizontal position control described above, and in addition to this, it is possible to perform vibration isolation of minute vibrations. That is, as shown in FIG. 4, a horizontal acceleration sensor (11) for detecting horizontal vibration acceleration of the vibration isolation table body 2) is arranged at the center of the vibration isolation table body 2).
A horizontal vibration integrating amplifier (20a) that integrates the output of the horizontal acceleration sensor (11), a horizontal vibration proportional amplifier (21, a) that amplifies the output, and a horizontal vibration differential amplifier (22a) that differentiates the output. ), or a vibration damping feedback compensation circuit (XSFb) using phase compensation.

Here, the combination of these amplifiers will be explained as follows.

■Horizontal vibration integrating amplifier (20a) only, ■Horizontal vibration differential amplifier 7 (22a) only, ■Horizontal vibration proportional amplifier (21a) only, ■Horizontal vibration integrating amplifier (20
Combination of a) and horizontal vibration differential amplifier (22a), ■Combination of horizontal vibration integral amplifier (20a) and horizontal vibration proportional amplifier (21a), ■Combination of horizontal vibration differential amplifier (22a) and horizontal vibration proportional amplifier The combination of (21a), ■Horizontal vibration integral amplifier (20a), horizontal vibration differential amplifier (22a), and horizontal vibration proportional amplifier (2
Combination of 1a).

The outputs from these amplifiers are added together in an adder (Ka), and then together with the horizontal position control signal described above, the drive circuit (17
), the control valve (6a) is controlled to adjust its valve opening, and the pressure of the air tank (4) of the air spring (3b) is adjusted.

Here, to explain the functions of each amplifier, the horizontal vibration integrating amplifier (20a) integrates the horizontal acceleration by 1 (K3, blue) and outputs it (flash, K, blue). It is something to do.

Now, controlling the valve opening with the control valve (6a) to control the flow rate and controlling the pressure of the air spring (3b) corresponds to integrating the flow rate.

Expressing this in the formula: (Z/(1+Ta-3)"it/s--■-・mHowever, in the frequency range higher than the time constant of the air spring (3b), S>1/Ta. It is.

Therefore, the output value (Seki, K, blue) is converted to the drive circuit (17
) and control the air spring (3b), the output value will be further integrated, and the absolute value of the vibration isolator body (2) at that horizontal position will be Control displacement. If this is expressed as a formula, it will be as follows.

Seki・K・・Blue・Blue=Y・K3・・・・・・・・・(2)
In other words, this functions to absorb minute vibrations from the floor surface or from the mounted equipment and eliminate vibrations from the vibration isolating table. Contains equivalent function.

The horizontal vibration proportional amplifier (21a) amplifies the acceleration four times, and serves to increase the damping efficiency of the air spring (3b).

The horizontal vibration differential amplifier (22a) multiplies the acceleration (2) by 5, differentiates it (K5S) and outputs it (K9.S), and inputs this output value to the drive circuit (17). The air spring (3b) is controlled, but this is the main body of the vibration isolation table (2)
The effect is equivalent to increasing the mass of . This can be expressed as a formula as follows.

Sen・K、S Onna-Seki K5・・・・・・・・・(3) By using the above amplifier, minute vibrations can be controlled according to the characteristics of the amplifier.

Further, the functions of the vibration damping feedback compensation circuit (XSFb) and the vibration damping feedforward control circuit (XSFf) are substantially the same as the feedback compensation circuit (XFb) and the footforward control circuit (XFf) described above, so a description thereof will be given below. Omitted.

Feedforward control is almost the same as the horizontal position return, and there is a method to eliminate vibration by selecting a predetermined vibration damping pattern according to the type of horizontal vibration.
There is a method of suppressing the vibration by catching the magnitude of the vibration that is being input in advance and inputting a control signal for canceling it to the drive circuit (17).

The method shown in Fig. 5 uses a pair of left and right air springs (3) <3'), inputs a control signal with a 180° phase inversion to each, and moves both air springs (3) (3'') in the same direction. In Fig. 6, (33) is an inverter, and (6a') is a control valve.

In the manner described above, the return to the horizontal reference position and the horizontal micro-vibration are controlled simultaneously.

(Blank below) Next, to explain level control, it is exactly the same as horizontal position control, and there is a level sensor installed in the part that moves up and down together with the vibration isolator main body (2) of the active vibration isolator (^>). 9) is installed, and its output is connected to a level differential amplifier (12b).
). Level sensor (
Similar to horizontal position sensor (1), sensor 9) also uses a non-contact analog output type proximity sensor.

In addition, a reference level voltage corresponding to the reference level (Ho> of the vibration isolation table main body <2) is input to the other end input of the level differential amplifier (12b). ) at the output end of the level integrating amplifier (13b),
Level proportional amplifier (14b), level differential amplifier (15)
b) or a phase compensation circuit (15b') are connected in combination. Furthermore, control by a foot-front control circuit (Yl()) is added as necessary to improve vibration damping control at the time of initial movement.

This combination is the same as that for the horizontal position sensor (1), so it will be omitted.

These outputs are summed by an adder (Kb) and then input to a control circuit (18) to control a control valve (6b), which controls the level maintenance air. It is connected to the air tank (4) of the spring (3e). The control valve (6b) is a servo valve, for example, in which the valve opening is accurately controlled by an input current, and the air spring (3e) for level maintenance has the ability to accurately control the pressure in the air tank (4). It is something that you have.

The functions of the level integral amplifier (13b), level proportional amplifier (14b), level differential amplifier (15b), or phase compensation circuit (15b') are the same as those for horizontal position control. A control circuit (YFf) is added, and since its configuration is as shown in FIG. 4, a description of the configuration will be omitted.

Next, the effect of maintaining the level will be briefly described.

When a load is applied to the vibration isolation table main body (2), the vibration isolation table main body (2)
When the vibration isolating table body (2) sinks, when the load is unloaded and the vibration isolating table body (2) rises, or when the load moves and the vibration isolating table body (2) tilts, Vertical movement amount (8
) is detected by the level sensor (9), output as a level voltage, input to the level differential amplifier (12b), and compared with a reference level voltage. When the vibration isolation table body (2) is lower than the reference level (H,), the reference level voltage becomes higher than the level voltage, the output of the differential level amplifier becomes positive, and the positive difference becomes the level integral. Amplifier(
13b) Enter other information.

In the case of only the analog level integrating amplifier (13b), the analog integrated value is output, and in the case of the analog level integrating amplifier (13b) and the feedback compensation circuit (YFb), the sum of the analog integrated value and the feedback compensation value is output, and the drive circuit (18 ). Furthermore, in order to enhance the control effect at the time of initial movement, a feedforward control circuit (YFf) is added, and the feedforward control value is added to the feedback compensation value. This causes the control valve (6b) to switch between the drive circuit (1
8), compressed air is supplied to the air tank (4) of the air spring (3e), and the vibration isolation table body 2) is lifted. When the vibration isolation table main body (2) begins to lift, the output voltage of the level sensor (10) gradually increases, approaches the reference level voltage, and finally becomes equal, and the output of the level differential amplifier (12b) becomes zero. The input value to the drive circuit (18) becomes stable at this point, and the vibration isolation table main body (2) is stably maintained at a horizontal position corresponding to the reference level (H,).

Conversely, when the vibration isolation table main body (2) is higher than the reference level, the output of the level differential amplifier (12b) becomes negative. Then, as mentioned above, when the vibration isolation table body (2) descends and reaches the reference level (H,), the output of the level differential amplifier (12b) becomes zero, and the output of the level proportional amplifier (14
b) etc., the standard level (
It will be fixed where it matches Ho).

Next, we will discuss isolation of minute vertical vibrations in an air spring type vibration isolation table. Vertical vibration acceleration (?
) is installed in a part of the active vibration isolator (^) that vibrates together with the vibration isolation table body (2), and the output of this vertical component acceleration sensor (10) is A vertical vibration integrator amplifier (20b) that integrates the output (<?) and multiplies it by 3, a vertical vibration differential amplifier (22b) that differentiates the output (<?) and multiplies it by
It is equipped with one to two or more vertical vibration proportional amplifiers (21b>) that amplify ten times, or a vibration damping feedback compensation circuit (YSFb) using phase compensation.

Here, the combination of these amplifiers is the same as in the case of horizontal position control, so a description thereof will be omitted.

The outputs from these amplifiers are input to the level drive circuit together with the above-mentioned level control signal, and are input to the control valve (6b) to adjust the valve opening degree.
) Adjust the pressure.

Here, the description of the functions of each amplifier and others is also omitted because it is the same as that for horizontal position control. Further, the output of the damping feedback control circuit (YSFf) is added as necessary.

In addition, in the case of Fig. 6, the horizontal air springs (3a) (3
b) [(3) (3')] and vertical air spring (3e
) is a cross-sectional view when the air springs (3a) (3b) [(
3) (3')] partition plate (26) is arranged to straddle the vertical air spring (3e).

In the case of Figure 7, horizontal air springs (3a) (3b)
[(3) (3°)] and the vertical air spring (3e) are placed together on the common base (28).

Figure 8.9 shows the case of three-axis control in the vertical direction and two horizontal directions.

Figure 10.11 shows the case of 3-axis control as described above, and Figure 8.
This is a case where the air springs (3a) to (3d) are attached in the opposite direction to the case shown in FIG.

FIG. 12 shows the air spring (3a) (
3b) are separated and independent, and the fixed base (25) is directly installed on the base (28). Also, the air tank (4) of the vertical air spring (3e) and the rubber spring part (
5) through the vertical support (B2) (or by bypass, not shown).

FIG. 13 shows that the fixed base (25) is connected to the vertical support (B2).
) and is controlled from the outside by air springs (3a).

Figure 14 shows a piezo element (3ap) (3bp)...
This is an example of using this for horizontal control.

FIG. 15 is an example in which the reference coil spring (3r) is used as described above.

Figures 16 and 17 are examples in which piezo elements (3ap) (3bρ), . . . (3ep) are used for horizontal and vertical control.

Figure 18.19 shows a linear motor (3
aQ) and a piezo element (3ap) for vertical control.
) (3ep) is used.

FIG. 20 shows an example in which an air spring (3e) is used for vertical control and a linear motor (3aQ) is used for horizontal control.

(Effects) The active vibration isolator of the present invention includes a fixed base, a vibration isolator body disposed above the fixed base, and a vibration isolator body disposed between the fixed base and the vibration isolator body, A vertical support that is freely deflectable in the horizontal direction and supports the vibration isolation table main body, and a vertical active vibration damper that is disposed between the fixed base and the vibration isolation table main body via the vertical support. It consists of a horizontally active vibration damper placed between the body, a fixed base, and the main body of the vibration isolator, and can bend and move almost freely in the horizontal direction. Since the vertical air spring is supported by the vertical support, the vertical active vibration damper and the horizontal active damper hardly interfere with each other, making it possible to integrate the two. . In this way, since we were able to have a vertical active vibration damper and a horizontal active vibration damper, it is possible to absorb vibrations in all directions, amplitudes, strengths and weaknesses, and frequencies with one active vibration isolator. This eliminates the need to install vertical active dampers and horizontal active dampers separately as in the past, which not only allows for flexible installation, but also makes it easier to downsize. It became.

In addition, claim (2) provides for a horizontally active vibration damper to be placed between the fixed base and the vibration isolator main body via a horizontal support that can be freely bent in directions other than the axial direction. As a result, vibrations parallel to the horizontal support are canceled by the active control of the horizontal active damper, and vibrations not parallel to the axis of the horizontal support are blocked by the deflection of the horizontal support. This has the advantage that the vibration is not transmitted to the vibration isolation table main body, and as a result, the vibration isolation table main body is provided with a high vibration isolation effect.

[Brief explanation of drawings]

Layout diagram of active vibration isolator according to the present invention Plane sectional view of the first embodiment of the present invention Vertical sectional view of the first embodiment of the present invention Block circuit diagram of the first embodiment of the circuit of the present invention Fig. 5... Block circuit diagram of a second embodiment of the circuit of the present invention FIG. 6 A cross-sectional view of a second embodiment of the present invention FIG. 7 A cross-sectional view of a third embodiment of the present invention FIG. 8 Fourth embodiment of the present invention Fig. 9 between the plane cross sections of the present invention - Fig. 10 of the reduced cross section whistle of the fourth embodiment of the present invention Plan cross section 1 of the fifth embodiment of the present invention 1st
Figure 1: Vertical sectional view of the fifth embodiment of the present invention. Figure 12:
Vertical cross-sectional view of the whistle according to the sixth embodiment of the present invention (Fig. 13)... Vertical cross-sectional view of the seventh embodiment of the present invention (Fig. 14)... Vertical cross-sectional view of the eighth embodiment of the present invention (Fig. 15)... Longitudinal cross-section whistle 16I121 of the ninth embodiment of the present invention...Plane cross-section 1 of the tenth embodiment of the present invention Fig. 17 Reduced cross-section whistle 18 of the tenth embodiment of the present invention
Figure 7 Plane cross section of the eleventh embodiment of the present invention Figure 1 Figure 2 Figure 3 Figure 4 Figure 19 Longitudinal cross section whistle 20 of the eleventh embodiment of the present invention
2I...Vertical plane cross-sectional view of the 12th embodiment of the present invention (^)...
・Horizontal vibration isolator (A1)...Horizontal active vibration damper (A
2) Vertical active vibration damper (Ka) (Kb) Adder (B1) Horizontal support (B2) Vertical support (Ho) Standard level (So) Standard Horizontal position (XFf) (YFf)・Feed forward circuit (XFb) (YFb)・7 E F buffer circuit (XS
F (> (YSF [)...Vibration damping feed foot circuit (1)...Position sensor (2)...Vibration isolation table main body (3aH3c)/Horizontal reference side air spring (3b)
(3d)・Horizontal control side air spring (3e)・・Vertical air spring (3) 3′)・Pair of air springs (4)・・Air tank (5・・Rubber spring part (6a) (6b)
)・Control valve (7 laminate <8)...Wire rod
9) Level sensor (10) Vertical acceleration sensor (11) Horizontal acceleration sensor (12a) Horizontal position differential amplifier (13a) Horizontal position integral amplifier Horizontal position proportional amplifier Horizontal position differential Amplifier, Level Differential Amplifier Level Integral Amplifier Level Proportional Amplifier Level Differential Amplifier Pneumatic i (17) Horizontal Direction Drive Circuit Level Drive Circuit (19) Reculator Horizontal Vibration Integral Amplifier/Horizontal Vibration Proportional Amplifier Horizontal Vibration Differential Amplifier Level Integral amplifier...Level proportional amplifier Level differential amplifier Fixed seat (25) Fixed base partition plate 27a) to (27e)...Circular washer base 29)...Arm caning 31)...Rubber plate/metal plate 33) Inverter (14a)... (15a) (+2b) (13b) (14b) (15b)... (16) (18) (20a (21a (22a (20b) (21b (22b (24 (26) (28 (30) (32! Figure 3u Tips Figure 13 Figure 12 Figure 14 Figure IB

Claims (5)

[Claims] (1) A fixed base, a vibration isolating table body disposed above the fixed base, and a vibration isolating table body disposed between the fixed base and the vibration isolating table body, which can be freely deflected in the horizontal direction and A vertical support for supporting the shaking table main body, a vertically active vibration damping body disposed between the fixed base and the vibration isolating table main body via the vertical support, and the fixed base and the vibration isolating table. An active vibration isolation table characterized by comprising a horizontal active vibration damper disposed between the main body and the main body. (2) The feature is that a horizontally active vibration damper is connected between the fixed base and the vibration isolator main body via a horizontal support that can be freely bent in directions other than the axial direction. Claim (1)
). Active vibration isolation table described in ). (3) The active vibration isolation table according to claim (1), wherein the vertical active damper and the horizontal active damper are constructed of air springs, piezo elements, or linear motors. (4) The active vibration isolation table according to claim (1) or (2), wherein the vertical and horizontal supports are made of a laminate of a rubber plate and a metal plate. (5) The active vibration isolation table according to claim (2), wherein the horizontal support is a wire rod.