JP3789750B2 - Active vibration isolator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an active vibration isolation device in which a mechanical device is mounted on a vibration isolation table using a rotating magnetic bearing device as a bearing.
[0002]
[Prior art]
Mechanical devices such as electron microscopes and semiconductor manufacturing devices that are extremely hated of vibration support most of the weight of the vibration isolation table with elastic springs instead of passive control vibration isolation devices using air springs or rubber. In addition, there is an active vibration isolator configured to remove vibration by controlling an electromagnetic actuator. FIG. 1 is a diagram showing a schematic configuration of this type of active vibration isolator. The active vibration isolation device 10 includes a vibration isolation table base 11 and a vibration isolation table 12, and the vibration isolation table 12 is supported by an elastic spring 13 such as an air spring installed on the vibration isolation table base 11. . An electromagnetic actuator 14 is disposed between the vibration isolation table base 11 and the vibration isolation table 12. The electromagnetic actuator 14 is controlled by an active vibration isolation control device 15 so as to remove vibration. Reference numeral 16 denotes a vibration sensor that detects vibration of the vibration isolation table 12.
[0003]
FIG. 2 is a diagram illustrating a configuration example of the active vibration isolation control device 15. The active vibration isolation control device 15 includes a vibration detection unit 15-1, a position detection unit 15-2, a vibration isolation control calculation unit 15-3, and a drive control unit 15-4. The vibration detecting means 15-1 detects the vibration of the vibration isolation table 12 from the output signals of the horizontal vibration sensor 16a for detecting the horizontal vibration of the vibration sensor 16 and the vertical vibration sensor 16b for detecting the vertical vibration. The detection signal is output to the vibration isolation control calculation means 15-3. The position detection means 15-2 detects the position of the vibration isolation table 12 from the output signal of the displacement sensor 17 (built in the electromagnetic actuator 14) that detects the displacement of the vibration isolation table, and uses the detected signal as the vibration isolation control calculation means. Output to 15-3.
[0004]
The vibration isolation control calculation means 15-3 performs vibration isolation control calculation for obtaining a position control signal for removing vibration of the vibration isolation table 12 from the detection signals of the vibration detection means 15-1 and the position detection means 15-2. The vibration isolation control signal is output to the electromagnetic actuator 14 via the drive control unit 15-4. Here, the loop L1 passing through the horizontal direction vibration sensor 16a, the vertical direction vibration sensor 16b, and the vibration detection means 15-1 is called an absolute system feedback loop, and the loop L2 passing through the displacement sensor 17 and the position detection means 15-2 is a relative system feedback. This is called a loop.
[0005]
In addition, the mechanical device mounted on the vibration isolation table 12 of the active vibration isolation device 10 is a semiconductor inspection device such as an electron microscope or a semiconductor manufacturing device that requires high vacuum. In the manufacturing process, it is necessary to make a vacuum with a vacuum pump and to remove vibration. As a means for generating a high vacuum, for example, there is a turbo molecular pump using a magnetic bearing device for a bearing of a rotating body.
[0006]
FIG. 3 is a diagram showing a configuration example of a conventional rotating body magnetic bearing control device. The rotating body magnetic bearing control device 20 includes a rotating body displacement detecting means 21, a rotating body phase compensation circuit 22, and a rotating body magnetic bearing control output means 23. The rotating body displacement detecting means 21 detects the displacement of the rotating body 31 from the displacement detection output of the rotating body displacement sensor 32 that detects the displacement of the rotating body 31 of the rotating body magnetic bearing 30. The displacement detection signal is phase-compensated and amplified by the rotating body phase compensation circuit 22 and is output to the rotating body magnetic bearing control output means 23, and the rotating body magnetic bearing control output means 23 forms the rotating body magnetic bearing 30 in the vertical direction. A drive current is applied to the magnetic coil 33 and the horizontal magnetic coil 34. This is called a relative feedback loop L.
[0007]
When mounting a mechanical device using a magnetic bearing device as a bearing of a rotating body on the vibration isolation table of the above active vibration isolation device, high-performance acceleration is required at various locations necessary to eliminate vibration of the vibration isolation table. It was necessary to install a sensor, the price was expensive, and there was a problem in handling.
[0008]
[Problems to be solved by the invention]
The present invention has been made in view of the above-described points, and an object thereof is to provide an inexpensive active vibration isolation device that can delete at least a part of a high-performance vibration sensor that has a simple configuration and is attached to a vibration isolation table. To do.
[0009]
[Means for Solving the Problems]
The invention according to claim 1 for solving the above problems, and mechanical devices using a rotating body magnetic bearing device on the bearing, the anti-vibration table table for mounting the rotator magnetic bearing device of the machine,該除vibration An elastic spring for supporting the table, an electromagnetic actuator for controlling the vibration of the vibration isolation table with an electromagnet, a first vibration detecting means for detecting vibration on the vibration isolation table, and a displacement of the vibration isolation table. A vibration sensor for performing vibration isolation control to obtain a control signal for removing vibrations of the vibration isolation table from the displacement sensor to be detected, the first vibration detection output of the first vibration detection means, and the displacement detection output of the displacement sensor. comprising a control unit, in an active anti-vibration apparatus that is configured to remove the vibrations by controlling the electromagnetic actuator in該除vibration control means, driving displacement detection output or rotator magnetic bearing of the rotary body magnetic bearing device The feedback loop signal of the current is input to the vibration isolation control means as the second vibration detection output, and the vibration isolation control means performs vibration isolation control calculation using the second vibration detection output and the first vibration detection output as the vibration detection output. It is characterized by that.
[0010]
As described above, the displacement detection output of the rotating body magnetic bearing device or the feedback loop signal of the rotating body magnetic bearing drive current is input to the vibration isolation control means as the second vibration detection output, and the vibration isolation control means detects the second vibration detection output. Since the vibration isolation control calculation is performed using the output and the first vibration detection output as the vibration detection output, at least a vibration sensor that detects, for example, horizontal vibrations in the vibration isolation table can be deleted.
[0011]
According to a second aspect of the present invention, in the active vibration isolation device of the first aspect, the displacement detection output of the rotating body magnetic bearing device or the feedback loop signal of the rotating body magnetic bearing drive current is passed through a low-pass filter and a high-pass filter. The second vibration detection output.
[0012]
As described above, the displacement detection output of the rotating body magnetic bearing device or the feedback loop signal of the rotating body magnetic bearing drive current is integrated by passing through the low pass filter to remove the specific component of the rotating body magnetic bearing and pass through the high pass filter. Thus, the DC component is differentiated and the horizontal vibration is detected by the second vibration detecting means similar to the acceleration sensor.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. 4 and 5 are diagrams showing a configuration example of an apparatus using the active vibration isolator according to the present invention. FIG. 4 shows an overall configuration, and FIG. 5 shows a partial configuration. Reference numeral 10 denotes an active vibration isolator, and the active vibration isolator 10 is installed on a mechanical device stand 42 provided on the surface of a vibration isolator mounting floor 41. A mechanical device 43 is mounted on the active vibration isolator 10. As shown in FIG. 5, the mechanical device 43 includes a rotating mechanical device 44 such as a turbo-molecular pump, and the rotating mechanical device 44 has a rotating body main shaft, which will be described in detail later, supported by a magnetic bearing. It has become.
[0014]
FIG. 6 is a diagram illustrating a configuration example of the electromagnetic actuator 14 of the active vibration isolation device 10. The electromagnetic actuator 14 includes a movable portion 14-1 and a fixed portion 14-2, and the fixed portion 14-2 includes a horizontal magnetic coil. A (radial magnetic coil) 14-3 and a vertical magnetic coil (axial magnetic coil) 14-4 are provided, and a displacement sensor 17 including a horizontal displacement sensor 17a and a vertical displacement sensor 17b is further provided. The movable part 14-1 is fixed to the vibration isolation table 12 and the fixed part 14-2 is fixed to the vibration isolation base 11. The horizontal direction magnetic coil 14-3 and the vertical direction magnetic coil 14-4 of the electromagnetic actuator 14 are controlled by an active vibration isolation control device 15 ', which will be described in detail later, so as to remove vibrations of the vibration isolation table 12. .
[0015]
FIG. 7 is a diagram showing a cross-sectional configuration of a rotating machine device (here, a turbo molecular pump is shown) 44. The rotating machine device includes a rotating body (rotating blade) 31, and the main shaft 31 a of the rotating body 31 includes a rotating body magnet including a vertical magnetic coil (axial magnetic coil) 33 and a horizontal magnetic coil (radial magnetic coil) 34. The bearing 30 is supported by levitation. The stationary body 35 provided with the vertical magnetic coil 33 and the horizontal magnetic coil 34 is fixed to the casing 43a of the mechanical device 43 mounted on the vibration isolation table 12 as shown in FIG. Further, the stationary body 35 includes a rotating body displacement sensor 32 (see FIG. 8) having a horizontal direction displacement sensor (radial displacement sensor) 32a for detecting the displacement of the rotating body 31 and a vertical direction displacement sensor (axial displacement sensor) 32b. Is provided. The vertical magnetic coil 33 and the horizontal magnetic coil 34 of the rotary magnetic bearing 30 are driven and controlled by the rotary magnetic bearing control device 20, as will be described in detail later, so that the rotary body 31 is levitated and supported at a predetermined position. Yes. In FIG. 7, reference numeral 36 denotes a rotational drive motor coil.
[0016]
FIG. 8 is a diagram illustrating a configuration example of the rotating body magnetic bearing control device 20 and the active vibration isolation control device 15 ′. The rotating body magnetic bearing control device 20 includes a rotating body displacement detecting means 21, a rotating body phase compensation circuit 22, and a rotating body magnetic bearing control output means 23, as in FIG. The rotator displacement detecting means 21 detects the rotator 31 from the displacement detection output of the rotator displacement sensor 32 (horizontal displacement sensor 32a, vertical displacement sensor 32b in FIG. 7) that detects the displacement of the rotator 31 of the rotator magnetic bearing 30. Displacement (water level direction displacement, vertical direction displacement) is detected. The displacement detection signal is phase-compensated and amplified by the rotating body phase compensation circuit 22 and is output to the rotating body magnetic bearing control output means 23, and the rotating body magnetic bearing control output means 23 forms the rotating body magnetic bearing 30 in the vertical direction. A drive current is applied to the magnetic coil 33 and the horizontal magnetic coil 34.
[0017]
The active vibration isolation control device 15 ′ includes first vibration detection means 15′-1, second vibration detection means 15′-2, position detection means 15′-3, vibration isolation control calculation means 15′-4, and drive control. Part 15'-5. The current supplied to the horizontal magnetic coil 34 of the rotating body magnetic bearing control device 20 is detected by the horizontal current detector 18 and integrated / differentiated through the low-pass filter / high-pass filter 19 to be detected by the active vibration isolation control device 15 ′. It is output to the second vibration detection means 15′-2. The second vibration detecting means 15′-2 detects horizontal vibration from the detected current and outputs the detected output to the vibration isolation control calculating means 15′-4.
[0018]
The first vibration detection means 15′-1 detects vertical vibration from the output of the vertical vibration sensor 16b and outputs the detection output to the vibration isolation control calculation means 15′-4. Further, the position detection means 15′-3 detects the position of the vibration isolation table 12 from the displacement sensor 17, and outputs the detection output to the vibration isolation control calculation means 15′-4.
[0019]
The anti-vibration control calculating means 15'-4 detects the vibration of the anti-vibration table 12 from the detection signals of the first vibration detecting means 15'-1, the second vibration detecting means 15'-2 and the position detecting means 15'-3. The vibration isolation control calculation for obtaining the vibration isolation control signal for removing the vibration is performed, and the vibration isolation control signal is transmitted to the horizontal magnetic coil 14-3 and the vertical magnetic field of the electromagnetic actuator 14 via the drive control unit 15'-5. A drive control current is applied to the coil 14-4 (see FIG. 6) to remove the vibration of the vibration isolation table.
[0020]
FIG. 9 is a diagram illustrating a displacement detection example of the rotating body of the rotating body magnetic bearing control device 20. When the rotator 31 is located at the mechanical center, the gap Gap (+) between the rotator 31 and the displacement sensor 32a (+ X) in the X-axis direction and between the rotator 31 and the displacement sensor 32a (−X). The gap Gap (−) becomes equal. At this time, the X-axis direction detection output of the rotating body displacement detecting means 21 becomes 0 potential, and is proportional to the difference between the gap Gap (+) and the gap Gap (−) when the rotating body 31 is moved to the displacement sensor 32a (+ X) side. A displacement detection signal is obtained. The same applies to the Y-axis direction having the displacement sensor 32a (+ Y) and the displacement sensor 32a (-Y). Although not shown, the same applies to the case of detecting the displacement in the vertical direction.
[0021]
The drive current command value amplified by the rotating body phase compensation circuit 22 from the rotating body displacement detecting means 21 includes an imbalance of the rotating body 31, but the rotational speed of the rotating body generally supported by a magnetic bearing is 400 Hz or more. The unbalanced frequency components are also equivalent. Further, since the natural frequency of the rotating body is also set to be equal to or higher than the rotational speed, it does not interfere with the frequency band of 100 Hz or less for controlling the active vibration isolator 10.
[0022]
Since the current flowing in the horizontal magnetic coil is a total control current obtained by adding the drive current command value and the bias current for supporting the rotating body to the magnetic bearing, the current value is detected by the horizontal current detector 18, By integrating with a low-pass filter unit of 100 Hz (40 Hz in the case of a rotating body) of the low-pass filter / high-pass filter 19, a specific component of the rotating body magnetic bearing 30 is removed. In order to remove the direct current component, it is differentiated by the high-pass filter section, and the horizontal vibration can be detected by the second vibration detecting means similar to the acceleration sensor.
[0023]
The second vibration detection means 15'-2 has narrower frequency characteristics than the first vibration detection means, but can also be used as an auxiliary means for the presence or absence of excessive vibration. In the case of slight vibration, control is performed by the first vibration detection means 15′-1, and in the case of excessive vibration that deviates from the control range, vibration suppression or control is performed by the second vibration detection means 15′-2.
[0024]
In the above example, the current flowing in the horizontal magnetic coil 34 of the rotating magnetic bearing 30 is detected by the horizontal current detector 18 to detect the horizontal vibration, but the present invention is not limited to this. Instead, for example, the current flowing in the vertical magnetic coil 33 is detected to detect the vibration in the vertical direction, and the vertical vibration sensor 16b of the vibration sensor 16 provided in the vibration isolation table 12 is omitted. May be. Further, the current flowing in the vertical magnetic coil 33 and the horizontal magnetic coil 34 may be detected, and the vibration sensor 16 including the horizontal vibration sensor 16a and the vertical vibration sensor 16b may be omitted.
[0025]
Further, one or both of the detection outputs of the horizontal direction displacement sensor 32a and the vertical direction displacement sensor 32b of the rotating body displacement sensor 32 of the rotating body magnetic bearing 30 are guided to a vibration detecting means (not shown), and the vibration detection output is vibration-isolated. Either or both of the horizontal direction vibration sensor 16a and the vertical direction vibration sensor 16b that are output to the control calculation means 15′-4 and provided on the vibration isolation table 12 may be omitted.
[0026]
【The invention's effect】
As described above, according to the invention described in each claim, the following excellent effects can be obtained.
[0027]
According to the first aspect of the present invention, the displacement detection output of the rotating body magnetic bearing device or the feedback loop signal of the rotating body magnetic bearing drive current is input to the vibration isolation control means as the second vibration detection output, and the vibration isolation control is performed. Since the means performs vibration isolation control calculation using the second vibration detection output and the first vibration detection output as vibration detection outputs, at least a part of the high-performance vibration isolation sensor attached to the vibration isolation table with a simple configuration is deleted. can do.
[0028]
According to the second aspect of the present invention, the displacement detection output of the rotating body magnetic bearing device or the feedback loop signal of the rotating body magnetic bearing drive current is integrated by passing through a low-pass filter, and the characteristic component of the rotating body magnetic bearing is obtained. It is possible to detect the vibration in the horizontal direction by the second vibration detecting means similar to the acceleration sensor by removing and differentiating by passing through a high-pass filter and removing the DC component.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a schematic configuration example of an active vibration isolation device.
FIG. 2 is a diagram illustrating a configuration of an active vibration isolation control device.
FIG. 3 is a diagram showing a configuration example of a conventional rotating body magnetic bearing control device.
FIG. 4 is a diagram showing an apparatus configuration example using an active vibration isolator according to the present invention.
FIG. 5 is a diagram showing a partial configuration of the apparatus shown in FIG. 4;
FIG. 6 is a diagram showing a configuration example of an electromagnetic actuator of the active vibration isolator according to the present invention.
FIG. 7 is a diagram showing a configuration example of a rotary machine device mounted on an active vibration isolator according to the present invention.
FIG. 8 is a diagram illustrating a configuration example of a control device of an active vibration isolator according to the present invention.
FIG. 9 is a diagram showing an example of displacement detection of a rotating body of the rotating body magnetic bearing control device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Active vibration isolator 11 Vibration isolation base 12 Vibration isolation table 13 Elastic spring 14 Electromagnetic actuator 14-1 Movable part 14-2 Fixed part 14-3 Horizontal direction magnetic coil 14-4 Vertical direction magnetic coil 15 'Active vibration isolation Control device 15'-1 First vibration detection means 15'-2 Second vibration detection means 15'-3 Position detection means 15'-4 Anti-vibration control calculation means 15'-5 Drive controller 16 Vibration sensor 17 Displacement Sensor 18 Horizontal current detector 19 Low-pass filter / high-pass filter 20 Rotating body magnetic bearing control device 21 Rotating body displacement detecting means 22 Rotating body phase compensation circuit 23 Rotating body magnetic bearing control output means 30 Rotating body magnetic bearing 31 Rotating body 32 Rotating body Body displacement sensor 33 Vertical direction magnetic coil 34 Horizontal direction magnetic coil 35 Stationary body 36 Motor coil 41 for rotational drive Vibration isolation table installation floor 42 Mechanical device mount 43 Mechanical device 44 Rotating mechanical device

Claims (2)

Electromagnet and mechanical apparatus using a rotating body magnetic bearing device on the bearing, the anti-vibration table table for mounting the rotator magnetic bearing device of the machine, and an elastic spring for supporting the該除vibration base table, the該除vibration base table An electromagnetic actuator for controlling vibration by the first vibration detecting means, first vibration detecting means for detecting vibration on the vibration isolation table, a displacement sensor for detecting displacement of the vibration isolation table, and first vibration of the first vibration detecting means. And a vibration isolation control means for performing vibration isolation control calculation for obtaining a control signal for removing vibration of the vibration isolation table based on the detection output and the displacement detection output of the displacement sensor, and the electromagnetic actuator is controlled by the vibration isolation control means. In an active vibration isolator configured to control and remove vibration,
The displacement detection output of the rotating body magnetic bearing device or the feedback loop signal of the rotating body magnetic bearing drive current is input to the anti-vibration control means as the second vibration detection output, and the anti-vibration control means and the second vibration detection output An active vibration isolation device that performs the vibration isolation control calculation using the first vibration detection output as a vibration detection output. The active vibration isolator according to claim 1.
An active vibration isolation device characterized in that a displacement detection output of the rotating body magnetic bearing device or a feedback loop signal of the rotating body magnetic bearing drive current is used as the second vibration detection output through a low-pass filter and a high-pass filter.

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