JP2000314442A - Active damping device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain effective damping with small and light mass. SOLUTION: A vibrating pendulum 4 is constituted, such that an arm 7 is oscillatingly pivotally supported at a base plate 3 fixed at an object 2 to be damped, and the object 2 to be damped and mass 8 is attached to the tip part of the arm 7 to damp the object 2 to be damped. One end part of an actuator 14, consisting of the laminate of a piezoelectric element, is mounted movably along the arm 7 and the other end is coupled to a base plate 3. A vibration detecting sensor 21 is provided at the object 2 to be controlled to detect vibration and by computing and processing the output of the vibration detecting sensor 21, the frequency and the period of the object 2 to be vibrated are determined. Based on the compution result, the period and the phase angle of an actuator 14 for damping vibration of the object 2 to be damped are determined, and a controller 23 is provided to output a drive signal corresponding to the period and the phase angle to an electrostatic actuator 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active vibration damping device, and more particularly, to an active vibration damping device that performs passive and active vibration damping using a vibration pendulum having a small and lightweight mass body.

[0002]

2. Description of the Related Art As a technique for suppressing vibration of an object to be damped, a mass (mass body) is arranged at the antinode of the vibration of the object to be damped, and the vibration is suppressed by the mass. The rigidity of the vibration surface of the object to be damped is enhanced by reinforcing materials such as ribs and stiffeners, and the resonance point is shifted from the normal frequency band to prevent resonance. 2. Description of the Related Art Various types of passive vibration damping devices are known, such as a vibration damping device that is mounted with a vibration absorber and absorbs vibration energy due to vibration of the mass body.

[0003] In order to control a heavy object to be damped with a passive damping device of this kind, the mass must be heavier and have a higher rigidity. The increase in space is undeniable.

For this reason, the vibration of the controlled object is detected by a sensor, and the vibration pendulum is oscillated in the opposite phase based on the detection signal, and the vibration is damped by an active vibration damping device which damps by the inertial reaction force. It is supposed, however, that a large-sized, high-output linear motor, a servomotor, a hydraulic motor, or the like must be used as the actuator, and it is difficult to cope with the above-mentioned small size and space saving. Further, since the mass of the mass body is constant and the spring constant of the whole vibration pendulum is also constant, it is difficult to cope with all higher-order resonances and local resonance phenomena.

[0005] Therefore, in the active vibration damping device, there are technical problems to be solved in order to achieve a small size and space saving and to enable vibration damping corresponding to the natural frequency of the vibration damping object. Thus, an object of the present invention is to solve the problem.

[0006]

SUMMARY OF THE INVENTION The present invention has been proposed to achieve the above object. An arm is pivotally supported on a base plate fixed to an object to be damped, and a tip of the arm is provided. A vibrating pendulum for attaching a mass body to the portion to dampen the object to be damped is configured, the arm and the base plate are connected by a vibrator, and the vibration is suppressed by forced vibration of the vibrating pendulum by the vibrator. Provided is an active vibration damping device configured to dampen a vibration target, and further includes an elastic body that resonates at a natural frequency of the vibration damping target, the vibrator connecting the base plate and the arm. An active vibration damping device connected through the arm is provided, and further, a guide portion for movably guiding the vibrator and the elastic body along the arm longitudinal direction is formed on the arm and the base plate, respectively. Husband to guide There is provided a vibrator and active vibration suppression apparatus provided with a fixing portion for fixing the elastic body. A first vibration detection sensor for detecting the vibration of the vibration damping object; calculating an output value of the vibration detection sensor to calculate a period of the vibration of the vibration object; And a controller that calculates a vibration suppression period and a phase difference for controlling the vibration of the vibration suppression target, and outputs a drive signal corresponding to the vibration suppression period and the phase difference to the vibrator. And a second vibration detection sensor for detecting the vibration of the vibration pendulum and outputting the vibration to the controller, wherein the controller detects the actual vibration of the vibration pendulum based on the output value of the second vibration detection sensor. And when the period of the actual vibration obtained by the calculation deviates from the vibration suppression period, the correction control is performed so that the period and the phase difference of the drive signal for the vibrator coincide with the vibration suppression period. Supplement Providing an active vibration damping device provided with a control unit, further provided with a preload load means to load a preload for horizontal forced vibration to at least one of the vibration pendulum or the vibrator, Provided is an active vibration damping device configured to dampen horizontal vibration of the object to be damped by the vibration pendulum, and a support shaft is integrally provided on a rotation fulcrum of the arm, and the base plate is provided on the base plate. A shaft support portion having a shaft support hole for rotatably supporting the support shaft is provided, and an elastic bearing for regulating shaft runout of the support shaft is provided between an inner surface of the shaft support hole and an outer peripheral surface of the support shaft. An active vibration damping device is provided.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention applied to vibration suppression of a base on which a semiconductor manufacturing apparatus is mounted will be described in detail with reference to FIGS.

FIGS. 1 and 2 show an active vibration damping device 1 for damping the base. A base plate 3 fixed to a base 2 as an object to be damped is formed. Pendulum 4 is pivotally supported for swinging. For example, a bearing portion 5 is provided on the base plate 3.
And a pair of arms 7, 7 are supported on the bearing portion 5 via a support shaft 6 so as to be swingable. A mass body 8 having a predetermined weight is fixed to the other end of the pair of arms 7, 7. To form the vibration pendulum 4 for vibration suppression.

Supporting means 9, 9 are provided on both sides of the pair of arms 7, 7, and the backlash of each arm 7 is regulated by the supporting means 9, 9. These support means 9, 9 are integrally attached to the side surface of each arm 7, and are viscoelastic bodies 10, 10 which are soft in the swinging direction and hard in the direction orthogonal to the swinging direction. The viscoelastic body 10 is formed by alternately laminating viscoelastic rubber and a steel plate. And a slip layer such as a Teflon resin layer having a low coefficient of friction and a sufficiently high abrasion resistance with respect to the contact surface with the support brackets 11 and 11. good.

In such a case, the sliding resistance between the viscoelastic bodies 10, 10 and the support bracket is significantly reduced, and the swing for damping the arms 7, 7 becomes smoother.

On the other hand, as shown in FIG. 3, an outer peripheral surface of a support shaft 6 for rotatably supporting the arms 7, 7 on the support portion 4,
Leaf springs 12, 12, 12, 12 projecting radially outward are provided at predetermined intervals in the circumferential direction, and each leaf spring 12, 12, 12,.
An elastic bearing may be configured to elastically contact the inner peripheral surface of the shaft support hole 13 of the bearing portion 12 with the inner peripheral surface. In that case,
The shaft runout of the arms 7, 7 is restrained by the support of the distal end surfaces of the leaf springs 12, and the support shaft 6 is elastically supported by the bending deformation of the leaf springs 12 in the rotation direction. Of course, for a smoother swing of the arms 7, 7, such an elastic bearing and
The support means 9 may be used in combination.

A vibrator for vibrating the arms 7, 7 is, for example, a responsive element in which piezo elements are connected in series and in another stage,
As shown in FIGS. 1 and 2, one of a pair of fastening rings 15A and 15B to be fastened to each other is attached to the outer periphery of a base end of a cylinder 16 of the electrostatic actuator 14 as shown in FIGS. The pair of arms 7 can be seated on the upper surfaces of the pair of arms 7, 7 while the cylinder inserted state of the electrostatic actuator 14 is held between the pair of arms 7
6 is fitted with the other fastening ring 15B.

Then, the bolts 18 inserted into the bolt insertion holes 17 formed in one of the fastening rings 15A are screwed into the corresponding screw holes 19 of the other fastening ring 15B, respectively. Accordingly, the pair of arms 7, 7 are vertically held.

For this reason, if the bolts 18 are loosened and the electrostatic actuator 14 is pushed out in the longitudinal direction of the arm, it can be moved to an arbitrary position and stopped.
8 can be fixed at an arbitrary position. As a result, the period and amplitude of the vibration pendulum 4 can be changed.

For example, the mass m of the mass body 8 and the vibration pendulum 4
Is the distance l from the support point of the actuator 14 to the center of gravity of the mass body 8 as the distance l from the support point of the electrostatic actuator 14 to the center of gravity of the mass body 8, and the amplitude of the mass body 8, that is, The position of the actuator 14 was set such that the swing width of the vibration pendulum 4 became the swing width for damping the base 2, and the telescopic rod 20 of the electrostatic actuator 14 was fixed to the surface facing the base plate 3 at this position. Thereafter, when the vibration pendulum 4 is vibrated by the electrostatic actuator 14 at a corresponding cycle and amplitude, active damping of the base 2 becomes possible.

The frequency of the base 2, that is, the frequency of the base 2, is detected by detecting the frequency of the object to be damped and vibrating the vibrating pendulum 4 in the direction opposite to the vibration direction at a period corresponding to the frequency. A first vibration detection sensor 21 is installed to detect the vibration, and a second vibration detection sensor 22 is installed to detect the frequency of the vibration pendulum 4. The first vibration detection sensor 21 and the second vibration detection sensor 22 The detection signal is input to an arithmetic processing unit (not shown) of the controller 23 for processing.

The controller 23 comprises a well-known microcomputer or sequencer.
The detection signal output from the vibration detection sensor 21 is arithmetically processed to determine the frequency and period of the vibration object, and based on the calculation result, the period and phase angle for damping the vibration of the base 2 are calculated. Then, a drive signal corresponding to the phase angle is output to the electrostatic actuator 14 to vibrate the vibration pendulum 4. Then, a real cycle and a real phase difference of the vibration of the vibration pendulum 4 are calculated by a calculation based on an output value of the second vibration detection sensor 22, and a drive control unit of the electrostatic actuator 14 is calculated based on the calculation result. The correction calculation of the drive signal is performed, and the feedback control increases the accuracy and reliability of vibration suppression. Therefore, the mass body 7 can be reduced in size, and the entire apparatus can be reduced in weight and size.

Although the vibration damping device 1 functions as an active vibration damping device, the function of a passive vibration damping device may be incorporated.

For example, as shown in FIG. 4, the telescopic rod 20 of the electrostatic actuator 14 and the base plate 3
Are connected via an elastic body 24, and the natural frequency of the elastic body 24 is equal to the natural frequency of the base 2 as a vibration damping target, or is appropriately smaller than the natural frequency of the base 2. Set to a number.

When the natural frequency of the elastic body 11 is set equal to the natural frequency of the base 2, vibration is coupled to the vibration pendulum 4 by resonance of the elastic body 11, and the vibration energy is absorbed by the coupling. This suppresses the vibration of the base 2 and the vibration of the semiconductor manufacturing apparatus. In addition, as the elastic body 24, any of a resilient means such as a coil spring and a leaf spring, rubber, a composite of rubber and the resilient means, or a viscoelastic body or a laminate of a viscoelastic body and a steel plate is used. Can be Therefore, the vibration of the base 2 is achieved even at the time of a power failure or at the time of failure of the electrostatic actuator 14, and it is possible to prevent a decrease in the semiconductor yield due to the vibration. Further, when the elastic body 24 is incorporated in the device, the vibrating force of the electrostatic actuator 14 can be small, and the response delay for vibration suppression can be eliminated. Therefore, in this case, a small-sized and low-capacity electrostatic actuator can be used.

In order to effectively control the vibration by the light and small mass body 8, for example, as shown in FIG. 5, an elongated hole 25 is formed in the base plate 3 along the arm longitudinal direction.
A guided body 26 having a rectangular cross section that slides and moves along the elongated hole 25 is formed integrally with the elastic body 24.
6, a bolt portion 27 for fixing is integrally formed, and a nut 28A is screwed and fastened to the bolt portion 27 so that the amplitude of the vibration pendulum 4 corresponds to the mass of the mass body 8. The controller 23 may be configured to vibrate the electrostatic actuator 14 at a cycle synchronized with the vibration of the base 2.

In order to perform vibration control with higher accuracy, the output value of the second vibration detection sensor 22 and the first
The vibration cycle of the electrostatic actuator 14 may be corrected based on the detection value of the vibration detection sensor 21 to stop the vibration of the base 2.

When the natural frequency of the elastic body 24 is set to be lower than and near the resonance point of the base 2, the vibration of the electrostatic actuator 14 before the vibration reaches the resonance point of the base 2.
Every time the vibration pendulum 7 vibrates. Therefore, in this case,
The controller 23 controls the first vibration detection sensor 21
The detected output signal is subjected to arithmetic processing to obtain the frequency and cycle of the vibration object, and the cycle and phase angle for damping the vibration of the base 2 are obtained based on the calculation result. A corresponding drive signal is output to the electrostatic actuator 14 to vibrate the vibration pendulum 4, and further, the actual cycle and the actual position of the vibration of the vibration pendulum 4 are calculated based on the output value of the second vibration detection sensor 22. The phase difference is calculated, and a correction calculation of a drive signal for a drive control unit of the electrostatic actuator 14 is performed based on the calculation result.

As in this embodiment, the left and right arms 5,
The electrostatic actuator 14 is interposed between the arms 5 and 5 to form a guide for moving the actuator, and the pair of fastening rings 15A and 15B and the bolt 18. The fixed structure has the further advantage that the electrostatic actuator 14 can be protected from shearing stress acting on it.

When the base 2 is to be controlled by the active vibration control device 1 against a vibration surface along the direction of gravity, the vibration pendulum 4 and the electrostatic actuator 14 are used.
Although the weight itself acts as a preload for the vibration, the active vibration damping device 1 is not provided with a preload load means for damping the vibration along the horizontal plane.

Therefore, in the present embodiment, FIGS.
As shown in the figure, brackets 28, 28 are erected on the base plate 3 with the arms 7, 7 interposed therebetween.
Elastic bodies 29 are fixedly provided so as to face the upper surfaces of the arms 7, 7 or the base end surface of the actuator 14, or one of the fastening rings 15A, 15A. And the elastic bodies 29, 2
The preload is given by the contact between the arm 9 and the arms 7, 7 or the base end face of the actuator 14, or one of the fastening rings 15A.

As a lower-cost preloading means, for example, as shown in FIG.
The viscoelastic layer 30, which is soft in the direction of rotation of the arms 7, 7 and hard in the direction perpendicular to the direction of rotation, is formed between the outer peripheral surface of the support shaft 6 and the inner surface of the shaft support hole 23 of the bearing portion 4. , A gel, more specifically, an elastomer of silicone rubber or superplastic rubber, or a viscoelastic layer 30 made of gel may be formed over the entire circumference, and as shown in FIG. 23
Spline grooves 31, 31, 31, 31 are formed on the inner peripheral surface of each of the springs to regulate the rotation of each leaf spring 12 in a predetermined range, respectively.
The preload may be loaded by the torsional reaction force of each leaf spring 12. Further, a torsion bar having an X-shaped cross section is connected to the shaft surface of the support shaft 6, and the torsion bar is connected to the shaft support 5. It may be subjected to torsional deformation.

Therefore, any preloading means can apply a horizontal preloading load. Therefore, a plurality of active vibration damping devices are mounted on the base 2 and both the vertical and horizontal Achieving vibration suppression and changing the period and amplitude of vibration of each active vibration damping device 1 can suppress broadband vibration and higher-order vibration.

As described above, the present invention can be variously modified without departing from the spirit of the present invention, and the present invention naturally extends to the modified invention.

[0030]

According to the first aspect of the present invention, as described in detail in the first embodiment, the position of the vibrating pendulum with respect to the arm is set according to the mounting position of the vibrator, and the swing width of the vibrating pendulum is reduced by the mass. Since it is configured to amplify to an amplitude corresponding to the mass of the body, the vibration of the object to be damped can be effectively damped by the lightweight and small mass body. In addition, when a lightweight and small mass body is used, the space occupied by the mass body can be reduced.

According to a second aspect of the present invention, the vibrator for connecting the base plate and the arm is connected via an elastic body that resonates at a natural frequency of the object to be damped. In the event of a failure, the vibration target can be damped without a response delay.

According to a third aspect of the present invention, a guide portion for movably guiding the vibrator and the elastic body along the longitudinal direction of the arm is formed on the arm and the base plate, respectively. Since the fixing portion for fixing the elastic body is provided, the setting position of the vibrator with respect to the arm can be set freely according to the mass of the mass body, and the swing width of the vibrating pendulum has an amplitude corresponding to the mass of the mass body. And vibration can be damped corresponding to the natural frequencies of various vibration damping objects.

According to a fourth aspect of the present invention, the output value of the first vibration detection sensor is calculated to calculate the period of the vibration of the vibration object, and the vibration of the vibration damping object is calculated based on the period of the vibration. Is calculated, and a drive signal corresponding to the vibration control period and the phase difference is output to the vibrator, so that active vibration control with high accuracy can be performed.

According to a fifth aspect of the present invention, the period of the actual vibration of the vibration pendulum is calculated, and when the period of the actual vibration obtained by the calculation deviates from the vibration suppression period, the driving of the vibrator is performed. Since the correction control is performed so that the signal period and the phase difference match the vibration suppression period, the reliability of the vibration suppression can be greatly improved.

According to a sixth aspect of the present invention, since a preloading means is provided for loading a preload for forced horizontal vibration to at least one of the vibrating pendulum and the vibrator, only the mounting direction is changed. Thus, vertical and horizontal vibrations can be suppressed.

According to the seventh aspect of the present invention, since an elastic bearing for regulating shaft runout of the support shaft is provided between the inner surface of the shaft support hole of the base plate and the support shaft of the arm, the vibration of the vibration pendulum for vibration is provided. The movement is smooth, and efficient vibration suppression is performed.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention and is a partially cutaway plan view of an active vibration damping device.

FIG. 2 illustrates an embodiment of the present invention, and illustrates AB- in FIG.
It is a figure which shows CDEF section.

FIG. 3 is a side view showing an embodiment of the present invention and showing a structure of a pivot portion of an arm.

FIG. 4 is a partially cutaway side view showing an embodiment of the present invention and showing a view in which an elastic body is interposed to enable passive vibration suppression.

FIG. 5 is a partially cutaway side view showing an embodiment of the present invention and showing a structure for enabling sliding movement of an elastic body for enabling passive vibration suppression.

FIG. 6 shows one embodiment of the present invention, and is a partially cut-away plan view in which a preload loading means is provided on a base plate to restrict horizontal vibration.

7 shows an embodiment of the present invention and is a partially cutaway side view of FIG. 6. FIG.

FIG. 8 shows an embodiment of the present invention, and is a side view in which a preload load means is provided on a shaft support portion.

FIG. 9 shows an embodiment of the present invention, and is a detailed explanatory side view of a main part in which a preload load means is provided on a shaft support.

[Explanation of symbols]

 2 Vibration suppression target 3 Base plate 4 Vibration pendulum (vibrator) 7 Arm 8 Mass 14 Electrostatic actuator 21 Vibration detection sensor 23 Controller

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Kiyomi Hasegawa 2-1 Tsukudo-cho, Shinjuku-ku, Tokyo Main office in Tokyo, Kumagaya Gumi Co., Ltd. F term (reference) in Kiki Co., Ltd. 3J048 AB07 AD03 AD07 CB19 EA38

Claims (7)

[Claims] An arm is pivotally supported on a base plate fixed to an object to be damped, and a mass body is attached to a tip of the arm to constitute a vibration pendulum for damping the object to be damped. On the other hand, the arm and the base plate are connected by a vibrator, and the object to be damped is damped by forced vibration of the vibrating pendulum by the vibrator. 2. The vibration damping device according to claim 1, wherein the vibrator that connects the base plate and the arm is connected via an elastic body that resonates at a natural frequency of the vibration damping target. 3. A guide portion is formed on the arm and the base plate to guide the vibrator and the elastic body movably along the longitudinal direction of the arm, and the vibrator and the elastic body are respectively provided on each guide portion. 3. The active vibration damping device according to claim 1, further comprising a fixing portion for fixing. 4. A first vibration detection sensor for detecting a vibration of the vibration damping object, calculating an output value of the vibration detection sensor to calculate a cycle of the vibration of the vibration object, and A controller that calculates a vibration suppression period and a phase difference for damping the vibration of the vibration suppression target based on the period, and outputs a drive signal corresponding to the vibration suppression period and the phase difference to the vibrator. Item 7. The active vibration damping device according to Item 1, 2, or 3. 5. A second vibration detection sensor for detecting the vibration of the vibration pendulum and outputting the vibration to the controller, wherein the controller detects the actual vibration of the vibration pendulum based on an output value of the second vibration detection sensor. When the period is calculated, and when the period of the actual vibration obtained by the calculation deviates from the vibration suppression period, correction control is performed so that the period and the phase difference of the drive signal for the vibrator coincide with the vibration suppression period. 5. The active vibration damping device according to claim 1, further comprising a correction control unit. 6. A vibratory pendulum and / or a vibrator which is provided with a preload loading means for applying a preload for forced vibration in a horizontal direction to at least one of the vibrator and the vibrating pendulum. 6. The active vibration damping device according to claim 1, wherein the active vibration damping device is configured to dampen horizontal vibration. 7. A support shaft is integrally provided at a rotation support portion of the arm, and a support portion having a support hole for rotatably supporting the support shaft is provided on the base plate, and an inner surface of the support hole is provided. 7. The active vibration damping device according to claim 1, wherein an elastic bearing for regulating shaft runout of the support shaft is provided between the support shaft and an outer peripheral surface of the support shaft.