KR100583075B1 - Active vibration control apparatus - Google Patents

Abstract

The present invention relates to a vibration suppression apparatus for removing vibration of an object to be damped, such as semiconductor equipment or precision measuring equipment. In particular, at least four vibration damping tables (20) mounted on and supported by the object to be damped are mounted on the base plate (10). Installed horizontally with two level adjusting mechanisms 30, at least six vibration damping actuators 50A-50F are installed between the vibration damping table 20 and the base plate 10, and the vibration controller 43 vibrates. Vibration control signals corresponding to the vibrations of the vibration damping table 20 detected by the sensing sensor 40 are provided to the plurality of vibration damping actuators 50A-50F so that the vibration damping actuators 50A-50F damp the thrust corresponding to the vibration. By acting on the table 20, the vibration of the six degree of freedom of the damping table is effectively eliminated.

Active vibration suppression, voice coil motor, level adjustment

Description

ACTIVE VIBRATION CONTROL APPARATUS}

1 is a schematic configuration diagram of a vibration suppression apparatus using a conventional air spring,

2 is a schematic conceptual view of a conventional vibration suppression apparatus shown in FIG. 1;

3 is a front view of an active vibration suppressing apparatus according to the present invention;

4 is a plan view of a state in which the vibration damping plate is separated from the vibration suppression apparatus of the present invention;

5 is a cross-sectional view of the coupling of the vibration suppression actuator used in the vibration suppression apparatus of the present invention,

6 is a schematic conceptual view of a vibration suppression apparatus according to the present invention;

7 is a graph showing the vibration suppression characteristic curve of the vibration suppression apparatus of the present invention compared with the characteristic curve of the conventional passive vibration suppression apparatus.

※ Explanation of code about main part of drawing ※

10: base plate W: subject to vibration

11: pedestal 12: slope

20: damping table 21: support base

22: 1st permanent magnet 23: 2nd permanent magnet

24: level detecting unit 25: level detecting sensor

26: printed circuit board 27: level control unit

30: level adjusting mechanism 31: feed shaft

32: spring seat 33: spring

33a-33c: Gear 34: Drive Motor

35: potentiometer 41: mount

42: support block 43: vibration control unit

50A-50F: Damping Actuator 51: Casing

52: magnet portion 53: yoke portion

54: coil portion 55: pole piece

56a, 56b: damper spring 57: damping rod

58: diaphragm 59: piezoelectric sensor

60: vibration detection unit 61: guide rod

62a, 62b: spring 64: cover

65: pressure rod 70: actuator portion

71: fixed plate

The present invention relates to a vibration suppression apparatus that supports vibration of a vibration control object by supporting a vibration control object such as a precision measuring device and a semiconductor device. In particular, the present invention relates to vibration by directly applying a thrust to damp the vibration of the vibration control object directly to the vibration control object. The present invention relates to an active vibration suppression apparatus that actively removes a gas.

Precision measuring instruments, optical test equipment, semiconductors, and ultra-precision equipment cause malfunction even in the case of minute vibrations, and therefore, a vibration damping device for eliminating self-vibration caused by external vibration or operation of the equipment is essential. However, in the conventional vibration suppression apparatus, a vibration suppression apparatus using an air spring has been used as shown in FIG. 1. As shown in FIG. 1, the conventional vibration isolator includes at least four supports 2 in which a vibration damping table 1 for supporting a vibration damping object (for example, a precision measuring instrument or a semiconductor device) to be damped is mounted upright on the ground. The vibration damping table 20 is elastically supported by the air spring 3 provided for each support 2. And the air spring (3) of each support (2) is connected to the compressed air supply source (4) for providing air pressure through the flow path, the support (2) is a vibration for detecting the vibration of the vibration damping table (1) A sensing sensor 5 is provided, and the compressed air of the compressed air supply source 4 is supplied to the air spring 3 according to the vibration amount of the vibration damping table 1 detected by the vibration detecting sensor 5 to provide an air spring. It consists of a control valve 6 which increases the pressure of (3) or discharges the air of the air spring (3).

In such a conventional air spring vibration damping device, when the vibration damping table vibrates, the vibration sensor detects the vibration of the vibration damping table, and the control valve opens and closes according to the vibration of the vibration damping table to selectively compress the compressed air into a plurality of air springs. By supplying or discharging the compressed air from the air spring, the vibration of the vibration damping table is controlled by adjusting the pressure of the air spring supporting the vibration damping table.

Such a conventional air spring type vibration suppression device is a so-called "passive vibration control device", and the conceptual diagram is as shown in FIG. The motion equation of the conventional passive vibration damping device is as shown in Equation 1 below, and the transmission force obtained from the equation of motion in Equation 1 is shown in Equation 2.

When the vibration transfer function T of the conventional passive vibration suppression apparatus is obtained from Equations 1 and 2, the following Equation 3 is obtained.

Where u is the ratio of the vibration frequency of the vibration damping table to the natural frequency of the vibration damping table, and ξ is the damping ratio indicating the ratio of the viscosity damping coefficient of the prevention material to the critical damping coefficient.

As can be seen through the equation (3), the conventional passive vibration damping device is determined according to the natural frequency of the material constituting the vibration damping device can not change the physical properties of the material to suit the situation, thereby There is a limitation that the vibration transmission rate of the device cannot be improved.

And the vibration transmission characteristics of the conventional passive vibration suppression apparatus according to the equation (3) as shown in the solid line of FIG.

As shown in FIG. 7, the conventional passive vibration suppression device not only amplifies the vibration when the frequency ratio u is less than 1.414, but also causes a problem that resonance occurs in the state where the frequency ratio u is 1, thereby reducing amplification. In order to increase the damping ratio ξ, there is a problem in that the damping efficiency is lowered in a state where the frequency ratio u is 1.414 or more.

In addition, the conventional air spring vibration damping device only removes vibration in a specific direction in which the support supports the vibration damping table, and has a disadvantage in that it cannot damp all degrees of freedom of vibration.

Accordingly, the present invention can increase the damping efficiency by removing the vibration by actively applying the vibration damping force in response to the vibration of the vibration damping object, in order to solve the disadvantages of the conventional vibration damping device, to effectively damp the vibration of six degrees of freedom It is possible to increase the damping efficiency, especially in the low frequency region, and to provide an active vibration suppression device that is particularly suitable for vibration suppression of precision measuring equipment.

The present invention for achieving the above object,

Base plate,

A plurality of voice coils which are deflected in a predetermined direction with respect to the horizontal direction of the vibration damping table and are inclined with a constant inclination with respect to the vibration damping table so that one end thereof is fixed to the bottom of the vibration damping table and the other end thereof is supported by the base plate. Including motor type vibration damping actuator,

Each of the vibration suppression actuators is a vibration sensing unit for detecting vibrations of the vibration damping table and outputting an electrical signal while vibrating in cooperation with the vibration damping table, and a vibration control signal for attenuating the vibration in response to the vibration detected by the vibration sensing unit. Vibration control unit for outputting a; and an actuator unit for providing a thrust to the vibration damping table while swinging up and down according to the vibration control signal of the vibration control unit.

In addition, the vibration suppression apparatus according to the present invention includes a plurality of level sensing sensors for detecting the level of each corner of the vibration damping table according to the change of the upper and lower positions of at least four corners of the vibration damping table, and each corner of the vibration damping table detected by the respective level sensing sensors. A level control unit for calculating a level deviation value with respect to the horizontal of the vibration suppression table by comparing the negative level value with a reference set value, and outputting a level control signal corresponding to the level deviation value of the vibration suppression table;

It is provided in at least four corners of the vibration damping table, each of which further comprises a level control mechanism for maintaining the level of the vibration damping table horizontally by moving each corner of the damping table up and down by the level control signal provided by the level control unit. do.

The level sensing unit is parallel to the first permanent magnet provided on the bottom surface of the vibration damping table, the second permanent magnet provided on a support stand installed on the base plate so as to face the first permanent magnet, and at regular intervals on the bottom surface of the vibration damping table. It is provided on the attached printed circuit board is made of a level sensor for detecting the level of the vibration damping table in accordance with the intensity of the magnetic field that changes in accordance with the position change of the first permanent magnet with respect to the second permanent magnet. The level sensor is mounted on a printed circuit board horizontally coupled to the bottom surface of the vibration damping table.

Each level adjusting mechanism includes a spring that is elastically installed between the bottom surface of the edge of the vibration damping table and the spring seat at a position corresponding to each corner of the vibration damping table, and a transfer shaft connected to the spring seat to move the spring sheet up and down. A drive motor connected to the feed shaft by a series of meshed gears and rotating the feed shaft to move the spring seat up and down according to the level control signal of the level control unit; It becomes the structure containing the potentiometer which feeds back to a control part.

Hereinafter, an embodiment of an active vibration suppression apparatus according to the present invention will be described in detail with reference to FIGS.

3 is a front view schematically showing the structure of a vibration suppression apparatus according to an embodiment of the present invention, Figure 4 is a plan view of a state in which the base plate is removed from the vibration suppression apparatus according to an embodiment of the present invention. As shown in FIG. 3, a base plate 10, a vibration damping table 20 horizontally supported on the base plate 10, and a level adjusting mechanism for horizontally maintaining the level of the vibration damping table 20 ( 30) and a plurality of vibration damping actuators 50A-50F for providing vibration to the vibration damping table 20 to attenuate the vibration of the vibration damping table 20 to eliminate vibration of the vibration damping table 20.

The base plate 10 is horizontally supported on the ground by a height adjustable pedestal 11 at four corners. At least four corners of the base plate 10 are provided with mounts 41, respectively, and a vibration damping table 20 is installed on the mount 41 so as to be movable upward and downward through the support block 42. The vibration damping table 20 is supported on the vibration damping object W such as a precision optical measuring device, a semiconductor device, and the like.

Further, below the vibration damping table 20, a plurality of level sensing sensors 25 for detecting each level value of at least four corners of the vibration damping table 20, and the vibration damping table detected by the level sensing sensor 25 are provided. A plurality of level adjusting mechanisms 30 are provided for removing the level deviation.

Each level sensor 25 is a so-called Hall sensor, and includes a first permanent magnet 22 and a first permanent magnet 22 installed on a bottom surface of the vibration damping table 20. The second permanent magnet 23 provided on the support 21 mounted upright on the base plate 10 and the printed circuit board 26 attached in parallel to the bottom surface of the vibration damping table 20 at regular intervals. It is provided in the level sensing section 24 for detecting the level value of the vibration damping table 20 according to the strength of the magnetic field according to the position change with respect to the second permanent magnet 23 of the first permanent magnet (22). The level value for the vibration suppression table 20 detected by the level detection unit 24 of the level detection sensor 25 is transmitted to the level control unit 27 of the printed circuit board 26.

The level adjusting mechanism 30 horizontally adjusts the vibration damping table 20 by individually adjusting the height of each corner of the vibration damping table 20 according to the level signal of the damping table 20 provided by the level controller 27. Keep it.

As shown in FIGS. 3 and 4, each of the level adjusting mechanisms 30 abuts against the bottom of the corner of the vibration damping table 20 at a position corresponding to each corner of the vibration damping table 20. A spring 33 which is supported by a spring seat 32 which slides up and down along the feed shaft 31 installed upright on the base plate 10 to support the edge of the vibration damping table 20, the feed shaft (31) is connected via a series of gears (33a-33c) that are externally engaged with each other, and is driven in accordance with the control signal of the level control unit 27 to rotate the feed shaft 31 in the forward or reverse direction spring seat And a potentiometer 35 which compares the rotation angle of the drive motor with the level value of the vibration damping table and feeds the difference value back to the level control unit 27. Include. The present embodiment uses a potentiometer as the level control feedback mechanism, but is not limited thereto, and other types of instruments having the same function may be used.

 Referring to the operation of the vibration damping table horizontal adjustment device of the present invention having the configuration as described above is as follows.

When the to-be-damped object W is placed on the damping table 20, the position where the to-be-damped object W is placed on the damping table 20 is deflected from the center so that the level deviation of the damping table 20 is either. When generated, the level deviation of the vibration damping table 20 is detected by the level sensor 25 and transmitted to the level control unit 27.

That is, the level controller 27 compares the level value detected by the level detection sensor 25 with the horizontal reference value, and transmits a control signal corresponding to the level difference value to the driving motor 34. The driving motor 34 rotates in one direction according to the control signal of the level control unit 27 to rotate the feed shaft 31 to move the spring seat 32 up and down, thereby reducing the vibration damping table 20. The force of the spring 33 supporting each corner is individually adjusted to automatically adjust the level of the damping table 20 horizontally.

For example, if one edge portion of the vibration damping table 20 rises above the horizontal position, the level sensor 25 provided at the edge portion detects the level of the edge portion and sends a signal to the level controller 27, and the level controller (27) compares the level value of the corner portion detected by the level sensor 25 and the horizontal reference value, and sends a control signal corresponding to the level deviation amount to the drive motor 34, and the drive motor 34 is the level control unit. According to the control signal of (27) , by rotating the feed shaft 31 in the direction of lowering the spring sheet to lower the corresponding corner portion of the vibration damping table 20 which is raised above the horizontal to the horizontal position. On the contrary, the edge portion of the vibration damping table 20 lowered below the horizontal position is kept horizontal through the above-described process, and the operation principle thereof is the same, and thus a detailed description thereof will be omitted.

On the other hand, as shown in Figure 4, between the vibration damping table 20 and the base plate 10 is provided three pairs of vibration damping actuator (50A-50F). The vibration damping actuators 50A-50F are deflected in different directions so as to suppress vibration of the six degrees of freedom of the vibration damping table 20 and at the same time inclined with respect to the base plate 10 at a predetermined angle.

As shown in FIG. 5, each of the vibration suppression actuators 50A-50F is provided with a casing 51 fixed to a bottom of the vibration suppression table 20 by a fixing means such as a bolt (not shown), and the inside of the casing 51. Vibration sensing unit 60 is installed on the upper side, and detects the vibration of the vibration damping table 20 transmitted through the casing 51 and outputs an electrical signal proportional to the vibration amount, and in the vibration sensing unit 60 Vibration control unit 43 for outputting a vibration control signal corresponding to the detected vibration amount of the vibration damping table 20, and thrust for attenuating the vibration of the vibration damping table 20 in accordance with the vibration control signal of the vibration control unit 43 It consists of an actuator part 70 which acts on the damping table 20.

The vibration detecting unit 60 is freely swingable in the vertical direction along a fixing plate 71 fixed to the inner wall of the casing 51 and a guide rod 61 fixed to the fixing plate 71, In the diaphragm 58 elastically supported by springs 62a and 62b respectively installed at the upper and lower portions of the rod 61, the piezoelectric sensor 59 provided in the diaphragm 58, and the fixing plate 71, The pressing rod 65 extends so that the tip abuts against the bottom of the diaphragm 58 and presses the piezoelectric sensor 59 to output an electrical signal proportional to the vibration amount as the diaphragm 58 vibrates.

As shown in FIG. 3, the vibration control unit 43 is provided on a circuit board 26 fixed to the bottom surface of the vibration damping table 20 so as to be electrically connected to the piezoelectric sensor 59 of the vibration sensing unit 60. Connected. The vibration control unit 43 is installed on a circuit board 26 fixed to the bottom of the vibration damping table 20 and an actuator for describing a vibration control signal corresponding to the vibration of the vibration damping table 20 provided by the piezoelectric sensor 59. Output to the unit 70.

The actuator portion 70 is a ring-shaped magnet portion 52 fixed to the lower portion of the casing 51, the yoke portion is installed in the center hole of the ring-shaped magnet portion 52 so as to swing in the vertical direction so as to swing in the vertical direction. (53), the coil unit 54 is wound around the yoke unit 53 and receives a vibration control signal from the vibration control unit 43, and is connected to the tip of the coil unit 54 and the coil unit 54 to enter and exit the gap. The pole piece 55 cooperating with the part 54, the pole piece 55 is installed to be slidably movable in the through-hole formed in the center axis direction of the pole piece 55 and one end thereof is in contact with the inclined surface 12 of the base plate 10 The damping actuator 50A-50F is formed by the first damping spring 56b provided between the outer circumferential surface and the bottom of the pole piece 55 and the second damping spring 56a provided between the other end and the bottom of the yoke portion 53. While elastically supporting the vibration sensing unit 60 from the outside The cover 64 is covered on the outside of the vibration detecting unit 60 to shield the vibration by the transmitted sound waves.

On the other hand, as shown in Figure 4, the first pair of vibration damping actuator (50A, 50B) of the three pairs of vibration damping actuator (50A-50F) is disposed on one edge of the base plate 10, the first vibration suppression actuator (50A) And a second vibration damping actuator 50B installed at an edge of the base plate 10 opposite to the first vibration damping actuator 50A. The first vibration damping actuator 50A is illustrated by the damping rod 57 at a predetermined angle (45 ° in the embodiment) along the counterclockwise direction with respect to the virtual horizontal axis HH of the base plate 10 as shown in FIG. 4. At the same time as shown in Figure 5, the base plate 10 is installed to be inclined upward by a predetermined angle (α). The second vibration damping actuator 50B is disposed opposite the first vibration damping actuator 50A at the opposite edge of the base plate 10 and faces 45 ° along the clockwise direction in FIG. 4 with respect to the virtual horizontal horizontal axis. At the same time, it is inclined upwardly by a predetermined angle α with respect to the plane of the base plate 10.

The pair of second vibration damping actuators 50C and 50D includes a third vibration damping actuator 50C and a fourth vibration damping actuator 50D which are disposed opposite to each other at both edges of the base plate 10. The third vibration damping actuator 50C is deflected in a direction orthogonal to the direction in which the damping rod 57 faces the fourth vibration damping actuator 50D at one edge of the base plate 10 and at the same time the plane of the base plate 10. It is installed inclined upward by a predetermined angle (preferably 45 °) with respect to the fourth vibration damping actuator 50D inclined in the same direction as the third vibration damping actuator 50C.

The third pair of vibration damping actuators includes a fifth vibration damping actuator 50E and a sixth vibration damping actuator 50F which are disposed to face each other at opposite edges of the base plate 10 and face each other in opposite directions. The fifth vibration damping actuator 50E has the damping rod 57 at one edge of the base plate 10 in the counterclockwise 45 ° direction with respect to the virtual horizontal horizontal axis and at the same time with respect to the plane of the base plate 10. It is inclined upward by an angle (preferably 45 °), and the sixth vibration damping actuator 50F is disposed opposite the fifth vibration damping actuator 50E at the opposite edge of the base plate 10 so as to be positioned on an imaginary horizontal horizontal axis. With respect to FIG. 4, it is turned in the clockwise direction along the clockwise direction and at the same time inclined upward by a predetermined angle α with respect to the plane of the base plate 10.

The three pairs of vibration damping actuators 50A-50F configured as described above are installed in various directions to suppress all vibrations of six degrees of freedom transmitted to the vibration damping table 20.

Hereinafter, the operation of the present invention configured as described above.

When a load member such as a precision measurement device or a semiconductor device is placed on the vibration damping table 20, the vibration damping table 20 is inclined to one side according to the position where the load is placed on the vibration damping table 20. At this time, the level sensor 25 provided at each corner of the vibration damping table 20 senses the level of each corner of the vibration damping table 20 and transmits the level to the level controller 27, and the level controller 27. Compares the level value of each corner of the vibration suppression table 20 detected by the level sensor 25 with a reference value, and transmits a control signal corresponding to the difference to the driving motor 34 to drive the tilted corner drive motor ( 34). The drive motor 34 receiving the control signal from the level control unit 27 rotates the feed shaft 31 while rotating in one direction to move the spring seat 32 upward or downward, thereby eliminating the vibration damping table 20. The force of the spring 33 supporting the corners of) is adjusted to automatically adjust the level of the vibration damping table 20 horizontally.

When the vibration damping table 20 is vibrated by the vibration of the load body mounted on the vibration damping table 20 or the vibration transmitted from the outside (ground) in the state where the vibration damping table 20 is horizontally adjusted through the above operation. The vibration of the vibration damping table 20 is transmitted to each vibration damping actuator 50A-50F connected to the bottom of the vibration damping table 20.

The vibration transmitted to the vibration suppression actuator 50A-50F vibrates the diaphragm 58 so that the piezoelectric sensor 59 provided on the diaphragm 58 is pressed by the pressure bar 65, and the piezoelectric sensor 59 is pressurized. The vibration detection signal corresponding to the strength of the force pressed by the rod 65 is output as an electrical signal and transmitted to the vibration control unit 43.

The vibration controller 43 outputs a control signal corresponding to the vibration of the vibration damping table 20 detected by the vibration detector 60 to the coil unit 54 of the actuator unit 70, and the coil unit 54 vibrates. In response to the control signal from the control unit 43, the control unit 43 oscillates up and down in the magnetic field of the ring-shaped magnet unit 52 according to the current strength of the control signal, and the oscillation of the coil unit 54 is connected to the coil unit 54. It is transmitted to the piece 55 to rock the damping rod 57 up and down. Since the damping rod 57 is elastically supported on the pole piece 55 and the yoke portion 53 by damping springs 56a and 56b, the damping rod 57 is provided with a thrust corresponding to the swing of the coil portion 54 and the pole piece 55. By transmitting to 20, the vibration of the vibration damping table 20 is actively attenuated.

Meanwhile, in the present embodiment, as illustrated in FIG. 4, a plurality of vibration damping actuators 50A-50F that damp the vibration of the vibration damping table 20 are disposed, and the vibration damping actuators 50A-50F are tilted in various directions. Since the plurality of vibration suppression actuators 50A-50F respectively damp the vibrations of the six degrees of freedom of the vibration damping table 20, the vibrations of the six degrees of freedom are damped.

6 is a schematic conceptual diagram of a vibration suppression apparatus according to an exemplary embodiment of the present invention as described above. According to the conceptual diagram shown in Figure 6 to obtain the vibration transfer function representing the vibration damping characteristics of the vibration suppression apparatus of the present invention as shown in Equation 4 below.

Where u is the ratio of the vibration frequency of the vibration damping table to the natural frequency of the vibration damping table, and ξeff denotes the damping ratio of the vibration suppression apparatus according to the present invention.

Referring to the vibration suppression characteristics of the active vibration suppression apparatus according to the present invention with reference to the graphs of Equations 4 and 7, the active vibration suppression apparatus of the present invention is a voice coil mechanism corresponding to the damping coefficient (Z) of the conventional passive vibration suppression apparatus. By replacing the motor-type vibration damping actuator 50A-50F, the vibration damping function is replaced with the controllable damping ratio.

Therefore, if an appropriate thrust is applied to the vibration damping table through the control of the vibration damping actuators 50A-50F, the vibration amplification at the resonance point u = 1 can be almost eliminated, as shown in the graph of FIG. In addition, even at a frequency ratio of 1.414 or more (u> 1.414), the damping efficiency can be improved compared to the conventional passive vibration suppression apparatus.

As described above, according to the vibration suppression apparatus according to the present invention, the time for the initial horizontal alignment of the vibration suppression table is shortened by the automatic horizontal adjustment device, and the vibration caused by the operation of the equipment under measurement when the equipment under measurement is installed. In this case, the vibration transmitted from the ground is damped at 6 degrees of freedom, so the vibration damping performance is excellent. In particular, the voice coil motor type vibration damping actuator is installed in various directions, which effectively damps all vibrations of the 6 degrees of freedom of the vibration damping table.

Claims (5)

delete Base plate 10, The front end of the vibration damping table 20 is deflected in a predetermined direction with respect to the horizontal direction and inclined with a constant inclination with respect to the damping table 20 so that one end is fixed to the bottom surface of the damping table 20 and the opposite end is It includes a plurality of voice coil motor type vibration damping actuator supported on the base plate 10, Each of the vibration damping actuators 50A-50F vibrates in conjunction with the vibration damping table 20 while detecting vibration of the vibration damping table 20 to output an electrical signal, and the vibration detecting part ( A vibration control unit 43 for outputting a vibration control signal for attenuating the vibration in response to the vibration detected by 60; and a thrust on the vibration damping table 20 while swinging up and down according to the vibration control signal of the vibration control unit 43. Actuator unit 70 and providing the, A plurality of level detection sensors 25 for detecting the level of each corner portion of the vibration damping table 20 according to the change of the upper and lower positions of at least four corners of the vibration damping table 20; Comparing the level value of each corner portion of the vibration damping table detected by the level detecting sensors 25 with a reference set value, a level deviation value with respect to the horizontal of the vibration damping table is calculated, and the level control corresponding to the level deviation value of the vibration damping table. A level control unit 27 for outputting a signal, It is provided on at least four corners of the vibration damping table 20, and each of the corners of the vibration damping table is moved up and down by a level control signal provided by the level controller 27 to maintain the level of the vibration damping table horizontally. In the active vibration suppressing apparatus further comprising a level adjusting mechanism 30, The vibration damping actuators are disposed at regular intervals from each other, each of which is disposed to be inclined by a predetermined angle with respect to the direction facing each other and at least two vibration damping actuators (50A, 50B) installed to be inclined upward at a predetermined angle with respect to the horizontal plane; At least two vibration damping actuators 50C and 50D disposed at regular intervals from each other, each of which is inclined in a direction orthogonal to an opposite direction and at an angle to an upward angle at a predetermined angle with respect to a horizontal plane; At least two vibration damping actuators 50E disposed at regular intervals from each other, each of which is installed to be inclined at a predetermined angle in an outward direction of the vibration damping table with respect to a direction orthogonal to the directions facing each other, and at the same time, at least two vibration damping actuators 50E which are inclined upward at a predetermined angle with respect to the horizontal plane , 50F) active vibration damper comprising a. According to claim 2 , wherein each of the damping actuator (50A-50F) is provided with a casing 51, the upper side one side is fixed to the bottom of the damping table 20, the vibration sensing unit 60 is the casing (51) The diaphragm 58 is installed to be freely swingable in the up and down direction along the guide rod 61 fixed with respect to the guide rod 61, and is elastically supported on the guide rod 61 by springs 62a and 62b. The piezoelectric sensor 59 provided therein and the piezoelectric sensor 59 are pressed in response to the vibration of the diaphragm 58 so that the piezoelectric sensor 59 outputs an electrical signal corresponding to the vibration intensity of the diaphragm 58. It consists of a cover 64 to block the pressure rod 65 and the diaphragm 58 from external sound, The actuator part 70 is rotatably vertically maintained by maintaining a constant gap with the inner wall in the central hole of the ring-shaped magnet part 52 fixed to the lower part of the casing 51, and the central hole of the ring-shaped magnet part 52. A coil part 54 which swings the yoke part 53 up and down according to the installed yoke part 53 and the outer wall of the yoke part 53 and is transmitted from the vibration control part 43; A damping rod for elastically supporting the yoke portion 53 and the casing 51 with the damping springs 56a and 56b with respect to the base plate 10 to transfer the swing of the yoke portion 53 to the casing 51 ( Active vibration suppression apparatus comprising: 57). delete The method of claim 2, wherein the level adjusting mechanism 30 A spring 33 elastically installed between the bottom of the edge of the vibration damping table and the spring seat 32 at a position corresponding to each corner of the vibration damping table 20, and a spring to move the spring seat 32 up and down; The spring seat (3) is connected to the feed shaft (31) by a feed shaft (31) connected to the seat (32) and a series of gears (33a to 33C) engaged with each other and in accordance with the level control signal of the level controller (27). A drive motor 34 for rotating the feed shaft 31 to move 32 up and down, and a potentiometer 35 for detecting a rotation angle of the drive motor 34 and feeding back to the level control unit 27. Active vibration suppression apparatus comprising a.

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