JPH05149379A - Active vibration omission device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an active vibration isolation device capable of absorbing positional deviations at the time of assembling, and being able to favorably control even minute vibrations. [Structure] On the end face in the driving direction of the laminated piezo element 10,
A piezo actuator 5Z, which is configured by interposing three or more layers of shearing force absorbing members 15 composed of a metal plate 13 and a thin elastic body 14 having a small wall thickness, is provided in a three-dimensional direction between a lower mount and a device mount. A vibration sensor that is drivable and that detects vibration in each of the three-dimensional directions is provided, and a control device that outputs a drive signal that cancels the vibration to the piezo actuator 5Z based on the vibration detected by the vibration sensor is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a horizontal two-dimensional or vertical microvibration caused by an earthquake, running of an automobile, walking of a worker, or the like in a semiconductor manufacturing factory, a laser application manufacturing factory or the like. In order to cancel out the propagation to the equipment mounting base, the equipment mounting base is provided on the lower mount via the piezo actuator that can be driven in each of the three-dimensional directions, and the vibration sensor that detects the vibration in each of the three-dimensional directions is provided. The present invention relates to an active vibration isolation device provided with a control device that outputs a drive signal for canceling the vibration to a piezo actuator based on the vibration detected by the vibration sensor.

[0002]

2. Description of the Related Art As a conventional active vibration isolator of this type, there is one disclosed in Japanese Patent Application Laid-Open No. 2-246382.

FIG. 8 is a vertical side view of the above-mentioned conventional example, and FIG. 9 is a sectional view taken along the line AA of FIG. 8. A lower mount 03 is placed horizontally on a support floor 02 or the like by a height adjusting screw 01.
, Two first piezo actuators 04X, 04X that can be driven in one of the horizontal two-dimensional directions (X direction) and two second piezo actuators that can be driven in the other of the horizontal two-dimensional directions (Y direction). Actuators 04Y, 04Y and vertical direction (Z
The device mounting base 05 is provided via four third piezo actuators 04Z ...

At positions facing the first and second piezo actuators 04X, 04X, 04Y, 04Y, the first and second coil springs 06X, 06X are provided between the lower mount 03 and the equipment mounting base 05. , 06
Y and 06Y are interposed so that a precompressing force is always applied to each of the first and second piezo actuators 04X, 04X, 04Y and 04Y so that a driving force can be favorably generated in the horizontal direction due to distortion. Is configured.

As shown in the side view of FIG. 10, each of the first, second and third piezo actuators 04X, 04X, 04Y, 04Y, 04Z ... A metal plate 08 is attached to the end face in the direction, and a thin film elastic body 01 is provided between the other face of the metal plate 08 and the metal plate 09 facing it.
0 is sandwiched in a crimped state. The precompression force of the elastic body 010 is set to be larger than the force generated by the laminated piezoelectric element 07, and the elastic body 010 is
However, it has rigidity in the driving direction of the laminated piezo element 07,
On the other hand, the first, second and third piezoelectric actuators 04 have elasticity (flexibility) in the direction orthogonal to the driving direction.
X, 04X, 04Y, 04Y, 04Z ... Are configured so that a large shearing force is not applied to each.

A vibration detector 011 for detecting vibrations in each of the three-dimensional directions is provided on the equipment mounting base 05, and a signal based on the vibration detected by the vibration detector 011 is output to a control device (not shown). , In the control device, the first, second and third piezo actuators 04X, 04X, 04Y, 04Y, 04Z, which are required to stop the equipment mounting base 05 based on the input signal from the vibration detector 011 are respectively extended. The quantity, that is, the voltage signal to be applied to them is determined, and the voltage signal is determined by the first, second and third piezo actuators 04X, 04X, 04Y, 04Y, 04.
Z ... is output to each to control the three-dimensional vibration of the equipment mounting base 05.

[0007]

However, in the active vibration isolator of the prior art, the elastic body 010 causes the first, second and third piezo actuators 04X, 0.
4X, 04Y, 04Y, 04Z ... It is configured so that a large shear force is not applied to each, but in the field,
When the device mounting base 05 is assembled to the lower mount 03, the first, second and third piezo actuators 04X, 0
4X, 04Y, 04Y, 04Z ... When there is a slight error in the relative position of the bolt hole for mounting any one of them, the elastic body 010 is orthogonal to the driving direction of each piezo actuator in the assembled state. It becomes elastically deformed in the direction in which the piezo actuator is driven, and the elasticity (flexibility) in the direction orthogonal to the driving direction hardly acts in that elastic deformation direction. It also acts in the direction orthogonal to the direction and interferes with the control force of other piezo actuators, making positioning difficult by control and lowering the control accuracy, and when a large load is suddenly applied, the piezo actuator will be sheared. There was an inconvenience that it took force.

Therefore, it is conceivable to increase the thickness of the elastic body in the driving direction of the piezo actuator to facilitate elastic deformation in the direction orthogonal to the driving direction, but as the thickness increases, the rigidity of the piezo actuator in the driving direction is impaired. Therefore, there was still room for improvement because it was not possible to control fine vibrations well.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide an active vibration isolator which can absorb a positional deviation at the time of assembling and can also control fine vibrations satisfactorily. To aim.

[0010]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention provides a lower mount with a device mount via a piezo actuator that can be driven in each of the three-dimensional directions. An active vibration isolation device comprising a vibration sensor for detecting each vibration, and a control device for outputting a drive signal for canceling the vibration to a piezo actuator based on the vibration detected by the vibration sensor. Each of the actuators is constructed by interposing three or more layers of shearing force absorbing members each made of a rigid plate member and a thin elastic member having a small thickness on at least one of both end faces in the driving direction of the laminated piezoelectric element.

[0011]

According to the structure of the active vibration isolator of the present invention,
When assembled, if there is a displacement between the lower mount and the equipment mount in the direction orthogonal to the driving direction of the piezo actuator, each thin-walled elastic body of each of the three or more layers of shear force absorbing members will be elastic by a small amount. While deforming, it is possible to absorb a relatively large positional deviation as a whole.

[0012]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a partial cutaway side view of an active vibration isolator according to an embodiment of the present invention, and FIG. 2 is an overall plan view of the active vibration isolator via support legs 2 having height adjusting screws 1. A lower base 3 having a square shape in a plan view is placed on a support floor 4 in a horizontal posture, and two first piezo actuators 5 that can be driven in one of the horizontal two-dimensional directions (X direction) are mounted on the lower base 3.
X and 5X, and two second piezo actuators 5Y and 5Y that can be driven in the other horizontal two-dimensional direction (Y direction),
A device mounting base 6 is provided via four third piezoelectric actuators 5Z ... Which can be driven in the vertical direction (Z direction).

As shown in the partially cutaway enlarged side view of the essential part of FIG. 3 and the partially cutaway enlarged plan view of the essential part of FIG. 4, respectively, the bottom surface of three of the four corners of the equipment mounting base 6 is shown. A sensor box 7 is provided in each, and a first vibration sensor 8 that detects horizontal vibration and a second vibration sensor 9 that detects vertical vibration are housed in the sensor box 7.

Each of the first, second and third piezo actuators 5X, 5X, 5Y, 5Y, 5Z ...
As shown in the side view of FIG. 5, a large-diameter mounting flange 11 to be mounted on the lower mount 3 is attached to one end face of the laminated piezo element 10 in the driving direction, that is, the laminating direction, and the other end face thereof is A small-diameter mounting flange 12 to be mounted on the equipment mounting base 6 is attached, and a shear-force absorbing member 15 composed of a metal plate 13 as a rigid plate material and a thin elastic body 14 having a small thickness is attached to the small-diameter mounting flange 12. It is configured by being laminated and laminated in multiple layers. Figure 5
In FIG. 7 described later, for convenience, the thin elastic body 14 is thinner than the metal plate 13 and is laminated in eight layers. For example, the metal plate 13 has a thickness of 0.3 to
The thickness of the thin elastic body 14 is 0.5 mm and the thickness of the thin elastic body 14 is 0.5 to 1.0 mm, and the metal plate 13 and the thin elastic body 14 each have a diameter of 3 cm.
The number of stacked layers and the size thereof can be appropriately changed according to the scale of the apparatus.

The first and second vibration sensors 8 ..., 9
... Each has a CPU, as shown in the block diagram of FIG.
16, a RAM 17, and a ROM 18 are connected to a microcomputer 19 as a control device via an input interface 20, and the microcomputer 19 is connected to the first, second and third piezo actuators 5X, 5X, 5Y, 5Y. , 5Z ... Each of which is connected via the output interface 21, and the first and second
The first, second and third piezo actuators 5X, 5X, 5Y, 5 necessary for stopping the equipment mounting base 6 based on the input signals from the respective vibration sensors 8 ,.
Y, 5Z ... Elongation amounts of each, that is, voltage signals to be applied to them are obtained, and the voltage signals are used as the first, second and third piezoelectric actuators 5X, 5X, 5Y, 5
Y, 5Z ... are output to generate a driving force in each of the horizontal direction and the vertical direction due to the occurrence of distortion, thereby controlling the three-dimensional vibration of the equipment mounting base 6.

At the lower part of the central portion of each of the four sides of the device mounting base 6, the lower mount 3 is provided with a first protrusion so that the amount of protrusion can be adjusted.
The stopper 22 is provided to prevent the device mounting base 6 from being largely displaced in the vertical direction by abutting, and to prevent a large load from being applied to each of the third piezo actuators 5Z.

Further, at each of the four corners of the equipment mounting base 6, a pair of second stoppers 23, 23 are provided on the lower pedestal 3 so that the protrusion amount can be adjusted, and the equipment mounting base 6 is largely displaced in the horizontal direction. Prevent it by abutment, first
And second piezo actuators 5X, 5X, 5Y, 5
It is configured to prevent a large load from being applied to each Y. In the drawing, 24 ... Shows a hanging metal fitting for transportation.

The large-diameter mounting flange 11 is mounted on the lower mount 3 by four bolts 25 ...
The small-diameter mounting flange 12 (also serving as the lowermost metal plate) and the first mounting flange 26 connected to the thin elastic body 14 on the lower end side of the shearing force absorbing member 15 ...
27, and the shearing force absorbing member 15
The second mounting flange 2 is attached to the thin elastic body 14 on the upper end side of.
8 are connected to each other, and the second mounting flange 28 is mounted on the device mounting base 6 by a pair of bolts 29, 29.

With the above construction, for example, the third piezoelectric actuator 5Z will be described as an example. As shown in the side view for explaining the effect of FIG.
When the mounting positions of the second mounting flange 28 and the device mounting base 6 are deviated from the mounting positions of the lower mount 3 and the lower mount 3, the thin elastic bodies 14 ...
The third piezoelectric actuator 5Z is elastically deformed by a small amount in a direction orthogonal to the driving direction of the piezo actuator 5Z and is capable of absorbing a relatively large positional deviation, and further has elasticity sufficient to elastically deform in the elastic deformation direction. It is possible to prevent the shear force from being applied to.

In the above embodiment, the shearing force absorbing member 15 is provided only on one side in the driving direction of the laminated piezo element 10, but it is also possible to provide the shearing force absorbing member 15 on both sides in the driving direction in the present invention. Further, the shearing force absorbing member 15 is not limited to eight layers, and may be one having three or more layers.

[0022]

As is apparent from the above description, according to the active vibration isolator of the present invention, when the thin elastic bodies of the shearing force absorbing members of three or more layers are elastically deformed by minute amounts, respectively, at the time of assembly. Since it is possible to absorb the positional deviation between the lower pedestal and the equipment mounting base, even if the positional deviation is relatively large, it is orthogonal to the driving direction of the piezo actuator in each thin elastic body after assembly. Direction becomes elastically deformable, and the force applied in the direction orthogonal to the driving direction of the piezo actuator can also be absorbed by the thin elastic body, avoiding the shearing force acting on the piezo actuator, and fine vibration is prevented. It became possible to control it well.

[Brief description of drawings]

FIG. 1 is a partial cutaway overall side view of an active vibration isolator according to an exemplary embodiment of the present invention.

FIG. 2 is an overall plan view.

FIG. 3 is a partially cutaway enlarged side view of a main part.

FIG. 4 is a partially cutaway enlarged plan view of a main part.

FIG. 5 is a side view.

FIG. 6 is a block diagram.

FIG. 7 is a side view for explaining effects.

FIG. 8 is a vertical sectional side view of a conventional example.

9 is a cross-sectional view taken along the line AA of FIG.

FIG. 10 is a side view.

[Explanation of symbols]

 3 ... Lower mount 5X ... 1st piezo actuator 5Y ... 2nd piezo actuator 5Z ... 3rd piezo actuator 6 ... Equipment mounting base 8 ... 1st vibration sensor 9 ... 2nd vibration sensor 10 ... Laminated piezo element 13 ... Metal plate as rigid plate material 14 ... Thin elastic body 15 ... Shear force absorbing member 19 ... Microcomputer as control device

 ─────────────────────────────────────────────────── ─── Continuation of the front page (71) Applicant 000224994 Patent Equipment Co., Ltd. 10-10 Minami-Hatsushimacho, Amagasaki City, Hyogo Prefecture (72) Inventor Nobuyoshi Murai 2-5-14 Minamisuna, Koto-ku, Tokyo Takenaka Engineering Co., Ltd. Inside the store technology research institute (72) Inventor Tamio Imazawa 3-18 No.8, Lumber Street, Mihara-machi, Minamikawachi-gun, Osaka Prefecture Takenaka Corp. Technical Research Institute, Osaka Branch (72) Yoshinori Takahashi, Mihara-machi, Minamikawachi-gun, Osaka Prefecture 3-18, Takenaka Co., Ltd., Technical Research Institute, Osaka Branch (72) Inventor, Hirokazu Yoshioka, Mihara-cho, Minamikawachi-gun, Osaka 3-8, Takenaka Technical Research Institute, Osaka Branch (72) Inventor Takashi Fujita 575-28, Nakano Hisagi, Nagareyama City, Chiba Prefecture (72) Inventor Sadao Shibuya, 537 Uehongo, Uchihongo, Chiba Prefecture Hitachi, Hitachi Land Construction Co., Ltd., Matsudo Research Institute (72) Inventor Masaki Hayatsu, 537, Uehongo, Chiba Prefecture, Chiba Pref., Matsuda Research Center, Hitachi Plant Construction Co., Ltd. (72) Inventor, Shoji Takeshita, Otsumachi, Niyochome, Chiyoda-ku, Tokyo Hitachi Construction Co., Ltd. (72) Taihei Hayakawa, Inventor Taihei Hayakawa No. 6, Otemachi 2-chome, Chiyoda-ku, Tokyo Incorporation company Hitachi Construction Co., Ltd. (72) Masashi Yasuda, No. 133, Minami-Hatsushima-cho, Amagasaki-shi, Hyogo 133 Patent Equipment Co., Ltd.

Claims (1)

[Claims] 1. A lower mount is provided with a device mounting base via a piezo actuator capable of driving in each of three-dimensional directions, a vibration sensor for detecting vibration in each of the three-dimensional directions is provided, and the vibration sensor detects the vibration. An active vibration isolation device provided with a control device for outputting a drive signal for canceling the vibration to the piezo actuator based on the vibration, wherein each of the piezo actuators has at least one of both end faces in a driving direction of a laminated piezo element. An active vibration isolator, further comprising: three or more layers of shearing force absorbing members made of a rigid plate material and a thin elastic body having a small thickness.