JPH09252585A - Electrostatic actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrostatic actuator which can secure sufficient output characteristics with friction between a movable member and a stator being lessened. SOLUTION: An electrostatic actuator 1 has a base substance 10 which has an electrode 11 being extended in a specified direction, stators 20a-20d, 21a-21d,... which are so installed as to face the base substance 10 at a specified distance from the base substance 10, a waving elastic plate 30 which is installed on the stators 20, 21, and a movable member 40 installed on the waving elastic plate 30. The stators 20, 21 are formed from elastic bodies made of conductive substance or semiconductor. When voltage is applied to the stators 20, 21 by a voltage application device 45 successively, the stators 20, 21 bend toward the side of the base substance 10 successively and progressive waves appear on the waving elastic plate 30 installed on the stators 20, 21. The movable member 40 which is brought into contact with the waving elastic plate 30 where the progressive waves appear, at the peaks of the waves, receives driving force from the waving elastic plate 30 and then moves.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic actuator utilizing electrostatic force.

[0002]

2. Description of the Related Art Conventionally, as a linear actuator for driving a micromachine, a combination of a motor utilizing electromagnetic force or a piezoelectric element and a mechanism such as a gear has been known. However, as this type of actuator becomes smaller in size, it becomes difficult to obtain sufficient output, and it becomes impossible to secure sufficient space for arranging the mechanism such as gears and the coil that is the electromagnetic force source. Therefore, it becomes difficult to design a compact and high-performance actuator. Therefore, in the case of a small size, an electrostatic actuator utilizing an electrostatic force, which is advantageous in terms of output, has been developed, but it does not necessarily have sufficient performance. One of the main causes is
It is a problem of friction between the mover and the stator.

In order to solve this problem, the present inventors have
An electrostatic actuator having an operating principle as shown in FIG. 15 has been developed. This electrostatic actuator is shown in FIG.
As shown in (a) to (d), the two electrodes 211, 212, 221 are arranged facing each other with a predetermined gap.
Stator 201, 202 having 222 and stator 20
1 and 202 and a movable element 203 arranged between them and sequentially applying voltage pulses to the electrodes 211, 212, 221, 222 (the electrodes to which the voltage pulse is applied are shown by hatching). The movable element 203 is alternately attracted to the stators 201 and 202 by the
It advances through the gap between the Nos. 1 and 202.

In this case, the mover 203 is the stator 201,
Since it advances while being alternately attracted to 202, the stator 2
Friction hardly occurs between 01 and 202 and the mover 203. However, during operation, the stators 201, 202
Since the movable element 203 and the movable element 203 contact each other at only one point, it is difficult to obtain a large output.

[0005]

As described above, it is difficult to obtain an electrostatic actuator having sufficient output characteristics while solving the problem of friction between the mover and the stator.

The present invention has been made in view of the above circumstances, and provides an electrostatic actuator capable of ensuring sufficient output characteristics while reducing friction between a mover and a stator. The purpose is to

[0007]

According to the first aspect of the present invention,
A base provided with electrodes extending in a predetermined direction, a stator made of an elastic body facing the base at a predetermined distance, and a stator on the surface opposite to the base. An electrostatic actuator comprising a stator and a mover provided in contact with the stator, and a plurality of electrodes arranged along the predetermined direction on a surface of the stator on a base side.

According to the first aspect of the invention, a voltage is sequentially applied to the electrodes provided on the stator, and a potential difference is generated between the electrodes of the stator to which the voltage is applied and the electrodes of the base body, and electrostatic force is applied. Works. By this, the stator is sequentially displaced to the base side,
A traveling wave traveling along the arrangement direction of the electrodes of the stator is generated in the stator. In this case, the stator and the mover are in contact with each other near the apex of the traveling wave formed by the stator, and the contact portion of the stator with the mover is moving in the direction opposite to the traveling direction of the traveling wave.
Therefore, the mover receives a driving force from the stator in the direction opposite to the traveling direction of the traveling wave, and the mover moves in the direction opposite to the traveling direction of the traveling wave.

According to a second aspect of the present invention, a base body provided with electrodes extending in a predetermined direction, and a plurality of stators made of an elastic body and facing the base body at a predetermined interval, are provided.
A wave elastic plate that extends in the predetermined direction and is provided in contact with the stator on a surface of the stator opposite to the base side; and a wave elastic plate that extends in the predetermined direction and is opposite to the stator side of the wave elastic plate. A movable element provided in contact with the wave elastic plate, the stators are arranged along the predetermined direction, and electrodes are provided on the surface of each stator on the base side. The electrostatic actuator is characterized in that

According to the second aspect of the invention, a voltage is sequentially applied to the electrodes provided on each stator, and the stator is sequentially displaced toward the base body due to electrostatic force. As a result, the wave elastic plate provided in contact with each stator is displaced according to the displacement of each stator, and a traveling wave is generated in the wave elastic plate. The mover arranged on the wave elastic plate receives a driving force from the wave elastic plate in the direction opposite to the traveling direction of the traveling wave, and the mover moves in the direction opposite to the traveling direction of the traveling wave.

According to a third aspect of the present invention, a base body provided with electrodes extending in a predetermined direction, and a plurality of stators made of an elastic body and facing the base body with a predetermined gap therebetween.
A wave elastic plate that extends in the predetermined direction and is provided in contact with the stator on a surface of the stator opposite to the base side; and a wave elastic plate that extends in the predetermined direction and is opposite to the stator side of the wave elastic plate. A movable element provided in contact with the wave elastic plate on the surface, and the stator is made of a conductive material or a semiconductor.

According to the third aspect of the present invention, a voltage is directly applied to the stator itself, and each stator is sequentially displaced toward the base body side, whereby a traveling wave is generated in the wave elastic plate in contact with each stator. To do. As a result, the mover arranged on the wave elastic plate moves in the direction opposite to the traveling direction of the traveling wave.

According to a fourth aspect of the present invention, there is provided a base body having a plurality of electrodes arranged in a predetermined direction, and an elastic body extending in the predetermined direction and facing the base body with a predetermined space therebetween. And a mover provided in contact with the stator on the surface of the stator opposite to the base body side extending in the predetermined direction, and the predetermined surface is provided on the base-side surface of the stator. The electrostatic actuator is characterized in that an electrode extending in the direction is provided.

According to the invention described in claim 4, a voltage is sequentially applied to the electrodes provided on the substrate, and a potential difference is generated between the electrode of the substrate to which the voltage is applied and the electrode of the stator, and electrostatic force is generated. work. As a result, the portion of the stator facing the electrodes of the base body to which the voltage is applied is sequentially displaced toward the base body side, and a traveling wave traveling along the arrangement direction of the electrodes of the base body is generated in the stator. As a result, the mover arranged on the stator moves in the direction opposite to the traveling direction of the traveling wave.

According to a fifth aspect of the present invention, there is provided a base body provided with a plurality of electrodes arranged in a predetermined direction, and an elastic body extending in the predetermined direction and facing the base body with a predetermined space therebetween. And a mover provided in contact with the stator on the surface of the stator opposite to the base body side extending in the predetermined direction, and the stator is made of a conductive material or a semiconductor. The electrostatic actuator is characterized by the following.

According to the fifth aspect of the present invention, a voltage is sequentially applied to the electrodes provided on the substrate, and a potential difference is generated between the electrode of the substrate to which the voltage is applied and the stator itself, and an electrostatic force acts. . As a result, the portion of the stator facing the electrodes of the base body to which the voltage is applied is sequentially displaced toward the base body side, and a traveling wave traveling along the arrangement direction of the electrodes of the base body is generated in the stator.
As a result, the mover arranged on the stator moves in the direction opposite to the traveling direction of the traveling wave.

The invention according to claim 6 is the electrostatic actuator according to claim 4 or 5, characterized in that a wave elastic plate is provided between the stator and the mover.

According to the sixth aspect of the invention, the wave elastic plate is displaced according to the displacement of the stator, and a traveling wave is generated in the wave elastic plate. As a result, the mover arranged on the wave elastic plate moves in the direction opposite to the traveling direction of the traveling wave.

The invention according to claim 7 is the electrostatic actuator according to any one of claims 1 to 6, characterized in that a convex portion is provided on the stator or the wave elastic plate.

According to the invention of claim 7, the tip of the convex portion provided on the stator or the wave elastic plate abuts on the mover. The displacement speed in the horizontal direction of the tip of the protrusion is increased in proportion to the height of the protrusion, and the mover moves at a higher speed.

According to an eighth aspect of the present invention, the base and the stator both have a cylindrical shape, the cylindrical stator is housed in the cylindrical base, and the mover is housed in the cylindrical stator. The electrostatic actuator according to claim 4, wherein the electrostatic actuator is provided.

According to the invention described in claim 8, a voltage is sequentially applied to the electrodes arranged on the inner peripheral surface of the cylindrical base body, and a traveling wave is applied to the cylindrical stator provided facing the cylindrical base body. appear. As a result, the mover that contacts the cylindrical stator moves in the axial direction.

According to a ninth aspect of the present invention, by sequentially applying a voltage to a plurality of electrodes or a stator arranged in a predetermined direction, the stator is sequentially displaced toward the base body side, whereby the mover is moved to the movable body. The electrostatic actuator according to any one of claims 1 to 8, further comprising voltage applying means for moving the electrostatic actuator in a predetermined direction.

According to the ninth aspect of the invention, the voltage is sequentially applied to the plurality of electrodes or the stator arranged in the predetermined direction by the voltage applying means, and the traveling wave is generated in the stator. As a result, the mover arranged on the stator moves in the direction opposite to the traveling direction of the traveling wave.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION First Embodiment Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 to 6 are views showing a first embodiment of the present invention.

As shown in FIG. 1, the electrostatic actuator 1
Is a plurality of stators 20a to 20d, 21a to 21 made of a base body 10 and elastic bodies provided so as to face the base body 10.
, and a plurality of stators 20a to 20d, 21a to 21
d, ... The wave elastic plate 30 and the wave elastic plate 3 provided above
And a mover 40 provided above.

Of these, the substrate 10 is made of a non-conductive substance (eg, glass substrate material), and an electrode 11 extending in the longitudinal direction of the substrate 10 is provided at the center of the substrate 10. Further, the electrode 1 is sandwiched between the electrodes 1 on the substrate 10.
1 are provided with conductive patterns 12a to 12d extending in parallel with each other, and these conductive patterns 12a to 12d are electrically independent from each other. Further, as shown in FIG. 1, the width of the conductive patterns 12a to 12d is sufficiently narrower than the width of the electrode 11. Electrode 11 and conductive pattern 12a-
12d is formed by a method of adhering a metal thin film having a predetermined shape on the substrate 10 or a method of forming a conductive film on the substrate 10 by using a method such as sputtering or vapor deposition and then patterning it by using an etching process or the like. Has been done.

Further, the stators 20a to 20d, 21a to 2
1d, ... Are made of a conductive material or a semiconductor (for example, silicon). That is, the stators 20a to 20d, 21a
21d, ... have a function as an elastic body,
It itself has a function as an electrode. These stators 20a to 20d, 21a to 21d, ... Include a beam portion 14 and a pair of leg portions 15 formed on both sides of the beam portion 14, respectively.
a and 15b, each having the same U-shape. The beam portion 14 extends in a direction orthogonal to the longitudinal direction of the base body 10, and a gap is formed between the beam portion 14 and the base body 10. Each stator 20 configured in this way
The beam portions 14 of a to 20d, 21a to 21d, ... Can elastically bend in the vertical direction (FIG. 1).
See the chain double-dashed line).

Further, the stators 20a to 20d, 21a to 2
1d, ... Are arranged in this order along the longitudinal direction of the base body 10, and the bottom surfaces 16a of the respective leg portions 15a, 15b,
It is fixed to the base 10 by adhering 16b to the base 10. In this case, the stators 20a to 20d, 21a
21d, ... bottom surfaces 16a of the conductive patterns 12a, 12
It is located between b and the stator 20a-20d, 21a-21
The bottom surface 16b of d, ... Is located between the conductive patterns 12c and 12d. In addition, the stators 20a to 20d and 21a to
21d, ... Are electrically connected to the conductive patterns 12a-12d to which the alphabets at the end of the reference numerals correspond, respectively. The potentials of, ... Can be adjusted.

Further, each of the stators 20a to 20d, 21a to
The wave elastic plate 30 made of a soft elastic material (for example, silicon rubber) is in contact with the upper surface 14a of the beam portion 14 of 21d, ....
Is provided. This wave elastic plate 30 is used for the stator 20.
a to 20d, 21a to 21d, ... Has a plate-like shape having substantially the same width as the length of the beam portion 14 in the longitudinal direction.
0 extends in the longitudinal direction.

A mover 40 is provided in contact with the wave elastic plate 30 at a substantially central portion of the upper surface of the wave elastic plate 30 in the width direction. The mover 40 has a width narrower than that of the wave elastic plate 30 and extends in the longitudinal direction of the base 10.
The mover 40 is made of a highly rigid material. As will be described later, the mover 40 receives the maximum driving force from the widthwise central portion of the wave elastic plate 30, and the mover 40 receives a smaller driving force from the wave elastic plate 30 as it approaches both ends in the width direction. Therefore, from the viewpoint of reducing the friction between the mover 40 and the wave elastic plate 30, it is preferable that the width of the mover 40 be narrow. For the same reason, a convex curve may be provided on the bottom surface 40a of the mover 40 so that the mover 40 and the wave elastic plate 30 contact each other only near the center of the wave elastic plate 30 in the width direction.

Next, the operation of this embodiment having such a configuration will be described with reference to FIGS. In addition,
In FIGS. 2A to 2D, a hatched stator means an electrode having a potential V, and a hollow stator means an electrode having a potential 0.

First, as shown in FIG. 1, the electrode 1 of the substrate 10 is
1 is grounded, and the potential of the electrode 11 is 0. Next, each of the conductive patterns 12a to 12d is connected to the voltage applying device 45 as shown in FIG. 1, and the stators 20a, 21a, ... And the stators 20b, 2 are connected via the conductive patterns 12a, 12b.
, And stators 20b, 2 as shown in FIG. 2 (a).
The potentials of 1b, ... In this case, the predetermined potential V may be positive or negative. In this case, the stators 20c and 21
The electric potentials of c, ... And the stators 20d, 21d ,.

When a voltage is applied to each stator in this way, a potential difference is generated between the electrode 11 of the base 10 and the stators 20a, 21a, ... And the stators 20b, 21b ,.
Static electricity works. Due to this electrostatic force, the stator 20a,
21a, ... and the beam portions 14 of the stators 20b, 21b ,.
Are attracted toward the electrode 11 side and are displaced downward from the reference position (solid line position in FIG. 1). In this case, the beam portion 14
Since both ends of the beam are restrained by the leg portions 15a and 15b, the beam portion 14 bends downward with the center portion in the longitudinal direction as the center, as shown by the chain double-dashed line in FIG. On the other hand, the potential is 0
Of the stators 20c, 21c, ... And the stators 20d, 21
The beam portions 14 of d, ... Are at the reference position (the solid line position in FIG. 1).
When the respective stators are displaced in this way, the wave elastic plate 30 formed of a soft elastic material bends according to the displacement of each stator, and the maximum displacement portion of the wave elastic plate 30, that is, the wave elastic plate 30 is displaced. The longitudinal cross section of the widthwise central portion is shown in FIG.
As shown in (a), it has a substantially wavy shape.

Next, the changeover switch 4 of the voltage applying device 45.
6 is switched, and as shown in FIG. 2B, the stator 20a,
The electric potentials of 20d, 21a, 21d, ...
Let V be the potentials of 0b, 20c, 21b, 21c, ....
In this case, the beam portions 14 of the stators 20a, 21a, ... Return to the reference positions, and the beam portions 14 of the stators 20c, 21c ,. On the other hand, the stators 20b, 20d, 21b,
The beam portions 14 of 21d, ... Are maintained at the same positions as those shown in FIG. 2 (a). In this case, the wave elastic plate 30 has the shape shown in FIG.
As shown in (b), the flexure follows the displacement of each stator,
It has a substantially wavy shape. Further, similarly, FIG. 2 (c)
As shown in (d), when the electric potential of the stator is sequentially switched, the wave elastic plate 30 causes the beam portion 14 of the stator at each time point.
It flexes according to the displacement of. 2A to 2D, the wave elastic plates 30 are bent in the same shape and are in contact with the mover 40 under the same conditions.

As described above, the waves generated in the wave elastic plate 30 in FIGS. 2A to 2D are as shown in FIGS.
(B), FIG. 2 (c), and FIG. 2 (d) in order toward the right side in the figure, but the wave elastic plate 30 itself is from FIG.
It is not moving to the left or right in (d).

Next, the action of the traveling wave generated in the wave elastic plate 30 will be described in detail with reference to FIG. Generally, in a traveling wave (deflection wave) with a medium that can be regarded as a beam, when focusing on only one point on the surface of the medium, it is known that the point makes an elliptical motion, not a simple vertical motion. In FIG. 3, the traveling direction of the traveling wave (arrow A) and the movement direction of each point on the surface of the medium (wave elastic plate 30) are indicated by arrows P1 to P8.
Are indicated by. As shown in FIG. 3, the surface of the wave elastic plate 30 near the apex of the traveling wave moves in the direction of arrow P1, that is, in the direction opposite to the traveling direction A of the traveling wave. As shown in FIGS. 2A to 2D, the wave elastic plate 30 is in contact with the mover 40 only in the vicinity of the apex of the wave. It receives the driving force in the left direction and moves toward the left side in FIG.
In addition, the mover 40, as shown in FIGS.
Wave elastic plate 3 under almost equal conditions at any time
Since it is in contact with 0 at a plurality of points, the wave elastic plate 30 can always give a sufficient driving force to the mover 40. Therefore, an electrostatic actuator having sufficient output characteristics can be obtained.

In this embodiment, the wave elastic plate 30 is made of a plate having a smooth surface. However, the wave elastic plate 30 is not limited to this, and as shown in FIG. A plurality of protrusions 31 may be provided on the surface of the plate 30. In this case, the convex portion 31 extends in the direction perpendicular to the wave elastic plate 30 and in the direction orthogonal to the longitudinal direction of the wave elastic plate 30 (the width direction of the wave elastic plate 30), and the longitudinal direction of each wave elastic plate 30. They are arranged at equal intervals along the direction. Since only the tip 32 of the convex portion 31 contacts the mover 40, it is possible to reduce the loss of the driving force due to the shear strain of the wave elastic plate 30. Further, since the horizontal displacement speed of the tip 32 can be increased in proportion to the height of the convex portion 31, the mover 40 can be moved at a higher speed without increasing the weight of the wave elastic plate 30. You can Therefore, a higher performance electrostatic actuator can be obtained.

In this embodiment, the stator 2
Although an example in which 0a to 20d, 21a to 21d, ... Are formed from a conductive material is shown, the present invention is not limited to this.
As shown in FIG. 5, the stators 20a to
20d, 21a to 21d, ... Form a stator base 17 having substantially the same shape as that of the electrode 11 or the conductive patterns 12a to 1 on the bottom surface 18a of the beam portion 18 of the stator base 17.
The stator may be formed by forming the electrode 19 made of a conductive material by a method similar to the method of forming 2d.
In this case, the conductive patterns 12a to 12d are directly connected to the electrode 19.

Further, when the stator is formed of the stator base 17 made of a non-conductive material and the electrode 19 as described above, it is not necessary to provide the stator base 17 corresponding to each electrode 19, As shown in FIG. 6, a stator base 17 is integrally formed, and a plurality of electrodes 19 are arranged in the longitudinal direction of the stator base 17 to form an integral type stator. You may connect directly to 12a-12d. In this case, similarly to the second embodiment described later, since a traveling wave is generated in the integral stator itself, it is not necessary to provide the wave elastic plate 30, and the integral elastic member is not provided on the integral stator. Even when the mover 40 is brought into direct contact, the mover 40 can be moved. Second Embodiment Next, a second embodiment will be described. 7 to 9 are diagrams showing a second embodiment of the present invention.

As shown in FIG. 7, the electrostatic actuator 1
The base 60 includes a base 60, a stator 70 made of an elastic material and facing the base 60, and a mover 80 provided in contact with the upper surface of the stator 70.

Of these, the base body 60 is made of a non-conductive substance (eg, glass substrate material), and comprises a bottom portion 61 and a pair of support portions 62a and 62b formed on both sides of the bottom portion 61 and extending in the longitudinal direction of the base body 60. , Has a U shape as a whole. A plurality of electrodes 6 are provided on the upper surface 61a of the bottom portion 61.
3a, 63b, ... Are provided and these electrodes 63a, 63
b, ... Are arranged in this order along the longitudinal direction of the base body 60. Each of the electrodes 63a, 63b, ... Extends in a direction orthogonal to the longitudinal direction of the base body 60 and has the same rectangular shape.

Further, as shown in FIGS. 7 and 8, grooves 64a, 64b, ... Are formed at positions corresponding to the electrodes 63a, 63b ,. Further, as shown in FIG. 8, these grooves 64a, 6
4b, ... Are provided with corresponding electrodes 63a, 63b,
The drawing patterns 65a, 65b, ... Formed integrally with. These withdrawal patterns 65a, 6
As shown in FIGS. 7 and 8, conductors 66a, 66b, ... Are connected to the ends of the conductors 66a, 6b.
The potentials of the electrodes 63a, 63b, ... Can be adjusted via 6b ,.

Further, as shown in FIG. 7, the stator 70 is
A pair of supporting portions 6 of the base 60 extending in the longitudinal direction of the base 60.
It is fixed to the upper surfaces of 2a and 62b by a method such as adhesion. The stator 70 is made of a conductive material or a semiconductor (eg, silicon). That is, the stator 70 has a function as an elastic body and also has a function as an electrode itself. In addition, a gap is formed between the bottom surface 70 a of the stator 70 and the top surface 61 a of the bottom portion 61 of the base body 60. The stator 70 configured as described above can elastically bend in the vertical direction (FIG. 7).
See the chain double-dashed line). A conductor wire 71 is connected to the end of the stator 70, and the potential of the stator 70 can be adjusted via the conductor wire 71.

Also in this embodiment, similarly to the first embodiment, a stator base having a shape substantially the same as that of the stator 70 is formed of a non-conductive material, and the bottom surface of the stator base ( The stator 70 may be formed by forming an electrode made of a conductive material on the surface facing the base body 60).

The mover 80 has a width narrower than that of the stator 70 and extends in the longitudinal direction of the base 10. Mover 80
For the same reason as described in the first embodiment, it is preferable to make the width narrower. Also, the bottom surface 80a of the mover 80 is provided with a convex curve, and only the vicinity of the widthwise center of the stator 70 is provided. The mover 70 and the stator 80 may come into contact with each other.

Next, the operation of this embodiment having such a configuration will be described with reference to FIGS. 7 and 9A and 9B. In FIGS. 9A and 9B, a blackened stator means an electrode having a potential of V, and a white stator means an electrode having a potential of 0.

First, as shown in FIG. 7, the conductor 71 is grounded and the electric potential of the stator 70 is set to zero. Next, the conductor 66a,
66b, ... Are connected to the voltage applying device 90 as shown in FIG. When no voltage is applied to any of the electrodes 63a, 63b, ..., The stator 70 is at the reference position (the solid line position in FIG. 7, the two-dot chain line position in FIG. 9A).

Next, by the voltage application device 90, as shown in FIG.
As shown in, the conductors 66a, 66b, 66e, 66f,
66i, 66j, ... Via electrodes 63a, 63b, 6
The potentials of 3e, 63f, 63i, 63j, ...
In this case, the electrodes 63c, 63d, 63g, 63
The potential of h, ... Is 0. That is, the electrodes 63a, 63
As shown in FIG. 9A, when the potentials of two electrodes adjacent to each other are V, the voltages are applied to the two electrodes adjacent to the two electrodes whose potentials are V. Is set to 0, and the potential of two electrodes adjacent to the two electrodes of which potential is 0 is set to V.

When the voltage is applied in this manner, the electrode 63
A potential difference occurs between a, 63b, 63e, 63f, 63i, 63j, ... And the stator 70, and an electrostatic force acts. Due to this electrostatic force, the electrodes 63a, 63b of the stator 70,
Parts facing 63e, 63f, 63i, 63j, ... Are drawn toward the base body 60 side and displaced downward from the reference position (two-dot chain line position in FIG. 7, solid line position in FIG. 9A). In this case, since the widthwise end of the stator 70 is constrained by the pair of supporting portions 62a and 62b of the base body 60, the widthwise center of the stator 70 is largely bent (FIG. 7).
See the chain double-dashed line). Further, in this case, the portion of the stator 70 facing the electrodes 63c, 63d, 63g, 63h, ... Of zero potential is at the reference position, and the maximum displacement portion of the stator 70, that is, the central portion in the width direction of the stator 70. 9 has a substantially wavy shape as shown in FIG. 9 (a).

Next, the changeover switch 9 of the voltage applying device 90.
1 to switch the electrodes 63a, 6 as shown in FIG. 9 (b).
The potentials of 3d, 63e, 63h, 63i, ... Are set to 0, and the potentials of the electrodes 63b, 63c, 63f, 63g, 63j ,. That is, in FIG. 9A, the potential of the electrode on the left side of the two electrodes having the potential of V is changed from V to 0, and the potential of the electrode on the right side of the two electrodes having the potential of 0 is adjacent to each other. Is switched from 0 to V. In this case, the electrodes 63b, 6 of the stator 70 are
The portions facing 3c, 63f, 63g, ... Are drawn toward the base body 60 side and displaced downward from the reference position,
The longitudinal cross section of the maximum displacement portion of the stator 70 is shown in FIG.
The shape is as shown in (1), which is a substantially wavy shape.

As described above, by changing the method of applying the voltage to the electrodes 63a, 63b, ..., As shown in FIG.
The wave formed by the stator 70 in FIG.
In the figure, the wave formed by the stator 70 is advanced by 1/4 cycle, and the apex of the wave in FIG. 9B moves to the right by one electrode from the apex of the wave in FIG. 9A. That is, as described above, by sequentially switching the voltage applied to each electrode, a traveling wave traveling to the right side in FIGS. 9A and 9B is generated in the stator 70. As shown in FIGS. 9A and 9B, the mover 80 provided on the stator 70 contacts the stator 70 only in the vicinity of the apex of this traveling wave, and the mover 80 is the first embodiment. According to the same operating principle as described in the above-mentioned embodiment, it moves to the left side of FIGS. 9 (a) and 9 (b). According to the present embodiment, a traveling wave is generated in the stator 70 itself, so the mover 80 can be directly driven by the stator 70. Therefore, the structure of the electrostatic actuator can be simplified as compared with the first embodiment.

In the present embodiment, the stator 70
Although an example in which the shape of is a smooth plate is shown, the shape is not limited to this, and for example, as shown in FIG.
A plurality of convex portions 71 arranged on the upper surface of the stator 70 at equal intervals.
May be provided. Further, as shown in FIG. 10B, a wave elastic plate 90 made of a soft elastic material (for example, silicon rubber) may be provided on the upper surface of the stator 70. Further, as shown in FIG. 10C, a plurality of convex portions 91 may be formed on the upper surface of the wave elastic plate 90. In this case, the same effect as the first embodiment can be obtained. Third Embodiment Next, a third embodiment will be described. 11 to 14 are views showing a third embodiment of the present invention.

As shown in FIGS. 11 to 14, the electrostatic actuator 100 includes a base 110 having a substantially cylindrical shape.
And a substantially cylindrical stator 12 disposed in the base 110.
0 and a mover 130 provided in the stator 120.

Of these, the substrate 110 will be described in detail.
The base 110 is made of a non-conductive material (eg glass),
In addition, FIGS. 11A and 11B are shown in FIG.
(A) shows a cross section taken along line AA) and FIG.
On the inner peripheral surface of the base 110, a plurality of rectangular electrodes 111a, 111b, ..., 112a, 112 extending in the circumferential direction.
, 113a, 113b, ... And 114a, 11
4b, ... Are provided. As shown in FIG. 12, among these electrodes, the electrodes having common numeral parts are arranged at predetermined intervals along the axial direction of the base 110 in the order of the alphabetical characters, and the common alphabet parts are common. The electrodes are arranged at predetermined intervals along the circumferential direction of the base 110 in the order of reference numerals. Also,
Electrodes having common reference numerals are electrically connected to each other, and electrode groups A, 111b, 112b, 1 composed of electrodes 111a, 112a, 113a and 114a.
An electrode group B made up of 13b and 114b, and similarly, electrode groups C, D, E, ... In addition, FIG.
As shown in (b), each of the electrode groups A,
Conductors 115 electrically connected to B, C, ...
a, 115b, ...
The potential of each electrode group can be adjusted via a, 115b, ....

Next, the stator 120 will be described in detail. The stator 120 has an outer diameter smaller than the inner diameter of the base 110, and is housed inside the base 110 as described above. Also,
As shown in FIG. 11A, at the positions where the outer circumference of the stator 120 is divided into four equal parts, support portions 121a to 121 extending in the axial direction are provided.
1d are formed respectively. These supporting portions 121a
The end portions of ~ 121d are adhered or press-fitted to the inner peripheral surface of the base 110 in the circumferential gap between the electrodes on the inner peripheral surface of the base 110, that is, in the portion where no electrode is provided.
As a result, the stator 120 is fixed to the base 110. A predetermined gap is formed between the outer peripheral surface of the stator 120 and the inner peripheral surface of the base 110, which are configured as described above, so that the stator 120 can elastically bend in the radial direction. (See FIGS. 14A and 14B).

Next, the mover 130 will be described in detail. FIG.
As shown in FIG. 3 and FIG. 14A, the mover 130 is housed inside the stator 120 and has a columnar shape as a whole. In addition, as shown in FIG.
The outer peripheral surface of 0 has four recesses 131a to 1 extending in the axial direction.
31d and four convex portions 132a to 132d are formed. The tips of the protrusions 132a to 132d are curved,
The radius of curvature of these curved surfaces is smaller than the radius of the inner peripheral surface of the stator 120. Also, the maximum outer diameter φ of the mover 130
max, that is, the convex portions 132a to 132d facing each other
The distance between the tips is equal to or slightly larger than the inner diameter of the stator 120. A conductor wire 135 is provided at the end of the mover 130 in the axial direction, and the potential of the mover 130 can be adjusted via the conductor wire 135.

Next, the operation of this embodiment having such a structure will be described with reference to FIGS. 11 (a) and 11 (b) and FIG.
(A) and (b) (FIG. 14 (b) shows the BB cross section of FIG. 14 (a)). In FIG. 14A, among the electrodes of the substrate 110, the hatched electrode means an electrode having a potential V, and the white electrode means an electrode having a potential 0.

First, as shown in FIG. 13, the conducting wire 135 is grounded and the potential of the mover 130 is set to zero. Next, the lead wire 11
5a, 115b, ... Are connected to the voltage applying device 90 as shown in FIG. Which electrode groups A, B, C,
When no voltage is applied to ..., The stator 120 is at the reference position (the position shown in FIGS. 11A and 11B).

Next, the conducting wire 115 is applied by the voltage applying device 140.
The potentials of the electrode groups A, B, E, F, I, ... Of the base 110 are set to V via a, 115b, 115e, 115f, 115i ,. In this case, the electrode groups C, D, G,
The potentials of H, ... Are zero. That is, the electrode group A,
The voltages are applied to B, C, ... In the same manner as in the second embodiment, and when the potentials of two adjacent electrode groups are V as shown in FIG. Is 0, the potential of the two electrode groups located next to the two electrode groups of V is 0, and the potential of the two electrode groups located next to the two electrode groups of 0 is 2
It is performed so that the potential of one electrode group becomes V.

When the voltage is applied in this manner, the base 11
A potential difference is generated between each electrode forming the electrode group A, B, E, F, I, ... Due to this electrostatic force, the portion of the stator 120 facing the electrode groups A, B, E, F, I, ...
B, E, F, I, ... Sides are attracted and displaced outward from the reference position in the radial direction (solid line positions in FIGS. 14A and 14B). In this case, the stator 130 has four support parts 12
The stator 12 is constrained by 1a to 121d.
In 0, the portion farthest from the supporting portions 121a to 121d is largely bent. Further, in this case, the portion of the stator 120 facing the electrode groups C, D, G, H, ... Of zero potential is at the reference position (the position indicated by the chain double-dashed line in FIG. 14A, and FIG. 11A).
(B) Solid line position). Stator 1 displaced in this way
The longitudinal section of the maximum displacement portion 20 has a substantially wavy shape as shown in FIG. 13 (b). In this case, the stator 120
The portion of the stator 120 facing the electrode groups C, D, G, H, ... Of zero potential is in contact with the four convex portions 132a to 132d of the mover 130, and the electrode group of the stator 120 having potential V is The part facing A, B, E, F, I, ...
Away from That is, the wave formed by the stator 120 is in contact with the mover 130 only in the vicinity of its apex.

Next, the changeover switch 141 of the voltage applying device 140 is changed over, and the electrode groups A, D, E, H, and
The potentials of I, ... Are set to 0, and the potentials of the electrode groups B, C, F, G ,. That is, in FIG. 14B, the potential of the electrode group on the left side of the two electrode groups whose potentials are V adjacent to each other is switched from V to 0, and the potential of the right electrode of the two electrode groups whose potentials are 0 adjacent to each other is changed. The potential of the electrode group is switched from 0 to V. By sequentially switching the potentials of the electrode groups A, B, C, ... In this way, the waves formed by the stator 120 are generated in the same manner as in the second embodiment.
(B) Proceed to the right. That is, a traveling wave traveling in the right direction in FIG. 14B is generated in the stator 120. In this case, the mover 130 that comes into contact with the stator 120 at the protrusions 132a to 132d moves in the leftward direction in FIG. 14B in the same manner as in the second embodiment. According to the present embodiment, the mover 130 is in contact with the stator 120 only in the vicinity of the apexes of the four protrusions, so that the stator 12
The frictional force generated between 0 and the mover 130 can be minimized.

[0063]

As described above, according to the present invention,
The mover is driven by the stator or the wave elastic plate where the traveling wave is generated, and moves in the direction opposite to the traveling direction of the traveling wave. In this case, the mover contacts the stator at a plurality of vertex portions of the traveling wave formed on the stator, and receives equal driving force from the plurality of vertex portions. That is, the stator constantly contacts the mover at a plurality of points during the operation of the electrostatic actuator, and a driving force is applied to the mover from the plurality of contacts, so that a large driving force is applied to the mover. be able to. Therefore, a high output electrostatic actuator can be obtained.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a first embodiment of the present invention.

FIG. 2 is a diagram showing an operation of the first embodiment.

FIG. 3 is a diagram showing the operating principle of the present invention.

FIG. 4 is a diagram showing an embodiment in which a wave elastic plate is provided with a convex portion.

FIG. 5 is a diagram showing another configuration of the stator.

FIG. 6 is a view showing an example in which a stator is integrally formed,
The perspective view which looked at the stator from diagonally downward.

FIG. 7 is an exploded perspective view showing a second embodiment of the present invention.

FIG. 8 is a plan view of a base body.

FIG. 9 is a view showing the operation of the second embodiment.

FIG. 10 is a sectional view showing another embodiment of the second embodiment.

FIG. 11 is a diagram showing a third embodiment of the present invention, which is a sectional view in a direction perpendicular to an axis and an axial sectional view.

FIG. 12 is a development view of an inner peripheral surface of a cylindrical substrate.

FIG. 13 is a perspective view showing a mover.

FIG. 14 is a view showing the operation of the third embodiment of the present invention, which is a sectional view in a direction perpendicular to an axis and an axial sectional view.

FIG. 15 is a view showing a conventional electrostatic actuator.

[Explanation of symbols]

10, 60, 110 Substrate 11, 63a, 63b, ..., 111a to 114a, 11
1b to 114b ,. . . Electrodes (of the substrate) 20a to 20d, 21a to 21d, ..., 70, 120
Stator 19 (stator) electrode 30, 90 Wave elastic plate 31, 71, 91 Convex portion 40, 80, 130 Mover 45, 95, 140 Voltage applying device

Claims (9)

[Claims] 1. A base body provided with electrodes extending in a predetermined direction, a stator formed of an elastic body facing the base body at a predetermined distance, and a stator on the side opposite to the base side of the stator. A mover provided in contact with the stator on the surface, and a plurality of electrodes are arranged along the predetermined direction on the base-side surface of the stator. Electric actuator. 2. A base body provided with an electrode extending in a predetermined direction, a plurality of stators made of an elastic body provided facing the base body at a predetermined interval, and a plurality of stators extending in the predetermined direction and fixed. A wave elastic plate provided in contact with the stator on a surface of the child opposite to the base side; and a wave elastic plate extending on the surface of the wave elastic plate opposite to the stator side. A movable element provided in contact with the plate, wherein the stators are arranged along the predetermined direction, and electrodes are provided on the base-side surface of each stator. Electrostatic actuator. 3. A base body provided with an electrode extending in a predetermined direction, a plurality of stators made of an elastic body facing the base body with a predetermined space therebetween, and a plurality of stators extending in the predetermined direction and fixed. A wave elastic plate provided in contact with the stator on a surface of the child opposite to the base side; and a wave elastic plate extending on the surface of the wave elastic plate opposite to the stator side. An electrostatic actuator, comprising: a mover provided in contact with the plate, wherein the stator is made of a conductive material or a semiconductor. 4. A base body provided with a plurality of electrodes arranged in a predetermined direction, and a stator made of an elastic body extending in the predetermined direction and facing the base body at a predetermined interval. A mover extending in the predetermined direction and provided in contact with the stator on a surface of the stator opposite to the base body side;
And an electrode extending in the predetermined direction on the surface of the stator on the base body side. 5. A base body provided with a plurality of electrodes arranged in a predetermined direction, and a stator made of an elastic body extending in the predetermined direction and facing the base body at a predetermined interval. A mover extending in the predetermined direction and provided in contact with the stator on a surface of the stator opposite to the base body side;
The electrostatic actuator, wherein the stator is made of a conductive material or a semiconductor. 6. A wave elastic plate is provided between the stator and the mover.
The electrostatic actuator described. 7. The electrostatic actuator according to claim 1, wherein a convex portion extending in the width direction is provided on the stator or the wave elastic plate. 8. The base and the stator each have a cylindrical shape, the cylindrical stator is housed in a cylindrical base, and the mover is housed in the cylindrical stator. The electrostatic actuator according to claim 4 or 5. 9. A voltage for sequentially displacing the stator toward the base by sequentially applying a voltage to a plurality of electrodes or a stator arranged in a predetermined direction, thereby moving the mover in the predetermined direction. 9. The electrostatic actuator according to claim 1, further comprising an applying unit.