JP3183319B2 - Electrostatic actuator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic actuator for moving a movable body using static electricity.

[0002]

2. Description of the Related Art Conventionally, it has been considered that an electrostatic actuator has a smaller generating force than an electromagnetic actuator and is not suitable for practical use. However, the electrostatic force is expected to be applied to minute actuators because it is proportional to the area and the structure is simple. In the area of small actuators, friction when moving has a large effect on motor output,
A low friction support mechanism is required. Japanese Patent Application Laid-Open No. 63-95863 discloses an electrostatic actuator which is formed as a bearing using rolling balls and is driven by applying a voltage between a movable body and a fixed body B. This is an electrostatic actuator in which a ball is inserted into a groove provided at an end portion of a fixed body and a movable body and is used as a bearing. The drive electrode to which the positive voltage is applied to the fixed body and the drive electrode to which the negative voltage is applied to the movable body are attracted by electrostatic force, and the movable body is driven in phase order.

[0003]

However, when the electrostatic attraction force is used, a problem of a reduction in driving force due to an increase in frictional force, and when rolling by a ball is used for a support mechanism, a highly accurate and small ball is required. Therefore, there was a problem that the cost was high. In view of the above, the present invention provides a low-cost electrostatic actuator having no frictional resistance and a large driving force by eliminating the support mechanism of the movable body and alternately sucking the movable body by the two fixed bodies. The purpose is to:

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a movable body having a plurality of strip-shaped electrodes arranged on both surfaces of an insulator at a predetermined pitch in a moving direction; And two fixed bodies having electrodes arranged on one surface of the insulator at a pitch having a predetermined relationship with the pitch of the electrodes of the movable body. In the electrostatic actuator disposed between two fixed bodies, the two fixed bodies have an electrode pitch of λ, and the electrode position of the first fixed body and the electrode position of the second fixed body are shifted by λ / 2. The movable body is placed on both surfaces.
Distribution electrode pitch of one piece with shiso as 2λ connect the pole
Electrodes on the first fixed body and the second fixed body.
The movable body is applied by applying a voltage having alternating characteristics.
Electrode by alternately contacting the electrodes of the two fixed bodies.
It is configured to move .

[0005]

According to the above-mentioned means, the movable body is alternately sucked by the one fixed body and the other fixed body and moves in one direction, so that the sliding portion is unnecessary, the frictional force is eliminated, and the driving force is increased. Further, since the structure is simple, it can be manufactured at low cost.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing an outline of a linear type electrostatic actuator using the present invention, and FIG. 2 is a sectional view of an electrode portion thereof. In the figure, 1 is a first fixed body, 2 is a second fixed body, 3 is a movable body, and 4 is a spacer for holding the two fixed bodies with a gap. The first fixed body 1 has strip-shaped electrodes 12 arranged on the surface of an insulator 11 at a pitch λ in the moving direction. Each of the electrodes is connected to two phases of common conductive wires A and B. That is, the electrodes 121, 123, 1
25 is an A phase, and the electrodes 122, 124 and 126 are a B phase. Similarly, the second fixed body 2 has strip-shaped electrodes 22 arranged at a pitch λ on the surface of the insulator 21 and is connected to two phases of the common conductive wires C and D for each electrode. That is, the electrodes 221, 223, and 225 are C-phase, and the electrodes 222, 22
4, 226 are D phases. Each of the phases A to D is connected to a drive circuit (not shown). The insulators 11 and 21 are made of glass, and the electrodes are made of copper. The movable body 3 has strip-shaped electrodes 32 arranged on the surface of an insulator 31 at a pitch of 2λ in the moving direction. The electrodes of the movable body 3 were manufactured by forming a metal film on the surface of a substrate made of an organic material and using an etching technique of photolithography. The electrode portions are connected by through holes 33 as shown in FIG. In the assembly of the electrostatic actuator, a gap is held between the first fixed body 1 and the second fixed body 2 by the spacer 4, and the electrodes are positioned and fixed so as to be shifted by the pitch λ / 2. After this, the movable body 3
Is inserted between the first fixed body 1 and the second fixed body 2 and assembled. Next, the operation will be described with reference to FIG. FIG. 4 shows the order of voltage application to each phase. Now
As shown in FIG. 2, a positive voltage (+ V) is applied to the C phase in a state where the electrode 32 of the movable body 3 is aligned and in contact with the electrode 22C phase of the second fixed body. Then, the electrode 32 of the movable body 3 is charged with a positive charge. When a negative voltage (−V) is applied to the electrode A phase of the first fixed body 1 while a positive voltage is applied to the C phase, the electrode 32 of the movable body 3 becomes the electrode A of the first fixed body 1.
The phases are attracted and contacted by electrostatic force. That is, it moves rightward in FIG. Here, the voltage of the C phase is set to zero. Next, a positive voltage (+
When V) is applied, the electrode 32 of the movable body 3 is attracted to the electrode D phase of the second fixed body 2 by electrostatic force, and the movable body 3 moves in the direction of the second fixed body 2 and moves rightward in the figure. Moving. Here, the voltage of the phase A is set to zero. Next, when a negative voltage (−V) is applied to the electrode B phase of the first fixed body 1,
The electrode 32 of the movable body 3 is attracted toward the electrode B phase of the first fixed body 1 by electrostatic force, and further moves rightward in FIG. Here, the voltage of the D phase is set to zero. Thus, the movable body 3 can be driven by sequentially repeating the voltages applied to the four voltage phases. To change the moving direction of the movable body 3, the order of the voltages applied to the four voltage phases may be reversed. You. In this embodiment, the linear type is used, but the rotary type can be used if the arrangement of the electrodes is changed. The electrode may be made of any material as long as it is a metal, and the insulator may be made of an inorganic material other than glass.

[0007]

As described above, according to the present invention, since the movable body is driven while alternately moving between the two fixed bodies, there is no sliding portion between the movable body and the fixed body, and the frictional resistance is reduced. Thus, there is an effect that it is possible to provide an electrostatic actuator without an output reduction due to the above.

[Brief description of the drawings]

FIG. 1 is a perspective view of an electrostatic actuator of the present invention.

FIG. 2 is a sectional view of the electrostatic actuator of the present invention.

FIG. 3 is a partial sectional view of a movable body according to the present invention.

FIG. 4 is a time chart showing the sequence of voltage application according to the present invention.

[Explanation of symbols]

 1: first fixed body 11: insulator 12, 121 to 126: electrode of first fixed body 2: second fixed body 21: insulator 22, 221 to 226: electrode of second fixed body 3: Movable body 31: Insulator 32, 321-324: Electrode 4: Spacer

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H02N 1/00

Claims (2)

(57) [Claims] 1. A movable body in which a plurality of strip-shaped electrodes are arranged at a predetermined pitch on both surfaces of an insulator in a moving direction, and opposes to the movable body via a minute gap. An electrostatic actuator having two fixed bodies having electrodes arranged at a pitch having a predetermined relationship with the pitch of the electrodes of the movable body, wherein the movable body is arranged between the two fixed bodies. The two fixed bodies have an electrode pitch of λ, and the electrode position of the first fixed body and the electrode position of the second fixed body are λ / 2.
Displaced, the movable body connects the electrodes on both surfaces
The electrode pitch is set to 2λ as an integral body,
The polarity of the electrodes of the first fixed body and the electrodes of the second fixed body are alternately changed.
By applying the obtained voltage, the electrode of the movable body is
An electrostatic actuator characterized in that it moves while being alternately contacted with electrodes of two fixed bodies . 2. The electrostatic actuator according to claim 1, wherein the electrodes of the fixed body and the electrodes of the movable body are linearly arranged.