JPS63136982A - Electrostatic actuator - Google Patents

Abstract

PURPOSE:To easily work an electrostatic actuator by composing a movable element of a conductive material, and disposing a dielectric layer on the surface of the element to simplify the construction. CONSTITUTION:An electrostatic actuator is composed of stators 10a-10c, and movable elements 30a, 30b. An electrode pattern 20 made of a conductor is formed at a predetermined interval on the stator 10, and a dielectric pattern 40 is formed at a pitch to become 1:1.16 ratio with the pattern 20 of the stator 10 is also formed on the element 30. The interval (d) of the electrode 20 of the stator 10 and the pattern 40 of the element 30 is held at 0.1-0.2mm, and all the elements 30 are supported integrally movably in directions of arrows A, B, as shown. Thus, in order to move the element 30, a predetermined pulselike voltage is sequentially applied in a moving direction to the electrodes 20 of the stator 10 to draw the element 30 between the electrodes to which the voltage is applied.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrostatic actuator using electrostatic force.

[Prior Art] In a conventional electrostatic actuator using electrostatic force, as shown in FIG. 4, for example, stators 10a and 10b each having a plurality of electrodes disposed on their surfaces at predetermined intervals face each other with a predetermined gap d. The movable element 2 is supported at an intermediate position between the stators 10a and 10b so as to be movable in parallel with the stators 10a and 10b without contacting the stators 10a and 10b. The movable element 2 is configured such that dielectric portions 3 and non-dielectric portions 4 are alternately arranged at predetermined intervals. In order to drive the movable element 2, a predetermined voltage is applied between the opposing voltages 8i11 of the stators 10a and 10b. Then, a force is generated that draws the dielectric part 3 between the opposing electrodes to which a voltage is applied so that the electrostatic energy generated between the electrodes is minimized, and this force is used to move the movable element 3. It is something to do.

As another configuration, an electrode pattern having a certain ratio with the stator electrode 11 of the movable element 2 is arranged on the opposing surface of the stator electrode 11, so that, for example, the electrode of the movable element 2 is held at a ground potential, and the electrode pattern is There is an actuator in which a movable element is moved using an attractive force acting between stator electrodes 11 to which a predetermined potential is applied.

In an actuator having such a structure, the driving force depends on the distance between the electrodes and the dielectric constant of the dielectric 3. Therefore, in order to strengthen the driving force, it is necessary to shorten the distance between the electrodes, increase the dielectric constant of the dielectric, etc.

Furthermore, what is most effective is to stack one unit of the stator and mover combination.

[Problems to be Solved by the Invention] However, stacking opposing stators to which electrodes are fixed as one unit has the disadvantage that the structure becomes large and the stacking density becomes low. Furthermore, the movable element must be held with a predetermined distance between the opposing electrodes of the stator, requiring precise processing and assembly accuracy of the parts. Furthermore, the structure of the movable element is also complicated, and each dielectric part 3 and non-dielectric part 4 must be formed, making manufacturing very time-consuming.

[Means for Solving the Problems] The present invention has been made for the purpose of solving the above-mentioned problems, and as a means for solving the problems, this embodiment has the following configuration.

That is, a stator made of an insulating material on which a plurality of electrodes are arranged at predetermined intervals on its surface, and a conductive material that maintains a predetermined gap with the stator and moves relative to the stator. It is composed of a movable element on which dielectric layers are disposed at predetermined intervals.

[Function] In the above configuration, since the movable element is made of a dielectric material, the movable element can be easily brought to a ground potential, etc., and it is easy to maintain the gap between the electrodes of the stator and the movable element in terms of accuracy. Became. Further, by disposing a dielectric layer on the surface of the movable element, the structure can be made smaller and the lamination density can be increased. Moreover, the movable element has a simple configuration and is easy to process.
It can also provide the necessary strength.

[Example] Hereinafter, an example according to the present invention will be described in detail with reference to the drawings.

[First Embodiment] FIG. 1 is a schematic configuration diagram of an embodiment according to the present invention, and components similar to those in FIG. 4 are designated by the same numbers, and explanations thereof will be omitted.

In the figure, 10a, 10b, and 10c are stators similar to those in FIG. 4, and 30a, 30b are movers. Electrode patterns 20 made of a conductor are formed on the surface of the stator 10 at predetermined intervals. The stator 10 is usually made of an insulating material such as glass or phenol resin, but in this embodiment it is made of glass. Stator 10
has a flat plate shape with a thickness of about 11 mm, and electrode patterns 20 made of a conductor, for example, An, are formed on the surface at predetermined intervals and with a predetermined width. This electrode is not limited to An, but also Cu.
, Ag, Au, Cr, or any other conductive metal.

In this example, the electrode pitch is about 2 mm. In addition, in the stator tab in which electrodes are arranged on both sides, the electrode pattern is exactly the same on the front and back sides. All of the stators 10 are integrally formed.

On the other hand, the mover 30 is made of #(Cu) and has a thickness of approximately o, smm.
In this embodiment, a dielectric pattern 4o is formed on the surface at a pitch having a ratio of (1, 1, 18) to the electrode pattern of the stator 10. PZT (lead zirconate titanate) is used as the dielectric. Between the electrode 20 of the stator 10 and the dielectric pattern 40 of the mover 3o [d is approximately 0.1 mm to 0.2 m]
m, and all the movers 3o are supported so as to be able to move as one in the direction of the arrow in the figure or in the direction of the arrow B while maintaining this gap; Although only two sets of bodies 4o are shown, the same structure continues on the left side of the figure.

In order to move the movable element 30 of this embodiment having the above configuration, the stator! A predetermined pulsed voltage is sequentially applied to each electrode 20 of the movable element 30 (the dielectric material 40 of the movable element 30).
) is performed by drawing the voltage between the electrodes to which this voltage is applied, that is, by sequentially applying a voltage of a predetermined value at a predetermined timing in the direction in which the electrode 20 is to be moved,
Since the movable element 30 is conductive, by grounding the movable element 30 at any one point, a potential difference can easily be generated between the electrode 20 to which voltage is applied and the movable element 30. A moving electric field is generated, charges are induced in the dielectric of the mover 30 located between the electrodes, and a driving force is exerted that follows the electric field in the same direction with a certain slippage.

In this example, when a maximum potential of 1.5 KV was applied to the electrodes of the stator 1o with the configuration shown in FIG. 1, a torque of about 3 g-cal was obtained. This means that approximately four times the output was obtained compared to the torque of 0.7 to 0.8 g-cIIl in a configuration in which the electrode patterns were arranged in a single layer on only one opposing surface of the mover. Become. In this way, by stacking pairs of electrode patterns and dielectrics, a large output can be obtained and a lack of output can be compensated for.

FIG. 2 shows an example in which the present embodiment having the above configuration is configured into a specific actuator.

In the figure, 17a and 17b are shaft support parts 31a and 3 that support the shaft 16a and tab on the outermost upper surface of the stator 1o.
Reference numeral 1b designates a movable arm portion that is slidably and loosely fitted onto the shafts 16a and 16b. Here, there are eight sets of six layers of electrodes and dielectrics. The mover 30 is a shaft 16a fixed to the stator 10.

It is a linear type actuator whose position is regulated by 16b and which moves only in the direction of the arrow in the figure.

[Second Embodiment] Although the above description has been made regarding a linear type actuator, the present invention is not limited thereto, and can also be applied to a rotary type actuator. FIG. 3 shows a schematic perspective view of a rotary type actuator according to an embodiment of the present invention.

In the figure, 15a, 15b, and 15c are the stator 1 shown in FIG.
A flat stator 35a made of insulating material like 0
, 35b, and 35c are rotors made of a conductive material similar to the mover 30 shown in FIG. 1, and 50 is a drive shaft fixed to the rotor 35. Drive@50 is a flat stator 35a
, 35c for rotation. Note that the flat stator 15b may be configured to rotatably support the drive shaft 50, or may be configured to have a center hole slightly larger than the drive shaft 50.

The flat stator 15 has a circular shape with a diameter of about 5 cm and a thickness of about 1 mm. Electrode patterns 25 made of conductors are formed on the surface of the flat stator 15 at predetermined intervals and with a predetermined width radially around the axis. In this example, the electrode pitch is about 2 mm. In addition, in the flat stator 15b in which electrodes are arranged on both sides, the electrode pattern is exactly the same on the front and back sides.

A common drive signal is applied to each of the radial corresponding electrodes of the flat stators 15a, 15b, and 15c, so that the same rotational force acts on all the radial specific positions.

On the other hand, the rotor 35 is a flat plate with a diameter of about 5 cm and a thickness of about 0.
．． 5 mm, and dielectric patterns 45 are formed on the surface at a pitch such that the electrode pattern of the flat stator 15 has a ratio of (1; 1.16). In this embodiment, PZT (lead zirconate titanate) is used as the dielectric. The gap d between the electrodes 25 of the flat stator 15 and the dielectric pattern 45 of the rotor 35 is 0.1 mm to 0.2 ml1.
It is kept at 1. These rotors 35 are all electrically connected via a drive shaft 50 and held at, for example, a ground potential.

When a voltage is applied to the electrodes 25 of the plate-shaped stator 15 having the above configuration, charges having the opposite polarity to the applied voltage are induced on the electrode-facing surface of the dielectric 45 of the rotating body 35 that faces the electrodes 25. In this state, the electrode 25 to which voltage is applied is sequentially changed,
When a predetermined pulsed voltage is sequentially applied in the rotational direction, a rotating electric field is generated by electric lines of force generated from the electrodes. Then, the charges induced in the dielectric 45 are pulled by this rotating electric field, and the rotor 35 rotates following the rotating electric field.

As explained above, according to this embodiment, a large torque can be obtained by stacking a plurality of pairs of the stator 10 or 15 and the movable element 30 or the rotating body 35.

[Effects of the Invention] As explained above, according to the present invention, the movable element can be easily brought to the ground potential, etc., it is easy to accurately maintain the gap between the electrodes of the stator and the movable element, and the movable element can be easily grounded. By disposing conductor layers on both sides of the element, the structure can be made smaller and the lamination density can be increased.

Moreover, the movable element has a simple structure, is easy to process, and can have the necessary strength.

Therefore, the stator and the movable element can be easily stacked on top of each other, making it easy to obtain a large torque.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of an embodiment according to the present invention, FIG. 2 is a perspective view of the outline appearance of this embodiment, and FIG. 3 is a perspective view of the outline appearance of another embodiment according to the invention. FIG. 4 is a diagram showing the configuration of a general electrostatic actuator. In the figure, 1.10.15... Stator, 2.30... Mover, 3, 40.45... Dielectric, 4... Non-dielectric,
16...Shaft, 20...Conductor, 31...Mover arm, 35...Rotor. Patent applicant Canon Co., Ltd. *+m Figure 2 Figure 4

Claims (4)

[Claims] (1) A stator made of an insulating material with a plurality of electrodes arranged at predetermined intervals on its surface, and a surface made of a conductive material that maintains a predetermined gap with the stator and moves relative to the stator. 1. An electrostatic actuator comprising: a movable element having dielectric layers disposed at predetermined intervals; and a movable element. (2) The dielectric layer is disposed on both the front and back sides of the movable element, and the stator is supported at a position where both the front and back sides of the movable element face each other with a predetermined gap maintained. Electrostatic actuator as described in section. (3) Stacking the stator and mover with a predetermined gap maintained,
3. The electrostatic actuator according to claim 2, wherein the movers are electrically connected to each other. (4) The electrostatic actuator according to any one of claims 1 to 3, wherein the mover is made of a conductive material, and a dielectric material is disposed on the surface at predetermined intervals. .