JPH0634598B2 - Electrostatic type two-dimensional moving actuator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention generates less dust and gas than an electromagnetic actuator and converts electrostatic energy that can be used as an actuator in clean and vacuum into mechanical energy. The present invention relates to an electrostatic type two-dimensionally movable actuator as a device.

[Conventional technology and its problems]

If you want to move the mover two-dimensionally in a plane,
As a conventional technique, a first example, a linear motor or a linear pulse motor, a second example, a piezoelectric actuator, a third example, a linear motor or a combination of a linear pulse motor and a piezoelectric actuator is used as a drive source.

As a fourth example, there is Japanese Patent Application No. 61-73730 (electret motor) shown in FIG. This method is provided with a movable element in which a metal and an insulator are arranged at equal intervals, and a ferroelectric material is coated on the surface of the movable element, and flexibility such that the surface of the movable element is slightly in contact with the surface of the movable element. An electret motor having at least two pairs of electrodes.

Further, as a fifth example, JP-A-50-85813 can be seen. This is a drive mechanism that can move freely on a flat surface or a curved surface. FIG. 6 is a partial view of an electret assembly joined on a support, FIG. 7 is a sectional view taken along the line AA ′, and FIG. FIG. 9 shows an electrode body diagram, and FIG. 9 shows a drive electric circuit block diagram. That is, the electrode groups 63, which are divided, are electrically insulated from each other, and are capable of independently applying electric charge,
64, 65 and the aggregate 66 of the divided electrets 61 or the composite body in which the electrets 61 are joined to the supporting body 62 face each other, and the relative positions of the electrodes and the electrets are moved by giving an electric charge to the divided electrodes. It is a means.

[Problems to be solved by the invention]

However, with the linear motor or linear pulse motor of the first example, there is a limit to downsizing, weight reduction, and thinning of the device, and when precise positioning is required, precision machining of parts and a complicated controller are required, It has the drawback of being expensive.

The piezoelectric actuator of the second example has a large generating force, but has a drawback that the amount of displacement is small. In the case of the third example, which is used in combination, such as a linear motor for coarse movement and a piezoelectric actuator for fine movement. There are many. Also in this case, the above-mentioned essential drawbacks of the electromagnetic motor cannot be avoided.

The first attempt to use static electricity as a driving source is very old in the first half of the 18th century. Nevertheless, since the limit of the energy density of the electric field is very small, about 1 / 20,000 of that of the magnetic field, the generated torque as a motor cannot be produced, and there has been no practical application up to now.

Further, in the fourth example, since the metal and the insulator are arranged at equal intervals in one direction, even if the voltage applied to the electrodes is sequentially switched, the mover moves only in one direction. That is, it cannot be used as a two-dimensional moving source.

Furthermore, in the fifth example, this is a small drive mechanism, and its application as a practical concrete tool remains questionable.

An object of the present invention is to provide an electrostatic actuator that overcomes the difficulties of the conventional example, generates a large force, and is capable of coarse movement, fine movement, and two-dimensional movement in a plane.

[Means for solving problems]

According to the present invention, the mover is a plate-shaped insulator, and a plurality of metals having substantially the same thickness as the insulator are embedded at predetermined positions and fixed to each other, and the insulator is attached to the surface of the plate made of metal. A thin film of ferroelectric material is created and movably supported, and the stators face each other through a gap through which the mover is inserted. Electrostatic type 2 composed of at least two pairs of electrodes in contact with each other, and composed of a metal of the mover and a stator electrode facing the front and back of the metal and spaced apart from the metal in a predetermined direction. It is a dimension movement actuator.

[Work]

When a voltage is applied to one electrode having a stator, a metal having an infinite dielectric constant in the vicinity of the electrode is drawn to a position where it overlaps with the electrode due to a suction action, and the mover moves.

Switching the applied voltage to another metal also draws in the metal of the moving element in the vicinity thereof.

According to the present invention, by sequentially switching the voltage to the electrodes of the stator in this manner, the metal parts of the mover, which are separated from the electrodes by setting the direction and distance in advance, are sequentially drawn to the position where they overlap the electrodes. Therefore, coarse movement, fine movement, and two-dimensional movement are possible within a preset range.

〔Example〕

1A and 1B are side sectional views and a plan view of a mover according to an embodiment of the present invention, and a side view and a plan view of a stator are second view.
3 (a) and 3 (b), the actuator side sectional view is shown in FIG. 3 (a), and the sectional view from the upper surface is shown in FIG. 3 (b).

In all the drawings, the same symbols represent the same or corresponding parts.

FIG. 4 shows the four electrodes 7 _a , 7 _b , 7 _c of the stator.
Shows a movement locus diagram mover and ₇ when switching the applied voltage to the _d, FIG. 4 (a) is electrode _{7 a → 7 b → 7 c} → 7
_The case where the applied voltage is switched to _d , and (b) shows the case where the order of the applied voltage to the electrode is changed, that is, the electrode 7 _a → 7.
_{This is when c} → 7 _b → 7 _d .

First, in the moving element 1 shown in FIG. 1, the alumina ceramic insulator 2 and the insulator 2 having the same expansion coefficient of 42% N
_The carbon steel 3 containing _i is embedded in the insulator 2 at four locations (3 _a , 3 _d , 3 _c , 3 _d ) with the same thickness and fixed to each other. Further on the surface of a plate made of the insulator 2 and the metal _{3, B a, T i,} O 3 thin film 4 is formed by sputtering.

In the stator shown in FIG. 2, when the polyimide or polyester film 6 having flexibility is overlapped with the mover shown in FIG. Surface area of four electrodes (7 _a ,
7 _b , 7 _c , 7 _d ) are formed by adhesion or vapor deposition.

The actuator according to the present invention in FIG. 3 shows the locus of movement in the plane of the mover when the order of applying the voltage to each fixed electrode is changed for the two examples of the operation shown in FIG.

In example 4 (a), completely electrode 7 is attracted by the charge of the metal 3 _a as seen from the application of a voltage Figure 3 (b) to the first electrode 7 _a electrode 7 _{a a} a metal 3 _a The mover 1 moves until the two overlap.

Then it pulled to a position where the metal 3 _b overlaps with the suction action of the charge likewise electrode 7 _b when switching the voltage to the electrode 7 _b.

Continued by switching the applied voltage to the electrode 7 _c and the electrode 7 _d, so that the trajectory shown in FIG. 4 (a) moving element is traced.

As described above, by appropriately selecting the order in which the voltage is applied to the plurality of electrodes, the coarse movement, the fine movement, and the moving direction can be variously changed.

It should be noted that, in this description, only one pair of the electrode 7 and the attracted metal 3 is shown in order to make the description easy to understand, but in order to increase the generated force, the electrode 7 and the attracted metal 3 are shown in FIGS.
It does not matter if a plurality of pairs of the mover and the stator shown in the figure are applied and voltage is applied at the same time.

Further, although the metal 3 and the electrode 7 are shown in an enlarged manner in FIGS. 1 and 2, if the fine processing technology in the recent VLSI is applied, the size of the electrode is 1 μm or less. Therefore, fine positioning is possible.

As another embodiment of the present invention, the electrodes may be arranged in a matrix.

〔The invention's effect〕

Thus, according to the present invention, an electrostatic actuator capable of coarse movement, fine movement and two-dimensional movement is realized within a range in which a plurality of electrodes are separated from the metal of the moving element in the distance and direction in advance. As an apparatus, it is possible to provide an ideal actuator with surely reliable operation and improved cost and reduced cost.

[Brief description of drawings]

FIG. 1 is a side sectional view and a top view of a mover in one embodiment of the present invention, FIG. 2 is a side view and a top view of a stator, and FIG. 3 is a side sectional view and an upper cross section of an actuator. FIG. 5 is a movement locus diagram of the moving element, and FIGS. 5 to 9 are explanatory views of a conventional example. 1 ... mover, 2 ... insulator, 3, 3 _a , 3 _b , 3 _c ,
3 _d ... Metal, 4 ... Ferroelectric material, 5 ... Stator, 6 ...
Flexible insulator, 7, 7 _a , 7 _b , 7 _c , 7 _d ... Electrodes.

Claims (1)

[Claims] 1. A plurality of metals are embedded in a plate-shaped insulator and fixed to each other, and a thin film of a ferroelectric is formed on the surface of the plate, and a movable element movably supported and a movable element are interposed. A direction in which the mover is moved, each of which has a stator provided with at least two pairs of electrodes that face each other through the space to be inserted, have flexibility in the direction of the space, and slightly contact the surface of the mover. An electrostatic type two-dimensional movement actuator characterized in that the metal and the electrode are preliminarily separated from each other by the distance.