JPS6292777A - Linear motor - Google Patents

Abstract

PURPOSE:To use a linear motor for precisely positioning an apparatus by mechanically amplifying strain generated in an electrostrictive element by employing the principle of the lever. CONSTITUTION:When voltage is applied to an electrostrictive effect element 1a, levers 4a, 4b push a guide against an amplifying mechanism 6a to fix the mechanism 6a. When voltage is applied to an electrostrictive effect element 1c, the width of the electrostrictive effect element 1c is extended to the left and the right, and an amplifying mechanism 6b is moved in the left direction. When voltage is applied to an electrostrictive effect element 1b, levers 4c, 4d push a guide against the amplifying mechanism 6b to fasten the mechanism 6b. When the voltage of the electrostrictive effect element 1a is brought to zero, the levers 4a, 4b are separated from the guide. When the voltage of the electrostrictive effect element 1c is brought to zero, the width of the electrostrictive effect element 1c is shortened, and the amplifying mechanism 6a is shifted in the left direction with the shortening of the the width of the element 1c. The same operation is repeated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an inchworm-shaped linear motor using an electrostrictive effect element used for precision positioning of equipment.

[Conventional technology]

Conventionally, this glazed inchworm-shaped linear motor has a structure shown in FIG. Clamp elements 7a and 7b consisting of two cylindrical electrostrictive elements serving as legs are fitted onto a shaft 8 made of an alumina rod or the like serving as a guide. When a voltage is applied to the electrodes provided on the end faces of the clamp elements 7a, 7b, the inner diameters of the cylinders of the clamp elements 7a, 7b become smaller due to the electrostrictive effect, thereby tightening the shaft 8. Normally, the change in the inner diameter of this cylinder is a voltage of 400 V.
It is about 5 μm when DC is applied. The elastic element 9 is made of a cylindrical electrostrictive element with electrodes attached to both end faces.
It has the property of expanding in the axial direction when a voltage is applied to the electrode.

The bonding material 10 is made of cylindrical alumina and connects the electrodes on the end faces of the expandable element 9 and the electrodes on the end faces of the clamp elements 7a, 7b.

[Problem that the invention seeks to solve]

The conventional inchworm type linear motor mentioned above has a shaft 8
and between the clamp elements 7a and 7b, the clamp element 7a,
Since the movable part is attached and detached by reducing and deforming 7b by 5 μm, the dimensional accuracy of the gap between the outer diameter of the shaft 8 and the inner diameter of the clamp elements 7a and 7b must be within 5 μm.

In order to obtain the dimensional accuracy of this gap, the shaft 8 and the clamp elements 7a, 7b are manufactured by ultra-precision machining while matching the actual parts. For this reason, the price of the conventional inchworm-type IJ near motor itself is extremely high, and it has the drawback that it cannot be replaced with an electromagnetic linear motor or the like.

[Means for solving problems]

SUMMARY OF THE INVENTION An object of the present invention is to provide a sunar motor that eliminates such conventional drawbacks.

The electrostrictive linear motor of the present invention includes a first electrostrictive effect element which is stretched in an E-shaped cross section with one end connected to a fixing member having a single-shaped cross section through a first hinge, and a first! A pair of upper and lower first and second elements are connected to the other end of the strain effect element via a hinge, and are in contact with a guide plate and rotate in different directions.
The movable member and the fixed member, which first holds the strain effect element and whose end on the open end side is connected to the first and second movable members via a hinge, are connected to the central axis of the 1'rlL strain effect element. The present invention is characterized in that a third strain effect element is connected via a hinge between the second electrostriction effect element and the third and fourth movable members, which are arranged symmetrically on an extension line above.

〔Example〕

Hereinafter, the present invention will be explained with reference to the drawings.

FIG. 1 is a plan view of one embodiment of the present invention.

The electrostrictive effect elements + (1a, xb, xc) are formed by laminating and integrating a ceramic electrostrictive material made of lead zirconate titanate or the like and an internal electrode made of a metal palladium alloy or the like. The length of the electrostrictive effect element 1 in the direction of expansion and contraction is 9 mm, and the strain is 6.5 μm when a voltage IQQV DC is applied. 2 The generated force is 13 kg. Amplification mechanism 1
sa, sb) are hinges 2a to 2h, base 3a
, 3b, and levers 4a to 4d. The material used is an invar material having approximately the same coefficient of thermal expansion as the electrostrictive element 1a and the IC, and the thickness is two plates. The amplification mechanism 6 is manufactured as a single piece from a metal plate by electrical discharge machining.

The amplification mechanism 6 (6a, 6b) is glued to both ends of the electrostrictive element IC, but since the electrostrictive element IC is generally weak against tension and twisting, it is not compressed to the electrostrictive element IC. The amplification mechanisms 6 (sa, 6b) are assembled so as to be pulled together using springs 11 so as to apply force.

Although a spring is used in this embodiment, the same effect can be obtained by tightening bolts or the like.

The electrostrictive elements 1a to 1c and the amplification mechanisms 6a and 6b are bonded together using an adhesive such as epoxy resin.

The guides 5a and 5b are made by cutting a metal rod such as a piece of material 8. The cross-sectional shape of the guides 5a and 5b is V-shaped as shown in FIG.
The cross-sectional shape of the contact portion with the guide of 6a, 6b) is an inverted V-shape, and there is a fitting relationship.

By making such a fit, the amplification mechanism 6 (
It is possible to prevent vibrations on the plane that sa, 6b) have in the ^U order. In this example, a V-shape was adopted, but the U
A similar effect can be seen in the shape of letters.

Next, a mechanism for mechanically amplifying the strain generated in the electrostrictive element 1a and the IC using the lever principle will be described. The distortion is amplified by the electrostrictive effect element 1aK! When pressure is applied, it twists 2
Move the lever 4a2 in the direction of pushing it up via the lever a. The lever 4a rotates the hinge 2b. At this time, the distortion amplification factor n is determined by the distance l between the hinges 2a and 2b and the length of the lever 4a represented by L shown in FIG.
It can be expressed as By the above-mentioned mechanism, the levers 4a to 4d extend in the direction of the arrow, and push and fix the guides 5a and 5b.

Next, the operation of the linear motor having the structure according to the embodiment of the present invention will be explained.

When a voltage having the waveform shown in FIG. 3 is applied to each of the electrostrictive elements 18 to IC, the driving section consisting of the electrostrictive element 1 and the amplification mechanism 6 moves in the steps shown in FIGS. 4(a) to (e). do.

First, as shown in FIG. 4(a), a voltage is applied to the electrostrictive element 1a, and the levers 4a and 4b are moved to the guide 5a.

5b to fix the amplification mechanism 6a. Next, as shown in FIG. 4(b), a voltage is applied to the electrostrictive element IC, and the width of the electrostrictive element IC increases by 6.5 μm in the left and right directions, and the amplifying mechanism 6b moves to the left.

Next, as shown in FIG. 4(C), a voltage is applied to the electrostrictive element 1b, and the levers 4c and 4d press the guides 5a and 5b to fix the amplification mechanism 6b. Next, as shown in FIG. 4(d), when the voltage of the electrostrictive element 1a is made zero, the levers 4a and 4b are separated from the guides 5a and 5b. Next, when the voltage of the electrostrictive element IC is made zero as shown in FIG. 4(e), the electrostrictive element I
The width of C is reduced by 65 μm, and the amplification mechanism 6a is reduced accordingly.
moves to the left. In this way, 6.5μ is produced in one process.
m Move to the left.

The performance of this IJ near motor is frequency 2.5 KHz
When driven with a periodic pulse of 12. fluency/sec, power 10
It was kg. Positioning accuracy is 1 stroke
In the case of 00mj+, it was 2 μm.

The figure is a drive voltage waveform diagram of an amotor according to an embodiment of the present invention.
4(a) to 4(e) are plan views showing the operating principles of an embodiment of the present invention, and FIG. 5 is a sectional view of a conventional linear motor.

1 (1a-lc)... Electrostrictive effect element, 2a-2
h...Hinge, 3a, 3b...Base, 4a-4d...Lever, 5a, 5b...
... Guide, 6 (sa, sb) ... Amplification mechanism,
7a, 7b... Clamp element, 8...
Shaft, 9... Telescopic element, 10...
Binding material, 11... Spring.

′-), Agent: Patent attorney: Susumu Uchihara, Yumi.

times Spout younger sister

Claims (3)

[Claims] (1) A mechanical amplifier that expands the amount of strain generated by the first electrostrictive element while rotating the direction thereof is connected to the first electrostrictive element, and the two mechanical amplifiers are connected to the second electrostrictive element. A linear motor, characterized in that two guide plates are connected to both ends of a strain effect element and an elastic body, and are circumscribed to the mechanical amplification device. (2) The linear motor according to claim 1, wherein a cross-sectional shape of a contact portion between the mechanical amplifying device and the guide plate is V-shaped or U-shaped. (3) The mechanical amplification device connects a U-shaped fixed member, first and second movable members connected to the fixed member via a hinge, and hinged to the first and second movable members. The linear motor according to claim 1, characterized in that the linear motor comprises a connecting member connected through the connecting member.