JPH06341369A - Actuator - Google Patents

Abstract

PURPOSE:To provide an actuator which is small, excels in responsiveness, and is fitted for micro-machine, etc., by installing an expansive body consisting of a shape memory alloy inside of an elastic body made from a polymer, and expanding the elastic body associate with expansion and contraction of the expansive body in compliance with temp. rise and fall. CONSTITUTION:An expansive body 2 consisting of a shape memory alloy is furnished inside of an elastic body 1 made from a polymer. The elastic body 1 is expanded and contracted associate with the expansion and contraction of the expansive body 2 in compliance with the rise and fall of the temperature, and thereby the expanding/contracting motions as actuator are secured. The expansive body 2 is installed, for example zigzag, inside of the elastic body 1 and set in a form which ensures smooth inter-transmission of the expanding/ contracting motions. Examples of the polymer are rubber of different sorts, plastics, etc., while examples of the shape memory alloy is Ti.Ni alloy atc. Accordingly the resultant actuator is embodied small, excels in the response, and is favorable for micro-machine, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is small in size and excellent in responsiveness.
The present invention relates to an actuator suitable for micromachines and the like.

[0002]

2. Description of the Related Art A small actuator suitable for maintenance of pipes, medical micromachines, and the like is required. Conventionally, as a small-sized actuator, a bias spring 6 is placed in opposition to a spring 5 made of a shape memory alloy as illustrated in FIG. Shrinkage of 6)
And the contraction operation of the spring 5 due to the temperature decrease (return of the spring 6)
It has been known that the target object 7 can be moved in two directions. However, there is a problem that a space is required for the bias spring 6 to be opposed to the space, which hinders downsizing of the actuator.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to develop a small actuator which can be formed in a size substantially conforming to that of a stretchable body made of a shape memory alloy, and which can easily achieve miniaturization and which has excellent responsiveness. .

[0004]

SUMMARY OF THE INVENTION The present invention provides an actuator characterized in that an elastic body made of a polymer and an expandable body made of a shape memory alloy are arranged in the elastic body.

[0005]

With the above structure, when the elastic body made of the shape memory alloy recovers its memory shape due to the temperature rise and expands, the elastic body made of the polymer also follows and the expanded state is achieved.
When the temperature is lowered, the restoring force of the elastic body made of polymer is increased and the stretchable body made of the shape memory alloy is contracted to return to the original shape. As a result, the function of the actuator as the expansion / contraction operation is achieved. Therefore, the actuator can be formed with a size substantially similar to that of the stretchable body made of a shape memory alloy, and the space required for the bias spring to be opposed can be omitted.

[0006]

EXAMPLE An actuator of the present invention comprises an elastic body made of a polymer and a stretchable body made of a shape memory alloy arranged therein. Examples thereof are shown in FIGS. 1 and 3. 1, 3 are elastic bodies made of a polymer, and 2, 4 are elastic bodies made of a shape memory alloy.

As the polymer forming the elastic body, various kinds of rubber such as natural rubber and synthetic rubber, and plastic such as polyolefin and block copolymer may be used. A preferred elastic body has an elastic modulus of 10
⁷ to 10 ⁹ dyn / cm ² and an elongation rate of 50 to 1000%.

As the shape memory alloy, an appropriate one may be used depending on its temperature characteristics and the like. For example, Ti
・ Ni type alloy, Ti ・ Ni ・ Cu type alloy, Ti ・ Ni ・ Fe type alloy, Ni ・ Al type alloy, Ag ・ Cd type alloy, Au ・ Cd type alloy, Cu ・ Al ・ Ni type alloy, Cu ・ Au・ Zn alloy, Cu
・ Sn alloy, Cu ・ Zn alloy, Cu ・ Zn ・ Al alloy,
Examples include In / Tl-based alloys and In / Cd-based alloys.

The shape of the elastic body made of a shape memory alloy can be appropriately determined, for example, a spring, a wire or a tape. From the viewpoint of elasticity and the like, a spring shape such as a zigzag shape illustrated in FIG. 1 or a coil shape illustrated in FIG. 3 is preferable.

The arrangement of the elastic body made of a shape memory alloy in the elastic body made of polymer is, for example, one in which a zigzag elastic body 2 is embedded in a plate-shaped elastic body 1 as shown in FIG. As shown in FIG. 3, a coil-shaped elastic body 4 may be embedded in the thick portion of the pipe-shaped elastic body 3, and the like may be appropriately determined. It is preferable that the force is smoothly transmitted between the restoring force (compressed state) of the elastic body made of polymer and the restoring force (extended state) of the elastic body made of shape memory alloy to the memorized shape.

Therefore, the formation of the actuator of the present invention comprises:
For example, it can be performed by an appropriate method such as a method of casting the polymer solution under the arrangement of the elastic body. In the examples, FIGS. 1 and 3 show a normal state (shrinking state) at a low temperature, and FIGS. 2 and 4 show a state in which they are extended by a temperature rise.

The actuator of the present invention can be preferably used for various devices such as thermostats and controllers in micromachines for maintenance of pipes and medical applications, controllers for automobiles, controllers for automatic opening / closing greenhouse windows and fire doors.

[0013]

According to the present invention, it is possible to effectively obtain a simple actuator having a size substantially equivalent to that of a stretchable body made of a shape memory alloy, easily achieving miniaturization, and excellent in responsiveness. You can

[Brief description of drawings]

FIG. 1 is a sectional view of an example.

FIG. 2 is a sectional view of the embodiment shown in an expanded state.

FIG. 3 is a cross-sectional view of another embodiment.

FIG. 4 is a sectional view of the embodiment shown in an extended state.

FIG. 5 is an explanatory diagram of a conventional example.

[Explanation of symbols]

 1, 3: Elastic body made of polymer 2, 4: Stretchable body made of shape memory alloy

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masahisa Sugihara 4-3 Ikejiri, Itami City, Hyogo Prefecture Mitsubishi Cable Industries, Ltd. Itami Works

Claims (1)

[Claims] 1. An actuator comprising an elastic body made of a polymer and an expandable body made of a shape memory alloy arranged therein.