JPH06257557A - Thermally expanding actuator - Google Patents

Abstract

PURPOSE:To provide a thermally expanding actuator which is so designed to be usable as a power source particularly for small mechine parts, etc. CONSTITUTION:A thermally expanding actuator comprises thermally expanding substances 131, 132,..., e.g., fluorocarbons dispersed within an elastic substance 12, e.g., silicone gel, and a heat wire is set within a fundamental structural body 11 comprising the elastic substance 12 and the thermally expanding substances 131, 132, and is intermittently supplied with a heating current to set the fundamental structural body 11 alternately in an expanded, displaced state and in an unexpanded state over and over again, and this repeated deformation causes a force to be outputted, together with displacement.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal expansion type actuator controlled by heating, which is adapted to be used as power for small mechanical parts and the like.

[0002]

2. Description of the Related Art As a drive source utilizing thermal expansion, for example, a wax for a thermostat used in a radiator, which is an automobile part, is known. As this wax, a silicone resin or a paraffin wax is used. Are known.

As a miniaturized drive source, which was announced at the Japan Society of Mechanical Engineers (No. 620-2), a photoheat exchange material and a low boiling point working fluid were enclosed in a silicon diaphragm, It is known that one cell is configured to generate driving force by introducing light into the cell. That is, the introduced light is converted into heat by the photo-heat exchange substance, and this heat causes the phase change of the low boiling point working fluid to raise the pressure inside the diaphragm, and this pressure displaces the diaphragm. .

However, when such an actuator is used as a power source for a small mechanical part or the like, there is no problem with the size of the wax itself when the thermal expansion wax is miniaturized and used, but when the size is reduced, The expansion amount inevitably becomes small, it is difficult to obtain a large displacement and force, and the usefulness as a power source becomes low.

For example, in a narrow tube for heat exchange of a power plant, an engine of a jet machine, a narrow space such as a blood vessel of a human body, or a thin tube, a person cannot directly perform some work. For this reason, the current situation is to use an endoscope or the like. However, there is a limit to the size of the endoscope, and its usage is limited in terms of operability and distance from the controller.

[0006] As a means for solving such a problem, research is being conducted on a micromachine that inspects and repairs by entering a narrow space or a narrow tube, and an electrostatic actuator is mentioned as part of the training. . This electrostatic actuator has a structure in which a voltage is applied to the comb-teeth electrodes that are set to face each other to generate an electrostatic attractive force, and the drive arm is moved by the electrostatic attractive force. However, since the force generated by such a method is small, it is difficult to use it as an actuator of a robot moving in a pipe, for example.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and a force is generated by a simple heating control or the like, so that a sufficient driving force can be secured together with a large displacement. It is an object of the present invention to provide a thermal expansion type actuator capable of easily configuring a mobile robot in a narrow space or in a narrow tube.

[0008]

In a thermal expansion type actuator according to the present invention, a volume is set at a heating temperature below a temperature at which the elastic substance can maintain its characteristics inside a basic structure made of an elastic substance as a base material. The expansion material to be expanded is included, and the heating means is set in combination with the basic structure. The heating means heats the expansion material in the elastic material, so that the volume of the basic structure is increased. It is designed to be inflated. here,
The elastic material forming the basic structure is composed of, for example, silicon gel, and the thermal expansion material is at a temperature below the temperature at which the elastic material can maintain its characteristics.
The elastic substance is made of a substance that increases the volume of the enclosed portion, such as CFC, or a hydrogen storage alloy that releases hydrogen when heated.

[0009]

In the thermal expansion type actuator constructed as described above, when the elastic material forming the basic structure is heated, for example, the thermal expansion material dispersed therein undergoes a phase change to expand in volume. . Therefore, the basic structure is expanded in volume up to the elastic limit, and a large displacement and force can be obtained by this expansion in volume. When the heat supply is stopped in such a state, the thermal expansion material returns to the state before the phase change due to heat, and the volume of the basic structure returns to the original state, so that the heat supply is intermittently performed. As a result, the expansion and contraction movement with large displacement and force is repeated. Here, by interspersing the thermal expansion material in the elastic material forming the basic structure,
It is possible to cut out an elastic material into any shape, and it is also possible to mold it into any shape.Therefore, when using this as a power source for small mechanical parts, etc. Is cut into a required size, and a heating means such as a heat transfer plate is brought close to or included therein, thereby forming an actuator most suitable for the purpose. Therefore, it becomes possible to configure a small-sized actuator which is versatile and whose application range is sufficiently expanded.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. Figure 1 shows the basic structure that constitutes the actuator.
11, the basic structure 11 is composed of an elastic material 12 as a base material. The elastic substance 12 is made of a substance that has a large elasticity and has a small leak property or no leak property, and is made of, for example, silicon gel. A large number of substances 131, 132, ..., For example, CFCs, which undergo a phase change due to heat and undergo a large volume change, are scattered inside the elastic substance 12.

Here, the silicone gel constituting the elastic material 12 has some leakage properties, and it is difficult to include CFCs for a long time, but CFCs are included for some time. Since it can be stored and does not cause a reaction between the silicon gel and the flon, it was adopted in this example.

That is, the basic structure 11 is formed by interspersing liquid fluorocarbons having a low boiling point inside a silicon gel, and the size of each particle of the liquid fluorocarbon is different from that of the base material. It is sufficiently smaller than the volume of the elastic substance 12 to be formed. Therefore, (B) of FIG. 1 shown with a part cut out
The structure shown in (1) is basically the same as that in FIG. (A), and the thermal expansion type actuator can be formed by the structures shown in (A) and (B). And although the shape of a rectangular parallelepiped is drawn in this figure, there is no limitation in this shape and it can be molded into any shape.

Here, the silicon gel forming the elastic material 12 is initially liquid, but is cured to some extent by leaving it in the air for a certain period of time. Therefore, by mixing and stirring CFCs while the silicon gel is still liquid, a large number of granular thermal expansion materials 131, 132, ... Are scattered inside the elastic material 12 which is the silicon gel. . In addition to CFCs, hydrogen expansion alloys that release hydrogen when heated and waxes used in radiator thermostats are conceivable as thermal expansion substances, and can be used as a base material with high elasticity (elastic substance 12). Any substance can be appropriately used as long as it is a substance that causes a large volume expansion by heat or electricity without affecting.

FIG. 2 illustrates an example of a driving mechanism using the basic structure 11 as shown in FIG. 1, in which the elastic material 12 has thermal expansion materials 131, 132, ... The body 11 is set inside the container 15, and the heating wire 16 such as a nichrome wire is set so as to penetrate the inside of the basic structure 11 set inside the container 15. A power source 18 is connected to the heating wire 16 via a switch 17, and the basic structure 11 is selectively heated by operating the switch 17.

That is, in the state where the switch 17 is opened and the heating wire 16 is not connected to the power source 18 as shown in FIG.
The thermal expansion substances 131 1, 132, ... Of the basic structure 11 have not undergone phase change and have not been expanded, and thus have a small structure.
On the other hand, when the switch 17 is turned on as shown in FIG. 6B, a heating current is supplied to the heating wire 16 so that the thermal expansion substances 131, 132, ... Of the basic structure 11 are heated to cause volume expansion. Then, the volume expansion causes displacement to be applied to other elements (not shown). That is, the displacement and the force can be obtained by repeating the states shown in FIGS.

An application example of the actuator using such an operation will be described below. The actuator shown in the example of FIG.
In 20, the heating element 22 is set so as to be wound around the outer circumference of the hollow tube body 21 as shown in FIG. Here, the heating element 22 is set, for example, by forming a corrugated metal plate that generates heat by passing an electric current, and winding it around the outer periphery of the tube body 21. A power source and a switch as shown in FIG. 2 are connected to the heating element 22.

On the outer circumference of the heating element 22 thus constructed, the basic structure 11 constituted by interspersing the thermal expansion materials 131, 132, ... Inside the elastic material 12 is wound and set. here,
The silicon gel forming the elastic material 12 can maintain its shape to some extent even if it is somewhat hard. Further, in the example shown in this embodiment, it is not particularly necessary that the outer shape of the basic structure 11 maintains its original shape accurately, and a change in shape can be allowed to some extent.

In the mechanism thus constructed, the heating element
When an electric current is applied to 22 to generate heat, the thermal expansion materials 131, 132, ... Inside the elastic material 12 expand, and the outer diameter of the basic structure 12 increases as shown in FIG. Therefore,
For example, in the state shown in (A), the actuator is inserted into a pipe having an inner diameter larger than the outer diameter of the basic structure 12, and a heating current is passed through the heating element 22 in the inserted state, and (B) is shown. If the outer diameter of the basic structure 11 is increased as
The outer circumference of the basic structure 11 is pressed against the inner wall of the inserted tube, and the actuator 20 is clamped in the tube.

FIG. 4 shows another example of the application example. This actuator 25 is composed of a bottomed first pipe body 26 and an inner diameter of the first pipe body 26 as shown in FIG. The second tubular body 27 has a slightly smaller outer diameter and also has a bottom, and the second tubular body 27 is fitted inside the first tubular body 26. Although details are omitted in the drawing, the first pipe body 26 and the second pipe body 27 are not shown.
The inner space defined by is filled with the basic structure in which the thermal expansion material is dispersed in the elastic material.

Here, the bottom of the first tubular body 26 and the second tubular body
A heating wire 28 in the shape of a coil spring is set so as to be connected to the bottom of 27, and a power supply 30 is connected to this heating wire 28 via a switch 29.

That is, if the switch 29 is opened as shown in FIG. 9A, the basic structure is not heated. Therefore, the volume of the basic structure at this time is set to a small state, and And the length of the actuator 25, which is a combination of the second pipe bodies 26 and 27, is set to a short state.

In this state, the switch 29 is turned on to turn on the heating wire 28.
When an electric current is applied to the inside, the volume of the thermal expansion material scattered in the internal basic structure is expanded, and the volume of this basic structure is also expanded. Therefore, as shown in FIG. Second
The tubular body 27 is pushed out, and as a result, the length of the actuator 25 becomes longer against the tension of the heating wire 28 due to the spring. When the switch 29 is opened in such a state, the volume of the internal basic structure is reduced, and the tension of the spring due to the heating wire 28 shortens the actuator 25 as shown in FIG.

By thus combining the actuator 20 shown in FIG. 3 and the actuator 25 shown in FIG. 4, a robot mechanism for moving inside the pipe body 31 as shown in FIG. 5, for example, is constructed.

That is, the first and second actuators 201 and 202 having the same construction as shown in FIG. 3 are inserted and set inside the tubular body 31, and the first and second actuators 201 and 202 are Are connected by the actuator 25 shown in FIG. First, in the state shown in FIG. 3A, a heating current is supplied to the first actuator 201 so that the first actuator 201 is clamped on the inner wall of the tubular body 31. In this state, the heating current is not supplied to the actuator 25 so that the actuator 25 is set to be short, and the heating current is not supplied to the second actuator 202 either. Make sure there is a gap between the inner wall of the and.

When a heating current is supplied to the actuator 25 connecting the first and second actuators 201 and 202 in this state, the actuator 25 is extended as shown in FIG. Based on the position of the first actuator 201 clamped on the inner wall of the
The second actuator 202 is moved by the extension amount of the actuator 25.

After the second actuator 202 is moved in this manner, the second actuator 202 is moved as shown in FIG.
When a heating current is supplied to 202 to expand its outer diameter, this second actuator 202 is clamped to the inner wall of the tube 31. If the heating current to the first actuator 201 is cut off in such a state, the first actuator 201
The outer diameter of 201 is reduced so that it can freely move with respect to the tube body 31.

As described above, when the second actuator 202 is clamped and the first actuator 201 is free to move, if the heating current to the actuator 25 connecting the actuators 201 and 202 is cut off,
As shown in (D), the length of the actuator 25 is shortened, and the first actuator 201 is moved so as to approach the direction of the second actuator 202. Therefore, such first and second actuators 201, 20
2. Further, if the control of the heating current for the actuator 25 connecting them is repeated, a robot that moves forward in the tube body 31 is configured.

The basic structure 11 shown in FIG. 1 can constitute a thermal expansion type actuator of any shape, and actuators of various shapes can be manufactured according to the process shown in FIG.

That is, first, as shown in FIG. 3A, a thin film 36 having elasticity is set on a substrate 35 having a concave shape on the upper portion thereof, and the surface of the substrate 35 is covered. After that, a volatile liquid 37 such as CFC having a low boiling point is filled in the recessed portion formed on the thin film 36 corresponding to the concave shape, and then the volatile liquid 37 is filled with an elastic thin film 38. cover. And a volatile liquid
Two thin films 36 set on the outer circumference of the part where 37 is stored
The joint portions of and 38 are heated and welded by the ultrasonic waves from the ultrasonic oscillator 39.

Therefore, by such a process, (B)
As shown in the figure, the elastic thin films 36 and 38 are welded parts.
A container whose outer peripheral portion is sealed by 40 is formed, and a structure in which the volatile liquid 37 is sealed is formed inside the container. Then, as shown in FIG. 6C, an arbitrary part of the sealed body is pressed into an arbitrary shape by the projection of the jig 41 and the ultrasonic oscillator 42, and this part is welded / cut.
In this way, the thermal expansion type actuator 43 in which the volatile liquid 37 is sealed in the container constituted by the elastic thin film as shown in FIG.

Such an actuator 43 can be manufactured by a jig having a predetermined shape having an ultrasonic oscillator and a protrusion. In this case, a plurality of patterns having a predetermined shape are processed and formed on the jig, and a large amount of thermal expansion type actuators can be manufactured at once by using such a jig.

A heating wire 44 is appropriately enclosed in the thermal expansion type actuator 43 manufactured as described above as shown in FIG.
If the power supply 46 is connected via 45, the switch
By adding 45, the volatile liquid 37 can be heated. Then, by supplying a heating current to the heating wire 44 through the switch 45, the actuator 43 is expanded and deformed as shown in FIG.

[0033]

As described above, according to the thermal expansion type actuator of the present invention, for example, CFCs, which are displaced by heat, are dispersed in the elastic material forming the basic structure, and therefore, the basic structure is improved. Regardless of the shape of the body, by intermittently controlling the heat supply,
The displacement operation is repeated. Therefore, by using such a thermal expansion type actuator,
This makes it possible to easily configure a robot mechanism or the like that operates in a narrow space such as a narrow tube, and also to effectively apply it as a power source for various mechanical parts.

[Brief description of drawings]

FIG. 1A is a diagram showing a basic structure of a thermal expansion type actuator according to an embodiment of the present invention, and FIG. 1B is a diagram showing a state in which a part thereof is cut out.

2 (A) and 2 (B) are views for explaining a basic shape and a state of expansion deformation of the basic structure, respectively.

FIG. 3 shows a first example of an actuator constructed by using the above basic structure, in which (A) shows a steady state (B).
The figure which shows each expansion state.

FIG. 4 is a view showing a second example of an actuator similarly constructed by using the above basic structure, in which (A) shows a steady state and (B) shows an expanded state.

FIG. 5 is a view for explaining an example of a moving device in a pipe configured by using the first and second actuators shown in FIGS. 3 and 4, respectively, and (A) to (D) respectively show the operation order thereof. Shows the state of.

6A to 6F are views for explaining another example of the thermal expansion actuator corresponding to the manufacturing order.

[Explanation of symbols]

11 ... Basic structure, 12 elastic material (eg silicon gel),
131, 132, ... Thermal expansion material (for example, Freon), 16 ... Heating wire, 17 ... Switch, 18 ... Power supply.

Claims (6)

[Claims] 1. A basic structure composed of an elastic substance as a base material, and a portion of the elastic substance encapsulated in the elastic substance at a heating temperature below a temperature at which the elastic substance can maintain its characteristics. An expansion material composed of a material that increases the volume of the basic structure, and heating means combined with and set to the basic structure. The heating means heats the expansion material in the elastic material, and the basic structure. A thermal expansion type actuator characterized in that the driving force is generated by expanding the volume of the. 2. The elastic material constituting the basic structure is
The thermal expansion type actuator according to claim 1, wherein the thermal expansion type actuator is made of silicon gel. 3. The thermal expansion actuator according to claim 1, wherein the thermal expansion material is formed into a plurality of particles and is set so as to be scattered inside the elastic material. 4. The expanding material is vaporized at the heating temperature,
The thermal expansion type actuator according to claim 1, wherein the thermal expansion type actuator is constituted by a substance that causes sublimation or expansion. 5. The thermal expansion material is CFCs.
The thermal expansion type actuator described. 6. The thermal expansion actuator according to claim 1, wherein the thermal expansion material is a hydrogen storage alloy that releases hydrogen gas at the heating temperature.