JPH0440585B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control valve that controls the opening of a valve hole by utilizing the displacement of a driving body made of a shape memory alloy due to temperature changes.

Shape memory alloys utilize the phenomenon that occurs when the low-temperature phase generated by thermoelastic martensitic transformation is deformed and then reversely transformed into the high-temperature phase by heating. At higher temperatures than this, it changes to an austenite structure, and at lower temperatures, it changes to a martensitic structure. When this shape memory alloy is cooled from the high temperature side, the austenitic structure transforms to the martensitic structure, and it has superelasticity.On the other hand, when it is heated from the low temperature side, the martensitic structure transforms to the austenite structure, and the forming process It returns to the memorized shape. The alloys that exhibit this shape memory effect are nickel-titanium, copper-
Aluminum-nickel, copper-aluminum, etc. are known, and those in which the valve hole is opened and closed by displacement due to temperature changes of these shape memory alloys are disclosed in Japanese Utility Model Application Publication No. 56-56969 and Japanese Patent Application Laid-Open No. 56-56969. It is known from Publication No. 57-25572.

However, in the operating means for opening and closing the valve shown in Japanese Utility Model Application Publication No. 56-56969, the opening/closing means is formed of a shape memory alloy and is dependent on the temperature of the control fluid that fluidizes the valve body. However, since temperature changes in the control fluid are essential, it is unsuitable for applications where such temperature changes cannot be obtained, and is therefore unsuitable for use in wide control valves.

Furthermore, according to Japanese Patent Application Laid-open No. 57-25572, a structure is shown in which the opening and closing of the valve hole is controlled by directly heating the valve drive element made of a shape memory alloy with a heater. In the structure in which the heater is wound, it is necessary to place an insulating film to provide insulation between the heater and these elements, which makes efficient heating difficult and poses a problem in the responsiveness of the valve.

The control valve using the shape memory alloy of the present invention was created in view of the above-mentioned problems, and the control valve that drives the valve body is not heated by the environmental temperature of the control fluid, etc., and is directly and electrically operated. The object of the present invention is to obtain a control valve that can be widely used as a control valve and has good valve control responsiveness.

Hereinafter, one embodiment of the control valve according to the present invention will be described with reference to FIG.

1 is provided with a flow path 2 passing through the inside thereof, and the flow path 2
The primary flow path 2A is
and a secondary flow path 2B,
The upper opening of the valve body 1 is closed by a closing plate 4.

Reference numeral 5 denotes a valve body that controls opening and closing of the valve hole 3. A guide rod 6, which is integrally screwed with the valve hole 5 and moves synchronously with the valve body 5, passes through the closing plate 4 and closes the valve body 1. ,
It protrudes upward from the closing plate 4.

Further, on the upper surface of the closing plate 4, a fixed part 7 that pivotally supports the guide rod 6 in a movable manner is fixedly arranged, and on the lower surface of the upper flange 6A at the upper end of the guide rod 6, it is synchronous with the guide rod 6. , and the movable part 8 facing the fixed part 7 is arranged.

There is a gap between the opposing surfaces of the fixed part 7 and the movable part 8.
L is formed. A disk-shaped second contact 9 connected to the electrode on one side is arranged on the fixed part 7, and a circular plate connected to the electrode on the other side is arranged on the surface of the movable part 8 facing the fixed part 7. A plate-shaped first contact 10 is arranged, and a gap is formed between the first contact 10 and the second contact 9. During this time, there are a plurality of coil spring-like driving bodies 11 made of shape memory alloy.
A, 11B, and 11C are arranged.

The first driving body 11A surrounds the outer periphery of the guide rod 6, and one end thereof is connected to the first contact 10,
The other end is connected to the second contact 9.

Further, the second driving body 11B is the first driving body 11A.
One end is connected to the first contact 10 and the other end is connected to the second contact 9. Furthermore, the third drive body 11C surrounds the outer periphery of the second drive body 11B, one end of which is connected to the first contact 10, and the other end connected to the second contact 9.

Furthermore, A is a ring-shaped insulator, which is attached to the first contact 10 and the second contact 9, and is connected to each driving body 11A, 1.
1B and 11C were arranged so that they were not directly electrically connected.

That is, one end of each of the driving bodies 11A, 11B, 11C is directly connected to the first contact 10 without contacting the other driving bodies, and the other end of each of the driving bodies 11A, 11B, 11C is The end is directly connected to the second contact 9 without contacting any other driving body.

Thus, the electric circuit formed by the first contact 10 and the second contact 9 includes the respective driving bodies 11A, 1
1B and 11C are connected in parallel.

This is shown in FIG.

A spring 12 is installed between the upper part of the valve body 5 and the lower surface of the closing plate 4, and biases the valve body 5 toward the valve hole 3.

Next, to describe its operation, the driving body 11
When A, 11B, and 11C are not energized,
Since no heat is generated in the driving bodies 11A, 11B, 11C, the driving bodies 11A, 11B, 11C do not rise to the reverse transformation temperature (point As), and therefore the driving bodies are maintained in a contracted state. The guide rod 6 is placed at a low position as shown by the solid line in the figure and held at the first position. In this state, the guide rod 6 including the valve body 5 is pressed downward by setting the tension of the spring 12 contracted above the valve body 5 to be larger than the tension of the drive bodies 11A, 11B, and 11C. , the valve hole 3 is closed by the valve body 5 to maintain the flow path 2 in a blocked state.

Next, when electricity is applied between the first contact 10 and the second contact 9, each drive body 11A, 11B, 11 is
A current flows through C, and according to this, the driving bodies themselves generate joules and self-heat, and as a result, the temperature of each driving body 11A, 11B, and 11C rises above the reverse transformation starting point (A point). As time passes, the driving bodies 11A, 11B, and 11C begin to expand, and the temperature further increases and reaches the end point of reverse transformation (Af point), where the expansion is completed. The movable portion 8 and the guide rod 6 are displaced upward against the spring force and held at the second position as shown by the dashed line in the figure. According to this, the valve body 5 also moves upward to open the valve hole 3, thereby communicating the primary flow path 2A and the secondary flow path 2B.

In this example, when the temperature decreased at the martensitic transformation starting point (Ms point), the driving body 11 contracted and deformed, and when the temperature rose, it was caused to expand and deform at the reverse transformation starting point (As point). The deformation may be reversed and the driving body 11 may be elongated and deformed when the temperature decreases at the martensitic transformation start point (Ms point).

As described above, according to the control valve using the driving body made of the shape memory alloy of the present invention, the flow passage passes through the inside, and the flow passage is divided into the primary flow passage and the secondary flow passage by the valve hole. In a control valve that includes a valve body, a valve body that controls opening and closing of a valve hole in the valve body, and a guide rod that moves synchronously with the valve body, a flat second contact connected to an electrode on one side is used. A flat first contact fixedly disposed on the valve body and connected to the electrode on the other side is disposed integrally with a guide rod that moves synchronously with the guide rod, and the first contact and the first contact A plurality of coil spring-shaped driving bodies made of a shape memory alloy are arranged between the two contacts, and each end of each driving body is directly connected to the first contact and the second contact. A plurality of driving bodies are arranged in parallel in an electric circuit formed by the first contact and the second contact, and this provides the following effects.

The drive body itself can generate heat, so there is little heat loss, and the entire drive body can be heated uniformly from inside the drive body.It has excellent heating characteristics and can be widely used as a drive body for all kinds of products.

A plurality of coil spring-shaped driving bodies are arranged between the first contact point and the second contact point, that is, a plurality of driving bodies are arranged on the same flat plane, so that the driving body can drive the guide rod. Since the force is the sum of the elongation change forces generated by each driving body, it is possible to increase the driving force for the guide rod. According to this, the operating load of the valve body can be easily set, and the force flowing through the flow path can be increased. A control valve that responds to changes in fluid pressure, etc. can be easily provided.

If there is a difference in the reverse transformation temperature of each drive body, the drive body will move in a stepwise manner as the temperature rises over time when electricity is applied, and according to this, the movement of the guide rod and valve body will be controlled. It can be controlled in a step-like manner and can provide a multi-stage control valve.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view showing one embodiment of the control valve according to the present invention, and FIG. 2 is a wiring diagram of a driving body. 1... Valve body, 2... Channel, 3... Valve hole, 5...
... Valve body, 6 ... Guide rod, 9 ... Second contact, 10 ...
...First contact, 11A, 11B, 11C...Driver.

Claims (1)

[Claims] 1 A valve body 1 through which a flow passage 2 passes and which divides the flow passage 2 into a primary flow passage 2A and a secondary flow passage 2B with a valve hole 3, and opening/closing control of the valve hole 3 of the valve body 1. In a control valve equipped with a valve body 5 that moves synchronously with the valve body 5 and a guide rod 6 that moves synchronously with the valve body 5, a flat second contact 9 connected to an electrode on one side is fixedly disposed on the valve body 1. At the same time, a flat first contact 10 connected to the electrode on the other side is arranged integrally with the guide rod 6 so as to move synchronously with the guide rod 6, and the first contact 10 and the second contact
A plurality of coil spring-shaped driving bodies 11 made of a shape memory alloy are formed between the contacts 9 and
A, 11B, and 11C, and each end of each drive body 11A, 11B, and 11C is
It is characterized in that a plurality of drive bodies 11A, 11B, 11C are directly connected to the contact 10 and the second contact 9, and arranged in parallel in an electric circuit formed by the first contact 10 and the second contact 9. control valve.