JPS61266892A - Thermosensing type automatic shut-off valve - Google Patents

Abstract

PURPOSE:To provide a thermosensing type automatic shut-off valve having an extremely simple structure, by utilizing the shape change of a spring made of shape memory alloy due to a temperature change, in order to move a valve element alone. CONSTITUTION:A slidable valve element 5 is fitted on a core shaft 3 secured in the inside of a cylindrical frame 1 made of arbitrary materials in an arbitrary shape, and a coil spring-like memory shape alloy spring 7 and a bias spring 8 is set being opposed to each other through the intermediary of the slidable valve element 5. When the temperature of a tank A is 30 deg. C, the shape memory alloy spring 7 is depressed by the bias spring 8 to be in its compressed condition so that the valve element 5 is made in close contact with a valve seat 4 to isolate the tank A from a tank B. When the temperature of the tank A exceeds 50 deg. C, The shape memory alloy spring 7 is to return its original memorized shape so that it expands to press the bias spring 8.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device that uses a shape memory alloy spring to open and close a valve.

When the temperature of a gas or liquid fluid delivered to a pipe changes, or when the temperature of a liquid in a storage tank changes, etc., a valve can be used to bypass, stop, or reverse the flow. There are times when it becomes necessary to distribute the product.

Conventionally, in such cases, the valves were opened and closed by linking sensors and motors, but this required external inputs such as electricity and hydraulic pressure, and problems remained with maintenance. .

Therefore, the present invention automatically opens and closes the valve by using a shape memory alloy spring that undergoes phase transformation and changes shape such as expansion, contraction, and deflection due to temperature changes. It is something that is meant to be reprimanded.

FIG. 2 is a cross-sectional view when it is in the open state.

FIG. 3 is a sectional view of a modified temperature-sensitive automatic on-off valve in which the cylindrical frame of the bias spring portion is omitted.

Based on FIG. 1 and FIG. 2, to explain the main groove bottoms, the cylindrical frame 1 is a cylindrical shape of any shape such as a cylinder or a prismatic shape, and can be made of iron, aluminum, or branutic.

It is made of ceramic or the like, and both ends of a cylinder frame 1 are closed with lids 2, and eight shafts 3 are fixed to the center of the cylinder frame 1.

A coil spring-like shape memory alloy spring 7 is placed between the valve body 5 and the lid 2 with a washer 6 in between, and a washer 6 is placed between the valve body 5 and the lid 2' to oppose it. Install the bias spring 8 between the two.

The operating temperature of the shape memory alloy spring 7 is finely adjusted depending on the thickness of the washer 6.

A screw thread or a flange 9 is installed on the outside of the cylinder frame 1 corresponding to the valve seat 4, and an arbitrary number of windows 10 and 10' of an appropriate size are opened on both sides of the flange 9 as a boundary.

The modified temperature-sensitive automatic on-off valve shown in Fig. 3 is obtained by omitting the cylindrical frame 1 of the bias spring 8 in Fig. 1 and Fig. 2.
Conversely, it can be said that the window lO' is expanded to its maximum limit.Therefore, the valve seat 4 is not necessarily necessary, and the edge frame of the cylinder frame 1 itself plays the role of the valve seat 4. However, the valve body 5 operates to open and close it.

The 8-shaft 3 is immovably fixed to the lid 2, and the other end 11 of the 8-shaft 3
A clasp 12 such as a nut is fixed to the clasp 12.

A coil spring-like shape memory alloy spring 7 is placed between the valve body 5 and the lid 2 with a washer 6 in between, and a washer is placed between the valve body 5 and the clasp 12 to oppose it. Install bias spring 8 by sandwiching 6.

The coil spring shape memory alloy spring 7 used here may be unidirectional or bidirectional.

Further, either a compression type or a tension type spring may be used.

However, when using the tension type coil spring-like shape memory alloy spring 7, the core shaft 3tIi is unnecessary, so
There is no need for a hole in the valve body 5 for the 8-shaft 3 to pass through, but it is necessary to provide a fulcrum on the valve body 5 and lids 2 and 2' to hook the spring hook. This is because the diameter of the cylinder frame 1 is small. This is an effective method in some cases.

As described above, this temperature-sensitive automatic on-off valve has eight shafts 3 fixed inside a cylinder frame 1 of arbitrary shape and material, and eight
A valve body 5 that is slidable on the shaft 3 is placed, and a coil spring-like shape memory alloy spring 7 and a bias spring 8 are installed so as to oppose each other around the valve body 5. This is a temperature-sensitive automatic opening/closing valve that senses temperature and opens and closes the valve.

The operation of the temperature-sensitive automatic on-off valve having the groove bottom described above is as follows.

- As an example, one or more temperature-sensitive automatic on-off valves are installed on a partition plate by the flange 9, and a chive tank, tank A, filled with water with the partition plate as a boundary.・B
Figures 1 and 2 are based on the assumption that when a tank is formed and the temperature rises above 50°C in test A, the valve will be opened to allow high temperature water to flow into test B. I will explain it first.

The shape memory alloy spring 7 used here is a unidirectional coil spring based on nickel titanium.

To simplify the explanation, the operating characteristics of the shape memory alloy spring 7 are that it is soft below 50°C and has a low yield stress, so it is pushed by the tension force of the opposing bias spring 8 and is in a net state as shown in Fig. 1. In this state, when the temperature exceeds 50° C., it tries to restore to its original memorized shape and expands, compressing the bias spring 8, resulting in the state shown in FIG. 2. That is, it is assumed that the stroke operation of expansion and contraction is simply performed using 50'C as a boundary.

Now, if the A measurement is 30°C, the shape memory alloy spring 7 is pushed by the bias spring 8 into a net state as shown in Figure 1, and the valve body 5 is in close contact with the valve seat 4. Therefore, the A inspection and B inspection are cut off.

When the temperature rises to 50 degrees Celsius or higher during A test, the shape memory alloy spring 7 tries to restore its original shape.
As shown in FIG. 2, the bias spring 8 is compressed and becomes an expanded state.

Therefore, the valve body 5 is pushed up and the valve seat 4 is 1″3 An open gap 2 is formed at u[, resulting in an open state as shown in Fig. 2.

Since an arbitrary number of windows 10 and 10' are opened in the cylinder frame l with the flange 9 as the boundary for both A and B inspections, these windows 10 and 10' and the valve body 5 are connected to each other. Between valve seat 4 and V
Thermal fluid is circulated between the A tank and the B type through the a seal.

When the temperature of tank A drops below 50°C, the shape becomes closed as shown in Figure 1, and the flow of thermal fluid between tank A and type B is cut off.

As mentioned above, this temperature-sensitive automatic opening/closing valve is characterized by utilizing the change in shape of the shape memory alloy spring due to temperature changes to move only the valve body to open and close the valve. Yes, it is extremely easy to make grooves.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the temperature-sensitive automatic on-off valve in the closed state of the present invention. Figure 2 is a cross-sectional view in the open state. FIG. 3 is a sectional view of a modified temperature-sensitive automatic on-off valve.

Claims (1)

[Claims] A mandrel is fixed inside a cylindrical frame of arbitrary shape and material, a valve body that can slide on the mandrel is placed, and a coiled shape memory alloy spring and a bias spring are opposed to each other around the valve body. A temperature-sensitive automatic opening/closing valve that senses temperature changes and opens and closes the valve.