JPS6018875B2 - temperature sensitive valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a temperature sensitive valve that automatically opens and closes a fluid passage in response to the temperature of the fluid.

Traditionally, valves have been used to stop or increase the flow of water. In addition, electromagnetic valves are usually used in order to increase the deviation of the opening and closing parts. However, since electromagnetic valves use the magnetic force created by electricity to drive the valve, they require electrical wiring when used, and if installed directly in water, the electrical circuit and wiring parts are waterproof. However, there are problems in that it is complicated and the equipment is expensive. On the other hand, if a means such as an electromagnetic valve is not used, there is a method of configuring it using bimetal, but bimetal has disadvantages such as not being able to obtain the desired performance because the amount of deviation due to temperature is small and the force is also small. there were. The purpose of the present invention is to provide a completely new temperature-sensitive valve with a simple structure and reliable operation that responds to the temperature of water and automatically opens and closes the flow of water without requiring energy from other sources such as electricity. Our goal is to provide the following.

Shape memory alloys are materials that can produce large deviations due to temperature changes. Shape memory alloys have the unique property of forming a shape in a high-temperature matrix, deforming in the martensitic transformation temperature range of 150 OO or less, and returning to the original shape when the temperature of the matrix is returned again. Also, for the same amount of strain, the tensile strength of the material in the martensitic transformation state is approximately 1/3 of that in the matrix state.
By roughly fitting it with a normal spring, it is possible to construct a temperature sensing device that can automatically deflect the valve as the temperature rises or falls. Shape memory property is a unique property that appears in Ti-Ni alloys with Nj of 49 to 51%, Cu-AI-Nj alloys, Cu-Zn-AI alloys, etc., but its origin has not been elucidated in detail, and Although it is known in the literature that shape memory alloys and conventional springs can be combined to form devices that operate due to changes in temperature, the details of how and by what means are not currently clear. Examples will be described below with reference to the drawings. FIG. 1 is an external view of an embodiment of a temperature-sensitive valve according to the present invention.

The threaded part on the right side is connected to another mechanism so that fluid such as water flowing in from the right end inlet through the valve flows out from the outflow hole 11 on the circumferential surface of the cover body 1. The fluid flow may be in the opposite direction. The internal foundations of this temperature sensitive valve are shown in FIGS. 2 and 3. First, in FIG. 2, a screw for attaching to another structure is provided on the outer circumferential surface of the portion of the temperature-sensitive valve body 1 that will become the water intake port 12.

The housing 1 is preferably made of a non-magnetic material such as an aluminum alloy, an aluminum-zinc alloy, or a resin. Intake port 12 of body 1
A permanent magnet 2, which serves as a valve seat, is installed and fixed near the valve seat. This permanent magnet 2 may be a rubber magnet, a barium ferrite magnet, an alnico magnet, or a rare magnet, and the magnetic poles are magnetized in all directions, or so that N and S poles occur in the plane. There is. The center of the permanent magnet 2 is hollow so that water can pass through it. Inside the body 1, a valve 4 made of a temperature-sensitive magnetic material is further provided so as to be movable in the direction of the ball.

When the temperature is below the Curie point, this valve 4 is attracted to the permanent magnet 2 as shown in Figure 2, and its surfaces come into close contact to stop the flow of fluid, but when it is separated from the permanent magnet 2 as shown in Figure 3. The outflow hole 11 is passed through the inlet 12 to allow passage of fluid. In order to improve the close contact between the surfaces of the permanent magnet 2 and the valve 4, a ring-shaped packing 3 made of rubber, cloth, resin, etc. is adhered to the surface of the magnet 2. The temperature-sensitive magnetic material forming the valve 4 is selected so that its magnetic transformation point (Curie point) approximately coincides with the opening/closing set temperature of the temperature-sensitive valve. Temperature-sensitive magnetic materials include metal oxide ferrite temperature-sensitive magnetic materials and Fe-Ni-Cr-based metal temperature-sensitive magnetic materials, but metal temperature-sensitive magnetic materials are preferred here. Further, inside the cover body 1, a temperature sensing element is provided which contracts and expands in response to temperature.

The temperature sensing element is composed of three tension springs 5 made by shaping shape memory alloy strips into a corrugated shape and three compression springs 6 made of a normal spring material. As is clear from FIG. 2b, these springs 5, 6 are comprised of shape memory alloy springs 5 and regular springs 6 which are alternately and symmetrically arranged next to each other. Assuming that the strength of the shape memory alloy spring 5 is Tw and the strength of the normal spring 6 is TN, when the temperature is high and the shape memory alloy is in the matrix state, the sensitive element contracts and the 3
In the state shown in the figure, the relationship is TN>TN. Next, when the temperature drops and the shape memory alloy enters the martensitic transformation region, the tensile strength of the shape memory alloy spring 5 decreases, and the force of the spring 6 usually prevails, and the temperature sensing element usually expands due to the spring pressure of the spring 6. do. In this case, the force of each spring is T
M<TN. In this way, as the temperature rises and falls, the forces of the shape memory alloy spring 5 and the normal spring 6 become opposite to each other.

Even in that case, the shape memory alloy spring 5 and the regular spring 6 are placed in symmetrical positions so that the shape memory alloy spring 5 and the regular spring 6 can provide an average force as a temperature sensing element. Must be placed alternately. Therefore, in order to constitute one temperature sensing element, at least two or more combinations of shape memory alloy springs 5 and normal springs 6 are required. Next, to explain the operation of this temperature-sensitive valve, in Fig. 2,
It is assumed that the temperature-sensitive valve is in a low temperature state.

Now, when water whose temperature has risen enters through the intake port 12 and boils, and the valve 4 exceeds the Curie point, the valve 4 made of temperature-sensitive magnetic material, which was previously strongly attracted by the permanent magnet 2, loses its attraction force. Because of this, it is pushed by water pressure and moves. Then, the heated water flows into the valve and floods the spring 5 of the temperature sensing element, so the shape memory alloy changes from the martensitic state to the matrix, and the temperature sensing element suddenly changes as shown in Figure 3. The water then passes through the valve and rapidly flows out from the outflow hole 11. Next, when the temperature of the flowing water drops, the shape memory alloy spring 5 of the overflow sensitive element becomes martensitic, so
TN>TM, and the force of spring 6 usually prevails in the temperature sensing element.
Stretch. On the other hand, the temperature-sensitive magnetic material constituting the valve 4 has a temperature below the Curie point, so it becomes magnetic, and when the temperature-sensitive element approaches the permanent magnet 2 due to extension, a magnetic path is formed between it and the permanent magnet 2, and the temperature suddenly increases. It is attracted to the magnetic surface and blocks the flow of water. Note that a temperature-sensitive magnetic material may be used in place of the permanent magnet 2 forming the valve seat, and the valve 4 may be formed of a permanent magnet material.

Moreover, it is of course possible to change the number of springs 5 and 6. As described above, according to the temperature-sensitive valve of the present invention, no power is required from other sources to drive the valve, the amount of deviation of the valve is increased, and a large valve closing force can be obtained. It is reliable, horizontal construction is simple, it can be provided at low cost, and it is industrially useful.

[Brief explanation of the drawing]

FIG. 1 is an external view of an embodiment of a temperature-sensitive valve according to the present invention;
FIG. 2a is a longitudinal cross-sectional view of the same embodiment at low temperature, FIG. 2b is a left side view, and FIG. 3 is a longitudinal cross-sectional view of the same embodiment at high temperature. 1... Goodbye body, 2... Permanent magnet, 3...
...Packing, 4...Valve, 5...Shape memory alloy spring, 6...Normal spring. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1. A housing that constitutes a fluid passage, a valve seat provided in the housing, a movable valve facing the valve seat, and a shape memory alloy that is made of a shape memory alloy, and the valve is a first spring built in so as to pull the valve away from the valve seat, and a spring made of ordinary spring material, so as to bring the valve closer to the valve seat at a temperature below the martensitic transformation point of the first spring. a second spring incorporated therein, a permanent magnet is used for one of the valve seat and the valve, and a temperature-sensitive magnetic material is used for the other; A temperature-sensitive valve characterized in that the temperature-sensitive bulb is selected and configured so that the Curie point of a thermomagnetic material is almost the same as that of the Curie point.