JPS6065980A - Valve device - Google Patents

Abstract

PURPOSE:To make it possible to simply and surely vary the area of a flow passage, by providing a coil spring made of shape memory alloy in a valve device body so that the coil spring is elongated and contracted in association with variations in the temperature of fluid so that the gap areas between the coil wire pitches are changed. CONSTITUTION:A coil spring 4 made of shape memory alloy having its coil wire pitches which are closely made into contact together upon a low temperature operation is disposed in a valve device body in a stepped pipe shape having a fluid inlet 2 and a fluid outlet 3 at both ends thereof, and is jointed at one end to the stepped inner surface of the body 1, and at the other end to an end plate 5. Further, the coil spring 4 is elongated or contracted in association with changed in the temperature so that the gap areas between the coil wire pitches are enlarged or narrowed to change the flow passage area of flow. With this arrangement, since the coil spring 4 is used as a main valve 4, the structure of the valve device may be simplified and as well the response of the valve operation may be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a valve device whose flow path area changes depending on the temperature of a fluid.

Conventional Structure and Problems Conventionally, a valve device constructed using a shape memory alloy as shown in FIG. 1 has been proposed. In this conventional device, when the coil spring 26 made of a shape memory alloy expands and contracts by sensing the temperature of the fluid, the injection nozzle connected thereto 20 to change the flow path area between the taper adjustment needle 14 and the injection nozzle 20. In this case, the coil spring 26 made of a shape memory alloy is used as a driving source for changing the flow path area of the valve device, and therefore the number of parts of the valve device increases and the structure It has the disadvantage that it is complicated.

Technical Problem of the Invention The present invention has been made in view of the drawbacks of the conventional example, and
The purpose of this invention is to obtain a valve device with a simple structure and low cost by using a coil spring made of a shape memory alloy not as a driving source of the valve device but as a valve body.

Technical Means of the Invention In order to achieve the above object, the present invention provides a valve device main body having a fluid inlet and a fluid outlet with a coil spring made of a shape memory alloy, and one end of the coil spring is a free end. The other end is a fixed end, the free end is sealed, and the open other end of the coil spring is connected to the fluid outlet or outlet. Effect of the Invention With this configuration, the shape memory alloy can be used as a material. The flow path is between the adjacent wires of the coil spring, and the area of this flow path is automatically varied depending on the fluid temperature. Also, by using the coil spring as the valve body, the structure is simple and inexpensive. DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 2 shows a valve device according to an embodiment of the present invention, in which "a" shows the state when the fluid temperature is low, and "b" shows the state when the fluid temperature is high. Figure 3 shows
It is a figure which shows operation|movement of the said valve apparatus.

In Fig. 2, reference numeral 1 denotes a stepped tubular valve device body having a fluid inlet or outlet 2 and a fluid outlet or inlet 3 at both ends. There is a coil spring 4 made of a shape memory alloy, one end of which is connected to the inner surface of the stepped part of the valve device main body 1, and the other end is connected to the end plate 5 by appropriate means such as welding or adhesive. The coil spring 4 has a fixed end and a free end.

Here, the coil spring 4 is a shape memory alloy that exhibits so-called two-way movement, and at high temperatures the shape of the spring is as shown in FIG. 2, that is, the length of the spring is 12. At low temperatures, the spring is pre-memorized to have the shape shown in FIG. 2(a), that is, the length of the spring is 11. This shape change occurs rapidly in a certain temperature range, and the shape change temperature range can be adjusted by the composition of the shape memory alloy or heat treatment.

In the above configuration, the point that the coil spring 4 performs the valve operation will be explained with reference to FIG. 3.

If the coil spring 4 is set so that its shape changes between temperatures T1 and T2, when the temperature T of the fluid flowing through the valve device body 1 is lower than the set temperature T1, the change in shape will occur as shown in Fig. 2 (a). The length of the coil spring 4 is 11, and the gap area between adjacent strands is A1.

On the other hand, when the fluid temperature T is higher than the set temperature T2, 5
As shown in FIG. 2(b) on page 2, the length of the coil spring 4 increases to 12, and at this time, the gap area between adjacent strands also increases to A2 (A2>A1). As a result, the flow rate can be controlled.

Effects of Example The present valve device has a coil spring 4 made of a shape memory alloy.
The change in the open area of the strands due to the expansion and contraction of the valve is considered to be the change in the flow path area of the valve device.The coil spring 4 is not used as the drive source of the valve device, but is used as the valve body, thereby increasing the valve speed. The structure of the device can be simplified.

In addition, in the valve device of this embodiment, when the fluid temperature becomes high, the length of the coil spring 4 is increased and the flow path area is increased. It is also possible to perform control such that the flow path area increases as the fluid temperature decreases.

(It is possible to completely close the flow path by bringing the strands into close contact with each other and reducing the gap area between the strands to zero when the coil contracts.0 Page 6 Effects of the Invention From the above embodiments As is clear, in the valve device of the present invention, a coil spring made of a shape memory alloy is provided in a valve device main body having a fluid inlet and a fluid outlet, and one end of the coil spring is a free end and the other end is a fixed end. At the same time, the free end is sealed, and the other open end of the coil spring is connected to the fluid inlet or outlet, and the valve body itself senses the fluid temperature and automatically starts the flow when the temperature exceeds or falls below the set temperature. Since the channel area is variable, the response is good.Furthermore, since the channel is between adjacent strands of the coil spring, even if a large change in channel area is obtained, the coil spring will not change easily. The amount of shear strain required is small, and therefore the coil spring has a long cycle life, and exhibits excellent effects.

[Brief explanation of the drawing]

Figure 1 is a sectional view of a conventional valve device, Figure 2 (a), Φ)7
Beno is a sectional view of a valve device showing one embodiment of the present invention, and FIG. 3 is a characteristic diagram showing the operation of the same valve device. 1...Valve device body, 2...Fluid inlet (
Outlet), 3...Fluid outlet (inlet), 4...
・Coil spring, 5...End plate. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2

Claims (1)

[Claims] A coil spring made of a shape memory alloy is provided in a valve device body having a fluid inlet and a fluid outlet, one end of the coil spring is a free end and the other end is a fixed end, and the free end is sealed. A valve device in which the other open end of the coil spring is connected to the fluid inlet or outlet.