JPS59110979A - Control valve - Google Patents

Abstract

PURPOSE:To obtain a control valve with a good response characteristic, by electrically connecting in parallel plural driving units made of shape memory alloy. CONSTITUTION:If the first contact 5A and the second contact 5B are electrified, an electric current, flowing in each driving unit 4A, 4B, 4C from the contacts, causes the driving unit itself to generate Joule heat and perform self heating. In this way, the driving units 4A, 4B, 4C start to extend as a temperature of each driving unit 4A, 4B, 4C rises from a reverse transformation start point and complete extension as the temperature further rises to reach a reverse transformation end point. A movable unit 2 is displaced upward against tension of a spring 9 by extension deformation of each driving unit, holding the second position.

Description

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

Shape memory alloys utilize the phenomenon that occurs when the low-temperature phase deformation caused by thermoelastic martensitic transformation is reversely transformed to a high-temperature phase by heating. It changes to an austenite structure on the high temperature side, and changes to a martensitic structure on the low temperature side. 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 austenitic structure, which leads to the formation process. It returns to the memorized shape. Nickel-titanium, copper-aluminum-nickel, copper-aluminum, etc. are known as alloys that exhibit such a shape memory effect, and the valve hole is opened and closed by the displacement of these shape memory alloys due to temperature changes. The ones are published in Utility Model Application Publication No. 56-56969 and Japanese Patent Application Publication No. 57-2.
It is known from Publication No. 5572, etc.

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 flowing down the valve body. Therefore, it is essential to change the temperature of the control fluid, and it is unsuitable for those in which such temperature changes cannot be obtained, and is therefore unsuitable for use in wide control valves.

Furthermore, Japanese Patent Laid-Open No. 57-25572 discloses a structure in which the opening and closing of the valve hole is controlled by directly heating a valve driving element made of a shape memory alloy with a heater. In the winding structure, it is necessary to place an insulating film to insulate the heater and these elements, which makes efficient heating difficult and has problems with valve responsiveness.

The control valve using the shape memory alloy of the present invention was created in view of the above-mentioned problems, and it heats the driving body that drives the valve body directly and electrically without heating it by the environmental temperature of the control fluid etc. It can be widely used as a control valve, and it is also possible to obtain a control valve that opens and closes the valve by directly heating the driver with a heater. The goal is to obtain a good control valve.

Hereinafter, one embodiment of the control valve according to the present invention will be described with reference to FIG. This is a fixed part that is fixed to the end of the valve body, etc., which will be described later.The movable part 2 is fully arranged with a gap (L) relative to the fixed part 1, and the fixed part 1 and the movable part 2 are connected to the guide rod. 3, and the movable part is engaged with three upper flange portions of the guide rod 3. Further, a valve element 7 for controlling the opening and closing of a valve hole 6 provided in a flow path 5 passing through the valve body 4 is arranged at the end of the guide rod 3, and one end thereof is engaged with the fixed part IK in the gap (L). Spring-like driving bodies 4A, 4B, and 40 (a plurality of pieces) made of a shape memory alloy whose other ends are engaged with the movable part 2 are arranged; The five first contacts connected to the power source are connected in parallel with the second contact 5B (disposed on 5B and the fixed part 1) connected to the power source, and the circuit is shown in FIG. 2.

Next, to describe its operation, drive body 4A + 4B
, 40 are de-energized, the driving bodies 4A, 4B
Since no heat is generated in , 4C, the driving bodies 4A, 4
B, 40 does not rise to the reverse transformation temperature (As point), so the driving body is kept in a contracted state,
The movable part 2 as an operating body is arranged at a low position as shown by the solid line in the figure and is maintained at a first position. In this state, compared to the tension of the driving bodies 4A, 4B, and 40, the valve body 7
By setting the tension of the spring 9 contracted at the upper part of the guide rod 3 to be large, the guide rod 3 including the valve body 7 is pressed downward, and the valve body 7 closes the valve hole 6 and keeps the flow path 5 in a blocked state. It is something.

Next, when the first contact 5A and the second contact 5B are energized, current flows from the contact to each driving body 4A, 4B, 40, and according to this, the driving body itself generates a jet and heats itself. As the temperature of the bodies 4A, 4B, and 40 rises above the reverse transformation starting point (As), the driving bodies 4A, 4B, and 4C begin to expand, and the temperature rise further reaches the reverse transformation end point (Af point) and expands. is completed, and the spring 9 is
The movable body 2 is displaced upward against the springing force and held at the second position indicated by the dotted line in the figure.In this example, the temperature decreases at the martensitic transformation starting point (MS point). Then, the driving body 3 is contracted and deformed, and on the other hand, as the temperature rises, it is expanded and deformed at the reverse transformation starting point (As point), but when this deformation is reversed and the temperature decreases at the martensitic transformation starting point (Ms point), the driving body 3 may be stretched and deformed.

As described above, according to the control valve using a drive body made of a shape memory alloy according to the present invention, a plurality of drive bodies made of a shape memory alloy are electrically arranged in parallel, and a current is passed directly to the drive body. Therefore, the drive body itself can generate heat, with little heat loss and uniform heating throughout the drive body.It has excellent heating characteristics and can be widely used as a drive body for all kinds of products. Furthermore, since multiple driving bodies are arranged in parallel, if multiple driving bodies are arranged on the same plane, the driving force will be the sum of the driving forces of each driving body, increasing the driving force. The operating load caused by the body can be easily set, and a control valve that can respond to changes in the pressure of the fluid flowing through the flow path 5 can be easily provided.

Furthermore, if the reverse transformation temperatures of the driving bodies 4A, 4B, and 40 are different, the driving bodies will operate in a stepwise manner as the temperature rises over time when electricity is applied; can be controlled in a stepwise manner, providing a multi-stage control valve. In this embodiment, the shape of the driving body is spring-like, but the shape is not limited to this shape in any way.

[Brief explanation of drawings]

Figure 1 is a longitudinal sectional view showing one embodiment of the control valve according to the present invention, and Figure 2 is a wiring diagram of the driving body. 1... Fixed part 2... Movable part 3... Guide rods 4A, 4B, 40... Drive body 5...
・Flow path 6... Valve hole 7... Valve body

Claims (1)

[Claims] A plurality of driving bodies 4A, 4B, . . . made of shape memory alloy are arranged between the fixed part 1 and the movable part 2, and the driving bodies are electrically connected Connect in parallel, drive body 4A. The driving body itself is made to generate heat by passing through to 4B, . . ., and the four driving members, 4B, .
A control valve 0 in which a valve hole 6 is controlled by a valve body 7 that moves according to the displacement of