JPS6037474A - Control valve - Google Patents

Abstract

PURPOSE:To improve the opening and closing characteristics of a valve by controlling a driving body made by a shape memorizing alloy in accordance with the temperature change of a fluid supplied to a fluid action chamber. CONSTITUTION:A coil-like driving body 3 made by a shape memorizing alloy is arranged on the outer periphery of an operating body 1 and between an upper surface 2A of an retaining base 2 and a frange 1A of the operating body 1. On the other hand, a coil spring 4 which provides a bypass force for the driving body 3 is compressedly arranged between a bottom surface 2B of the retaining base 2 and a frange 1B of the operating body 1. When a hot fluid passage 7 is opened and a hot fluid flows into a fluid action chamber 5, the driving body 3 moves upward opposing the force of the spring 4, which detaches a valve body 12 from its valve seat and opens a fluid passage 10.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control valve that controls the opening of a valve seat by utilizing displacement due to temperature changes in a driving body made of a shape memory alloy. This method utilizes the phenomenon that occurs when the low-temperature phase generated in The structure changes to martensitic structure. When this shape memory alloy is cooled from the high temperature side, a transformation occurs from an austenite structure to a martensitic structure, and it has superelasticity.1. Conversely, when heated from the low temperature side, the martensite structure transforms into an austenite structure and returns to the shape memorized in the forming process. Part 1. Known alloys that exhibit such a shape memory effect include nickel-titanium, copper-aluminum-nickel, and copper-aluminum.

The control valve of the present invention uses the displacement of a shape memory alloy to open and close the valve seat, and the object is to obtain a control valve with particularly excellent opening and closing dynamic characteristics. An embodiment of the actuating device will be described with reference to FIG. 1. Reference numeral 01 is an operating body that is inserted into the holding base 2 and is disposed so as to be movable in the vertical direction of the holding base 2, and has a flange IA at each end.

◎ At the outer periphery of the operating body 1 and on the upper surface 2 of the holding table 2
Between the person and the flange IA of the operating body 1, there is a coil-shaped driving body 3 made of a shape memory alloy, such as the one in this embodiment.
A bias member 4 such as a coil spring is arranged between the lower surface 2B of the holding base 2 and the flange part IB of the operating body 1. Also, a bias member 4 such as a coil spring for imparting a bias bias to the drive body 3 is arranged. has a sealed fluid action chamber 5 surrounding it.
is arranged, and a fluid inflow path 5A and a fluid outflow path 5B are opened in the fluid action chamber.

The fluid inflow path 5A is connected to the pure mixed flow path 7 and the cold flow path 8 via the switching valve 6. On the other hand, a flow path 10 passes through the inside of the fluid inflow path 9, and a valve is connected to the flow path 10 in the middle thereof. It is a valve body in which a seat 11 is arranged, 12 is fitted into the flange part IB of the operating body 1,
This is a valve body disposed corresponding to the valve seat 11.

Next, its effect will be explained.

First, when the switching valve 6 is closed and fluid is not supplied into the fluid action chamber 5 from either the wet or cold channels 7 and 8, the drive body 3 made of a shape memory alloy is not heated and is in a cold state. Since the driving body 3 is in a superelastic state and does not generate any stretching force (3), the operating body 1 is pressed downward by the pulley member 4. Therefore, the valve body 12 closes and holds the valve seat 11 by the pressing force of the bias member 4, and the flow path 10
is blocked. Next, when the switching valve 6 is operated to open the hot flow path 7 and the heated fluid flows into the fluid action chamber 5 from the fluid inflow path 5A, the temperature of the driving body 3 is increased by the heat of this fluid. When the temperature rises to the reverse transformation temperature, the driving body 3 moves upward in the figure against the bias member 4's bias force.
Therefore, the valve body 12 is separated from the valve seat 11 to open the flow path 10. When the valve body 12 is driven, the outer periphery of the drive body 3 is surrounded by the fluid action chamber 5, Since the heated fluid is allowed to flow in, the volume of the fluid action chamber 5 can be kept at an appropriate constant value, and thereby the displacement speed of the driving body 3 can be freely set, that is, the opening operation of the valve body 12 can be adjusted. It should be possible to freely select the characteristics and be able to reliably prevent the occurrence of water hammer, etc.
Next, in order to change the valve body 12 from the open state to the closed state (14), the switching valve 6 is operated again to shut off the hot body flow path 7, and
The cold flow path 8 is opened to allow the cooled fluid to flow into the fluid action chamber 5 from the fluid inflow path 5A. When the driving body 3 is cooled, the extension force of the driving body 3 gradually decreases, and the bias member 4 causes the operating body 1 to move downward in the figure. Therefore, the valve body 12 is 0, which keeps the valve seat 11 closed, and even when the valve is closed, 91 circumferences of the driver 3 are surrounded by the fluid operation chamber 5, and the volume of the chamber can be limited, so that the fluid can flow in from the 5 fluid inflow channels. The cooling performance of the driving body 3 by the cooled fluid can be accelerated, and the closing movement characteristics of the valve body can be improved.In addition, if cooling fins are provided on the outer periphery of the fluid action chamber, the closing movement of the valve body can be further improved. As described above, the control valve of the present invention has a driving body made of a shape memory alloy that operates the operating body, a bias member that imparts a bias to the driving body, and a fluid that surrounds the driving body. Since the control valve is formed by the action chamber and the valve body that opens and closes the valve seat by the movement of the operating body, heating and cooling effects on the drive body can be enhanced by appropriately selecting the volume of the fluid action chamber. A control valve with excellent opening/closing dynamic characteristics of the valve body can be obtained.

[Brief explanation of the drawing]

The figure is a longitudinal cross-sectional view showing an embodiment of a control valve using a shape memory alloy according to the present invention. 5
... Fluid action chamber, 11... Valve seat, 12... Valve body Patent applicant: Keihin Seiki Seisakusho Co., Ltd.

Claims (1)

[Claims] A movably arranged operating body, a driving body made of a shape memory alloy that operates the operating body, a bias member that imparts a bias bias to the driving body, a fluid action chamber surrounding the driving body, and a driving body that operates the operating body. A control valve that has a valve body that opens and closes a valve seat provided in a flow path by movement, and controls the opening and closing of the valve seat by operating a driving body according to changes in the temperature of the fluid supplied into the fluid action chamber.