JPH0198787A - Passage closing gear - Google Patents

Abstract

PURPOSE:To reduce costs and frequency in a breakdown and simplify a mechanism by reducing the number of parts by opening and closing a fluid passage by only a pipe-like thermosensitive operation element made of shape memory alloy or shape memory resin. CONSTITUTION:The entrance 1 and exit 7 for fluid to be controlled are formed of a pipe-like thermosensitive operation element made of shape memory alloy or shape memory resin. A portion of the thermosensitive operation element 2 in the side of the exit 7 has a shut-off section 5 memorising the shape when closing the exit due to the shrinkage of all the circumference when the temperature of fluid to be controlled becomes higher than specified temperature. This constitution allows the fluid to be controlled of temperature lower than specified temperature to be discharged.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention uses a shape memory alloy or shape memory resin as a temperature-responsive element and utilizes its thermal deformation to open and close a flow path, thereby allowing air flow from a fluid piping system to a temperature below a predetermined temperature. The present invention relates to a channel opening/closing device that automatically discharges fluid. Discharges condensate from heating radiators, discharges low-temperature water from trace pipes that keep oil pipes warm with steam or hot water, and discharges water below a specified temperature to prevent equipment that uses steam or hot water from freezing. Used when doing something.

2. Description of the Related Art A temperature-responsive valve as an example of a conventional flow path opening/closing device using a shape memory alloy will be described with reference to FIGS. 3 to 5.

The casing parts 71, 72 form fluid passages 73, 74 and a valve 75. The valve chamber 75 is connected to the fluid passage 73 through a through hole 77 formed in a guide wall 76 of the casing member 71 and a valve lower 9 of a valve seat member 78 screwed to the casing member 72.
．． It is connected to 74. A valve element 80 is disposed within the valve element 75 so as to face the valve lower 9. A valve rod 82 is integrally formed with the valve body 80 via a collar portion 81 and is slidably guided by a guide wall 76 .

A temperature-responsive element 83 made of a shape memory alloy and formed into a coil is disposed between the guide wall 76 and the collar portion 81.

A coiled bias spring 84 is disposed between the valve seat member 78 and the collar portion 81.

As shown in FIG. 5, the temperature-responsive element 83 undergoes thermoelastic martensitic transformation from an austenite phase to a martensite phase when cooled to a predetermined temperature or lower, and undergoes the reverse transformation when heated to a predetermined temperature or higher.

It is made to elongate in the austenite phase and contract in the martensite phase.

As shown in FIG. 4, the bias spring 84 has a load and displacement in direct proportion. FIG. 3 shows a state in which the temperature of the fluid to be controlled is low, the temperature-responsive cord 83 is contracted, and the valve body 80 is listening to the valve lower 9 by the force of the bias spring 84. When the temperature of the controlled fluid increases from this state, the temperature-responsive element 83 expands against the horn of the bias spring 84, and the valve body 80 closes the valve lower 9. When the temperature of the fluid to be controlled becomes low again, the temperature-responsive rope 83 contracts and enters the state shown in FIG. 3.

Problems to be Solved by the Invention The above-mentioned conventional temperature-responsive valve operates the valve body 80 by utilizing the displacement force of the coiled shape-memory alloy temperature-responsive rope 83 that occurs as the temperature of the fluid to be controlled changes. The collar portion 81 receives the displacement force of the temperature-responsive element 83, the valve stem 82 and the guide wall 76 guide the sliding movement of the valve body 80.
, bias spring 84, etc., the number of parts increases, the structure becomes complicated, and there are problems that increase costs and increase the frequency of failures.

A technical object of the present invention is to solve the above problems by minimizing the number of parts and simplifying the structure.

Means for Solving the Problems The technical means of the present invention taken to solve the above-mentioned technical problems is to use a cylindrical tube made of a shape memory alloy or shape memory resin that undergoes reversible transformation in response to temperature changes. A pressure fluid passage is formed by a response element, and the pressure fluid passage is opened and closed only by expansion and contraction of the cylindrical temperature response element.

action The operation of the above technical means is as follows.

A cylindrical temperature-responsive element made of a shape memory alloy or shape memory resin is heated and cooled by a controlled fluid flowing through a fluid passage, and reversibly transforms and expands and contracts in response to temperature changes. By opening or closing the fluid passage only by this expansion and contraction action, fluid at a temperature below a predetermined temperature is automatically discharged.

Effect of the invention The present invention produces the following unique effects.

By opening and closing the fluid passage only with a cylindrical temperature-responsive element made of shape-memory alloy or shape-memory resin, there is no need for a separate valve body, valve port, bias spring, etc., compared to conventional temperature-responsive valves. , the number of parts is extremely small, the structure can be simplified, and costs can be reduced and failure frequency can be reduced.

Embodiment An embodiment illustrating a specific example of the above technical means will be described. (
(See Figures 1 and 2) Cylindrical temperature-responsive elements 2 and 4 made of shape memory alloy or shape memory resin are used to control the inlet 1°3 and outlet lower part of the fluid to be controlled.
form 8. When the temperature of the controlled fluid reaches a predetermined temperature or higher, the lower and 8 side parts of the temperature-responsive elements 2 and 4 contract uniformly around the entire circumference to close off the controlled fluid (see Figure 1). ), the entire circumference contracts unevenly and closes (see Figure 2)
A closure 5.6 with a memorized shape is formed. When the temperature of the controlled fluid falls below a predetermined temperature, it expands into a circular tube shape and opens the outlet lower 8 due to fluid pressure.

The shape memory alloy or shape memory resin shall be appropriately selected from conventionally known ones depending on the application and usage conditions.

In this way, a passage for the controlled fluid is formed only by the temperature-responsive cords 2 and 4, and by opening and closing the outlet lower 8, fluid at a temperature below a predetermined temperature is automatically discharged.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views of a channel opening/closing device according to an embodiment of the present invention; Figure 2 and (b) are cross-sectional views showing a state in which the flow path is closed, Figure 3 is a cross-sectional view of a temperature-responsive valve as an example of a conventional flow path opening/closing device, and Figure 4 is a cross-sectional view showing a state in which the flow path is closed. FIG. 5 is a diagram showing the characteristics of the temperature-responsive element shown in FIG. 3. 1.3: Inlet 2, 4: Temperature-responsive element 5.6: Closure part 7, 8: Exit

Claims (1)

[Claims] 1. A pressure fluid passage is formed by a cylindrical temperature-responsive element made of a shape-memory alloy or shape-memory resin that undergoes reversible transformation in response to temperature changes, and the pressure fluid passage is created only by the expansion and contraction of the cylindrical temperature-responsive element. A channel opening/closing device that opens and closes.