JPH0527168U - Piping freeze damage prevention device - Google Patents

Abstract

(57) [Summary] [Purpose] To realize a freeze damage prevention device for pipes that automatically prevents a freeze damage accident by allowing a small amount of water to automatically flow out in cold weather when there is concern about freezing of the pipe. [Structure] Main flow path 3 of main pipe section 2 provided in pipe P
A slide valve body 6 for opening and closing the drain flow passage 5 is provided in the drain flow passage 5 branched from the above, and the spring constant is rapidly increased at a transformation temperature near the freezing point while the slide valve body 6 is opposed to the opposing spring 8. The spring 9 made of a shape memory alloy, which decreases to the above, is urged in the valve body closing direction. In this way, when the outside air temperature drops near the freezing point, the valve body opening force of the opposing spring 8 overcomes the valve body closing force of the shape memory alloy spring 9 to automatically open the slide valve body 6, and a small amount from the drain flow path 5. Water is drained.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a device for preventing damage accidents due to freezing of industrial water supply pipes and domestic water supply pipes.

[0002]

[Prior art and its problems]

 For example, in plastic molding factories, there are cases in which, during cold weather, the water supply piping for supplying cooling water to the cooling water of the molding machine freezes, causing pipe damage accidents.

As a countermeasure against this, at present, a heat insulating material is wrapped around the pipe, and when it is difficult to cool the pipe, the faucet and the water flow valve are slightly opened to allow a small amount of water to flow out to prevent freezing. Not only is it labor-intensive, but the operation of opening and closing the faucet is troublesome.

The present invention eliminates such inconvenience and prevents freezing breakage of pipes by automatically allowing a small amount of water to flow out in a cold weather when freezing of pipes is feared, thereby preventing accidents of freezing breakage. A device is provided.

[0005]

[Means for Solving the Problems]

 In the freeze damage prevention device based on the present invention, as a means for achieving the above object, the drain flow path is opened and closed in a drain flow path branched from the main flow path of the main pipe section provided in the pipe. A slide valve body is provided, and this slide valve body is made to oppose the fluid pressure of the opposing spring or the main pipe part, while the spring constant of the shape memory alloy that changes the spring constant at the transformation temperature near the freezing point is used to close the valve body. Alternatively, the valve element is biased toward the opening direction.

[0006]

[Operation] In this device, a spring made of a shape memory alloy exerting a valve closing force or a valve opening force on the slide valve disc changes the spring constant at the transformation temperature near the freezing point, When the air temperature drops below the freezing point, the slide valve body can be automatically opened from the valve body closed state at room temperature.

That is, when a spring made of a shape memory alloy is applied in the valve closing direction, if a spring whose spring constant decreases at the transformation temperature near the freezing point is used, the transformation temperature is used as a branch point to close the valve. The slide valve body is automatically opened by overcoming the valve body opening force exerted by the opposing spring that counteracts the force or the fluid pressure of the main pipe section.

When a spring made of a shape memory alloy is actuated in the valve opening direction, if a spring having a characteristic that the spring constant increases at a transformation temperature near the freezing point is used, the transformation temperature is used as a branch point. The force overcomes the valve closing force exerted by the opposing spring or the fluid pressure of the main pipe that counteracts this force, and the slide valve is also automatically opened.

[0009]

【Example】

 1 and 2 show one embodiment of the present invention described above.

First, the outline of the entire device will be described. A freeze damage prevention device 1 includes a main pipe portion 2 having a main flow passage 3, a drain portion 4 having a drain flow passage 5 branched from the main flow passage 3, A slide valve body 6 that opens and closes the drain passage 5 and a valve box portion 7 that houses the slide valve body 6 together with the operating springs 8 and 9 are integrally provided. The present device 1 has screw portions 2a and 2b provided at both ends of the main pipe portion 2 screwed into an existing pipe D to connect the existing pipe D and the faucet K illustrated in FIG. Will be installed in the department.

The slide valve body 6 that opens and closes the drain flow path 5 has its tip portion orthogonal to the drain flow path 5 from the valve box portion 7 through a valve through hole 7 a provided in the valve box portion 7, and the outside air temperature is room temperature. When it is in the area, the front end surface 6A is in close contact with the valve seat portion 6a which is cut out at the inner surface facing portion of the drain passage 5 to liquid-tightly close the drain passage 5.

The slide valve body 6 is provided with two operation springs 8 and 9 that oppose each other on both sides of the base end flange portion 6B housed in the valve box portion 7 so that the drain flow path 5 is removed. It is designed to open and close automatically depending on the temperature. Here, a coil spring having a constant spring constant is incorporated in the spring 8 that biases the slide valve body 6 in the valve body opening direction, while the slide valve body 6 is biased in the valve body closing direction. The spring 9 has a relatively large spring constant that keeps the slide valve body 6 in a valve closed state by overcoming the opposing spring 8 that antagonizes at room temperature. A spring made of shape memory alloy is incorporated, which has the characteristic that the spring constant decreases sharply when the temperature decreases to 100 degrees.

If the freeze damage prevention device 1 configured as described above is provided in the middle of the pipe, the outflow treatment of a small amount of water, which is effective as a freeze prevention measure for the pipe D in cold weather, is automatically performed without human operation. Will be done.

That is, in the normal temperature range, the spring 9 made of a relatively predominant shape memory alloy keeps the slide valve body 6 in the closed state, while the outside temperature decreases to a temperature near the freezing point, the transformation temperature As a result, the spring constant of the shape memory alloy spring 9 sharply drops, and as a result, the valve body opening force exerted on the slide valve body 6 by the opposing spring 8 overcomes the valve body closing force. Like the chain line, the front end surface 6A of the slide valve body 6 is automatically opened from the valve seat portion 6a. Along with this, as shown in FIG. 2, a small amount of water W continuously flows out (drips) from the drain flow path 5 branched from the main flow path 3 of the main pipe section 2 to cause a breakage accident. It is possible to avoid complete freezing in the area. The amount of water flowing from the drain passage 5 when the valve body is opened can be adjusted by moving the adjusting screw 10 inserted into the valve box portion 7 from the side opposite to the slide valve body 6 to move the valve body opening degree. It can be adjusted by changing. Then, when the outside air temperature rises again from the temperature near the freezing point to the normal temperature range, the spring 9 made of shape memory alloy that biases the slide valve body 6 in the closing direction restores the original spring constant, and the drain flow path is restored. 5 will be automatically returned to the closed state.

As another embodiment of the freeze damage prevention device 1 according to the present invention, the springs 8 and 9 may be replaced with each other. However, when the shape memory alloy spring 9 is applied in the valve body opening direction, a spring having a characteristic opposite to the above is used. That is, in the normal temperature range, the spring constant is relatively smaller than that of the opposed spring 8, and the spring constant is rapidly increased at the transformation temperature near the freezing point to overcome the opposing valve closing force of the opposed spring 8. Is. In this case as well, the same operational effects as those shown in FIG. 1 are exhibited.

Further, the biasing means for exerting a valve body closing force or a valve body opening force on the slide valve body by antagonizing the spring made of a shape memory alloy may be replaced by the opposed spring instead of the fluid pressure of the main pipe part. Can also be used. FIG. 3 shows another embodiment having such a configuration, in which the valve seat portion 11a formed in the drain passages 5A and 5B of the drain portion 4 branched from the main passage 3 of the main pipe portion 2 is provided. Direct-acting type slide valve elements 11 are arranged so as to oppose each other, and the fluid pressure P of the main pipe portion 2 is applied to the valve element tip end surface 11A to exert a valve element opening force on the slide valve element 11, while fluid is applied to the valve element rear surface side. A spring 9 made of a shape memory alloy intervenes the slide valve body 11 in the valve body closing direction by antagonizing the valve body opening force by the pressure P.

In the case of this embodiment, the spring 9 made of a shape memory alloy is overcome by the opening force of the valve body due to the fluid pressure P in the normal temperature range to keep the slide valve body 11 in the closed state, so that at the transition temperature near the freezing point. If a valve with a characteristic that rapidly reduces the spring constant is used, when the outside air temperature drops to a temperature near the freezing point, the slide valve body 11 is automatically opened as shown by the chain double-dashed line in the figure. Freezing prevention measures will be automatically executed to continuously discharge a small amount of water from 5B.

[0018]

As described above, if the freeze damage prevention device of the present invention is interposed in the pipe, the slide valve body is attached in the valve body closing direction or the valve body opening direction in cold weather when there is a fear of freezing of the pipe. As the spring constant of the energizing shape memory alloy spring changes near the freezing point, the slide valve element is automatically opened, and a small amount of water continuously flows out from the drain flow path. The measures required to prevent freeze damage accidents will be carried out in the maintenance free without human intervention.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a freeze damage prevention device showing an embodiment.

FIG. 2 is a side view showing a pipe connection use state of the freeze damage prevention device of FIG.

FIG. 3 is a cross-sectional view of the essential parts of a freeze damage prevention device showing another embodiment.

[Explanation of symbols]

 D Piping K Faucet 1 Freeze breakage prevention device 2 Main pipe part 2a, 2b Screw part 3 Main flow path 4 Drain part 5 Drain flow path 5A, 5B Drain flow path 6 Slide valve body 6a Valve seat part 6A Tip surface 6B Base flange part 7 Valve Box 7a Valve Through Hole 8 Opposed Spring 9 Shape Memory Alloy Spring 10 Adjustment Screw 11 Slide Valve Body 11a Valve Seat 11A Tip Surface P Fluid Pressure W Water

Claims (1)

[Scope of utility model registration request] 1. A slide valve body for opening and closing the drain flow path is provided in a drain flow path branched from a main flow path of a main pipe section provided in a pipe, and the slide valve body is provided with an opposing spring or a main pipe section. Device for preventing freezing damage of a pipe, characterized in that a spring made of a shape memory alloy that changes its spring constant at the transformation temperature near the freezing point is urged in the valve body closing direction or the valve body opening direction while competing with the fluid pressure of ..