JP2004092877A - Intake valve for hot water - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an intake valve for hot water, in which water does not remain in piping and the possibility of water leakage is prevented. <P>SOLUTION: A shape memory alloy spring 5 having a transformation point in a constant water temperature area is used for pressing a valve element 3. When constant negative pressure is generated in a pipe, a closed state of the valve is kept at a temperature of the transformation point or higher, and on the other hand, the valve is opened at a temperature of the transformation point or lower. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an intake valve that is connected in the middle of a water supply pipe in a cold region and introduces air into the pipe at the time of drainage to smoothly drain water, and is particularly used at a low pressure. The present invention relates to an improvement of a hot water intake valve, which often causes water leakage.
[0002]
[Prior art]
Conventionally, in a cold region, when draining water in a pipe, it is not necessary to open a faucet, or in the case of a so-called portal pipe having upper and lower bent portions, so that water and hot water can be completely drained. Therefore, it is common practice to attach an intake valve in the middle of the pipe. However, in the case of an intake valve in a hot water pipe, the pressure supplied from the water heater is often low, and when the intake valve is attached near the falling pipe, when the hot water flows, the falling pipe pressure becomes negative pressure. As a result, an unstable state in which the intake valve opened and closed was likely to occur.
[0003]
Of course, a large negative pressure is not generated, but since the intake valve is opened with a small negative pressure to minimize the residual water in the pipe, especially when connected sideways to the pipe, This can easily lead to water leaks, and even if the valve is connected vertically, frequent opening and closing of the valve can cause rust or other foreign matter in the pipe to get caught in the valve body of the intake valve and cause water leakage. But often.
[0004]
[Problems to be solved by the invention]
The present invention has been filed in order to solve the above-described problems, and has as its object to provide a hot water intake valve that does not generate remaining water in a pipe and further reduces the possibility of water leakage. .
[0005]
[Means for Solving the Problems]
In order to solve the above problems, the intake valve of the present invention uses a shape memory alloy spring having a transformation point in a constant water temperature region to press the valve body, and a constant negative pressure is generated in the pipe. When the temperature is equal to or higher than the transformation point, the valve is kept closed, and when the temperature becomes equal to or lower than the transformation point, the valve is opened for the first time.
[0006]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments will be described in detail with reference to the drawings. FIG. 1 shows an embodiment of a hot water intake valve according to the present invention. Reference numeral 1 denotes a valve box which is connected to a joint of a water supply pipe by a screw portion 2 and accommodates a resin valve body 3 therein. The valve body 3 is pressed by a shape memory alloy spring 5 locked on a ring 4 so that the attached O-ring 6 comes into close contact with a valve seat 7 to stop water.
[0007]
The upper end of the valve body 3 has a tapered shape that spreads out. The lower end 8 of the taper has a larger diameter than the guide hole 9 of the valve box 1 and serves as a downward stopper. Further, since the vertical groove 10 is drilled from the upper end to above the O-ring 6, when the valve body 3 is set, the elasticity of the resin is used. 3 is housed in the valve box 1. Reference numeral 11 denotes a water stop cover. If water leaks, the clip 12 is removed and the packing 13 is fastened to the upper valve seat 14 to stop water.
[0008]
The figure shows a normal state in which a water drain plug (not shown) provided on the upstream side of the pipe is opened and water reaches the faucet at the end, but the water temperature is set to the shape memory alloy spring 5. When the temperature is higher than the transformation point, the generated load is several times higher than that at the time of low temperature. Therefore, the valve body 6 is pressed against the valve seat 7 with a large force. The valve body 6 does not open, that is, does not open when the pressure is about the negative pressure generated when the valve is opened. Therefore, there is no risk of water leakage in that state.
[0009]
Even if the hot water is not used for a while and the water temperature in the pipe becomes lower than the transformation point, the valve body 6 is in close contact with the valve seat 7 due to the water pressure, that is, the valve is closed. When the internal pressure becomes negative, the generated load of the shape memory alloy spring 5 is reduced, and the valve is opened. However, this is temporary, and when the water temperature rises, or when the water temperature rises and the negative pressure is eliminated, the valve closing state is maintained again.
[0010]
Next, when the drain valve is operated to drain the water inside the pipe, the head difference between the drain port (not shown) of the drain plug buried in the soil and the intake valve is large, and the water temperature is higher than the transformation point. However, the shape alloy spring 5 is compressed by the negative pressure in the pipe, the valve body 3 descends, and the atmosphere passes through the vertical groove 10 of the valve body 3 from the gap between the water stop lid 11 and the valve box 1 and enters the pipe. The drain valve is introduced and drained.If the water is drained smoothly at a certain height, the drainage is stopped in a balanced state in that state. In the case where drainage is stopped halfway, when the temperature of the room falls and the temperature of the shape memory alloy spring 5 becomes lower than the transformation point, all remaining water is drained.
[0011]
When the drainage is completed, the O-ring 6 of the valve body 3 is pressed against the shape memory alloy spring 5 and comes into close contact with the valve seat 7, similarly to a normal intake valve. In this embodiment, the taper lower end portion 8 is designed to prevent the valve body 3 from descending greatly due to a large negative pressure when the water is drained, and to prevent the shape memory alloy spring 5 from becoming in close contact with the intake air and obstructing the intake. Is a stopper, but a stopper is not always necessary.
[0012]
As the transformation temperature of the shape memory alloy spring 5 is set lower, the valve is not opened due to the negative pressure when the hot water flows from the faucet, and the possibility of water leakage is reduced. If the room temperature around the intake valve is high and the temperature under the floor is negative, it may take time to completely drain the water, and in some cases, the piping may freeze. It is usually desirable to set the temperature within the range of about 10 to 30 ° C.
[0013]
As another embodiment of the present invention, for example, a sub-valve is provided above the valve body 3, an O-ring 6 is mounted on the valve box 1 side to form a valve seat 7, or the O-ring 6 is used as a packing of another shape. Change, guide the valve body 3 downward, position the shape memory alloy spring 5 above the guide hole 9, make the valve body 3 including the shape memory alloy spring 5 into a cartridge type, and replace it. Although various design changes are possible, such as to facilitate the above, the changes are not limited to the extent not departing from the present invention.
[0014]
In this embodiment, the case where the intake valve is attached to the pipe in the vertical direction has been described, but it is needless to say that the intake valve may be attached in the horizontal direction. In addition, the present invention has a great effect as a hot water intake valve. In the case of high pressure water, there is little possibility that the inside of the pipe becomes negative pressure even if the faucet is opened. In addition, it is only necessary to prepare an intake valve using a normal weak spring, but it is effective especially at low water pressure points, and the contractor must carry two types of intake valves for water and hot water Of course, it can be used for both hot and cold water so as to eliminate the trouble and prevent the wrong installation.
[0015]
【The invention's effect】
As described above, in the present invention, while having a very simple structure of merely changing the spring of the intake valve to a shape memory alloy spring, when hot water flows, the inside of the pipe becomes a negative pressure and the valve element opens and closes, Accidents that lead to water leakage can be greatly reduced, and the bias spring, which is normally required when using a shape memory alloy spring, can be omitted by changing to a negative pressure, so that the shape can be reduced in size, simplified, and inexpensive. There is an effect that can be.
[Brief description of the drawings]
FIG.
It is a longitudinal section showing one example of a hot-water intake valve of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Valve box 3 Valve element 5 Shape memory alloy spring 7 Valve seat

Claims (1)

The valve body is pressed against the valve seat with a shape memory alloy spring having a transformation point in the constant water temperature range.Even if a constant negative pressure is generated, the valve remains closed at temperatures above the transformation point and below the transformation point. A hot water intake valve characterized in that the valve can be opened when the temperature reaches a predetermined temperature.

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