JPH0550636B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a check valve opening device that temporarily cancels the backflow prevention function of a check valve that prevents backflow of liquid in a pipe such as tap water. .

[Prior Art] As is well known, check valves are installed in the middle of water supply pipes and hot water supply pipes in various water supply and hot water supply equipment, but the check valves are used to drain water on the primary side and drain water on the secondary side. There is a conventional drain plug that can be used for draining and draining at the same time, as disclosed in Japanese Utility Model Publication No. 56-47256.
Its structure is basically the same as that of the check valve part in the hot water mixing faucet shown in Figs. 4 to 6, so the structure will be explained according to the figure. , b is a hot water supply pipe, c is a water supply pipe, d is a discharge port, e is a hot water mixture ratio adjustment handle, f is a discharge handle, and the check valve part g provided in the hot water supply pipe b and the water supply pipe c is the fifth It is shown in an enlarged longitudinal section in Fig. 6. The check valve h has a four-pronged guide fitting i secured to its back side by screws j, and the check valve is biased by a coiled spring k to close the valve port m. n is a water drain plug screwed into the cylindrical part o, a T-shaped through hole p is formed in the center, and the rubber q fixed to the inner end surface communicates with the primary side of the check valve h. The drain hole r and the drain hole s communicating with the secondary side can be sealed, and by loosening the drain plug n, water can be simultaneously drained from the primary side and the secondary side of the check valve h through the drain holes r and s. I'm trying to make it possible. However, with the conventional anti-freezing water drain structure constructed in this way, water can be drained from the primary side and the secondary side of the check valve at the same time by simply operating a single drain valve n, which has the advantage of requiring less effort. It is something you have. However, this structure has the following drawbacks. In other words, even if water is drained, the check valve h, its guide fitting i, valve port m, etc. are still wet with water, and it is difficult to completely drain the water, so the remaining water freezes and the reverse occurs. If the stop valve h blocks the valve port m and becomes stuck, and the water supply pipe c is set in an inclined manner as shown in Figure 6, and the drain holes r and s are not located directly below. In this case, residual water t accumulates, and once it has accumulated in this way, even if the water is supplied again, it will fill up to the front of the check valve h, but it will not flow to the secondary side at all, and the cooling There was a problem in that because the water temperature was low in the ground, it was impossible to thaw the secondary side, and there was a risk that it could not be reused.

On the other hand, in the check valve installed in the hot water mixing faucet disclosed in Japanese Utility Model Publication No. 59-4207, a through hole is bored in the outer wall of the primary side of the valve body, and the operating shaft (pressure rod) is inserted into the through hole. movably penetrates the valve body so that the operating shaft faces the valve body,
The sliding resistance of the actuating type is kept higher than the closing force of the spring that biases the valve body, and by pushing the actuating shaft, the sliding resistance keeps the valve open, and the valve is opened again. It is disclosed that the operating shaft is configured to return to its original state due to water pressure when water is supplied.

However, in the above publication, the amount of sliding resistance exerted on the operating shaft is adjusted by the friction of an O-ring provided on the outer periphery of the operating shaft. However, the sliding resistance of an O-ring is not only affected by its dimensions and shape and material deterioration over time, but also varies greatly depending on environmental temperature, humidity, etc. It was extremely difficult to keep the water pressure below that level at all times, and it was not possible to operate as expected.

[Object of the Invention] Therefore, the present invention provides a check valve opening device that can temporarily release the backflow prevention function of the check valve as necessary during anti-freezing, etc., and prevent the above-mentioned troubles caused by the check valve. This is what we are trying to provide.

[Means for Achieving the Object] In order to achieve the object, the present invention provides an operating shaft on the primary side of the check valve which is biased by a spring so as to close with the valve port, and the tip thereof is opposite to the check valve. The diaphragm is provided so as to be movable back and forth so that its end protrudes outside, and is formed into a substantially dome shape from an elastic material.The actuating shaft is fixed in a penetrating manner through the dome center of the diaphragm, so that the front surface of the diaphragm is brought into contact with the primary side. The diaphragm has a first stable configuration in which the back surface is in contact with the atmosphere side, and the diaphragm has a first stable configuration in which the tip of the bulge actuating shaft is spaced from the check valve on the atmosphere side, and a first stable configuration in which the tip of the bulge actuating shaft is separated from the check valve by the diaphragm on the primary side. The second stable form is pressed, and the shape retention force of the second stable form is set to be stronger due to the elastic restoring force of the spring and weaker than the water pressure applied to the primary side. It is.

[Operation] When the diaphragm is in the first stable configuration, the check valve normally has a backflow prevention function. On the other hand, by opening the drain valve and releasing the residual pressure inside the pipe or faucet, and then pressing the end of the operating shaft that protrudes outside, the diaphragm changes from the first stable mode to the second stable mode, and the elastic restoring force of the spring The check valve is held open against the In addition, when water is recirculated and the water pressure on the primary side is applied to the front of the diaphragm, the diaphragm
Returning to the stable state, the tip of the operating shaft separates from the check valve, and the check valve's backflow prevention function automatically returns. Even if the remaining water freezes, it will be easily thawed by flowing water to the secondary side.

[Example] An example of the present invention will be described below with reference to FIGS. 1 to 3. The check valve 1 has a four-pronged guide fitting 2 fixed to the back side by a pin 3 and is arranged to move forward and backward into a valve chamber 5 in a main body 4, and a coiled spring 6 is attached to the check valve 1. The valve 1 is biased in the direction of closing the valve port 7. A ring 8 receives the other end of the spring 6. 9 is a water supply pipe connected to the secondary side of the check valve 1, 10 is its union nut, 1
1 is a water seal gasket interposed between the frozen end faces. Now, Fig. 1 shows the normal water stop state, and when there is water flowing in the forward direction as shown by the arrow in Fig. 3, the water pressure causes the check valve 1 to close against the elasticity of the spring 6.
moves backward and the valve port 7 opens. Reference numeral 12 denotes an operating shaft provided on the primary side of the check valve 1 so that its tip 12a faces the check valve 1 and can move forward and backward in the same axis direction as the check valve 1. The actuating shaft 12 is inserted into the center hole of the lid-shaped body 13, which is partially screwed, so as to be freely retractable and forward, and the end 12b of the actuating shaft 12 projects to the outside.
Note that a collar 12c is integrally formed at the middle portion of the operating shaft 12 to prevent it from coming off. Reference numeral 14 denotes a substantially dome-shaped diaphragm whose center is fitted into a groove 12d formed on the outer periphery of the actuating shaft 12, and the outer periphery 14a of the diaphragm is crimped by the inner end periphery of the lid-shaped body 13 via a washer 15. As a result, the diaphragm 14 is airtightly attached, and the front side of the diaphragm 14 is in contact with the primary side of the check valve 1, and the back side is in contact with the atmosphere side. Note that reference numeral 16 designates a ventilation hole opened in the lid-like body 13 so that the back surface of the diaphragm 14 is exposed to atmospheric pressure. Therefore, this diaphragm 14 is
As shown in the figure, there is a first stable form in which the tip 12a of the operating shaft 12 is bulged toward the atmosphere and separated from the check valve 1, and as shown in FIG. There is a second stable form in which the tip 12a of the operating shaft 12 presses against the check valve 1. That is, the diaphragm 14 is made of an elastic body such as rubber or synthetic resin, and is in the first stable state (FIGS. 1 and 3) when no external force is applied. The diaphragm 14 is expanded toward the primary side by pressing with fingers, and the tip 12a of the operating shaft 12 is
When the diaphragm 14 is released from the pressed state of the check valve 1, the diaphragm 14 becomes the second stable state (FIG. 2), and the shape retention force of the second stable state is due to the elastic restoration of the spring 6. Stronger than force. However, the shape of the diaphragm 14 and the material constituting it have been selected so that the shape retention force in the second stable state is weaker than that force and returns to the first stable state when water pressure on the primary side is applied to the front surface of the diaphragm 14. ing. In this way, the diaphragm 14
can have two stable forms, the first and the second, because
For example, if we assume a hat-shaped object such as a hollow rubber ball cut in half, when the center is pressed, it will elastically return to its original form (first stable form) until a certain pressing force is reached. However, when the strength of the pressing force exceeds the required limit, it becomes like a hat turned inside out and maintains that form (second stable form) until an external force acts in the opposite direction. The principle is the same.

However, in order to prevent freezing during cold blockage in water supply and hot water supply equipment equipped with such check valves, it is necessary to open the drain valve (not shown) installed in the piping on the primary side of the check valve. Then, the remaining pressure inside the pipe is released, and the end 12b of the actuating shaft 12 is pressed with a finger, and the check valve 1 is pressed with the end 12a as shown in FIG. At this time, the diaphragm 14 assumes the second stable configuration as described above and maintains this configuration even if the hand is released. That is,
The valve port 7 is kept open at all times, and water on the primary side and water on the secondary side can freely flow and be discharged from the drain valve. When the water is recirculated, the water enters the secondary side through the valve port 7 which is kept open, so even if the check valve 1 and its guide fittings 2 are frozen, the flowing water will easily thaw them. . Furthermore, when the water is recirculated, water pressure is applied to the front surface of the diaphragm 14, thereby returning the diaphragm from the second stable state to the first stable state, so that the function of the check valve 1 is immediately restored.

[Effect of the invention] As described above, the check valve opening device according to the present invention has the following effects:
Utilizing the two stable configurations of a diaphragm formed in a roughly dome shape, the operating shaft is used to open the check valve, and it automatically returns to normal state due to the water pressure when water is recirculated, so it is possible to control environmental temperature, humidity, etc. This has the beneficial effect of making it possible to reliably drain water to prevent freezing and automatically return the water to the intended level, with less influence from changes in water. By using this opening device, the conventional problems with freezing are therefore eliminated.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view showing a normal water-stop state of a check valve opening device according to an embodiment of the present invention, and FIG.
The figure is a longitudinal sectional view of the check valve in its open state, and FIG. 3 is a longitudinal sectional view of the check valve in its normal water flowing state. 4 is a plan view of the hot water mixing faucet, FIG. 5 is a sectional view taken along the line X-X in FIG. 4, and FIG. 6 is a sectional view taken along the line Y-Y in FIG. 1... Check valve, 6... Spring, 12... Operating shaft, 14... Diaphragm.

Claims (1)

[Claims] 1. An operating shaft is provided on the primary side of the check valve, which is biased by a spring to close the valve port, so that it can move forward and backward so that its tip faces the check valve and its end protrudes outside, and is made of an elastic material. By fixing the operating shaft in a penetrating manner to the center of the dome of the diaphragm formed in a dome shape, the diaphragm is stretched so that its front side is in contact with the primary side and its back side is in contact with the atmosphere side. There are two stable modes: a first stable mode in which the tip of the bulging actuating shaft is separated from the check valve, and a second stable mode in which the tip of the bulging actuating shaft presses the check valve on the primary side. A check valve opening device characterized in that the shape retention force is set to be stronger than the elastic restoring force of the spring but weaker than the water pressure applied to the primary side.