JPS6231782A - Check valve opening device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

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 pipes such as tap water. .

[Prior Art] As is well known, check valves are provided in the middle of water supply pipes and hot water supply pipes in various water supply and hot water supply equipment.

As a drain valve that can simultaneously drain water from the primary side and secondary side of the check valve, for example, Utility Model Publication No. 56-472
There is one disclosed in Publication No. 56.

Its structure is basically the same as that of the check valve part in the hot water mixing faucet shown in Figures 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 mixing ratio adjustment handle, and f is a discharge handle. It is shown in an enlarged longitudinal section in Fig. 6. The check valve is made up of four stages of guide fittings i fixed 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 drain plug screwed into the cylindrical part Q.

A T-shaped through hole p is formed in the center, and the rubber q fixed to the inner end surface closes off the drain hole R that communicates with the primary side of the check valve and the drain hole S that communicates with the secondary side of the check valve. By loosening the drain plug n, water can be drained simultaneously from the primary and secondary sides of the check valve through the drain holes r and s. However, with the conventional anti-freezing water drain structure configured 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 the - number of drain valves n, which is an advantage in that it does not require much effort. It is something that has. However, this structure has the following drawbacks. In other words, even if the water is drained, the check valve valve, its guide fittings i, valve m, etc. are still wet and it is difficult to completely drain the water, so the remaining water freezes and the check valve stops. Water may block the valve port m and become stuck, making it impossible to move.
is set in an inclined manner as shown in Fig. 6, and the drainage holes r and s are
If the water is not directly below the check valve, the remaining water will accumulate, and once the water has accumulated, even if the water is supplied again, the water will fill up to the front of the check valve, but it will not reach the secondary side. There was a problem in that the secondary side could not be thawed and could not be reused because the water temperature was low in cold regions.

[Purpose of the Invention] Therefore, the present invention provides a check valve opening device that can temporarily release the backflow prevention function of the above-mentioned backflow valve when necessary, such as during freezing prevention, to 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 the valve port, and the tip thereof is connected to the reverse valve. A diaphragm having a substantially dome shape is attached to the actuating shaft, the front side of which is in contact with the primary side and the back side of the diaphragm with its back side being in contact with the atmosphere side. There is a first stable form in which the tip of the shaft is separated from the check valve, and a second stable form in which the tip of the actuating shaft bulges on the primary side presses the check valve, and the shape retention force of the second stable form is is characterized in that it is set to be stronger than the elastic restoring force of the spring and weaker than the water pressure applied to the primary side.

[Operation] When the diaphragm is in the first stable configuration, the check valve normally has a backflow prevention function. On the other hand, when opening the drain valve, the residual pressure inside the pipe or faucet is released, and then the end of the operating shaft protruding to the outside is pressed down, and the diaphragm changes from the first stable mode to the second stable mode and the spring recovers its elasticity. Holds the check valve open against a force. 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. In addition, even if the remaining bottles are frozen at that time, they can be easily thawed by running 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-stage guide fitting 2 fixed to the back by a pin 3 and is arranged to move forward and backward in a valve chamber 5 in a main body 4, and a coiled spring 6 is attached to the check valve. l
is biased in the direction of closing the valve lower. 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 connecting end faces.

Now, Figure 1 shows the normal water stop state, and if there is water flowing in the forward direction as shown by the arrow in Figure 3, the water pressure will increase.
, =, the check valve 1 moves backward against the elasticity of the spring 6, and the valve lower opens. 12 is the tip 1 on the primary side of the check valve 1.
2a is an operating shaft provided so as to face the check valve 1 and move forward and backward in the same axis direction as the check valve 1; The actuating shaft 12 is inserted into the center hole so as to be movable forward and backward, and the end 12b of the actuating shaft 12 projects to the outside. Note that 1' is located in the middle of the operating shaft 12! , a collar 12c is integrally formed to prevent it from coming off. 14 is a substantially dome-shaped diaphragm whose center is fitted into a groove 12d formed on the outer periphery of the operating shaft 12.

The outer periphery 14a of the diaphragm 11 is crimped with the inner periphery of the lid-shaped body 13 via the washer 15, so that the diaphragm 11 is airtightly attached.The front surface of the diaphragm 14 is in contact with the primary side of the check valve 1, and the back surface is It is in contact with the atmosphere.

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. However.

As shown in FIGS. 1 and 3, this diaphragm 14 has a first stable configuration in which it bulges toward the atmosphere and separates the tip 12a of the operating shaft 12 from the check valve 1.

As shown in FIG. 2, there is a second stable form on the primary side of the check valve 1 in which the distal end 12a of the expansion 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 2) when no external force is applied. Suppress diaphragm 1
When the diaphragm 4 is expanded to the primary side and the check valve 1 is pressed by the tip 12a of the operating shaft 12, when the diaphragm 14 is released, the diaphragm 14 becomes the second stable state (Fig. 2). The shape retention force of the second stable form is stronger than the elastic restoring force of the spring 6. 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 l/l is the first. The second reason why it can have two stable forms is that, for example, if we assume a hat-shaped object such as a hollow rubber sphere cut in half, when the center is pressed, the object will not return to its original state until a certain suppressing force is reached. It elastically restores its shape (first stable shape), but if the strength of the pressing force exceeds the required limit, it becomes like a hat turned inside out until an external force acts in the opposite direction. is basically the same as maintaining its form (second stable form a).

However, in order to prevent freezing in cold weather in water and hot water supply equipment equipped with a check valve, open the drain valve (not shown) installed in the piping on the primary side of the check valve. The residual pressure inside the pipe is released, and the end 12b of the actuating shaft 12 is pressed down with fingers, 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 lower 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 from the valve lower which is kept open, so even if the check valve 1, its guide fitting 2, etc. are frozen, they are easily thawed by the flowing water. Further, the water pressure applied to the front surface of the diaphragm 14 during water re-flow returns the diaphragm from the second stable state to the first stable state, so that the function of the check valve 1 is immediately restored.

[Effects of the invention] The function of the check valve can be canceled as needed to prevent freezing, and the function of the check valve is automatically restored by the water pressure applied to the diaphragm when water is recirculated. This has a remarkable effect, such as eliminating the need for troublesome operations and eliminating problems caused by forgetting to perform a return operation. The use of this opening device therefore eliminates the various conventional problems with regard to freezing.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view showing a check valve opening device according to an embodiment of the present invention in a normal water-stop state, Fig. 2 is a longitudinal sectional view of the check valve in an open state, and Fig. 3. is a vertical cross-sectional view in a normal water flow 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 Y=Y line in FIG. 1...Check valve, 6...Spring, 12...
- Operating axis, 14... diaphragm.

Claims (1)

[Claims] 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. A substantially dome-shaped diaphragm is installed with the front side in contact with the primary side and the back side in contact with the atmosphere side. There is a second stable form in which the tip of the operating shaft presses against the check valve, and the shape retention force of the second stable form is stronger than the elastic restoring force of the spring but weaker than the water pressure applied to the primary side. A check valve opening device characterized in that the check valve is set to