JPH018606Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a check valve that is used in cold regions by being connected to indoor piping on the downstream side of an antifreeze faucet.

Conventionally, backflow prevention valves have been installed in the downstream piping of boilers and other water heaters to prevent thermal deformation of plastic parts such as meters due to backflow of hot water when negative pressure is generated in the water mains due to a water outage, etc. It is often done to make a profit. In addition, even when the water heater is not in use, in order to prevent sewage from being sucked in from the faucet at the end of the pipe and contaminating the main pipe, a backflow prevention valve should be installed downstream of the antifreeze faucet. It can also be found inside indoor plumbing. However, in any case, even if you try to drain the water by operating the anti-freeze water faucet during the freezing season, the backflow prevention valve will operate and the water in the pipes will not be able to be drained. Faucets were installed at the front and rear, and after operating the antifreeze faucet, both faucets were opened to drain the water.

As a result, the cost is high and the operation is complicated, and when water is flowing, water may come out if you forget to close the faucet, or the backflow prevention valve may remain closed, causing the valve to freeze and prevent water from flowing when water is flowing. There were also some drawbacks.

In view of the above, the present invention allows for reliable water removal with simple operations, without interfering with water reflow.
Moreover, the purpose is to provide a backflow prevention valve for use in cold regions that automatically returns to normal state due to water pressure when water is recirculated, and the basic structure of the present invention for this purpose is as follows.

In other words, an inlet, an outlet, and a non-return surface adjacent to the inlet are provided on the same axis, and a valve chamber between the inlet and the outlet, and an operation chamber that opens perpendicularly or obliquely to the valve chamber. A check packing is installed in a valve box having a spring, and the valve body is always pressed in the direction of the inlet by a spring, and the valve body is pressed from a right angle or an oblique direction to open the space between the inlet and the outlet. A large-diameter pressing part is formed at the tip end of the operating stick on the valve body side, and a stop part is formed by making the adjacent downstream part slightly smaller in diameter. When the operating stick is pressed, there is a doorway in the downstream end of the doorway.
It has a locking part to which the large diameter part is locked. Therefore, after draining the antifreeze faucet, simply pressing the operating rod opens the space between the inflow and outflow ports. There is no possibility that drainage will be obstructed or the flow path will freeze and become blocked, and the operating rod and valve body will not return to their original positions due to the water pressure during draining, and when water is recirculating, the operating rod will not be moved by the water supply pressure. is designed to return automatically.

The present invention will be described below with reference to embodiments shown in the drawings.

In FIG. 1, reference numeral 1 denotes a valve box of the non-return valve of the present invention, which has an inlet 2 and an outlet 3 on the same axis. A mounting bracket 4 is connected to the outlet 3 side in consideration of ease of connection to piping and repair. A cylindrical check face 5 is provided adjacent to the inlet 2 on the same axis as the inlet 2 and the outlet 3.
A valve chamber 6 having a larger diameter than the check surface 5 is formed on the downstream side of the valve.
The inner surface is used as a sliding surface 7. An operating chamber 8 is formed by opening the upper part of the valve chamber 6 at an angle of 45 degrees, and an upper lid 9 is connected to the upper end. As shown in FIG. 2, the valve body 10 housed in the valve box 1 has a check part 12 on the tip of which a check packing 11 is attached, a guide part 13 that slides on the sliding surface 7, and a guide part 13. It is composed of a spring locking part 14 adjacent to the downstream side of the guide part 13, and a water passage 15 is formed by boring the inside, and a large hole is made on the side of the guide part 13, leaving a part on the upstream side and downstream side of the guide part 13. An inlet/outlet 16 is provided by opening into the passageway 15. The valve body 10 is constantly pressed in the direction of the inlet 2 by the spring 17, and in the state shown in the figure, the tip of the guide portion 13 comes into contact with the left end of the check face 5 to prevent further movement. 18 is an operation stick, and the operation room 8
A large-diameter pressing portion 19 is formed at the tip of the side, and a stop portion 20 is formed at a downstream adjacent portion with a slightly smaller diameter.

An operating part 21 is provided at the upper end, and gaskets 23 and 24 that are in close contact with the sealing surface 22 in the upper lid 9 are attached to the middle part.

The pressing portion 19 partially enters into the entrance/exit 16 of the valve body 10 and restricts rotation of the valve body 10. The upstream end of the entrance/exit 16 is pressed by the pressing part 19
The flat part 25 is scraped flat to the extent that it does not touch the
, so that the operating rod 18 does not have to be removed when the valve body 10 is taken out from the valve housing 1. The downstream end 26 of the inlet/outlet 16 is shaved off at right angles to the water passage 15, and the contact portion serves as a locking portion 27 with which the large diameter portion 19 of the operating rod 18 locks.
Check gasket 11 of valve body 10 and operating rod 18
The gaskets 23 and 24 use one-way sealing gaskets with a Y-shaped cross section, which reduces frictional resistance compared to using a normal O-ring, making the valve operation easier and more reliable. In the figure, two gaskets are attached to the operating stick 18 for safety, but the gasket 23 may be omitted or a diaphragm or the like may be used to make the operation even easier. Reference numeral 28 is a clip ring for holding the spring, and also serves as a stopper when the valve body 10 moves to its maximum.

Next, the operating mode of the present invention will be explained.

Figure 1 shows a state in which the antifreeze faucet is open and the faucet at the end of the pipe (not shown) is closed, that is, the water is stopped. The water compresses the spring 17 to push open the valve body 10, enters the water passage 15 from the operation chamber 8 through the inlet/outlet 16, and flows out from the outlet 3 to the downstream piping. At this time, Patsukin 23, 24
Since it is in close contact with the sealing surface 22, there is no leakage from there. When you close the faucet in this state, or when negative pressure occurs on the water main side,
Since the water no longer flows from the inlet 2 to the outlet 3 side, the valve body 10 is pressed by the spring 17 and immediately moves to the right, and the check packing 11 comes into close contact with the check surface 5 as shown in the figure. Stop moving in the state. That is, even if negative pressure is generated on the main pipe side, hot water or sewage will not flow back from the outlet 3 side, and the above-mentioned accidents can be completely prevented.

Next, when you operate the antifreeze faucet to set it to the drain state, it is best to press down the operating rod 18 from the state shown in the figure, so that the pressing part 19 comes into contact with the downstream end 26 of the inlet/outlet 16 of the valve body 10. When pressed further down from that state, the valve body 10 moves to the left using the sliding surface 7 as a guide, the operating part 21 of the operating rod 18 comes into contact with the upper cover 9, and the pressing part 19 presses against the downstream end of the valve body. 26, the movement is stopped. That is,
The state shown in Figure 3 will be reached.

At this time, the check portion 12 of the valve body 10 has completely separated from the check surface 5, so the water flow path will not be blocked due to freezing, so water will not come out when water is recirculated. Such a thing does not happen. During drainage, the water pressure of the difference between the heads of the downstream piping acts as a lifting force on the operating rod 18, but the downstream end 2
6 comes into contact with the stop portion 20 of the operation stick 18, and the spring 17
Since the pressing force of the valve body 10 due to the water pressure during draining acts as a frictional force on the operating rod 18, the operating rod 18 does not naturally rise in the normal state. However, when there is a large head difference between the downstream piping, such as when piping is installed on the second floor, or when the backflow prevention valve of the present invention is installed vertically, the operation stick 18 may become unstable due to vibrations, etc. It returns to its natural state and returns to the state shown in Figure 1, and the outlet 3,
There is a risk that the flow path between the inflow ports 2 will be blocked and drainage will not take place. However, in the present invention, as shown in FIG.
7, and since the valve body 10 is always pressed in the direction of the inlet by the spring 17, the operating rod 18 will not return naturally due to vibrations or the water flow level during drainage. Also, at this time, the seal 23 has separated from the sealing surface 22,
Since the packing 24 is in close contact with the sealing surface 22,
There is no water leakage from that part.

Next, when the antifreeze faucet is opened and water is supplied again, the valve body 10 moves to the left due to the water pressure.
Therefore, the locked state between the valve body 10 and the operating rod 18 is released, and the operating rod 18 is raised by the water pressure and returns to its previous position. When the valve body 10 moves to the left to the maximum, the left end of the spring locking portion 14 of the valve body 10 touches the clip ring 2.
If the length of the inlet/outlet 16 in the axial direction is determined so that the valve body 10 does not come into contact with the operation stick 18 in this state, the return of the operation stick 18 will be prevented. It will not affect you. In addition, if you want to return the operation stick 18 manually, it is best to rotate the operation stick 18 and pull it up. When rotating, a slight pressure force is generated on the valve body 10 in the downstream direction, and the pressing part 19 is disengaged from the locking portion 27, and the operating rod 18 can also be smoothly returned to its original position. Since all the water from the inlet 2 flows through the operation chamber 8 to the outlet 3 side, a flow path change occurs, and the head loss increases accordingly.
Instead, a large amount of heat is supplied to the operating rod 18, so that even if the operating rod 18 freezes due to residual water droplets after draining, the ice is quickly thawed and the operating rod 18 returns to its normal state when water is supplied again. become. This is especially required in extremely cold regions;
However, in places where it is not necessary to melt ice so quickly, the shape of the valve body 10 can be changed to further reduce the head loss.

An embodiment of the valve body is shown in FIGS. 4 to 6, and other differences from the valve body shown in FIG. 1 are as follows. Note that parts similar to those in FIG. 1 are given the same reference numerals.

The valve body 10 in the embodiment shown in FIG. 4 has four inlets and outlets 16 as shown in FIG. Instead, the water, including the operation chamber 8, enters the bulging space 29 provided adjacent to the downstream side of the non-return surface 5, and flows to the outlet 3 side through the four entrances and exits 16 and the water passage 15. . Therefore, although the heat supply to the operating rod 18 is reduced accordingly, the head loss can be reduced by that amount. The spring 17 is housed inside the spring locking part 14, and the guide part 13 is made as long as possible. The operating rod 18 has only a portion of its lower portion made slightly smaller in diameter to form a stop portion 20, and a flat packing 30 is attached thereto, so that it is pressed against a valve seat 31 provided in the upper cover 9 by an auxiliary spring 32. Control stick 1
8 is made to rise quickly.

In the embodiment shown in FIG. 6, the guide portion 13 of the valve body 10 is formed into a rod shape as shown in the figure, and is configured to move within a guide plate 33 having several passages 15. Therefore, the water from the inlet 2 does not flow through the outlet 16 to the outlet 3 side as in the embodiment shown in FIGS. 1 to 5, but through the gap between the valve body 10 and the bulging space 29. Then, it flows to the outlet 3 side. The downstream end 26 of the entrance/exit 16 is pushed further downstream a little to form a locking part 27. An operation chamber 8 is provided perpendicularly to the side of the valve box 1, and therein,
A large-diameter pressing part 19 whose tip is formed into a conical shape as shown in the figure, and an operating rod 18 having a slightly smaller diameter and a stop part 20 on the downstream side thereof protrude. When the operating rod 18 is pressed, the valve body 10 is pushed back by the tapered surface of the pressing part 19 and compresses the spring 17, and the pressing part 19 is locked with the locking part 27, preventing the operating rod 18 from returning. are doing. The valve box 1 has a valve seat-like check surface 5, and the valve body 10 is equipped with a plate-like check packing 11, so that when water is flowing,
Alternatively, it is possible to reduce the moving distance of the valve body even during drainage. In addition, valve body 1
At the maximum movement of 0, the spring locking portion 14 engages the guide plate 3.
It is arranged so that it touches the right end of 3.

Other operating modes are almost the same as those in FIG.

In the above embodiment, the operation stick 18 is the valve body 1
Since the valve body 10 protrudes into the entrance/exit port 16 of
For example, as seen in conventional upper stop valves, when water flows through the valve body, the valve body rotates due to the water flow, causing the valve body itself or the seal to wear out and lose its water stop function. There is no such thing. Also,
If a one-way sealing packing is used as the check packing 11 as shown in FIGS. 1 to 5, compared to using a plate-shaped check packing as shown in FIG.
There is an advantage that the water stopping effect is more reliable, and in addition, for example, by cutting out a part of the upstream side collar of the check gasket 11, the check gasket 11 can prevent abnormal pressure rise when the water is forgotten to drain and freezes. It is also possible to deform the water and release it to the upstream side, thereby preventing damage to piping and fittings. When connecting the non-return valve of the present invention to piping, it may be connected horizontally as shown in the figure or vertically; however, when connecting horizontally, It is preferable to have the operation chamber 8 face upward as this will reduce the amount of water remaining in that area, but if it is turned sideways or even downward, it will only take longer to de-ice that area and will interfere with other functions. has no negative effect. Furthermore, it goes without saying that the mounting bracket 4 can be omitted and the valve box 1 can be directly connected to the pipe.

As described above, the water of the present invention can be easily and reliably drained, the valve body will not freeze and block the water passage, and water will not come out when the water is recirculated, and the operation rod will not let water flow out. It can be automatically reset when water is flowing, and the cost is lower than the conventional one that has two faucets before and after the backflow prevention valve, and there is no need to forget to close the faucet and water will gush out. Furthermore, the operating rod is locked to the valve body during draining, so there is no possibility of vibration or a large head difference with the downstream piping until water is passed through the inlet 2. This has the great advantage that it will not return to normal even if it occurs.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view showing an embodiment of the present invention in a water-stopped state, Fig. 2 is a perspective view of the valve body in Fig. 1, and Fig. 3 is a longitudinal cross-sectional view in the same draining state. , FIG. 4 is a longitudinal sectional view showing another embodiment of the present invention, FIG. 5 is a perspective view of the valve body, and FIG.
The figure is a longitudinal sectional view showing another embodiment of the present invention. 1...Valve box, 2...Inflow port, 3...Outflow port, 5
... Check surface, 6 ... Valve chamber, 8 ... Operation chamber, 9 ...
Upper lid, 10...Valve body, 11...Check gasket, 1
2...Return check part, 13...Guide part, 14...Spring locking part, 15...Water passage, 16...Entrance/exit, 17
... Spring, 18 ... Operation stick, 19 ... Pressing part, 2
0...Stopping part, 21...Operation part, 22...Sealing surface, 23, 24...Packing, 26...Downstream end, 27...Locking part, 28...Clip ring,
29...Bulging space section, 33...Guidance board.

Claims (1)

[Scope of utility model registration request] It has an inlet, an outlet, and a non-return surface adjacent to the inlet on the same axis, a valve chamber between the inlet and the outlet, and an operation chamber that opens perpendicularly or obliquely to the valve chamber. A valve box, a valve body that is housed in the valve chamber and is fitted with a non-return gasket that is in close contact with the non-return surface, and a spring that applies a pressing force to the valve body in the direction of the inflow port; and an operation stick with the other end exposed to the atmosphere, the operation stick having a large diameter pressing part at the tip end on the operation chamber side, and a stop part formed by making the diameter of the adjacent downstream part slightly smaller. , the valve body is characterized in that the side wall is bored to form an entrance/exit for the operating stick, and further, a locking part is provided inside the downstream end of the opening, to which the large diameter part is locked when the operating stick is pressed. A backflow prevention valve for cold regions.