JPH0344846Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field This invention relates to a drain valve having a pressure reduction and backflow prevention mechanism.

(b) Prior Art Figure 1 shows an example of piping for a high-rise condominium in a cold region such as Hokkaido.

Tap water sent by a pump (not shown) is supplied to an elevated tank 2 via a lift pipe 1, and is guided from the elevated tank 2 to each house via a water supply pipe 3. The piping for each house is a water stop valve 4, a water meter 5, a drain valve 6, a branch pipe 7, a horizontal drain pipe 8, and a vertical drain pipe 9.
From branch pipe 7 onwards, piping suitable for each house is installed.

By the way, if tap water is left unused for a certain period of time in cold weather, the water from the branch pipe 7 onward in each house may freeze. Therefore, it is necessary to drain the water from branch pipe 7 onward when going out for a long time or when going to bed.
By operating the drain valve 6 at this time,
The water from the water supply pipe is cut off at the water supply pipe installation side of the drain valve 6, and at the same time, the water from the branch pipe 7 onwards is drained.
It prevents freezing.

Although not shown in the figure, if a hose or the like is connected to the tip of the branch pipe 7 and is directly connected to an electric washing machine, etc., and the water supply is stopped for some reason, there will be negative pressure inside the water supply pipe. This can cause dirty water from electric washing machines, etc. to back up and flow into the downstairs area.

Furthermore, in high-rise housing, the lower the number of floors, the higher the water pressure, which can cause water hammer to damage water fixtures or cause the sound of water to be almost noisy. To prevent this, a pressure reducing valve 10 is installed between the drain valve 6 and the branch pipe 7.

(c) Problems that the invention aims to solve As mentioned above, it is possible to install a backflow prevention valve, a pressure reducing valve, or a drain valve with a backflow prevention mechanism, each of which has an independent function to prevent backflow or reduce pressure. However, in order to satisfy all of the above functions, the piping space becomes larger, the unit cost becomes higher, or the user has to perform complicated operations to completely drain the water from branch pipe 7 onwards. There were some drawbacks, such as not being able to handle it. This idea is
In view of the above points, it is an object of the present invention to provide a drain valve having a pressure reduction/backflow prevention mechanism that is easy to operate.

(d) Means for solving the problems The present invention has the following configuration in order to achieve the above purpose. The embodiments shown in the accompanying drawings will be described in more detail below. FIG. 2 shows a drain valve having a pressure reduction and backflow prevention mechanism according to the present invention, and is installed in the position of the drain valve 6 in FIG. 1.

In the figure, 11 is the main body, which has a water supply pipe attachment part (primary) 12, a branch pipe attachment part (secondary) 13, and a horizontal drain pipe attachment part 14 at the bottom. The bonnet 16 is fixed with screws 15, and a handle 17 and a spring receiver 18 are attached to the male and female threads carved on the outside and inside of the bonnet 16 above.
A spring 20 is installed above the piston 19 built into the main body 11 to give a downward force to the piston 19 at all times. )
A pressure chamber 22 communicating with the piston 13 is provided, and a diaphragm 23 which receives pressure from the branch pipe attachment part (secondary) 13 and applies upward force to the piston 19 is fixed with a stopper 24, a diaphragm fixing fitting 25, and a nut 26. The above is the same as the well-known drain valve with a pressure reducing mechanism, and the following points are new. Inside the main body 11, three discontinuous cylinders 27, 28, and 29 are provided in order from the top. cylinder 2 here
7 and 28 have the same diameter, but the lowest cylinder 29
The diameter of the cylinder is made smaller than that of the cylinders 27 and 28. The above-mentioned cylinder 27 has a packing 30 inside,
O-ring 3 that is always in close contact with the cylinder 27 on the outside
A piston 19 enclosing a cylinder 2 is housed in a hollow portion 32 below the piston 19.
A valve piece 36 is loosely fitted around an O-ring 33 that is tightly attached to or detached from the valve 8. Here, the valve piece 36 is constantly receiving a weaker upward force from the spring 34. Furthermore, inside the piston 19 and inside the valve piece 36, there is a gasket 30 which is fixed to the handle 17 at the upper part by retaining rings 37 and 38 and which is attached to the inside of the piston 19.
Gaskets 39 and 40 that are always in close contact with the inner surface of the valve piece 36 are mounted around the valve body, and by turning the handle 17, the O-ring 41, which is attached at the lowest position, is moved up and down, and the O-ring 41 is attached to the cylinder 29 and removed. Loosely fit the operation stick 42 that you want to use. Here, 43 is a retaining ring, 44 is a collar, 45 is an O-ring, 46 is a collar, and 47 is a retaining ring.

(E) Action Figure 2 shows the device of the present invention when water is being supplied, and water is flowing from the branch pipe 7 onwards. At this time, the pressure in the branch pipe attachment part (secondary) 13 is low, and therefore the pressure in the pressure chamber 22 communicating with the branch pipe attachment part (secondary) 13 through the water conduit 21 is also low, so that the pressure acts on the diaphragm 23. Spring 20 than the lifting force
The downward force of is greater. For this reason, the piston 19
is the lowered position. Also, the stepped portion 3 of the valve piece 36
The spring 34, which is housed in the valve 5 and always applies a lifting force to the valve piece 36, is set to be much weaker than the spring 20, so the water pressure in the water supply pipe attachment part (primary) 12 causes the lower end flange of the hollow part 32 of the piston 19 to 48 until the protrusion 49 of the valve piece 36 comes into contact with it. Therefore, the o-rings 31 and 41 are connected to the cylinder 2.
7 and 29, but since the O-ring 33 is separated from the cylinder 28, water flows from the water supply pipe attachment part to the branch pipe attachment part 13 in the direction of the arrow.

Next, when the faucet (not shown) attached to the tip of the branch pipe 7 is closed from this state, the pressure in the branch pipe attachment part (secondary) 13 rises, and the pressure in the pressure chamber 22 increases through the water conduit 21. pressure also increases. Therefore, the upward force applied to the diaphragm 23 also gradually increases, compressing the spring 20. At this time, the diaphragm 23 and the piston 19 are connected to the stopper 24,
Since the piston 19 is fixed by the diaphragm fixing fitting 25 and the nut 26, the piston 19 rises. Further, since the flange portion 48 at the lower end of the hollow portion 32 of the piston 19 and the projection portion 49 of the valve piece 36 are in contact with each other, the valve piece 36 also rises. Furthermore, when the faucet is completely closed, Natsutto 26
The state shown in FIG. 3 is reached in which the upper end of the bonnet has been raised until it touches the inner end surface 50 of the bonnet 18. At this time Benkoma 3
The O-ring 33 surrounding the cylinder 6 contacts the cylinder 28, and the flow of water is blocked. At this time, piston 1
The upward force exerted on the diaphragm 23 by the water pressure and the downward force exerted by the spring 20 are balanced. Also, at this time, the water supply pipe attachment part (primary)
The water pressure in the branch pipe attachment part (secondary) 13 is reduced from the water pressure in the branch pipe attachment part (secondary) 12, which is the set pressure state, and this pressure becomes the set pressure of the drain valve with the pressure reduction and backflow prevention mechanism of the product of the present invention. If a strong spring is installed, the set pressure will be high; conversely, if a weak spring is installed, the set pressure will be low. In this state, the pressure of the water supply pipe attachment portion (primary) 12 acts on the piston 19 as an upward force and acts on the valve piece 36 as a downward force. But cylinder 27
and 28 have the same diameter, so the upward force and downward force are equal. Therefore, the set pressure is not affected by the level of water pressure in the water supply pipe attachment portion (primary) 12. When you open the faucet from this state, the branch pipe attachment part (secondary) 1
3 decreases, and the downward force received by the spring 20 becomes greater than the upward force exerted by the diaphragm 23 acting on the piston 19.
The piston 19 descends, and the valve piece 36 also descends due to water pressure, as shown in FIG.
water flows from the faucet.

FIG. 4 shows a backflow prevention state where negative pressure is generated on the water supply pipe attachment (primary) 12 side. At this time, the water supply pipe attachment part (primary) 12 and the branch pipe attachment part (secondary) 13
Since there is no water pressure in the piston 19, only the downward force of the spring 20 acts on the piston 19. Therefore, the stopper 24 descends until the lower end touches the upper end of the cylinder 27. On the other hand, the valve piece 36 is raised by the action of the spring 34 until the upper end of the valve piece 36 comes into contact with the stepped portion 51 of the operating rod 42 . Therefore, O mounted around the valve piece 36
The ring 33 is in close contact with the cylinder 28, and the water supply pipe attachment part (primary) 12 and the branch pipe attachment part (secondary) 13 are cut off, thereby preventing backflow. Next, when it is necessary to drain water from the branch pipe attachment part (secondary) 13 onwards, such as during cold weather, remove the handle 17, which is fixed by the operating rod 42 and retaining rings 37 and 38, from the state shown in Fig. 2. When you turn the control stick 4 in the specified direction,
Since the lower end of the valve piece 36 is in contact with the collar 46 attached to the operating rod 42, the valve piece 36 also rises, and the O-ring 33 mounted on the cylinder 28 comes into close contact with the cylinder 28. Ring 41 is cylinder 2
Move away from 9. Therefore, the water supply pipe attachment part (primary) 12
Although the flow of water to the branch pipe attachment part (secondary) 13 is blocked, the water in the branch pipe is discharged through the horizontal drain pipe attachment part 14 as shown by the arrow, so freezing is prevented. In addition, in the process of turning the handle 17 and raising the operating stick 42, the O-ring 33 attached to the valve piece 36
is in close contact with the cylinder 28, the O-ring 41 attached to the lowest part of the operation stick 42 is attached to the cylinder 29.
Each dimension is set so that water is separated from the water in a neutral state in which water does not flow in any direction.This invention can also be applied to the embodiments shown in FIGS. 2, 3, 4, and 5. As I explained above, the operation stick 42
The handle 17 attached to the handle 17 can be used as a lever, or instead of being operated manually, a motor can be attached to the top of the operation stick 42 and driven electrically.
Alternatively, the design may be changed without departing from the gist of the present invention, such as by attaching a vacuum breaker, strainer, etc. to an appropriate position.

(f) Effects of the invention Since the present invention is constructed as described above, it not only can supply and drain water with a single operation like a conventional drain valve, but also has a depressurization and backflow prevention mechanism. .

[Brief explanation of the drawing]

FIG. 1 is a simple piping diagram showing the installation position of the product of the present invention. FIG. 2 is a front cross-sectional view showing a state in which water is flowing after the branch pipe when the product of the present invention is being supplied with water. FIG. 3 is a front sectional view showing the set pressure state when water is being supplied to the product of the present invention and no water is flowing beyond the branch pipe. FIG. 4 is a front sectional view showing the backflow prevention state when negative pressure is generated on the water supply pipe installation side during water supply of the product of the present invention. FIG. 5 is a front sectional view showing the water drained state of the product of the present invention.

Claims (1)

[Scope of utility model registration request] It has a water supply pipe attachment part (primary) 12 and a branch pipe attachment part (secondary) 13 on the side, and a horizontal drain pipe attachment part 14 at the bottom, and above the main body 11 that houses a piston 19 therein is an operation section. In particular, a bonnet 16 to which a handle 17 for supplying and draining water is screwed is fixed, a spring 20 is installed inside the piston 19 above it to give a constant downward force to the piston 19, and a branch pipe attachment part ( In this device, a diaphragm 23 that receives the pressure of the secondary cylinder 13 and applies a lifting force to the piston 19 is fixed.
8. Provide a small diameter cylinder 29, and cylinder 2
The lower hollow part 32 of the piston 19 is equipped with an O-ring 31 that is in close contact with the cylinder 28 at all times. The O-ring 33 to be removed is mounted, and the valve piece 36, which is always given a weak upward force by the spring 34, is fitted loosely, and the operating rod 42 is loosely fitted inside the piston 19 and the valve piece 36. The operation stick 42 is the piston 19
The operation stick 4 is also attached to the packing 30 installed inside the
The gaskets 39 and 40 attached to the cylinder 29 are moved up and down by turning the handle 17 attached above while being in close contact with the valve piece, and the O-ring 41 mounted below is brought into close contact with the cylinder 29 or detached from the cylinder 29. Drain valve with pressure reduction and backflow prevention mechanism.