JPH027982Y2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Field of Industrial Application This invention relates to a drain valve with a backflow prevention valve, and relates to a valve structure of the drainage valve with an abnormal pressure relief mechanism.

(b) Conventional technology In cold regions such as Hokkaido, water pipes are buried underground below the freezing depth. This is because no matter how much the temperature on the ground drops, water will not freeze underground below the freezing depth. However, the branch pipes connected to the water pipes are led to each house, and if the tap water is left unused for a certain period of time, the water in the branch pipes of each house may freeze. Therefore, when people were out for long periods of time during the day or when they went to bed, it became necessary to release the water in the branch pipes into the ground, and a drain plug was devised. As shown in FIG. 1, the drain valve 1 has a water pipe attachment part 3 attached to the water pipe 2, a branch pipe attachment part 4, a discharge part 5, and a branch pipe 6.
One end is connected to the branch pipe attachment part 4, and the other end is connected to the faucet 7.
is connected to. Normally, tap water is used by opening and closing the faucet 7, but when going to bed, the handle 8 of the drain valve is operated to discharge the water in the branch pipe 6 from the drainage part 5 into the ground. If you are connecting a hose 9 to a faucet 7 and connecting it directly to an electric washing machine or washbasin 10 to supply water, if there is a sudden water outage due to water main construction, etc., negative pressure will occur in the main pipe, causing the washing machine to shut off. The dirty water in the washbasin may flow back into the water pipe 2 through the hose 9, the faucet 7, and the branch pipe 6. Furthermore, in apartment complexes, it is increasingly common for each room to have a water drain valve in addition to the main water drain valve. Various drain plugs have been devised to prevent this.

(c) Problems that the invention aims to solve However, in the unlikely event that drainage is neglected and the riser pipe on the outflow (secondary) side freezes, abnormally high pressure will occur inside the pipe due to volumetric expansion. However, because the valve is equipped with a non-return valve, pressure cannot escape to the inflow (primary) side, which may cause further damage to pipes and equipment on the outflow (secondary) side. This device eliminates the drawbacks mentioned above and prevents backflow at all times, but in the event of an emergency such as freezing, the abnormally high pressure generated on the outflow (secondary) side is allowed to escape to the inflow (primary) side. It is.

(d) Means for solving the problem In the figure, 11 is the outer tube, and 12 is the external body.
The spindle 13 has a handle 8 attached to its upper part, and an intermediate shaft 14 attached to its lower part.
Attach the piston 15 to the lower part of the piston 15.
A valve piece 16 is attached to the lower part of the valve. The upper part of the valve piece is a round bar part 17, and the lower part is a piece body. A square internal thread is cut inside the upper body 12 and is screwed into a square thread 18 provided at the center of the spindle 13. Therefore, when the handle 8 is turned, the square screw 18 moves up and down, and the valve piece 16
goes up and down. The middle shaft 14 may be considerably longer than the freezing depth, and the length of the middle shaft 14 is also long when drain plugs are provided on the second or third floor. 1
9, 20, 21, and 22 are all Patsukin. FIG. 2 shows the position when water is supplied. Water from the water pipe 2 is led to the branch pipe 6 via the branch pipe attachment part 4, and does not flow out to the drain part 5. To shut off the water at night when going to bed, operate the handle 8 to lower the valve piece 16 to the state shown in FIG. 3. The water from the water pipe 2 is closed, and the water in the branch pipe 6 passes through the branch pipe attachment part 4 and is discharged from the drainage part 5 into the ground below the freezing depth. The above is a description of publicly known products.

The novel points of the present invention are as follows. Reference numeral 23 denotes a check valve, and as shown in FIGS. 6 and 7, it is shaped like a soroban bead, with an upper part 24 and a lower part 25 having conical shapes, and a gasket groove 26 in the center.
There is a gasket 27 on the top 24, and a notch 28 on the top 24.
is provided, has a groove 29 inside, and the inner diameter above the groove 29 is smaller than the inner diameter below the groove 29. 30 is a small hole. Here, 31 is a spring, and the force of the spring 31 is made smaller than the water pressure when water is supplied. A spring 31 is mounted around the round rod portion 17 of the valve piece 16, and a check valve 23 is also mounted around the round rod portion 17 of the valve piece 16. 32 is Patsukin.

(E) Function When water is supplied, as shown in FIG. 2, the water pressure is stronger than the force of the spring 31, so the check valve 23 is pushed down, so that it does not interfere with the water supply. If water is cut off during the water supply and negative pressure is generated, water pressure is no longer applied, so the force of the spring 31 is transferred to the gasket 32.
acts on the check valve 23 through the check valve 23.
is lifted upward, and the gasket 27 which is encased in the center of the check valve 23 as shown in FIG.
closes the opening 33 and closes the groove 2 of the check valve 23.
The gasket 32 attached to the tube 9 is in close contact with the round bar portion 17, thereby preventing backflow. When the water is stopped, no water pressure is applied, so the check valve 23 is positioned as shown in FIG. 3 and does not obstruct the discharge of water in the branch pipe 6. When the drain valve 1 is in the water supply state and the faucet 7 is closed, water does not flow and no water pressure is applied, so the backflow prevention valve 23 is pushed up by the force of the spring 31 and becomes the state shown in FIG. If the water is not drained when going out or going to bed and a long period of time has passed, the water in the branch pipe 6 will gradually freeze and the expansion force will work downward. In this case, a part of the packing 27 encircled by the check valve 23 is pushed into the notch 34 and the small hole 30 is exposed, so that the high pressure generated by the expansion is transferred to the fifth
As shown in the figure, it escapes to the inflow (primary) side through the small hole 30, the gap between the round bar part 17 and the check valve 23, and the notch part 28. When this high pressure is removed, the gasket 27 has elasticity, so it returns to its original position and comes into close contact with the small hole.

(f) Effect of the device This device has the above structure and operates as described above, so it prevents backflow even if there is a sudden water outage, and also prevents the branch pipe 6 and faucet 7 from being destroyed even if drainage is neglected in cold weather. It has an effect that will never be used.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing a drain valve. FIG. 2 is a front sectional view of the product of the present invention, showing the state when water is being supplied. Third
The figure is a partially cutaway front sectional view of the product of the present invention, and shows the state during drainage. FIG. 4 is a partially cutaway front sectional view of the product of the present invention, showing the state when the faucet is closed while water is being supplied. FIG. 5 is a cutaway front sectional view of a part of the product of the present invention, and shows the condition when the water in the branch pipe 6 freezes after a long period of time has elapsed without drainage. FIG. 6 is a partially cutaway perspective view of the check valve. FIG. 7 is a front sectional view of the check valve.

Claims (1)

[Scope of utility model registration request] It consists of an upper main body 12, an outer shell pipe 11, and has a water pipe attachment part 3, a branch pipe attachment part 4, and a drainage part 5. Inside thereof, a spindle 13, an inner shaft 14, a piston 15, and a valve piece 16, which are moved up and down by the operation of a handle 8, are installed. In the case where the valve piece 16 is housed, a spring 31 is placed in the upper round bar part 17 of the valve piece 16, the valve piece 16 has a bead-like shape, a packing 27 is mounted in the center, and a notch 34 is provided at the upper part connected to the packing groove 26. In addition, a notch 28 is provided in the circumferential direction in the upper part 24, a small hole 30 is bored toward the center directly below the notch 34, and a gasket 3 is inserted into the groove 29 inside.
A drain valve with a backflow prevention valve having an abnormal pressure resolving mechanism, which is equipped with a backflow prevention valve 23 containing a valve 23.