JPH027981Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field This invention relates to prevention of backflow of sewage from the drain valve 5 in a drain valve.

(b) Conventional technology In cold regions such as Hokkaido, water in water pipes often freezes during the winter. As a countermeasure to this problem, drain valves have been devised that drain the water from the pipes and drain them underground before going to bed, and these are currently in common use.

Fig. 1 shows a known water drain valve, and shows 2
1 is the outer pipe, 1 is the lower main body, 3 is the water pipe, 4 is the riser pipe, and 5 is the drain valve. Operate the handle 8 provided at the top of the outer pipe 2 to open the valve and drain the water in the riser pipe 4. It is discharged from the drain valve 5. Fig. 2 shows the interior of a well-known drain valve, with reference numeral 2 indicating an outer shell pipe and 1 indicating a lower main body.A water pipe 3 is connected to an inlet 6 in the lower main body 1, and a rising pipe 4 is connected to an outlet 7 in the lower main body 1. is connected, and a drain valve 5 is provided on the side. The drain valve 5 has a check valve structure that drains the water in the riser pipe 4 into the ground when the water is stopped. Lower body 1
The inside of the is a cylinder, and the inside has a horizontal hole 16 and a vertical hole 15, and a groove for accommodating an O-ring is carved on the outside. to open and close the water in the water pipes. At this time, the piston 10 rises to drain the water from the riser pipe 4, and then comes down to a state where water comes out. Figure 2 shows the drainage state. The above are known drain plugs.

(c) Problems to be solved by the invention Foreign matter gets mixed around the drain ball 20 of the drain valve 5, making it less effective, and the underground water level fluctuates and the drain ball 20 moves, causing wastewater to flow into the outlet 7 and riser pipe 4. may flow backwards. This is the case when the drain valve is in the draining state.

(d) Means for solving the problem The present invention focuses on this point and eliminates the drawbacks of known products so that when the drain valve is in the draining state, sewage does not flow back from the drain valve 5 to the outlet 7 and the riser pipe 4. To eliminate this, the present invention is as follows. Fig. 3 shows the drainage state of the product of the present invention, which is the same as the known product except for the piston 10.
A unidirectional packing 21 having a thin tapered part that contacts the cylinder surface 17 of the lower main body 1 is additionally attached to the middle part of the unidirectional packing 21.
The diameter of the taper part is the cylinder surface 1 of the lower body 1.
It is slightly larger than 7. The shape of the unidirectional packing 21 is shown in FIG. 6, with the inside being a straight hole and the outer tapered portion having a thin umbrella shape. FIG. 7 shows another embodiment, which differs from the previous embodiment in that the inside is a tapered hole.

(E) Function When the wastewater from the drain valve 5 flows back into the riser pipe 4, the tapered part of the unidirectional gasket 21 attached to the piston 10 is expanded as shown in Fig. 4, creating a structure that prevents backflow. ing. Also, when draining water from the riser pipe 4, the direction is forward, and the tapered part of the unidirectional gasket 21 is pushed by water pressure as shown in FIG. 5, allowing water to be drained in the direction of the drain valve 5. It is.

(f) Effects of the invention As described above, according to the invention, there is an effect that sewage does not enter the riser pipe 4 even when foreign matter gets mixed into the drain valve 5 of the drain valve and the action is not sufficient or when the underground water level fluctuates. There is.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing a known product. FIG. 2 is a front cross section of a known product, showing the state of drainage. FIG. 3 is a front cross section of the product of the present invention, showing the drained state. FIG. 4 is a front cross section of the main part of the product of the present invention, showing a state in which backflow is prevented. FIG. 5 is a front cross section of the main part of the product of the present invention, showing the state of drainage. FIG. 6 shows the appearance and cross-sectional view of the unidirectional packing. FIG. 7 shows the appearance and cross-sectional view of a unidirectional packing according to another embodiment.

Claims (1)

[Scope of utility model registration request] A cylinder is formed inside the lower body 1, which has an outer shell pipe 2 on the upper side and an inlet 6, an outlet 7, and a drain valve 5 on the sides, and several O-rings are installed therein. This drain plug has a piston 10 that communicates a horizontal hole and a vertical hole that moves up and down to drain, stop, and drain water, and a unidirectional gasket 21 having a thin tapered part is added to the middle part of the piston 10.