JP3900573B2 - Backflow prevention type water drain valve - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a backflow prevention type water drain valve, and more particularly to a water drain valve that further ensures backflow prevention.
[0002]
[Prior art]
Conventionally, this type of drain valve has a separate backflow prevention valve that is pressed against a small diameter portion of a piston by a spring, as in, for example, Japanese Patent Application No. 6-79480 by the same applicant. Many have been used. However, in the case of the above, since two packings are mounted on the inside and outside of the backflow prevention valve, for example, there is a possibility that backflow may occur due to damage to the packing or foreign matter caught in the packing. In that case, there is a problem that there is no means to prevent backflow, or when checking the backflow prevention function, pull out the piston and disassemble it, and check whether there is any abnormality in the packing. The actual situation is that it was not actually inspected because it was troublesome.
[0003]
[Problems to be solved by the invention]
Therefore, an object of the present invention is to provide a backflow prevention type drain valve that eliminates the defects of the above known examples, hardly causes backflow even if the packing is damaged, and can easily inspect the backflow prevention function. .
[0004]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, a check ring packing for sealing a cylinder between an inlet and an outlet from below is attached to the lower end of an operation rod having a means for sealing water from the inlet, and the spring is turned upward by a spring. Connect the pressed check piston so that it can move up and down, and at the lower end, attach a drain valve equipped with a drain packing that closes the drain valve seat with a smaller diameter than the cylinder, and is provided upward between the outlet and drain port. Since it is connected in a vertically movable manner and only one annular packing for backflow prevention is required, the probability of a packing accident is reduced accordingly, and when backflow occurs, the area difference between the cylinder and the drain valve seat The non-return piston is raised further than the normal non-return piston position where the faucet is closed. Since the water on the side is discharged from the drain, even if the check ring packing is damaged, backflow to the main side is less likely to occur, and further, whether the water from the drain stops in the drained state. If it is confirmed, the presence or absence of a backflow prevention function can be easily inspected.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
The basic structure of the present invention is to connect a check piston for blocking between the inlet and outlet at the lower end of the operating rod and a drain valve to the lower end of the check piston so as to be movable up and down. The connection mode is not limited. It may be connected from the side with a pin or screw, or the O-ring may be used as a retaining member, and after insertion, it can be mechanically deformed so that it cannot be detached.
[0006]
Instead of moving the operating rod up and down with a screw, it can be moved up and down with a cam, a lever, etc. to reduce the number of rotations of the handle, and it can be electrically operated remotely using a motor. Further, as a means for sealing water from the inlet, an annular packing may be attached to the operating rod so as to be in close contact with the cylinder formed above the inlet of the valve box. It may be attached to the part.
[0007]
If a spring that presses the check piston upward is provided between the check piston and the drain valve, the spring is pressed downward by the spring, which is advantageous in terms of preventing water leakage to the drain port. It can also be positioned between the operating rod and the check piston or at the lower end of the check piston, and there is an advantage that the lifting force of the check piston at the time of negative pressure becomes larger.
[0008]
【Example】
An embodiment will be described with reference to the drawings. In FIG. 1, reference numeral 1 denotes a valve box, and an inlet 2 is provided above the side wall, an outlet 3 is provided below the side wall, and ends thereof are positioned coaxially. A drain port 4 is provided at the lower end. Inside, the cylinder 5 is provided between the inlet 2 and the outlet 3, and the upward valve seat 6 having a smaller diameter than the cylinder 5 is provided between the outlet 3 and the drain outlet 4.
[0009]
The operation unit main body 8 is connected and fixed to the upper end via a stopper 7 therebetween, and an operation rod 10 provided with an operating male screw 9 is accommodated therein. An annular packing 11 is provided below the male screw 9 of the operation rod 10. The attached sealing portion 12 is provided, and the narrow-diameter portion 13 is suspended therefrom, and the flange portion 14 is formed at the lower end. A handle 15 is attached to the upper end.
[0010]
Reference numeral 16 denotes a check piston, which is provided with a tube suspension part 17 having a side wall at its upper end and connected to the operating rod 10, and a check ring packing 18 for sealing the cylinder 5 from below is mounted below it. A drainage horizontal hole 20 is formed between the locking portion 19 provided on the drainage side. Inside, a drainage packing 21 that closes the valve seat 6 is mounted at the lower end, and a drainage valve 23 having a projection 22 at the upper end is connected and accommodated via a spring 24. The drain valve 23 is made of resin, and is provided with a notch 25 that is cut from the upper end to the upper part of the drain packing 21. When the drain valve 23 is connected to the check piston 16, the protrusion 22 is made of the elasticity of the resin. You can insert it so that A guide cylinder 26 serves as a guide for the check piston 16.
[0011]
The figure shows a water flow state, where water from the inlet 2 compresses the spring 24, lowers the check piston 16 along the guide cylinder, and passes through the outlet 3 to the outlet downstream pipe end. Water is discharged from a faucet (not shown). At this time, the annular packing 11 and the drainage packing 21 do not leak water to the male screw 9 for operation and the drainage port 4 side.
[0012]
When the faucet is closed, the check piston 16 rises due to the restoring force of the spring 24, and the downward water received by the drain valve 23 in a state where the locking portion 19 provided at the lower end is in contact with the protrusion 22 of the drain valve 23. The rise is stopped by pressure. At this time, the check annular packing 18 is in close contact with the cylinder 5.
[0013]
If a negative pressure is generated on the main pipe side due to a water breakage or the like in the water flow state, the cylinder 5 and the drain valve seat 6 In response to the ascending force multiplied by the area difference, the check piston 16 further rises from the state where the faucet is closed, and the upper end of the pipe suspension portion 17 comes into contact with the lower end of the stopper 7 and stops. Since the drainage packing 21 of the valve 23 is completely detached from the drainage valve seat 6, the water on the outlet pipe side is discharged from the drainage port 4, and there is a case where the check annular packing is damaged. However, it is possible to effectively prevent sewage from entering the main pipe.
[0014]
Next, in order to drain the water in the pipe in winter, when the handle 15 is rotated from the state shown in the figure, the operating rod 10 is raised while being rotated by the operating male screw 9, and accordingly, the collar portion at the lower end of the small-diameter portion 13. 14, the tube suspension 17 is locked and the check piston 16 is also lifted. First, the check annular packing 18 is in close contact with the cylinder 5 to block water from the inlet 2, and is further lifted to lock 19. Comes into contact with the protrusion 22 and raises the drain valve 23. Eventually, the upper end of the tube suspension part 17 comes into contact with the lower end of the stopper 7 to stop the rise, and the state becomes drained. Therefore, the water in the outflow side pipe is discharged from the drainage port 4 through the drainage horizontal hole 20 and the notch 25, and the pipe is emptied, so that freezing is prevented.
[0015]
In addition, if water is discharged from the drain port in a drained state forever, it can be immediately understood that it is a check ring packing accident, so pull out the piston from the valve box and disassemble the piston as before. If you do not take a look at the packing, you can use it as a check valve. In addition, when the outlet side pipe is frozen due to forgetting to drop water, abnormal pressure may occur and the pipe may be ruptured.In the present invention, however, the abnormal pressure is released from the drain outlet. This is effective in preventing damage to piping caused by
[0016]
【The invention's effect】
As described above, in the antifreeze water faucet of the present invention, since only one non-return annular packing is required, the possibility of an accident is reduced, and when a negative pressure occurs on the main pipe side, Because it is opened, the possibility of sewage being sucked into the main pipe is reduced even if the check ring packing is damaged, and the function of the check valve is easily checked. In addition to the effect of being able to perform, it also has the advantage of being effective in preventing damage to the piping due to freezing.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view in a water passage state showing one embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Valve box 2 Inlet 3 Outlet 4 Drain outlet 5 Cylinder 6 Drain valve seat 7 Stopper 8 Operation part main body 9 Actuation male screw 10 Operation rod 11 Annular packing 12 Sealing part 13 Narrow diameter part 14 Ridge part 15 Handle 16 Check piston 17 Pipe hanging part 18 Non-return annular packing 19 Locking part 20 Drainage side hole 21 Drainage packing 22 Protrusion 23 Drain valve 24 Spring 25 Notch part 26 Guide cylinder

Claims (1)

The inlet is above the side wall, the outlet is below it, the drain is at the lower end, the inside is a cylinder between the inlet and outlet, and the drain valve is upwardly smaller in diameter than the cylinder between the outlet and outlet. A valve box provided with a seat, an operating rod having means for sealing water from the inlet, and a reverse annular packing that is connected to the lower end of the operating rod so as to be movable up and down and seals the cylinder from below. Back flow prevention comprising a stop piston, a drain valve connected to the lower end of the stop valve, and a drain valve having a drain packing for closing the drain valve seat at the lower end, and a spring for applying an upward pressing force to the check piston Mold drain valve.

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