JPH09317919A - Freeze-breakage preventive air valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate volume expansion of water in a valve box by means of a float valve element in a device where an air hole is opened and closed by means of the float valve element interlocked with fluctuation of level in the valve box by composing the float valve element of a core member on which recession is formed and a surface which can be elastically deformed. SOLUTION: A large diameter air hole 10 is opened in the case that water does not flow from a piping into a valve box 1. Water is charged in the piping, and residual air in the piping is discharged from the large diameter air hole 10. When the water level rises due to water charge in the valve box 1, a loose valve element 12 and a float valve element 15 rise due to floating force. The loose valve element 12 is abutted against a valve seat 1b for closing the large diameter air hole 10. In such an air valve, inner pressure of the valve box 1 is increased due to icing and expansion of the water in the valve box 1 during a cold time. A surface 15b of the float valve element 15 is pressed into a recession 16 of the core member 15a. Volume expansion due to icing is eliminated and breakage of the valve box 1 is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a freeze damage preventing type air valve connected to, for example, a water supply and sewer pipe.

[0002]

2. Description of the Related Art Since an air valve of this kind is installed in a pipe in a protruding state, there is a risk that the water in the valve box will freeze and expand during cold weather, causing damage to the valve box. is there.

Therefore, the one shown in FIG. 4 has been proposed as an example of an air valve for preventing such a damage accident. This is because a float valve body 2 and a piston 3 are arranged to be able to move up and down in a valve box 1 connected to a pipe through a lower end opening 1a, and a piston rod 3a of the piston 3 is a top plate of the valve box 1. It is inserted into a through hole 4 formed in the piston rod 3a, and a retaining cap 5 is fixed to the upper end of the piston rod 3a, and a disc spring 6 is provided between the piston 3 and the top plate of the valve box 1.
An air hole 8 with a valve seat 7 is formed through the piston 3 and the piston rod 3a, and the air hole 8 communicates with the outside through a hole 9 of the cap 5.

In the above structure, the float valve body 2 is caused by the flow of water from the pipe into the valve box 1 to change the water level.
Moves up and down to come into pressure contact with and separate from the valve seat 7, and
It opens and closes, which allows exhaust when filling water and introduction of air when draining.

When the water in the valve box 1 freezes and expands, the piston 3 compresses the disc spring 6 and ascends to prevent the valve box 1 from being damaged.

[0006]

According to the above structure, the structure of the air valve is special and large, and the manufacturing cost is high. The present invention has been made in view of the above problems, and an object thereof is to provide a freeze damage preventing type air valve which has a simple structure, can be downsized, and can be manufactured at low cost.

[0007]

In order to achieve the above object, the present invention is designed so that an air hole communicating with the pipe is opened and closed by a float valve body which is interlocked with a water level change in a valve box connected to the pipe. In the air valve configured as described above, the float valve body is characterized by having a core member having a recess formed on the outer peripheral surface thereof, and an elastically deformable skin covered with the core member.

In the above structure, when the water flows from the pipe into the valve box and the water level changes, the float valve body moves up and down to open and close the air hole, thereby exhausting water during filling and draining water during draining. It is designed to introduce air.

Further, when the internal pressure in the valve box rises due to the freezing and expansion of the water in the valve box, the internal pressure of the float valve element pushes the skin of the float valve element into the concave portion of the core material, which causes ice. It is possible to prevent the valve box from being damaged by absorbing the volume expansion due to the change.

In this case, the volume expansion due to the freezing of the water in the valve box is absorbed by the skin of the float valve body being pushed into the recess of the core material, and the existing standard air valve is used. Since it is only necessary to use the float valve body of the present invention in place of the float valve body, the structure is simple, there are few failures, downsizing can be achieved, and the manufacturing cost can be reduced.

A second aspect of the invention is characterized in that, in the first aspect of the invention, the recess is filled with a pressurized gas. According to the above configuration, when the freezing of the water in the valve box is eliminated, the epidermis can be pushed out of the recess by the pressurized gas in the recess, and the epidermis can be surely returned to the original state.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a freezing breakage prevention type air valve of a rapid air valve type which is an embodiment of the present invention, in which a valve box 1 is connected to a pipe through a lower end opening 1a. A guide cylinder 11 is arranged concentrically with the large air hole 10 penetrating the top plate portion of No. 1, and a floating valve body 12 for opening and closing the large air hole 10 in the guide cylinder 11.
A float valve body 15 for opening and closing a small diameter air hole 14 of a nozzle 13 provided in a central through hole of the floating valve body 12 is arranged so as to be able to move up and down.

As shown in FIG. 2, the float valve body 15 has a spherical core 1 having a large number of recesses 16 formed on the outer peripheral surface thereof.
5a and an elastically deformable skin 15b made of rubber, synthetic resin, or the like, which covers the core material 15a.

Although air may be simply introduced into each of the recesses 16, a pressurized gas made of an inert gas such as nitrogen is enclosed. As a result, the skin 15b can be pushed out of the recess 16 by the gas pressure of the pressurized gas.

In the above structure, in the state where water does not flow into the valve box 1 from the pipe, the large diameter air hole 10 is opened as shown by the solid line in FIG. 1, and the pipe is filled with water from this state. By doing so, residual air in the pipe is discharged from the large-diameter air hole 10, and when the filling water enters the valve box 1 and the water level rises, the floating valve body 12 and the float valve body 15 are lifted by buoyancy. , The floating valve body 12 is brought into contact with the valve seat 1b,
As shown by the phantom line in FIG. 1, the large air hole 10 is closed.

As a result, as shown by the phantom line in FIG. 3A, the portion of the float valve body 15 facing the recess 16 is elastically deformed by the water pressure in the valve box 1 and slightly enters the recess 16.

When air accumulates in the valve box 1 with the large air hole 10 closed and the water level drops, the float valve body 15 descends to open the small air hole 14 and the air in the valve box 1 is removed. It is discharged to the outside through the small-diameter air hole 14, and also the valve box 1
The residual air inside is discharged and the water level rises, the float valve body 15 rises and closes the small diameter air hole 14, and by repeating this, the air accumulated in the valve box 1 is automatically discharged. be able to.

When the water in the valve box 1 freezes and expands during cold weather, the internal pressure P in the valve box 1 rises as shown in FIG. 15b
Is pushed into the concave portion 16 of the core material 15a, thereby absorbing the volume expansion due to the icing and preventing the valve box 1 from being damaged.

In this case, since it is only necessary to replace the existing standard float valve body of the air valve with the float valve body 15 of the present invention, the structure is simple, there are few failures, and downsizing can be achieved. Production costs can be reduced.

When the freezing of the water in the valve box 1 is eliminated, the skin 15b is pushed out of the recess 16 by the pressurized gas in the recess 16 and the skin 15b can be surely returned to the original state. See FIG. 3 (a).

In the above-described embodiment, a large number of circular recesses 16 are formed on the outer peripheral surface of the core material 15a. However, in addition to this, for example, a plurality of long groove-shaped recesses 16 are formed on the outer peripheral surface of the core material 15a. You may form.

Although the quick air valve type freeze damage preventing type air valve has been described as an example, the present invention can be applied to various air valves other than this.

[0023]

According to the first aspect of the present invention, the volume expansion due to the freezing of water in the valve box is absorbed by the skin of the float valve body being pushed into the recess of the core. Since it is only necessary to use the float valve body of the present invention in place of the existing standard air valve float valve body,
The structure is simple, there are few failures, and downsizing can be achieved.
Production costs can be reduced.

According to the second aspect of the present invention, when the freezing of the water in the valve box is eliminated, the skin is pushed out from the recess by the pressurized gas in the recess, and the skin is surely returned to the original state. Can be returned.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a freeze damage preventing type air valve according to an embodiment of the present invention.

FIG. 2 is a partially cutaway front view of the float valve body.

3 (a) and 3 (b) are enlarged cross-sectional views of essential parts showing the principle of freeze damage prevention.

FIG. 4 is a vertical sectional view showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Valve box 10 Large diameter air hole 12 Floating valve body 14 Small diameter air hole 15 Float valve body 15a Float valve body core material 15b Float valve body skin 16 Recess

Claims (2)

[Claims] 1. An air valve configured such that an air hole communicating with the pipe is opened and closed by a float valve body connected to a water level change in a valve box connected to the pipe, wherein the float valve body has an outer peripheral surface. An antifreeze breakage type air valve, comprising: a core member having a recess formed in the core member; and an elastically deformable skin covered with the core member. 2. The freeze damage preventing type air valve according to claim 1, wherein a pressurized gas is filled in the recess.