JP2002340209A - Air valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air valve capable of preventing the outflow of liquid even if an exhaust hole is left in a completely nonclosable state by influence of an impurity such as refuse. SOLUTION: This air valve has a valve casing 5 having a connecting part to a pipe in a lower part, and having a valve seat 4 for forming the exhaust hole 3 in an upper part, a valve element 6 for opening-closing the exhaust hole 3, and a float 11 arranged inside the valve casing, and pressing the valve element 6 in the closing direction by buoyancy. A splash shelter 15 having an air vent 15a is arranged under the valve element 6. An auxiliary float 20 for opening-closing the air vent 15a is arranged just under the splash shelter 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air valve, and more particularly to a technique for discharging air from a sewage pipe.

[0002]

2. Description of the Related Art FIGS. 3 to 5 show an air valve of this type. This air valve has a flange portion 1 for connection to the sewage pipe A at a lower portion, a valve seat sheet 4 forming an exhaust hole 3 on an upper cover 2, and the upper cover 2 is connected to a valve box 5.
It is fixed to. A valve body 6 that opens and closes the exhaust hole 3 has a diaphragm 7 fixed to the upper end of a valve shaft portion 6a, and a lid member 8 having a pressure release hole 8a to the atmosphere is disposed above the diaphragm 7 to provide a valve shaft. Small-diameter air hole 9 penetrating part 6a
A pressure chamber 10 communicating with the inside of the valve box 5 is formed.

A float 11 moves up and down in the valve box 5 in response to a change in the liquid level, and presses the valve 6 in the closing direction by buoyancy.
Has been arranged. Shaft 14 supporting float 11
Engages with the pin 13 of the valve element 6 in the elongated hole 12 and
The upper end surface 14a of the shaft 14 abuts on and separates from the air hole valve seat 9a to open and close the small-diameter air hole 9 in the vertical direction.

A splash guard 15 is arranged below the upper cover 2, and a ventilation hole 15a is formed in the splash guard 15, and a strainer 16 is mounted above the ventilation hole 15a. A predetermined opening (not shown) is formed in the protective cover 17 disposed so as to cover the upper part of the exhaust hole 3.

The operation of the air valve having the above configuration will be described. When the pipe A is filled with water, the float 11 and the valve body 6 move downward, and the exhaust hole 3 is opened, so that a large amount of air in the pipe A is exhausted to the outside through the exhaust hole 3 of the valve box 5.

When the water level rises due to the progress of water filling, as shown in FIG. 4, buoyancy acts on the float 11 to move the float 11 upward, so that the shaft 14 is moved to the upper end surface 14a.
And closes the small-diameter air hole 9 and pushes up the valve body 6, and the valve body 6 closes the exhaust hole 3.

After completion of the water filling, when the air in the liquid flowing through the pipe A flows into the valve box 5 and accumulates therein, the liquid level drops, and the float 11 moves down due to the drop in the liquid level. Along with this, as shown in FIG. 5, the shaft 14 also moves down, and its upper end surface 14a is separated from the valve seat 9a to open the small-diameter air hole 9. By opening the small-diameter air hole 9, the internal pressure of the valve box 5 acts on the pressure chamber 10 through the small-diameter air hole 9, and a downward force acts on the valve body 6 via the diaphragm 7.

As a result, a downward force acting on the valve element 6 via the diaphragm 7 and an upward force acting on the internal pressure of the valve box 5 act on the valve element 6, and as shown in FIG. The weight of the valve body 6 and the float 11 pushes down the valve body 6, and a large amount of air accumulated inside the valve box 5 through the exhaust hole 3 is discharged.

As the air is discharged, the water level inside the valve box 5 rises, and the upward movement of the float 11 causes the shaft 14 to close the small-diameter air hole 9 at the upper end surface 14a and push up the valve body 6. The valve body 6 closes the exhaust hole 3 by closing movement and pushes up the diaphragm 7, and the air accumulated in the pressure chamber 10 is discharged through the pressure release hole 8a.

[0010]

By the way, when the air inside the valve box 5 is exhausted, impurities such as dust and the like are mixed with the air through the small-diameter air hole 9 of the valve shaft portion 6a.
And the contaminants may clog the pressure release hole 8a of the lid member 8.

As a result, the internal pressure of the pressure chamber 10 cannot be released, and a downward force continues to act on the diaphragm 7, so that the valve body 6 is pushed down and the exhaust hole 3 remains open. Thus, the liquid inside the valve box 5 flows out.

Further, even when foreign matter adheres to the valve seat of the exhaust hole 3, the valve element 6 cannot adhere to the valve seat sheet 4,
A part of the exhaust hole 3 remains open, and there is the same problem as described above.

An object of the present invention is to solve the above-mentioned problems, and an air valve capable of preventing the liquid from flowing out even if the exhaust hole is not completely closed due to the influence of foreign substances such as dust. It is intended to provide.

[0014]

In order to solve the above-mentioned problem, an air valve according to the present invention has a connection portion to a pipe at a lower portion and a valve seat having an exhaust hole at an upper portion. In a pneumatic valve including a box, a valve body that opens and closes an exhaust hole, and a float that is disposed inside the valve box and presses the valve body in the closing direction by buoyancy, a spray having a vent hole below the valve body is provided. An auxiliary float for opening and closing the ventilation hole is provided immediately below the splash guard.

With the above structure, even if the valve body is not completely closed for some reason, such as the influence of foreign matter, and the exhaust hole remains open, the liquid in the valve box is discharged with the exhaust. When the position rises above a certain level, the auxiliary float rises and closes the ventilation hole for splashing, thereby preventing the liquid inside the valve box from flowing out.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. Since the basic configuration of the air valve according to the present embodiment is the same as that shown in FIGS. 3 to 6, members performing the same operation are denoted by the same reference numerals and description thereof will be omitted.

In FIG. 1 and FIG. 2, immediately below the splash guard 15 installed inside the valve box 5 below the valve seat 4, when the liquid level inside the valve box 5 reaches a certain level or more, it rises. The auxiliary float 20 is arranged to be able to move up and down. The auxiliary float 20 has an annular shape capable of closing the ventilation hole 15a of the splash guard 15, and is made of rubber, plastic, or a thin metal sheet.

An annular projecting portion 20a projecting outward in the radial direction is formed at a peripheral edge of an upper end of the auxiliary float 20, and an auxiliary float receiver 21 engaged with the annular projecting portion 20a is fixed to the valve box 5. Accordingly, the auxiliary float 20 is received so as not to drop below a certain height position. In order to increase the water stoppage under low pressure, it is desirable to attach a soft rubber sealing material around the upper end surface of the auxiliary float 20 or around the ventilation hole 15a of the splash guard 15.

The operation of the above configuration will be described below. At the time of the exhaust operation, foreign substances such as dust mixed into the air and flowing into the inside of the pressure chamber 10 are clogged in the pressure release hole 8a of the cover member 8, and the internal pressure of the pressure chamber 10 cannot be released. The downward force continues to act, and the valve body 6 is pushed down to leave the exhaust hole 3 open, or impurities adhere to the valve seat of the exhaust hole 3 and the valve body 6
When the liquid level inside the valve box 5 rises above a certain level even when the exhaust port 3 remains open due to failure to adhere to the valve seat 4 as shown in FIG. In addition, the auxiliary float 20 floats up and the ventilation hole 15a
Can reliably prevent a large amount of liquid inside the valve box 5 from flowing out to the outside through the exhaust hole 3.

[0020]

As described above, according to the present invention, a large amount of liquid inside the valve box unexpectedly leaks to the outside by closing the ventilation hole provided below the exhaust hole with the auxiliary float. This can be reliably prevented, and is effective as an air valve used by being installed in a pipe of sewage.

[Brief description of the drawings]

FIG. 1 is an enlarged longitudinal sectional view of a main part showing a normal state of an air valve according to an embodiment of the present invention.

FIG. 2 is an enlarged longitudinal sectional view of a main part showing an operation of an auxiliary float of the air valve.

FIG. 3 is an overall vertical sectional view of a conventional air valve.

FIG. 4 is an enlarged vertical sectional view of a main part showing the operation of a conventional air valve.

FIG. 5 is an enlarged longitudinal sectional view of a main part showing the operation of a conventional air valve.

FIG. 6 is an enlarged vertical sectional view of a main part showing the operation of a conventional air valve.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Connection flange part 3 Exhaust hole 4 Valve seat 5 Valve box 6 Valve body 7 Diaphragm 8 Lid member 8a Pressure release hole 9 Small diameter air hole 10 Pressure chamber 11 Float 14 Shaft 15 Splash prevention 15a Vent hole 20 Auxiliary float

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2D063 EA00 3H055 AA05 AA22 BA12 CC06 GG26 GG37 JJ01 JJ08

Claims (1)

[Claims] 1. A valve box having a connection portion to a pipe at a lower portion and a valve seat sheet forming an exhaust hole at an upper portion, a valve element for opening and closing the exhaust hole, and a buoyancy disposed inside the valve box. An air valve having a float for pressing the valve body in the closing direction, wherein a splash guard having a ventilation hole is arranged below the valve body, and an auxiliary float for opening and closing the ventilation hole is provided immediately below the splash guard. An air valve characterized by the above.