JP2003014150A - Exhaust structure for air valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust structure for an air valve, capable of preventing external outflow of a liquid even when an exhaust hole is not completely closed due to foreign matters such as contaminant. SOLUTION: The air valve is provided with a valve casing 5 having, in its lower part, a flange part 1 for connecting to pipes and in upper part of the valve casing, a valve seat 4 forming the exhaust hole 3; a valve element 6 that opens and closes the exhaust hole 3; and a float 16, disposed in the valve casing, which presses the valve element 6 by buoyancy in a closing direction. A spray cover 31 is vertically movably provided, which has vent holes 31a under the valve element 6 and can press the valve element 6 in the closing direction, and an auxiliary float 32 is provided just below the spray cover 31, which opens and closes the vent holes 31a.

Description

Description: BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to an exhaust structure of an air valve, and more particularly to a technique for discharging air from a sewage pipe. 2. Description of the Related Art FIGS. 5 to 8 show an air valve of this type. This air valve has a flange portion 1 for connection to a sewage pipe at a lower portion, a valve seat 4 forming an exhaust hole 3 on an upper cover 2, and fixing the upper cover 2 to a valve box 5. . The valve body 6 that opens and closes the exhaust hole 3 is a valve shaft portion 6.
The upper end of the diaphragm 7a penetrates the diaphragm 7, and the diaphragm 7 is disposed by sandwiching the peripheral portion between the lid member 8 having the pressure release hole 8a to the atmosphere and the spring box 9 having the atmosphere release hole 9a. A pressure chamber 11 is formed which communicates with the inside of the valve box 5 through a small-diameter air hole 10 penetrating through the shaft portion 6a. A diaphragm pressing plate 12 is disposed below the diaphragm 7, and a spring 13 for pressing the diaphragm pressing plate 12 toward the diaphragm 7 is disposed inside the spring box 9. The valve shaft portion 6a is provided with a pair of nuts 15 for fastening the diaphragm pressing plate 12 to the valve shaft portion 6a via a metal collar 14. A float 16 which moves up and down in the valve box 5 in accordance with the fluctuation of the liquid level and presses the valve body 6 in the closing direction by buoyancy.
Is placed. Shaft 17 supporting float 16
Is engaged with the snap pin 19 of the valve body 6 in the elongated hole 18 and is provided so as to be movable relative to the valve body 6 in the vertical direction within a certain range. The small diameter air hole 10
Open and close. [0005] A splash guard 20 is arranged below the upper cover 2, a vent hole 20 a is formed in the splash guard 20, and a strainer 21 is attached above the vent hole 20 a. A predetermined opening (not shown) is formed in the protective cover 22 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. At the time of filling the pipe A with water, the float 16 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 in the valve box 5 rises due to the progress of filling, as shown in FIG. 6, buoyancy acts on the float 16 to move the float 16 upward, and the shaft 17 is moved to the upper end face 17a.
Then, the small-diameter air hole 10 is brought into contact with the air hole valve seat 10 a to close the small diameter air hole 10 and push up the valve body 6, and the valve body 6 closes the exhaust hole 3. After the 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 16 moves down due to the drop in the liquid level. Along with this, as shown in FIG. 7, the shaft 17 also moves down, and its upper end face 17a is separated from the air hole valve seat 10a to open the small diameter air hole 10. By opening the small-diameter air hole 10, the internal pressure of the valve box 5 acts on the pressure chamber 11 through the small-diameter air hole 10, and a downward force acts on the valve body 6 via the diaphragm 7. For this reason, 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 16 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 16 causes the shaft 17 to close the small-diameter air hole 10 at the upper end face 17a and push up the valve body 6. The valve body 6 closes the exhaust hole 3 by closing and pushes up the diaphragm 7, and the air accumulated in the pressure chamber 11 is discharged through the pressure release hole 8a. When the air inside the valve box 5 is exhausted, foreign substances such as dust mixed with the air enter the pressure chamber 11 through the small-diameter air hole 10 of the valve shaft portion 6a. Inflow, the contaminants are removed from the pressure release hole 8a of the lid member 8.
May be clogged. As a result, the internal pressure of the pressure chamber 11 cannot be released, and the 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 be in close contact with 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 liquid from flowing out even if the exhaust hole is not completely closed due to the influence of foreign substances such as dust. An object of the present invention is to provide an exhaust structure. [0015] In order to solve the above-mentioned problems, an exhaust structure of an air valve according to the present invention has a connection portion to a pipe at a lower portion and an exhaust hole at an upper portion. In an air valve provided with a valve box having a valve seat, a valve element for opening and closing an exhaust hole, and a float disposed inside the valve box and pressing the valve element in the closing direction by buoyancy, A splash guard which has a ventilation hole and can press the valve body in the closing direction is arranged so as to be movable up and down, and an auxiliary float for opening and closing the ventilation hole is provided immediately below the splash protection. With the above-described structure, the valve element is normally opened and closed by raising and lowering the float that follows the water level in the valve box,
The air in the valve box is exhausted through the exhaust hole. If the valve is not completely closed and the exhaust hole remains open for some reason such as the influence of impurities, if the water level in the valve box rises above a certain level due to the exhaust, Auxiliary floats rise to close the splash vents. When the vent hole is closed, the auxiliary float and splash guard rise due to the pressure inside the valve box, and the splash guard pushes the valve body in the closing direction to forcibly close the exhaust hole, and the inside of the valve box. Prevents liquid from flowing out. Embodiments of the present invention will be described below with reference to the drawings. Since the basic configuration of the air valve in the present embodiment is the same as that shown in FIG. 5, members performing the same function are denoted by the same reference numerals and description thereof is omitted. In FIG. 1 and FIG. 2, a splash guard 31 is installed so as to be vertically movable inside the valve box 5 below the valve seat 4, and immediately below the splash guard 31, the inside of the valve box 5 is disposed. An auxiliary float 32 that floats when the water level reaches a certain level or higher is arranged to be able to move up and down. The auxiliary float 32 has an annular shape capable of closing the ventilation hole 31a of the splash guard 31, and is made of rubber, plastic, or a thin metal sheet. The splash guard 31 is held at a predetermined position by a vertical edge engaging a step 33 formed on the inner surface of the valve box 5 in a vertical direction, and is held at a predetermined position by a boss 34 through which the shaft 17 is inserted. Contact 6 An auxiliary float receiver 35 is disposed on the step portion 33, and the auxiliary float receiver 35 is provided by the auxiliary float receiver 35.
2 so that it does not drop below a certain height. In order to increase the water stoppage under low pressure, it is desirable to bond a soft rubber sealing material 36 around the upper end surface of the auxiliary float 32 or around the ventilation hole 31a of the splash guard 31. The operation of the above configuration will be described below. During a normal exhaust operation, the air is exhausted by the operation described above with reference to FIGS. In the case of an abnormality, for example, in a case where impurities adhere to the valve seat of the exhaust hole 3 and the valve element 6 cannot be in close contact with the valve seat sheet 4 and a part of the exhaust hole 3 remains open, When the water level inside the valve box 5 rises above a certain level, as shown in FIG. 2, the auxiliary float 32 floats up and closes the ventilation hole 31a of the splash guard 31 to thereby prevent the valve box 5 from rising.
Prevents the liquid inside the liquid from flowing out. Alternatively, contaminants such as dust mixed into the air and flowing into the pressure chamber 11 may be removed from the pressure release hole 8 of the lid member 8.
a, the internal pressure of the pressure chamber 11 cannot be released, and a downward force continues to act on the diaphragm 7, and the valve body 6
Is pushed down, and the exhaust hole 3 remains open, the auxiliary float 32 rises up to prevent the splash 3
By closing the ventilation hole 31a, the pressure inside the valve box 5 acts on the auxiliary float 32 and the splash guard 31, the area of the splash guard 31 is larger than the diaphragm 7, and the pressing force by the splash 31 is reduced by the diaphragm. By exceeding the pressing force by 7, the auxiliary float 32 and the splash guard 31 rise and press the valve body 6 in the closing movement direction to forcibly close the exhaust hole 3. Therefore, the liquid inside the valve box 5 does not flow out. As shown in FIG. 3, a spring 37 is disposed between the splash guard 31 and the upper cover 2, and when the water level of the valve box 5 is lowered, the spring 37 is used.
Facilitates returning to the initial position. Further, the spring 37 can be disposed between the valve body 6 and the boss portion 34 as shown in FIG. As described above, according to the present invention, the auxiliary float is closed by the auxiliary float to be provided below the exhaust hole, so that the auxiliary float is further compressed by the pressure in the valve box. By raising the splash and forcibly closing the valve body, it is possible to reliably prevent a large amount of liquid inside the valve box from unexpectedly flowing out.

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 vertical cross-sectional view of a main part showing an action of an auxiliary float and a splash prevention of the air valve. FIG. 3 is an enlarged longitudinal sectional view of a main part showing a normal state of an air valve according to another embodiment of the present invention. FIG. 4 is an enlarged longitudinal sectional view of a main part showing a normal state of an air valve according to still another embodiment of the present invention. FIG. 5 is an overall vertical sectional view of a conventional air valve. FIG. 6 is an enlarged longitudinal sectional view of a main part showing the operation of a conventional air valve. FIG. 7 is an enlarged vertical sectional view of a main part showing the operation of a conventional air valve. FIG. 8 is an enlarged vertical sectional view of a main part showing the operation of a conventional air valve. [Description of Signs] 2 Upper cover 3 Exhaust hole 4 Valve seat 5 Valve box 6 Valve element 6a Valve shaft portion 7 Diaphragm 8 Cover member 8a Pressure release hole 10 Small diameter air hole 10a Air hole valve seat 11 Pressure chamber 16 Float 17 Shaft 17a Upper end surface 18 Slot 19 Snap pin 31 Splash prevention 31a Vent 32 Auxiliary float 33 Step 34 Boss 35 Auxiliary float receiver

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 body for opening and closing the exhaust hole, and the inside of the valve box. And a float that presses the valve element in the closing direction by buoyancy and has a ventilation hole below the valve element to raise and lower the splash that can press the valve element in the closing direction. An exhaust structure for an air valve, which is movably disposed and has an auxiliary float for opening and closing a vent just below a splash guard.