JPH0765693B2 - Air valve - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure balance type air valve for exhausting air in a pipe or the like into the atmosphere.

2. Description of the Related Art A conventional air valve of this type has a float 2 and a floating valve 3 in a valve box 1 as shown in FIG. 3, for example. Installed in the pipeline. The valve box 1 has a floating valve box 5 above the float chamber 4.
The exhaust chamber 6 and the pressure chamber 7 are provided via the. The float chamber 4 has a fluid inflow hole 8 at the bottom, and a plurality of strainers 10 are provided on the upper surface of a protective wall 9 fixed to the upper end. The fluid inflow hole 8 communicates with the inside of the conduit via the on-off valve. The protective wall 9 is for blocking splashes scattered from the liquid surface of the fluid and has a plurality of air holes 11. The strainer 10 is for collecting the dust scattered with the splash. The floating valve box 5 has an air hole in the center.
It has 12 and is fixed on the float chamber 4 by a bolt 13. The exhaust chamber 6 has an exhaust hole 14 at the bottom and is fixedly mounted on the floating valve box 5 by bolts 15. The exhaust hole 14 communicates with the atmosphere through an opening 16 in the side wall. The pressure chamber 7 is composed of an upper chamber 18 and a lower chamber 19 with a diaphragm 17 sandwiched therebetween, and is fixedly installed on the exhaust chamber 6 by means of bolts 20 and nuts 21.
The upper chamber 18 is sealed. The float 2 has an elliptic spherical shape, has a guide rod 22 extending upward from the center, and is arranged in the float chamber 4 so as to be able to move up and down. The upper end of the guide rod 22 penetrates the central portion of the protective wall 9 so as to be able to move up and down, projects into the floating valve box 5, and has a long hole 23 at its tip. The idle valve 3 is
The valve body 24 is formed below the valve rod 25. Disc 24
Is a circular plate valve, and is a floating valve box 5 that opens and closes the exhaust hole 14.
It is arranged so as to be able to move up and down in the air hole (12). The lower end of the valve rod 25 is connected to the elongated hole 23 of the guide rod 22 via a pin 26 so as to be movable up and down by a certain amount with respect to the float 2. Valve rod
The upper end of 25 extends upward and protrudes into the pressure chamber 7, and the upper and lower washers 28 and 29 are fitted to the tip by a nut 27.
A diaphragm 17 is sandwiched between. A communication hole 30 penetrates through the center of the valve rod 25 to communicate the inside of the floating valve box 5 and the inside of the upper chamber 18. Lower washer 29 of diaphragm 17 and pressure chamber 7
A compression spring 31 is provided between the bottom of the lower chamber 19 and
The valve rod 25 is biased upward. The on-off valve is always open, and is closed for maintenance, inspection, replacement, etc. of the air valve.

In the above air valve, when the water in the pipeline is not flowing into the float chamber 4, the float 2 and the floating valve 3 descend, and the weight of these causes the lower washer 29 of the valve rod 25 to compress the compression spring 31. Against the bottom of the lower chamber 19 of the pressure chamber 7. The valve body 24 opens the exhaust hole 14, opens and closes the air in the pipeline,
A large amount of air is exhausted from the opening 16 into the atmosphere via the fluid inflow hole 8, the air holes 11 and 12, and the exhaust hole 14. At this time, the guide rod 22 of the float 2 separates from the lower end surface of the valve rod 25 and opens the communication hole 30, so that the air pressure in the floating valve box 5 and the air pressure in the upper chamber 18 are balanced. Then, when the fluid in the pipeline flows into the float chamber 4 from the fluid inflow hole 8 via the on-off valve,
As the float 2 starts to float, internal pressure is generated in the floating valve box 5, and this internal pressure is transmitted to the upper chamber 18 via the communication hole 30 and urges the valve rod 25 downward. When the float 2 further floats and the guide rod 22 closes the communication hole 30, the upper chamber 18
Since the air inside is not discharged anywhere, it resists the floating of the float 2. The float 2 lifts the floating valve 3 against this resistance force, the valve body 24 closes the exhaust hole 14, and prevents the fluid in the float chamber 4 from overflowing into the atmosphere. Along with this, internal pressure is generated in the float chamber 4 based on the pressure in the pipeline. Therefore, next float chamber 4
When the amount of air in the inside increases and the water level of the fluid decreases, the float 2 descends by its own weight, but the floating valve 3 is prevented from descending by the internal pressure. Therefore, the guide rod 22 separates from the valve rod 25 and opens the communication hole 30, so that the internal pressure in the floating valve box 5 and the internal pressure in the upper chamber 18 are balanced. Therefore, the pushing force acting on the back surface of the valve body 24 and the pushing force acting on the upper end portion of the valve rod 25 are balanced, and the floating valve 3 descends by its own weight to open the exhaust hole 14 and Exhaust a small amount of air. As a result, the internal pressure in the float chamber 4 decreases, and when the water level of the fluid in the float chamber 4 next rises, the floating valve 3 lifts the floating valve 3 by the buoyancy of the float 2 as in the case already described.
The exhaust hole 14 is closed to prevent the fluid in the float chamber 4 from overflowing into the atmosphere. In this way, by opening and closing the exhaust holes 14 according to the water level of the fluid in the float chamber 4, a large amount of air in the pipe line or a small amount of air in the valve box 1 is exhausted.

However, in the above-described conventional configuration, when the float 2 floats to lift the floating valve 3 and the exhaust hole 14 is closed to prevent the fluid from overflowing into the atmosphere, Since the air in the chamber 18 is not discharged anywhere, there is a great resistance to the floatation of the float 2, the closing of the exhaust hole 14 is delayed, and the water level in the float chamber 4 at the time of water stop becomes high. Therefore, in order to prevent this, there is a problem that the float chamber 4 needs to be enlarged and the float 2 needs to be enlarged to increase its buoyancy.

It is an object of the present invention to improve the conventional air valve and eliminate such problems.

Means for Solving the Problems In order to achieve the above object, the air valve of the present invention comprises a float and a floating valve having a valve element in the lower part of the valve rod in the valve box, and the valve box is A float chamber having a fluid inflow hole at the bottom, and an exhaust chamber provided at the upper part of the float chamber through a floating valve box and having an exhaust hole communicating with the atmosphere,
It is equipped with a pressure chamber divided into an upper chamber and a lower chamber by a diaphragm, a float is arranged to be able to move up and down in the float chamber, and a valve body is arranged to be able to move up and down in a floating valve box so as to open and close an exhaust hole. The lower end of the valve rod is connected to the float so that it can move up and down by a certain amount so that the valve body closes the exhaust hole upward due to the buoyancy acting on the float, and the upper end of the valve rod moves upward. A communication hole that extends and is connected to the diaphragm and that penetrates through the center of the valve rod communicates the inside of the floating valve box with the upper chamber, and the upper end of the float opens the lower end of the communication hole by the buoyant force acting on this float. In the air valve configured so as to close, a small exhaust hole having a diameter smaller than that of the communication hole is provided in the upper chamber so as to communicate with the atmosphere.

The small exhaust hole may be provided in an exhaust member detachably attached to the upper chamber.

Action In the above-described configuration of the present invention, when it is attempted to prevent the fluid from overflowing into the atmosphere by closing the exhaust hole by raising the water level in the float chamber and floating the float, the float contacts the valve rod. Since the communication hole is closed, air does not flow into the upper chamber from the communication hole, and only air is discharged from the small exhaust hole. Therefore, the upper chamber is at atmospheric pressure, and there is no force to urge the valve rod downward. As a result, the float lifts the floating valve to close the exhaust hole without any resistance, so that the delay of water stop can be prevented and the float can be small. On the contrary, when the amount of air in the float chamber increases and the water level decreases, the float descends and opens the exhaust hole, and when trying to exhaust a small amount of air in the floating valve box, the float descends by its own weight, Since the floating valve is prevented from descending by the internal pressure in the floating valve box, the float separates from the valve stem and opens the communication hole, and the internal pressure in the floating valve box is transmitted to the upper chamber via the communication hole. Part of the air in the upper chamber is discharged into the atmosphere through the small exhaust holes, but the small exhaust holes are formed with a diameter smaller than that of the communication holes, and the amount of air flowing in from the communication holes is discharged from the small exhaust holes. Since it is larger than the air amount, the internal pressure remains in the upper chamber, and the internal pressure in the floating valve box and the internal pressure in the upper chamber are balanced. Therefore, the push-up force acting on the back surface of the valve body and the push-down force acting on the upper end portion of the valve rod are balanced, and the floating valve descends due to its own weight to open the exhaust hole, and a small amount of air in the floating valve box is released. Exhaust.

If a small exhaust hole is provided in the exhaust member that is detachably attached to the upper chamber, the hole diameter can be changed by replacing the exhaust member, and the air valve of the air valve can be changed according to various usage conditions. The function can be kept optimal.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 and 2, the air valve of the present embodiment comprises a float 42 and a floating valve 43 in a valve box 41. Although not shown in the figure, a normal opening / closing valve is used. Set up in the pipeline.

The valve box 41 includes an exhaust chamber 46 and a pressure chamber 47 above the float chamber 44 with a floating valve box 45 interposed therebetween. The float chamber 44 has a fluid inflow hole 48 at the bottom and a protective wall 49 fixedly provided at the upper end.
A plurality of strainers 50 are provided on the upper surface of the. The fluid inflow hole 48 communicates with the inside of the conduit via the on-off valve. Protective wall 49
Has a plurality of air holes 51 for blocking the splashes scattered from the liquid surface of the fluid. The strainer 50 is a disc having a large number of small holes, and collects the dust scattered with the splash. The floating valve box 45 has an air hole 52 in the center and is fixed on the float chamber 44 by a bolt 53.
The exhaust chamber 46 has an exhaust hole 54 at the bottom, and is fixed on the floating valve box 45 by bolts 55. Exhaust holes 54 are side wall openings 56
Communicates with the atmosphere via. The pressure chamber 47 has a diaphragm 57.
It consists of an upper chamber 58 and a lower chamber 59 with a bolt 60
It is fixed on the exhaust chamber 46 by a nut 61. Upper chamber 58
Is sealed. Reference numeral 62 denotes a plug-shaped exhaust member that is detachably screwed to the wall portion of the upper chamber 58 and has a small exhaust hole 63.

The float 42 has an elliptic spherical shape and is made of a material having a specific gravity of less than 1, and has a guide rod 64 extending upward from the central portion,
The float chamber 44 is arranged so that it can be raised and lowered. Guide bar 64
Has an upper end that penetrates the center of the protective wall 49 so as to be able to move up and down and projects into the floating valve box 45, and has a long hole 65 at the tip.

The floating valve 43 has a structure in which a valve element 66 is formed below a valve rod 67. The valve element 66 is a circular plate valve and is arranged so as to be able to move up and down in the air hole 52 of the floating valve box 45 so as to open and close the exhaust hole 54. The lower end of the valve rod 67 is connected to the elongated hole 65 of the guide rod 64 via a pin 68 so as to be vertically movable with respect to the float 42. The upper end of the valve rod 67 extends upward to extend the pressure chamber 47.
Top and bottom 2 protruding inside and fitted with a nut 69 at the tip
A diaphragm 57 is sandwiched between individual washers 70 and 71.
A communication hole 72 penetrates through the center of the valve rod 67 to connect the inside of the floating valve box 45 and the inside of the upper chamber 58. A rubber valve seat 73 is fitted into the lower end opening of the communication hole 72. The small exhaust hole 63 of the exhaust member 62 needs to have a smaller diameter than the communication hole 72. A compression spring 74 is provided between the lower washer 71 of the diaphragm 57 and the bottom of the lower chamber 59 of the pressure chamber 47, and biases the valve rod 67 upward.

The on-off valve is always open, and is closed during maintenance, inspection, replacement, etc. of the air valve.

Next, the operation of the above configuration will be described.

When the fluid in the pipeline does not flow into the float chamber 44, the float 42 and the floating valve 43 descend, and the lower washer 71 of the valve rod 67 resists the compression spring 74 and the lower chamber 59 of the pressure chamber 47. Abut on the bottom (see the chain double-dashed line in FIG. 2). The valve body 66 opens the exhaust hole 54, and exhausts a large amount of air in the pipeline from the opening 56 into the atmosphere via the on-off valve, the fluid inflow hole 48, the air holes 51, 52 and the exhaust hole 54. At this time, the guide rod 64 of the float 42 separates from the valve seat 73 of the valve rod 67 and opens the communication hole 72, so that the air pressure in the floating valve box 45 and the air pressure in the upper chamber 58 are balanced. Then, when the fluid in the pipeline flows into the float chamber 44 from the fluid inflow hole 48 via the on-off valve, the float 42 starts to float and internal pressure is generated in the floating valve box 45. The internal pressure is transmitted into the upper chamber 58 via the communication hole 72. Upper chamber
Some of the air in 58 is discharged into the atmosphere through the small exhaust holes 63, but the small exhaust holes 63 are formed with a diameter smaller than that of the communication holes 72, and the amount of air flowing in from the communication holes 72 is small. Since it is larger than the amount of air discharged from 63, the internal pressure remains in the upper chamber 58 and urges the valve rod 67 downward. When the float 42 further floats up and the guide rod 64 closes the communication hole 72, the upper chamber 58 stops the inflow of air from the communication hole 72 and only discharges from the small exhaust hole 63. Therefore, the inside of the upper chamber 58 is at atmospheric pressure,
The force that urges valve stem 67 downward is removed. As a result, the float 42 lifts the floating valve 43 without any resistance,
66 closes the exhaust hole 54 and prevents the fluid in the float chamber 44 from overflowing into the atmosphere. Therefore, there is no delay in water shut-off and no need to increase the float as in conventional air valves. With the closing of the exhaust hole 54, the float chamber
Inside 44, internal pressure is generated based on the water pressure in the pipeline.
Therefore, when the amount of air in the float chamber 44 next increases and the water level of the fluid decreases, the float 42 descends due to its own weight, but the floating valve 43 is prevented from descending due to the internal pressure. Therefore, the guide rod 64 separates from the valve seat 73 of the valve rod 67 and opens the communication hole 72, and the internal pressure in the floating valve box 45 passes through the communication hole 72 and the upper chamber 58.
It is transmitted inside. Part of the air in the upper chamber 58 is discharged into the atmosphere through the small exhaust holes 63, but for the same reason as described above, the internal pressure remains in the upper chamber 58 and the internal pressure in the floating valve box 45 The internal pressure in the upper chamber 58 reaches a balance. Therefore, the valve body
The push-up force acting on the back surface of 66 and the push-down force acting on the upper end portion of the valve rod 67 are balanced, and the floating valve 43 descends by its own weight to open the exhaust hole 54, and the air in the floating valve box 45 is removed. Exhaust a small amount. As a result, the internal pressure in the float chamber 44 decreases and the inside of the upper chamber 58 becomes atmospheric pressure. Next, when the water level of the fluid in the float chamber 44 rises, the floating valve 43 is lifted by the buoyancy of the float 42, the exhaust hole 54 is closed and the fluid in the float chamber 44 is released into the atmosphere, as in the case already described. Prevent it from overflowing. In this way, the float chamber 44
By opening / closing the exhaust hole 54 according to the water level of the fluid inside, a large amount of air in the pipe line or a small amount of air in the valve box 41 is exhausted.

Since the small exhaust hole 63 is provided in the plug-like exhaust member 62 that is detachably screwed to the wall of the upper chamber 58 of the pressure chamber 47, the hole diameter can be changed by replacing the exhaust member 62. Is possible. Therefore, the function of the air valve can be optimally maintained according to various usage conditions.

As described above, the present invention has a very simple structure in which a small exhaust hole having a smaller diameter than the communication hole of the valve rod is provided in the upper chamber of the valve box in communication with the atmosphere, Even though the pressure chamber communicates with the atmosphere, a force can be generated that pushes down the floating valve to open it, and the water level in the float chamber rises to float the float and close the exhaust hole. In order to prevent the fluid from overflowing into the atmosphere, the atmospheric pressure in the upper chamber is immediately set so that the internal pressure in the upper chamber does not become a floating resistance of the float. As a result, there is an advantage that the delay of the water stop is prevented and the float is small, so that the entire air valve is small. further,
If a small exhaust hole is provided in the exhaust member that is detachably attached to the upper chamber, the hole diameter can be changed by exchanging the exhaust member. The function can be kept optimal.

[Brief description of drawings]

FIG. 1 is a sectional view of an air valve showing an embodiment of the present invention, and FIG.
FIG. 3 is an enlarged sectional view showing a main part of the present invention, and FIG. 3 is a sectional view showing an example of a conventional air valve. 41 ... Valve box, 42 ... Float, 43 ... Floating valve, 44 ... Float chamber, 45 ... Floating valve box, 46 ... Exhaust chamber, 47 ... Pressure chamber, 48 ... Fluid inflow hole, 54 ... Exhaust hole, 57 ... Diaphragm, 62 ... Exhaust member, 63 ... Small exhaust hole, 66 ... Valve body, 67 ... Valve rod, 72 ... Communication hole.

Claims (2)

[Claims] 1. A float and a floating valve having a valve element at a lower portion of a valve rod are provided in a valve box, and the valve box has a float chamber having a fluid inflow hole at a bottom and an upper part of the float chamber. It is equipped with an exhaust chamber that has an exhaust hole that is provided through the floating valve box and that communicates with the atmosphere, and a pressure chamber that is divided into an upper chamber and a lower chamber by a diaphragm, so that the float can move up and down in the float chamber. It is arranged so that the valve body can move up and down in the floating valve box to open and close the exhaust hole, and the lower end of the valve rod floats so that the valve body closes the exhaust hole upward due to the buoyant force acting on the float. On the other hand, it is connected to the float so that it can move up and down by a certain amount, the upper end of the valve rod extends upward and is connected to the diaphragm, and the communication hole that penetrates the center of the valve rod connects the inside of the floating valve box and the upper chamber. It is in communication, the upper end of the float In the air valve configured to close the lower end opening of the communication hole by buoyancy acting on the float, a small exhaust hole having a smaller diameter than the communication hole is provided in the upper chamber in communication with the atmosphere. Air valve to do. 2. The air valve according to claim 1, wherein the small exhaust hole is provided in an exhaust member detachably attached to the upper chamber.