JPH0747988B2 - Air valve - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air valve that is erected in a pipeline and discharges air in the pipeline to the atmosphere.

2. Description of the Related Art Conventional air valves of this type have a float that can be raised and lowered in a valve box that has an exhaust hole at the top and a fluid inflow hole at the center of the bottom. A floating valve that opens and closes was attached.

This air valve, when the fluid in the pipeline is not flowing into the valve box, floats down and sits on the upper surface of the bottom of the valve box, the floating valve opens the exhaust hole, and the air in the pipeline flows in. A large amount of air is exhausted from the exhaust hole to the atmosphere via the hole and the air inflow hole.
Then, when the fluid in the pipeline flows into the valve box through the fluid inflow hole, the float floats up, the floating valve closes the exhaust hole, and the fluid in the valve box is prevented from overflowing into the atmosphere. At this time, the inside of the valve box is pressurized by the fluid in the pipeline. Therefore, when the water level of the fluid in the valve box drops next time, the float descends due to its own weight, but the floating valve remains pressed against the exhaust hole due to the internal pressure and does not descend. However, the floating valve is provided with a small air hole penetrating in the vertical direction, and opens when the float separates from the floating valve. Therefore, a small amount of residual air is exhausted from the small air hole to the atmosphere via the exhaust hole. When the water level of the fluid in the valve box rises accordingly, the float rises to close the small air holes of the floating valve, preventing the fluid in the valve box from overflowing into the atmosphere. In this way, when the fluid is sent into the pipeline, a large amount of air in the pipeline is exhausted, and by opening and closing the small air holes according to the water level of the fluid in the valve box, the air in the pipeline is Is exhausted in small quantities.

However, in the conventional air valve described above, when a large amount of air in the pipeline is exhausted, air flows between the bottom surface of the float and the bottom of the valve box, and the air pressure pushes up the float. Therefore, there is a problem that the floating valve may close the exhaust hole even though a large amount of exhaust is still in progress.

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 is provided with a float capable of moving up and down in a valve box having an exhaust hole at the top and a fluid inflow hole at the center of the bottom. In an air valve with an air inlet passing vertically through the center and a floating valve attached to the upper surface of the float to open and close the exhaust hole by raising and lowering the float, a plurality of air vent holes are provided around the air inlet of the float. Is configured to penetrate vertically.

In the above configuration of the present invention, when a large amount of air in the pipeline is exhausted, even if air flows in between the lower surface of the float and the bottom of the valve box, the air is escaped from the air vent hole to the upper side of the float, The float is never pushed up pneumatically. Therefore, there is no possibility that the floating valve closes the exhaust hole during the exhaust.

Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

As shown in FIG. 1, the air valve of the present embodiment is provided with a float 2 capable of moving up and down in a valve box 1, a floating valve 3 being attached to the upper surface of the float 2, a ball valve 4 and a mounting flange. It is erected on a pipe line (not shown) via 5.
The valve box 1 is composed of an upper valve box 6 and a lower valve box 7 connected by a plurality of bolts 8 and nuts 9. An exhaust hole 10 is provided at the top of the upper valve box 6 so as to communicate with the atmosphere inside the valve box 1 in the vertical direction, and a fluid inlet hole 11 that communicates with the ball valve 4 is provided at the center of the bottom of the lower valve box 7. Is provided. As shown in FIG. 2, the float 2 is made of a foamed rubber or the like having a disc shape and a specific gravity smaller than 1, and has a floating valve mounting recess 12 formed on the upper surface thereof and an air inflow hole 13 at the center thereof. While penetrating in the vertical direction, a plurality of air vent holes 14 (three in the figure) penetrate the peripheral portion of the air inflow hole 13 in the vertical direction. A vertical guide groove 15 is formed on a side surface of the float 2 to prevent the float 2 from rotating, and is engaged with a guide protrusion 16 formed on the inner surface of the valve box 1 so as to be able to move up and down.

As shown in FIG. 3, the floating valve 3 is a plate valve for opening and closing the lower opening of the exhaust hole 10 by moving the float 2 up and down, and the rubber valve seat 18 is provided in the lower recess of the circular floating valve body 17. Is fitted,
A small air hole 19 penetrates through the central part, and the recess of the float 2
It is fitted in 12 so that it can be raised and lowered. On the upper surface of the floating valve body 17, an annular projection 20 for centering the valve body 17 with respect to the exhaust hole 10 is formed. Reference numeral 21 is a retainer for preventing the floating valve body 17 from coming out of the recess 12.

22 is a cylindrical strainer for the fluid flowing into the valve box 1, the upper end of which is fixed to a lid 23 provided at the center of the top of the upper valve box 6 via a pin 24 and the lower end of which is a float. It penetrates through the air inflow hole 13 of No. 2 and is inserted in the fluid inflow hole 11 of the lower valve box 7. On the top of the lid 23,
25 are provided. The ball valve 4 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 valve box 1, the float 2 descends and is placed on the upper surface of the bottom of the lower valve box 7, and the floating valve 3
Opens the exhaust hole 10 and exhausts a large amount of air in the pipeline from the exhaust hole 10 to the atmosphere via the ball valve 4, the fluid inflow hole 11 and the air inflow hole 13. Then, the fluid in the pipeline is changed to the ball valve
When flowing into the valve box 1 from the fluid inflow hole 11 via the, the float 2 floats and presses the floating valve 3 against the exhaust hole 10.
Therefore, both the small air hole 19 and the exhaust hole 10 are closed to prevent the fluid in the valve box 1 from overflowing into the atmosphere. At this time, the inside of the valve box 1 is pressurized by the fluid in the pipeline. Therefore, when the water level of the fluid in the valve box 1 drops next time, the float 2 descends due to its own weight, but the floating valve 3 remains pressed against the exhaust hole 10 due to the internal pressure and does not descend. Therefore, the float 2 separates from the valve seat 18 of the floating valve 3 and opens the small air hole 19. As a result, a small amount of residual air in the valve box 1 is exhausted from the small air hole 19 to the atmosphere via the exhaust hole 10. When the water level of the fluid in the valve box 1 rises accordingly, the float 2 rises to close the small air holes 19 and prevent the fluid in the valve box 1 from overflowing into the atmosphere. In this way, when the fluid is fed into the pipeline, a large amount of air in the pipeline is exhausted, and the small air holes 19 are opened / closed according to the water level of the fluid in the valve box 1 so that Exhaust a small amount of air.

In the operation of the air valve, when the float 2 descends and is placed on the upper surface of the bottom of the lower valve box 7, and when a large amount of air in the pipeline is exhausted from the exhaust hole 10, the lower surface of the float 2 and the bottom of the lower valve box 7 Although air may flow in between the two, the air is escaped from the air vent hole 14 to above the float 2. Therefore, the float 2 is pushed up by its air pressure, and the floating valve 3 moves through the exhaust hole 10 even though a large amount of air is being exhausted.
There is no way to close the.

EFFECTS OF THE INVENTION As described above, according to the present invention, since the plurality of air vent holes penetrate vertically around the air inlet hole of the float, the float descends and the bottom surface of the bottom of the valve box is lowered. When exhausting a large amount of air in the pipeline from the exhaust hole,
Even if air flows in between the bottom surface of the float and the bottom of the valve box, the air is escaped above the float from the air vent hole. Therefore, there is no possibility that the floating valve will be pushed up by the air pressure and the floating valve will close the exhaust hole even though a large amount of air is being exhausted. as a result,
It has the advantage that the exhaust performance of the air valve is significantly improved.

[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 a plan view of the float of the present invention, and FIG. 3 is III- of FIG.
It is a III line sectional view. 1 ... Valve box, 2 ... Float, 3 ... Floating valve, 10 ... Exhaust hole, 11 ... Fluid inlet hole, 13 ... Air inlet hole, 14 ... Air vent hole.

Claims (1)

[Claims] 1. A float is vertically movable in a valve box having an exhaust hole at the top and a fluid inflow hole at the center of the bottom. An air inlet penetrates vertically through the center of the float, and a float is provided on the upper surface of the float. An air valve provided with a floating valve that opens and closes an exhaust hole by raising and lowering the air valve, wherein a plurality of air vent holes penetrate vertically around an air inflow hole of the float.