JPH0579866B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an air valve installed in a water supply pipe.

[Prior art] Air valves exhaust air from the pipe when water is flowing through the pipe, and supply air into the pipe when draining water from the pipe, pressurizing the inside of the pipe and producing pressurized water. When the pipe is in a flowing state, it is installed for the purpose of discharging air or gas separated from the water from the pipe when the water is full.

Conventionally, many technologies have been disclosed regarding air valves. Figure 4 is established in the Japanese Industrial Standards.
JIS B 2063 single-port air valve for water supply. This is because the lower opening 42 provided at the bottom of the valve box 41 installed at the top of the water pipeline is inserted into the pipeline, and the apparent specific gravity of the valve body stored in the valve box 41, which can be raised and lowered, acts as a valve body. A float 43 of 1 or less (0.75 to 0.80) moves up and down in conjunction with fluctuations in the water level inside the valve box 41.
An air hole 46 provided in an elastic valve seat 45 fixed to the center of an upper lid 44 that closes the upper part of the valve is opened and closed.

To explain the function of this air valve in detail, when water is flowing, the air in the pipe is discharged from the air hole 46,
When the inside of the pipe becomes full of water and the water level in the valve box 41 rises, the float 43 also rises and comes into close contact with the valve seat 45 to close the air hole 46. When draining water from the pipe, when the water level in the valve box 41 drops, the float 4
3 also descends away from the valve seat 45 and opens the air hole 46, so that air is supplied into the pipe line from the air hole 46.
In addition, so-called pressure exhaust, in which air and gas separated from water are discharged when the pipe is pressurized and full of water, is performed when the float 43 is in a fully closed state with the valve seat 45 in close contact with the inside of the valve box 41 and the atmosphere. The product of the pressure difference (hereinafter referred to as the pressure difference between the inside and outside of the valve) and the cross-sectional area of the air hole 46 is the force that tries to bring the float 43 into close contact with the valve seat 45, and by this force and the weight of the float 43, The forces that try to separate the float 43 from the valve seat 45 are opposed to each other, and when air or gas separated from the water accumulates in the upper part of the valve box 41 and the water level falls, the buoyant force acting on the float 43 decreases. As the weight of the float 43 increases, the float 43 moves away from the valve seat 45 and descends, opening the air hole 46 and exhausting the air. When exhaust is performed and the water level rises, the float 43 rises again and comes into close contact with the valve seat 45, closing the air hole 46.

[Problems to be Solved by the Invention] As mentioned above, in conventional air valves, the force that tries to bring the float into close contact with the valve seat is equal to the product of the differential pressure inside and outside the valve multiplied by the cross-sectional area of the air hole. Therefore, in order to exhaust air under pressure, there are structural limitations depending on the relative relationship between the differential pressure inside and outside the valve, the cross-sectional area of the air hole, and the weight of the float. In other words, from the above relative relationship, when the differential pressure is large, the air hole will not open and the valve will not operate unless the weight of the float is increased.If the air hole is made larger at the same differential pressure, the weight of the float must be increased. Otherwise, the valve will not operate. Furthermore, if the weight of the float is the same, the air hole must be made smaller when the differential pressure is large. In general, the functions required of an air valve are to be applicable over a wide range of differential pressures inside and outside the valve, and to have the air hole as large as possible in cross-sectional area and the float to be as small as possible. If the float is large, the entire valve box will also be large and heavy, which will be an obstacle when installing it in the pipeline. Furthermore, the smaller the air holes are, the more likely they are to become clogged, which can be fatal in the case of agricultural water or sewage that contains a large amount of solid matter.

The conventional technology listed above (Figure 4) is intended for fresh water, and since the close contact area between the air hole valve seat and the float is close to the water surface, there is an opportunity for solids to adhere with the water. This tends to cause sewage to spray out to the top of the valve box along with the exhaust air, and this often clogs the small air holes and causes the valve to lose its function. Recently, specifications for pumping sewage have been increasing, and it is difficult to use the air valves used in clean water (water supply) pipes as they are, and even if they are used, it is difficult to expect sufficient functionality. be.

In order to solve the above-mentioned problems, the present invention has developed a new air valve that keeps the force required when opening and closing the air hole almost constant regardless of the differential pressure inside and outside the valve or the cross-sectional area of the air hole. For the purpose of providing.

[Means for Solving the Problems] The air valve according to the present invention is supported by a fulcrum 4 erected approximately above the center of a sealing lid 3 of a valve box 1 having a lower opening 2 communicating with a water supply pipe. Link lever 5
The valve body 7 is hung horizontally so as to be tiltable, and the valve body 7 is suspended from one end point 6 of the link lever so as to be freely raised and lowered to open and close the air hole 8 penetrating the sealing lid. A weight 1 is suspended from a hanging point 9 through a first push rod 10 that is suspended in a vertically movable manner within a through hole of the airtight lid.
1, and the first push rod 10 is provided with a compression spring 13 surrounding it that urges upward on the sealing lid, and the lower end of the first push rod 10 moves in conjunction with a diaphragm 18 stretched over the bottom surface of the sealing lid. A diaphragm piston 12 is formed, and a second push rod 15 that can be raised and lowered from the end point 14 is suspended from the other side of the fulcrum 4, and the lower end of the second push rod 15 also extends to the bottom surface of the through hole. The second diaphragm piston 16 is formed to move together with the stretched diaphragm, and (1) the distance from the fulcrum 4 to the end point 6 that suspends the valve body is La, (2) the cross-sectional area of the air hole 8 is Aa (3) The distance from the fulcrum 4 to the suspension point 9 that suspends the first push rod is L ₁ (4) The pressure receiving area of the first diaphragm piston 12 is A ₁ (5) The distance from the fulcrum 4 to the second push rod End point 14 for suspending the rod
L ₂ (6) The pressure receiving area of the second diaphragm piston is
When A ₂ is assumed, the above-mentioned problem is solved by substantially establishing the following relationship: L ₂ ×A ₂ =L ₁ ×A ₁ +La ×Aa.

[Operation] Figures 1 to 3 show examples of the operation of the present invention.
This will be explained based on the diagram.

A fulcrum 4 is erected approximately at the center of the sealing lid 3 of the valve box 1 connected to the water supply pipe A through the lower opening 2, and a link lever 5 that engages with this fulcrum is horizontally suspended on the sealing lid. . A valve body 7 is suspended from an end point 6 of the link lever so as to be freely raised and lowered to open and close an air hole 8 penetrating the sealing lid. Furthermore, a weight 11 is suspended from a suspension point 9 near the fulcrum of this link bar via a first push rod 10 so as to be able to rise and fall freely. This push rod 10 is surrounded by a first diaphragm piston 12 formed in the upper part of the valve body above the weight, and a compression spring 1 is mounted on the first diaphragm piston 12 with a sealing lid 3 in between.
It is also surrounded by 3. That is, at the suspension point 9 of the link lever 5, the gravity of the weight 11 that pulls the first push rod 10 downward and the urging force that tries to pull it upward are applied to the first diaphragm piston 12. The structure is such that it is acting in the same way. A second push rod 15 is suspended from an end point 14 on the other side beyond the fulcrum of the link lever 5 so as to be able to move up and down, and is acted upon by a second diaphragm piston 16 formed at the upper part of the valve box.

In the above configuration, when the above relational expression is established, A ₂ ×L ₂ =S ₂ , Aa × La = Sa, A ₁ ×L ₁ =S ₁ , S ₂ =Sa + S ₁ , so the valve body 7 Analyzing the force acting on
The pressure difference between the inside and outside of the valve is P, the urging force f that exceeds the weight of the weight 11, the force that tries to bring the valve body 7 into close contact with the valve seat is F,
Using the above symbols for the cross-sectional area Aa of the air hole 8 and the distance between supporting points, and ignoring the weight other than the weight 11, F = P x (Sa + S ₁ - S ₂ ) ÷ La + f x L ₁ ÷ La S ₂ = Sa + S ₁ , so F = f × L ₁ ÷ La = W The force that closes the valve is approximately the pressing force W due to the urging force that overcomes the gravity of the weight, and the gravity of the weight is It remains the same as long as it does not change, and changes only when the buoyancy changes due to changes in the water level, and the valve opens or closes depending on that force relationship.

In this way, the force acting on the valve body due to the differential pressure inside and outside the valve is canceled out by the force generated on the diaphragm piston, and the force that moves the valve body to close the air hole is due to the gravity of the weight. Only the pressing force due to the overcoming biasing force becomes a substantially constant value regardless of the size of the differential pressure between the inside and outside of the valve or the size of the cross-sectional area of the air hole. Therefore, if this biasing force is set between the maximum and minimum buoyancy of the weight, which fluctuates as the water level rises and falls, the air valve will always remain unaffected even if other conditions change. Able to function normally.

[Examples] Preferred embodiments of the present application will be described while avoiding duplication with the previous section.

In the figure, an elastic first diaphragm 18 is stretched over the lower end of a first through hole 17 formed in the sealing lid 3 of the valve box 1, and the lower end surface of the first push rod 10 and the mounting member 19 are connected to each other. A first diaphragm piston 12 is sandwiched therebetween. In this example, a float having a specific gravity smaller than that of water is selected as the weight 11, and is suspended downward by a rope 20. End point 6
The valve body 7 that is suspended from the valve body 7 is attached and detached from the valve seat 21 to open and close the valve, and the valve seat has an air hole 8 in the center, and the valve seat surface 23 of the valve body and the valve box are connected to the valve seat 21 at the bottom. Valve seat surfaces 22 of the valve seat 21 face each other. Valve seat 21
A plurality of screw holes 25 communicating with the air holes are opened in a supporting member 24 fixed to the sealing lid 3 and placed thereon, thereby forming an air inlet/outlet between the inside and outside of the valve box.

The end point 6, the suspension point 9, and the end point 14 of the link lever 5 are mounted through elongated holes 26, 27, and 28, respectively, and are connected to the pins by movement of the pins 29, 30, and 31 that loosely fit into the elongated holes. Metal fittings 32, 33, 34
The link lever can also be tilted as the valve body and push rod underneath it move up and down.

The compression spring 13 is located between the support plate 37 and the connecting member 35, and its biasing force can be adjusted by adjusting the tightening condition of the nut 36.

In FIG. 1, water has not yet been sent to the water supply pipe A and there is no water in the valve box, so no buoyancy is acting on the float 11, so its weight acts as a load, and the valve body 7 The valve seat surface 23 overcomes the upward biasing force of the compression spring 13.
2 and the air hole 8 is fully opened.

When water starts flowing in this state and the inside of the pipe becomes filled with water, the air in the pipe enters into the valve box 1 through the lower opening 2 and into the air hole 8 and the screw hole 25, as shown in FIG. After that, it is discharged to the outside. When the pipe becomes full and water enters the valve box and the water level rises, the buoyant force acting on the float increases and the downward force of gravity decreases, causing the biasing force of the compression spring to decrease. The valve seat surface 23 is brought into close contact with the valve seat surface 22, the air hole 8 is closed, and the valve is in a fully closed state.

While the valve remains closed, air and gas mixed in the water separate and accumulate in the upper part of the valve box.As the water level drops, the buoyant force acting on the float also decreases, and the compression spring finally stops attaching. When the force is exceeded, the valve seat surface 23 becomes the valve seat surface 22 as shown in FIG.
The air hole 8 opens when the valve body is pulled away from the valve body, and air and gas are discharged to the outside of the valve box. When exhaustion under pressure is finished, the water level in the valve box rises and the air hole closes again, returning to the state shown in FIG. 2.

[Effects of the Invention] Since the present invention produces the effects described above, it brings about the following effects. In other words, the cross-sectional area of the air hole is large over a wide range of differential pressure inside and outside the valve.
The weight allows the specification of small compact air valves. Even if the differential pressure is the same as before, the size of the air hole can be changed significantly without changing the size of the air valve, so it can be used for agricultural water, sewage, etc. that contain countless fine solids. It is suitable as a water pipeline for contaminated water. In addition, the opening and closing of the air hole is not done directly by attaching and detaching it to the float, but is done at the top, far away from the rising and falling water surface, so there is no need to worry about it becoming contaminated by being immersed in sewage, and sewage does not flow outside the valve box. There is no danger that it will blow up.

The unique effect of this embodiment is that since the weight is a float with a specific gravity of 1 or less, the gravity on the valve body is extremely small in the closed state, and the constant of the compression spring that balances this is also small, allowing its length to be reduced. Can be shortened. In addition, since the communication port for air and gas with the outside is formed by the screw hole 25,
Even if dirt or the like adheres to the air hole 8 or both valve seat surfaces, it can be easily washed away by screwing the screw at the end of the cleaning water pipe into the screw hole and supplying water.

[Brief explanation of the drawing]

1 to 3 are vertical sectional views showing an embodiment of the present invention, and FIG. 4 is a vertical sectional view showing a conventional technique. 1...Valve box, 2...Lower opening, 3...Tight lid,
4...Fully point, 5...Link lever, 6...End point,
7...Valve body, 8...Air hole, 9...Hanging point, 10...
...First push rod, 11... Weight (float), 12
...first diaphragm piston, 13 ... biasing means (compression spring), 14 ... end point, 15 ... second push rod, 16 ... second diaphragm piston, L ₁ ... first from the fulcrum Distance from the fulcrum to the second push rod, L ₂ ... Distance from the fulcrum to the second push rod,
La...Distance from the fulcrum to the valve body, Aa...Cross-sectional area of the air hole, _A1 ...Pressure receiving area of the first diaphragm piston, _A2 ...Pressure receiving area of the second diaphragm piston, A...Feed water pipe.

Claims (1)

[Scope of Claims] 1. A link lever 5 supported by a fulcrum 4 erected approximately at the center of a sealing lid 3 of a valve box 1 having a lower opening 2 communicating with a water supply pipe is mounted horizontally so as to be freely tiltable. , the valve body 7 is suspended from one end point 6 of the link lever so as to be freely raised and lowered, and the air hole 8 penetrating the sealing lid is opened and closed. A weight 11 is provided via a first push rod 10 which is suspended in a vertically movable manner within a through hole, and a compression spring 13 is provided around the first push rod 10 to bias it upwardly on the airtight lid. Its lower end forms a first diaphragm piston 12 that moves together with a diaphragm 18 stretched over the bottom surface of the sealing lid, and a second push rod 15 that can be raised and lowered from an end point 14 is suspended from the other side of the fulcrum 4. The lower end of the second push rod 15 also forms a second diaphragm piston 16 that moves together with the diaphragm stretched over the bottom surface of the through hole; (2) The cross-sectional area of the air hole 8 is Aa (3) The distance from the fulcrum 4 to the suspension point 9 where the first push rod is suspended is L ₁ (4) The pressure receiving area of the first diaphragm piston 12 is A ₁ (5) The end point 14 where the second push rod is suspended from the fulcrum 4
When the distance to L ₂ (6) and the pressure-receiving area of the second diaphragm piston 16 is A ₂ , the following relationship is approximately established: L ₂ ×A ₂ =L ₁ ×A ₁ +La ×Aa air valve.