JPH0544619Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a technology related to an air valve that discharges air from a pipe.

[Prior Art] Conventionally, air valves have been installed in pipes of so-called air conditioning equipment installed in buildings to discharge air that evaporates due to the temperature difference between cold and hot water passing through the pipes.
They are mainly used to discharge air that has entered the water supply/sewage system during repairs or water outages to the outside of the pipe when water is flowing. A typical configuration is to have a float inside the valve box that moves up and down in response to fluctuations in water level, and this up and down movement opens and closes the valve opening, and many improved technologies have already been proposed. has been done.
For example, Japanese Utility Model Publication No. 58-15718 discloses a method of releasing the pressure bond between the valve body and the valve port by tilting the valve stem connected to the float by raising and lowering the float.
Figure 3 A, B, C, Special Publication No. 53-27007.
Figure 4 etc.

Of these, the former has a long hole 1 at the top of the float 7a.
A connecting plate 100 having a number 01 protrudes, and the valve rod 9a is engaged with this elongated hole. There is a valve body 6 at the tip of the valve stem.
a is attached, and the valve body 6a is always urged by the spring 5a in the direction of closing the valve port 2a (Figure 2). As shown in Figure A, the surface of the float 7a opposite to the valve port 2a is tilted outward from the center and diagonally upward, so when air accumulates in the valve box 1a and the water level falls, As shown in Figure C, the valve stem 9a
is pushed down and tilted within the elongated hole 101, and the spring 5a
The valve element 6a is pulled away from the valve port 2a by overcoming the urging force. The company claims that this allows the bubbles generated from the water to burst at the surface of the water, away from the valve opening.

Furthermore, in the latter prior art, a lever 9 is provided inside the valve box 1b.
b is attached, and one end of the lever constitutes a valve body 6b to open and close the valve port 2b. The valve body 6b is always elastically biased by a spring 5b to push it up in the direction of closing the valve port 2b.

On the other hand, since the other end of the lever is engaged with the float 7b, when the water level drops, one end of the lever is pulled to separate the valve 6b from the valve port 2b, as before.

[Problems to be solved by the invention] All of the conventional technologies described here are mainly aimed at emitting air that evaporates in response to differences in air solubility due to rises and falls in water temperature, and the amount of air emitted is small. Therefore, a small cross-sectional area of the valve opening is sufficient. In other words, the valve itself can also be made smaller.

However, when the inner diameter of the pipe is large and the amount of water that passes through it is large, such as in the case of upper and lower water pipes, the amount of air that must be discharged is also large, so in order to rapidly let this large amount of air in and out, it is necessary to The cross-sectional area must also become larger, and the valve body that opens and closes it will also need to be larger. As the valve body becomes larger, a large driving force is required to open and close it, and it is difficult to function satisfactorily by simply utilizing the force generated by the lifting and lowering of the float.

In particular, when air is discharged while pressure is applied inside the pipe, a large force is required to open the valve because the valve body is pressed against the valve seat by the pressure inside the pipe.

Fig. 5 is a diagram explaining the basics, where the total length of the valve stem is L, the distance from the fulcrum to the point of force is l,
The force acting to close the valve due to water pressure or the urging force of a spring is f, and the force required to open the valve by tilting the valve stem is F.
Then, the condition for opening the valve is F.L>f.l, and from the balance of moments around the fulcrum, M=F.L-f.l>0.

In addition, it is also possible to use the raising and lowering of the float in a configuration other than tilting the valve stem, but if the valve body becomes large, the entire valve body will be large in order to generate a large pulling force in order to open it, and many pipe lines will be required. It is economically disadvantageous to intervene.

This invention aims to solve the above-mentioned problems.
The purpose of the present invention is to provide a pneumatic valve which is used in relatively large pipelines, is small and lightweight, uses the lifting and lowering of a float for opening and closing, and is still fully functional.

[Means for Solving the Problems] In the air valve according to the present invention, the tilting body 4 supported in a cantilever shape by a fulcrum 3 provided near the valve port 2 in the upper part of the valve box 1 has a structure in which the fulcrum is A spring 5 that constantly biases the shaft upward; a thin steel plate 6A that is easily elastically deformed and fixed on the spring; and a soft rubber 6B that is attached to the thin steel plate and press-fitted to an annular protrusion 21 provided on the outer periphery of the valve opening. The rear end side of the tilting body is made up of a rigid lever 9, which engages with a suspension rod 8 that suspends the center of the upper surface of a float 7 housed in a vertically movable manner within the valve box. The above problem was solved by

[Operation] The operation of the present invention will be explained with reference to FIG. 1 showing an embodiment. In the figure, a tilting body 4 is supported by a fulcrum 3 provided at one end immediately below the valve port 2 in the valve box 1, and the fulcrum side of this tilting body 4 is placed on a torsion coil spring 5. Easily deformable thin steel plate 6A and soft rubber 6
Elastic valve bodies 6 made of B are formed by overlapping each other, and are always urged upward so as to press against the valve port 2. That is, the air valve is normally closed as shown by the two-dot chain line in FIG. 1, and the passage of air is prevented. However, as the air evaporates from the water and the water surface falls, the buoyant force acting on the float 7 decreases, pulling the suspension rod 8, which suspends the zenith of the float 7, downward. The tip of the rigid lever 9, which is the rear end side of the tilting body 4 that is engaged with the upper end of the rod 8, is tilted downward in an attempt to open the valve.

The force acting to open the valve acts as a bending moment on the valve body 6 at the end that is in close contact with the valve port 2 and is close to the connection part 10 with the rigid lever 9. When the bending moment acts on the valve body 6,
Since is a deformable elastic body, as the float 7 descends, the part on which this bending moment acts bends and is pulled away from the valve orifice 2, starting to open the valve, and as the water level descends, the position on which the bending moment acts also moves, gradually widening the valve opening and discharging the water. When the discharge ends and the water level rises, the float 7 also rises and the valve body closes the valve orifice.

By the way, when a bending moment acts on the end of the valve body 6 that is in close contact with the valve port 2, and this portion bends and is pulled away from the valve port, a force that attempts to close the valve body acts as a reaction force ( As shown in Figure 2, the range of force f (mainly due to pressure inside the pipe) is extremely small, like the range where a straight line and a circular arc touch.
This small range (almost twice the distance 1 from the fulcrum)
The force f acting on a very small area is extremely small, and the distance 1 from the point of application of the force f that forms a moment opposing the bending moment due to the float 7 to the fulcrum is from the hanging point of the float 7 to the fulcrum. Since the distance L is much smaller than the distance L, the force F acting on the rigid lever 9 to pull the valve body away from the valve port may be small.

Therefore, the present invention exhibits a remarkable effect in that only a small amount of force is required, which is not a problem, compared to the conventional valve body which has a rigid valve body and requires opening the entire valve port at once.

[Embodiment] To add a little additional information to the embodiment shown in FIG. 1, a valve port 2 is opened in the center of a lid 11 of a valve box 1, and an upper cover 12 is placed on the lid with a gap between the valve port 2 and the lid. A plurality of guide rods 13 are screwed into the valve body 1, and the float is restrained by the guide rods and moves up and down within a predetermined range within the valve body.

[Effects of the invention] As mentioned above, although the present invention is an air valve that can be applied to large pipelines such as water pipes, it has a simple structure, requires only a small number of parts, and is relatively small. It has fewer breakdowns and is easy to maintain.
It has great practical benefits. Taking advantage of this feature, even when a large-capacity valve with a large cross-sectional area is required, there is no need to apply proportionally large driving force to open and close the valve, making it possible to create an extremely advantageous design configuration. .

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view showing an embodiment of the present invention, Fig. 2 is a partial vertical cross-sectional view showing the operation of the present invention, Fig. 3 A, B, C, and Fig. 4 each show different prior art. Vertical sectional view, FIG. 5 is a partial vertical sectional view showing the operation of the prior art. 1... Valve box, 2... Valve port, 3... Fulcrum, 4...
Tilting body, 5... Torsion coil spring, 6... Valve body,
7... Float, 8... Hanging rod, 9... Rigid lever, 10... Connection section.

Claims (1)

[Scope of utility model registration request] The air valve has a valve port opening to the atmosphere at the top and a pipe connection at the bottom, and is supported in a cantilever shape by a fulcrum 3 provided near the valve port 2 in the upper part of the valve box 1. The body 4 includes a spring 5 that always urges upward about a fulcrum, a thin steel plate 6A that is easily elastically deformed and fixed on the spring, and an annular protrusion 21 that is attached to the thin steel plate and provided on the outer periphery of the valve opening. The rear end of the tilting body is made up of a rigid lever 9 that suspends the center of the upper surface of the float 7 housed in the valve box so as to be able to move up and down. An air valve characterized in that it is engaged with a rod 8.