JP2001323521A - Storage tank and air adjusting valve used therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water storage tank capable of surely preventing the occurrence of a backflow by negative pressure inside of a water supply pipe when there is something wrong in the water supply pipe. SOLUTION: A male screw 22a of a mounting cylinder 22 is screwed in a screw hole 13e so as to connect with an inside passage T of a conduit 13b. A valve storage easing 23 is screwed in the mounting cylinder 22, and a cover plate 24 is screwed in the valve storage casing 23. A valve disc 25 is stored in the valve storage casing 23 so that it is capable of reciprocating in the vertical direction, and water supply is so executed that the valve disc 25 is brought into contact with a valve seat 22e by negative pressure caused by the current when water supply is executed in the conduit 13b. When water supply is not executed, the valve disc 25 is held in an open position, and even if the inside of the inside passage T beconres negative pressure in an air atmospheric state, an air is absorbed in the inside passage T from an upper space A in the tank through a close prevention opening 23b, and the backflow of water in the storage tank is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a storage tank and an air control valve used for the storage tank.

[0002]

2. Description of the Related Art Conventionally, for example, a storage tank for storing tap water to be supplied to a building temporarily stores tap water pumped from an underground water tank and then uses the stored tap water in a building downstairs. Supply to water pipe. As a method of supplying water to the storage tank, it is common to provide a water discharge space above the storage tank, but this causes noise and vibration when water is supplied. In order to avoid this, a water supply system has been adopted in which the distal end of the water supply pipe is partially immersed in the lowest stored water in the storage tank. In this method, as shown in FIG. 9, a water supply pipe 63 is connected to a tank body 62 of a water storage tank 61 in an inverted U shape, and a drain pipe 64 to a water pipe in a building is provided.
Is connected.

The water supply pipe 63 is disposed in an inverted U-shape, and its outlet is immersed in the stored water W at the lowest water level. ,
Water in the pipe leaks out due to the principle of siphon.
As a result, the stored water W flows backward through the water supply pipe 63 and is discharged to the outside. To prevent this, the water supply pipe 63 outside the tank body 62 is provided with a backflow prevention valve 65.

As shown in FIG. 10, the check valve 65 has a valve housing 66 interposed in the water supply pipe 63 and a valve hole 66a connected to the valve housing 66 via a support shaft 67 so as to be openable and closable. A valve plate 68 and a cap fitting 6 screwed to a boss 66b formed integrally with the valve housing 66
9.

Accordingly, the tank main body 62 is connected to the water supply pipe 63.
When water is supplied to the inside, the valve plate 68 is opened by receiving the water pressure, and after the water supply is completed, if the water tries to flow backward in the water supply pipe 63, the valve plate 68 closes the valve hole 66a. To prevent backflow of the stored water.

[0006]

However, it is necessary to use a large check valve 65 according to the outer diameter of the water supply pipe 63, which not only increases the material cost but also increases the manufacturing and manufacturing costs. The assembling work is also troublesome, and there has been a problem that the cost cannot be reduced.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems in the prior art. For example, when the liquid supply pipe is damaged due to an earthquake or the like and the liquid leaks, the liquid stored in the tank body flows backward. An object of the present invention is to provide a storage tank and an air control valve used for the storage tank, which can prevent cost reduction and can reduce the cost.

[0008]

In order to solve the above-mentioned problems, the invention according to claim 1 comprises a tank body for storing a liquid, a supply pipe for supplying a liquid into the tank body, and the supply pipe. Is disposed in the tank body so that the outlet portion is located from the upper space to the lower stored liquid, and the supply pipe communicates with the internal passage of the supply pipe and the upper space of the tank body. In the storage tank provided with a ventilation opening formed in the middle of, and an air control valve that opens and closes the ventilation opening, a valve body that constitutes the air control valve,
At the time of liquid supply, the supply passage is held in the closed position by utilizing the flow of the liquid flowing toward the inside of the tank body through the internal passage of the supply pipe, the liquid supply operation is stopped, and the air pressure of the internal passage of the supply pipe increases. When the air pressure is reached, the air is held at the open position, and when the air pressure in the internal passage becomes a negative pressure, air is sucked into the internal passage from the upper space through the ventilation opening to return the stored liquid to the backflow. The air control valve is provided with closing prevention means for preventing the valve body from being moved to the closed position by the intake air to the internal passage.

According to a second aspect of the present invention, in the first aspect, the air control valve is connected to the mounting cylinder having a valve hole and a valve seat mounted on the ventilation opening of the supply pipe, and to the mounting cylinder. A valve body housed in a covered cylindrical valve housing casing,
An opening for closing prevention provided on the outer periphery of the valve housing casing so as to communicate the upper space and the valve hole, and having a function as a closing prevention means, wherein the valve body always has a valve housing casing due to its own weight. Is held at an open position separated from the valve seat at the lower part, and at the start of liquid supply by the supply pipe, liquid is supplied to a chamber provided at the lower part of the valve housing casing, and the valve body floats in the closing direction by its buoyancy, At the time of steady liquid supply, the valve body is attracted to the valve seat by the negative pressure of the internal passage of the supply pipe, and in the non-liquid supply state, when the air pressure of the internal passage of the supply pipe becomes negative pressure, the upper space passes through the opening for closing prevention The gist is that air is sucked into the internal passage and the valve body does not move in the closing direction due to the sucked air.

According to a third aspect of the present invention, in the first aspect, the air control valve is a mounting cylinder connected to the ventilation opening of the supply pipe, and a closed cylindrical valve housing casing connected to the mounting cylinder. And a first valve hole and a second valve hole provided at two locations on the outer periphery of the valve housing casing and communicating the upper space and the internal passage, respectively, and the first valve hole is provided in the valve housing casing. A first valve body that opens and closes is provided, and a second valve body that opens and closes the second valve hole is provided outside the valve housing casing. The two valve bodies are synchronized by a lever mechanism provided in the valve housing casing. The tip of the tilting lever of the lever mechanism senses the pressure of the liquid so as to be located in the supply pipe, and the first position is detected.
The gist is that a pressure receiving plate for opening and closing the second valve body is supported.

According to a fourth aspect of the present invention, in the first aspect, the air control valve is mounted on the mounting tube mounted on the ventilation opening of the supply pipe via a bearing and a rotating shaft. A valve body, and a pressure receiving plate attached to an end of the rotation shaft and opening and closing the valve body by sensing the pressure of the liquid in the internal passage. The gist of the present invention is configured to be urged to the open position and move in a direction substantially perpendicular to the flow direction of the intake air to the internal passage to open and close the ventilation opening.

According to a fifth aspect of the present invention, there is provided an air control valve used in the storage tank according to the first aspect, wherein the air control valve has a valve hole and a valve seat attached to a ventilation opening of a supply pipe. And a valve body accommodated in a covered cylindrical valve accommodating casing connected to the attaching cylinder, and provided so as to communicate an upper space and a valve hole with an outer periphery of the valve accommodating casing, and closed. The valve body is always held at an open position separated from the valve seat at a lower portion of the valve housing casing by its own weight, and when the liquid supply by the supply pipe is started, The liquid is supplied to a chamber provided in the lower part of the valve housing casing, the valve body floats in the closing direction by its buoyancy, and the valve body is adsorbed on the valve seat by the negative pressure of the internal passage of the supply pipe at the time of steady liquid supply, In non-fluid state When the air pressure in the internal passage of the supply pipe becomes negative, air is sucked from the upper space into the internal passage through the closing prevention opening, and the intake air does not move the valve body in the closing direction. The point is that

According to a sixth aspect of the present invention, there is provided an air control valve for use in the storage tank according to the first aspect, wherein the air control valve includes a mounting cylinder connected to a ventilation opening of a supply pipe; A valve-containing casing in the form of a covered cylinder connected to the mounting cylinder,
A first valve hole and a second valve hole are provided at two locations on the outer periphery of the valve housing casing and communicate the upper space and the internal passage, respectively.
A first valve body that opens and closes the first valve hole is provided in the valve housing casing, and a second valve body that opens and closes the second valve hole is provided outside the valve housing casing. The two valve bodies are supported so as to be opened and closed in synchronization by a lever mechanism provided in the valve housing casing, and the tip of a tilting lever of the lever mechanism is provided with a liquid so as to be located in the supply pipe. Detecting the pressure and detecting the first and second
The gist is that a pressure receiving plate for opening and closing the valve body is supported.

According to a seventh aspect of the present invention, there is provided an air control valve for use in the storage tank according to the first aspect, wherein the air control valve includes a mounting cylinder mounted on a ventilation opening of a supply pipe; A valve body attached to the mounting cylinder via a bearing and a rotating shaft, and a pressure receiving plate attached to an end of the rotating shaft and opening and closing the valve body by sensing the pressure of the liquid in the internal passage. The valve body is always urged to an open position by an urging member, and is configured to move in a direction substantially perpendicular to a flow direction of intake air to an internal passage to open and close the ventilation opening. The gist is that it has been done.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described.
An embodiment will be described with reference to FIGS. As shown in FIG. 3, a water supply pipe 13 is connected to a tank main body 12 constituting the water storage tank 11. The water supply pipe 13 is composed of a pumping pipe 13 a outside the tank body 12, a water guide pipe 13 b penetrating the side wall of the tank body 12, and a downcomer pipe 13 c provided inside the tank body 12 below. The base end of the pumping pipe 13a is connected to a water source 14 via a pump 15. Lower end exit portion 13d of the downcomer 13c
Is provided with a strainer 16. A drain pipe 17 is connected to a lower portion of the tank body 12. An exhaust pipe 18 for discharging gas in the upper space A to the outside is provided at an upper portion of the tank body 12. The maximum water level HL of the tank body 12 is controlled by the control of the pump 15,
The minimum water level LL is set.

An air control valve 2 for preventing the stored water W in the tank body 12 from being discharged to the outside is provided to the water pipe 13b.
1 is attached. The air control valve 21 is disposed above the maximum water level HL. A screw hole 13e as a ventilation opening is formed in a part of the water pipe 13b, and a male screw portion 22a of the mounting cylinder 22 is screwed into the screw hole 13e. A flange 2 is provided at an intermediate portion of the outer periphery of the mounting cylinder 22.
2b is formed, and a female screw 23a of a cylindrical valve accommodating casing 23 is screwed into a male screw 22c formed on the tip side of the flange 22b. A female screw 23c is formed at the tip of the valve housing casing 23, and a male screw 24a formed on the cover plate 24 is screwed to the female screw 23c. In the cover plate 24, communication holes 24b communicating the inside of the valve housing casing 23 and the upper space A are provided at a plurality of locations. A spherical valve body 25 is housed in the valve housing casing 23. The valve housing casing 23 is provided with a plurality of openings 23b for closing prevention for communicating the upper space A and the internal passage T of the water conduit 13b at a plurality of locations.

As shown in FIG. 2, the valve element 25 is accommodated in the valve accommodating casing 23 so as to be able to reciprocate obliquely up and down, and at the uppermost position, an internal passage of the mounting cylinder 22, ie, a ventilation opening. The valve hole 22d contacts the valve seat 22e formed at the outer end of the valve hole 22d to close the valve hole 22d. In a state where the valve body 25 is moved to the lowermost position of the valve housing casing 23, the valve hole 22d is opened, and the internal passage T in the water pipe 13b is opened by the closing prevention opening 23b and the valve hole 22d. The upper space A is communicated.

A gap G is provided between the valve body 25 and the inner peripheral surface of the valve housing 23. This gap G
Is set larger than the entire passage area of the communication hole 24b.

Next, the operation of the water storage tank and the air control valve 21 configured as described above will be described. 1 and 2 show a state in which the valve body 25 of the air control valve 21 is held at the open position. The pump 15 is operated by an operation signal from a control device not shown in FIG. 3, and water is supplied from the water source 14 into the tank main body 12 through the internal passage T of the water supply pipe 13. At the start of water supply, the internal passage T is kept at the atmospheric pressure state, which corresponds to open-circuit water supply. For this reason, in FIG. 1, the water flowing in the internal passage T of the water guide pipe 13b in the water supply (left) direction flows into the valve housing casing 23 via the valve hole 22d by gravity. Then, some water leaks to the outside through the closing prevention opening 23b, but other water passes through the gap G between the valve body 25 and the inner peripheral surface of the valve housing casing 23,
Flows into the chamber R formed between the cover plate 24 and the valve body 25,
After that, it flows down into the tank body 12 from the communication hole 24b of the lid plate 24. At this time, the passage area of the gap G is
Since the passage area is set to be larger than the passage area b, the chamber R is filled with water, and the water level rises. As a result, the valve 2
5 floats due to the buoyancy of water. Further, when the water flow in the internal passage T of the water guide pipe 13b becomes a steady flow, the internal passage T becomes a negative pressure, the valve body 25 moves obliquely upward in the valve housing casing 23 and comes into contact with the valve seat 22e, and the valve hole 22d is closed. As a result, the water flowing through the internal passage T of the water pipe 13b is smoothly supplied into the tank body 12 from the upper space A without sucking air. In this state, since water does not enter the valve housing casing 23, the water in the valve housing casing 23 is discharged to the outside through the communication hole 24b.

When the water level in the tank body 12 reaches the maximum water level HL, the supply of water by the water supply pipe 13 is stopped, and
The internal passage T of 3b is in an atmospheric pressure state, and the suction force on the valve body 25 decreases. Therefore, the valve body 25 is moved away from the valve seat 22e to the lower part of the valve housing casing 23 by its own weight, and the internal passage T and the upper space A are communicated with each other through the valve hole 22d and the closing prevention opening 23b.

In the water supply stop state, the pumping pipe 13a shown in FIG. 3 is filled with water up to the height position E of the water pipe 13b. In this state, if water is leaked due to breakage at point B at the base end of the pumping pipe 13a due to, for example, an earthquake, the internal passage T of the water pipe 13b in a gaseous atmosphere becomes negative pressure. For this reason, the internal passage T in the water pipe 13b is connected to the storage water W in the tank body 12 from the downcomer 13c.
Try to pump up. However, since the valve hole 22d and the closing prevention opening 23b remain open, the internal passage T and the upper space A remain in communication with each other, and only the air in the upper space A enters the internal passage T, and the stored water Backflow of W is prevented.

Next, the air control valve 2 constructed as described above is used.
Effect 1 is listed together with the configuration. (1) In the first embodiment, when the water supply is stopped, the water pipe 1
Even if the internal passage T of 3b becomes negative pressure in the air atmosphere state,
The valve body 25 is not moved in the direction to close the valve hole 22d by the intake air flowing from the upper space A to the internal passage T through the closing prevention opening 23b, and the valve body 25 is held at the open position. . For this reason, even if an abnormality occurs in the pumping pipe 13a and water tries to flow backward in the water pipe 13b,
Since the air is reliably sucked from the upper space A into the internal passage T, the backflow of the stored water W is prevented.

(2) In the first embodiment, since the valve accommodating casing 23 of the air control valve 21 is provided inclined, the valve body 25 is easily separated from the valve seat 22e by its own weight,
The opening operation is performed smoothly.

(3) In the first embodiment, the water pipe 13
The mounting cylinder 22 is screwed into the screw hole 13e of FIG.
2, a valve housing casing 23 was screwed, a lid plate 24 was screwed to the valve housing casing 23, and a valve body 25 was housed in the valve housing casing 23. Therefore, the configuration of the air control valve 21 can be simplified, manufacturing and assembly can be easily performed, and costs can be reduced.

(4) In the first embodiment, the closing prevention opening 2 in which the closing prevention means is formed in the valve housing casing 23.
3b. Therefore, the structure of the closing prevention means can be simplified, the manufacturing can be facilitated, and the cost can be reduced.

Next, a second embodiment of the present invention will be described with reference to FIG. In the following embodiments, members having the same functions as those in the first embodiment are denoted by the same reference numerals, and the description is simplified.

In the second embodiment, a screw hole 13e is formed in a part of the downcomer 13c in the tank body 12,
A male screw 23 e of the valve housing casing 23 is screwed into a screw hole 22 f of the mounting cylinder 22, and a lid 23 f is formed integrally with the base end of the valve housing casing 23. Valve housing casing 2
A first ventilation tube 26 and a second ventilation tube 27 having a cylindrical shape are fitted and fixed to the outer peripheral wall portion 3.

The mounting cylinder 22 and the valve housing casing 23
Inside, a tilting lever 28 is supported by a support shaft 29 so as to be tiltable. A connecting rod 30 is rotatably connected to a base end of the tilting lever 28 by a connecting pin 31. One end of the connecting rod 30 is provided with the first ventilation tube 2.
A first valve plate 32 that opens and closes a valve seat 26b formed at the inner end of the sixth valve hole 26a is attached. The other end of the connecting pin 31 extends through the valve hole 27a of the second ventilation cylinder 27 and is led out to the outside. A valve seat 27b formed at the outer end of the valve hole 27a is opened and closed at the tip. Second valve plate 33 for
Are connected. A pressure receiving plate 34 is attached to the tip of the tilting lever 28 so as to be located in the internal passage T.

In the second embodiment, when water is supplied from the water supply pipe 13 into the tank main body 12, the downcomer 13
The water moves down the internal passage T in c. At this time, since the pressure receiving plate 34 is pushed downward, the first valve plate 32 closes the valve seat 26b of the first ventilation tube 26, and the second valve plate 33 closes the valve seat 27b of the second ventilation tube 27. I do. Therefore, the upper space A
Air is prevented from entering the internal passage T through the valve holes 26a and 27a, and water supply into the tank body 12 is performed smoothly.

When the above water supply operation is stopped, the pressure receiving plate 3
4 is in a free state, so that the first valve plate 32 is
Therefore, the second valve plate 33 is separated from the valve seat 27b, and the upper space A and the internal passage T are communicated with each other through the valve holes 26a and 27a.

When damage occurs on the pumping pipe 13a side and water flows downward in the pumping pipe 13a, the internal passage T of the downcomer 13c in the air atmosphere becomes negative pressure. At this time, the first valve plate 32 causes the valve seat 26b to flow from the upper space A to the internal passage T through the valve hole 26a toward the internal passage T.
, And the second valve plate 33 is moved to the valve seat 27b.
Receive the power to close the door. The first valve plate 32 and the second valve plate
Since the air pressure received by the valve plate 33 is substantially balanced, the air pressure is maintained at the open position where the upper space A and the internal passage T communicate with each other.
Backflow of the stored water W can be reliably prevented.

In the second embodiment, since the opening and closing operations of the first valve plate 32 and the second valve plate 33 can be performed with a small force, the pressure receiving plate 34 is made small and applied to the downcomer 13c having a small diameter. be able to.

Next, a third embodiment of the present invention will be described with reference to FIGS. In this embodiment, a mounting cylinder 41 is fixed to one side of the water guide pipe 13b by welding in a horizontal direction, a bearing plate 42 is screwed into an inner end of the mounting pipe 41, and a valve hole 43a is formed in an outer end. And a bearing plate 43 having a valve seat 43b. A rotation shaft 44 is supported through the bearing plates 42 and 43, and a valve plate 45 is attached to the outer end of the rotation shaft 44, and a seal ring 46 fitted to a valve seat 43 b of the bearing plate 43 is provided. The inner surface of the valve plate 45 is brought into contact. A pressure receiving plate 4 is provided at the inner end of the rotating shaft 44.
7 is mounted so as to be located in the internal passage T. Coil springs 48 and 49 as urging members are wound around the outer periphery of the rotating shaft 44, and these coil springs 48 and
One end of 49 is connected to a bracket 50 attached to an intermediate portion of the rotating shaft 44, and the other end is locked to bearing plates 42 and 43.

FIGS. 5 and 6 show the coil springs 48 and 4 respectively.
9, the valve plate 45 is held at the open position, and the pressure receiving plate 47 is held so as to receive the water pressure in the internal passage T of the water pipe 13b. In this state, when water flows in the internal passage T of the water guide pipe 13b in the direction of the arrow, the pressure receiving plate 47 receives the water pressure and resists the urging force of the coil springs 48, 49 in the counterclockwise direction around the rotation shaft 44. It is turned. For this reason,
Since the valve plate 45 is moved from the open position to the closed position shown in FIGS. 7 and 8 and the internal passage T of the water guide pipe 13b has a negative pressure, the valve plate 45 is sucked to the seal ring 46, The valve plate 45 is completely closed, and the water supply to the tank body 12 is performed smoothly without taking in air from the valve hole 43a.

When the supply of water into the tank body 12 is stopped, the suction force of the water guide pipe 13b against the valve plate 45 becomes weak. For this reason, the pressure receiving plate 47 is provided with the coil springs 48 and 49.
5 and 6, the valve plate 4 is returned to the position shown in FIGS.
5 is held in the open position.

In this state, when the pumping pipe 13a is broken and the pressure in the internal passage T of the water pipe 13b becomes negative,
Air is sucked into the internal passage T from the upper space A through the valve hole 43a, and the backflow of the stored water W is prevented.

In the third embodiment, the valve plate 45 is configured to open and close in a direction substantially perpendicular to the flow direction of the air sucked into the internal passage T from the upper space A through the valve hole 43a. For this reason, the valve plate 45 does not receive the force in the closing direction due to the intake air, and the valve plate 45 is held at the open position, and the backflow of the stored water can be reliably prevented.

The above embodiment can be modified and embodied as follows. The present invention can be embodied as a liquid storage tank for chemicals or the like in addition to the water storage tank 11.

[0039]

As described above in detail, the inventions according to claims 1 to 7 can reliably prevent the backflow of the liquid stored in the tank body at the time of disaster such as an earthquake and reduce the cost. Can be planned.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an air control valve according to a first embodiment of the present invention.

FIG. 2 is a sectional view of an air control valve.

FIG. 3 is a cross-sectional view of the entire water storage tank.

FIG. 4 is a sectional view of an air control valve according to a second embodiment of the present invention.

FIG. 5 is a horizontal cross-sectional view showing an air regulating valve in an open state according to a third embodiment of the present invention.

FIG. 6 is a front sectional view of an air control valve according to a third embodiment in an open state.

FIG. 7 is a horizontal cross-sectional view of a closed state of an air control valve according to a third embodiment.

FIG. 8 is a front sectional view of a closed state of an air control valve according to a third embodiment.

FIG. 9 is a cross-sectional view of a conventional water storage tank.

FIG. 10 is a cross-sectional view of a conventional check valve.

[Explanation of symbols]

A: upper space, T: internal passage, W: stored liquid, 12: tank body, 13: supply pipe, 13d: outlet, 13e, 1
3f: ventilation opening, 21: air control valve, 22, 41: mounting cylinder, 22d: valve hole, 22e: valve seat, 23: valve housing casing, 23b: closing prevention opening, 25, 45: valve body,
26a: first valve hole, 27a: second valve hole, 28: tilting lever, 32: first valve body, 33: second valve body, 34, 47: pressure receiving plate, 44: rotating shaft.

Claims (7)

[Claims] 1. A tank body (12) for storing a liquid, and a supply pipe (13) for supplying the liquid into the tank body (12).
And the supply pipe (13) is provided in the tank body (12).
The outlet (13d) is disposed so as to be located from the upper space (A) to the lower stored liquid (W), the internal passage (T) of the supply pipe (13) and the tank body (1).
A storage provided with ventilation openings (13e, 13f) formed in the middle of the supply pipe so as to communicate with the upper space (A) of 2), and an air control valve (21) for opening and closing the ventilation openings. In the tank, the valve body (25, 32,
33, 45) are kept in a closed position by utilizing the flow of the liquid flowing toward the inside of the tank body (12) through the internal passage (T) of the supply pipe (13) at the time of liquid supply. When the pressure is stopped and the air pressure in the internal passage (T) of the supply pipe becomes the atmospheric pressure, it is held at the open position, and when the air pressure in the internal passage becomes the negative pressure, the upper Air is sucked into the internal passage (T) from the space (A) through the ventilation openings (13e, 13f) to prevent backflow of the stored liquid, and the air control valve (21) is connected to the internal passage. Closing prevention means (23b, 26, 27, 32, 33, 46, 46) for preventing the valve body from being moved to the closed position by the intake air of
48, 49). 2. The air control valve (21) according to claim 1, wherein:
A mounting cylinder (22) having a valve hole (22d) and a valve seat (22e) mounted on the ventilation opening (13e) of the supply pipe (13); and a covered cylinder connected to the mounting cylinder (22). A valve body (25) housed in a valve-shaped casing (23), and an upper space (A) on the outer periphery of the valve casing (23).
Blocking opening (23) provided so as to communicate with the valve hole (22d) and having a function as a closing preventing means.
b), the valve body (25) is always held at an open position separated from the valve seat (22e) at a lower portion of the valve housing casing (23) by its own weight, and supplied by a supply pipe (13). At the start of the liquid, the liquid is supplied to the chamber (R) provided at the lower part of the valve housing casing (23), and the buoyancy causes the valve (2) to move.
5) is floated in the closing direction, and the supply pipe (1)
The valve body (25) is adsorbed to the valve seat (22e) by the negative pressure of the internal passage (T) of (3), and the air pressure of the internal passage (T) of the supply pipe (13) is reduced to the negative pressure in the non-liquid supply state. Then, air is sucked into the internal passage (T) from the upper space (A) through the closing prevention opening (23b), and the intake air does not move the valve body (25) in the closing direction. Storage tank. 3. The air control valve (21) according to claim 1, wherein:
A mounting tube (22) connected to the ventilation opening (13e) of the supply pipe (13); a closed-tube-shaped valve housing casing (23) connected to the mounting tube (22); A first valve hole (26a) and a second valve hole (27a) provided at two locations on the outer periphery of the casing (23) and communicating the upper space (A) and the internal passage (T), respectively; The first valve hole (2) is provided in the casing (23).
A first valve element (32) for opening and closing 6a), and a second valve element (33) for opening and closing the second valve hole (27a) outside the valve housing casing (23); The two valve bodies are supported by a lever mechanism (28, 29, 30, 31) provided in the valve housing casing (23) so as to be opened and closed in synchronization with each other, and the tip of a tilting lever (28) of the lever mechanism is provided. The first and second valve bodies (32, 32) sense the pressure of the liquid so as to be located in the supply pipe (13).
A storage tank on which a pressure receiving plate (34) that opens and closes 33) is supported. 4. The air control valve (21) according to claim 1, wherein:
Is mounted on a mounting tube (41) mounted on the ventilation opening (13f) of the supply pipe (13), and mounted on the mounting tube (41) via bearings (42, 43) and a rotating shaft (44). And a pressure receiving plate (47) attached to the end of the rotating shaft (44) and opening and closing the valve (45) by sensing the pressure of the liquid in the internal passage (T). ), The valve body (45) is always urged to the open position by the urging members (48, 49), and moves in a direction substantially orthogonal to the flow direction of the intake air to the internal passage. And a storage tank configured to open and close the ventilation opening (13f). 5. An air control valve (21) for use in a storage tank according to claim 1, wherein the air control valve (21).
A mounting cylinder (22) having a valve hole (22d) and a valve seat (22e) mounted on the ventilation opening (13e) of the supply pipe (13); and a covered cylinder connected to the mounting cylinder (22). A valve body (25) housed in a valve-shaped casing (23), and an upper space (A) on the outer periphery of the valve casing (23).
Blocking opening (23) provided so as to communicate with the valve hole (22d) and having a function as a closing preventing means.
b), the valve body (25) is always held at an open position separated from the valve seat (22e) at a lower portion of the valve housing casing (23) by its own weight, and supplied by a supply pipe (13). At the start of the liquid, the liquid is supplied to the chamber (R) provided at the lower part of the valve housing casing (23), and the buoyancy causes the valve (2) to move.
5) is floated in the closing direction, and the supply pipe (1)
The valve body (25) is adsorbed to the valve seat (22e) by the negative pressure of the internal passage (T) of (3), and the air pressure of the internal passage (T) of the supply pipe (13) is reduced to the negative pressure in the non-liquid supply state. Then, air is sucked into the internal passage (T) from the upper space (A) through the closing prevention opening (23b), and the intake air does not move the valve body (25) in the closing direction. Air control valve used for storage tank. 6. An air control valve (21) used in the storage tank according to claim 1, wherein the air control valve (21).
A mounting tube (22) connected to the ventilation opening (13e) of the supply pipe (13); a closed-tube-shaped valve housing casing (23) connected to the mounting tube (22); A first valve hole (26a) and a second valve hole (27a) provided at two locations on the outer periphery of the casing (23) and communicating the upper space (A) and the internal passage (T), respectively; The first valve hole (2) is provided in the casing (23).
A first valve element (32) for opening and closing 6a), and a second valve element (33) for opening and closing the second valve hole (27a) outside the valve housing casing (23); The two valve bodies are supported by a lever mechanism (28, 29, 30, 31) provided in the valve housing casing (23) so as to be opened and closed in synchronization with each other, and the tip of a tilting lever (28) of the lever mechanism is provided. An air control valve for use in a storage tank supporting a pressure receiving plate (34) for sensing the pressure of the liquid and opening and closing the first and second valve bodies so as to be located in the supply pipe (13). 7. An air control valve (21) used in the storage tank according to claim 1, wherein the air control valve (21).
Is mounted on a mounting tube (41) mounted on the ventilation opening (13f) of the supply pipe (13), and mounted on the mounting tube (41) via bearings (42, 43) and a rotating shaft (44). And a pressure receiving plate (47) attached to the end of the rotating shaft (44) and opening and closing the valve (45) by sensing the pressure of the liquid in the internal passage (T). ), The valve body (45) is always urged to the open position by the urging members (48, 49), and moves in a direction substantially orthogonal to the flow direction of the intake air to the internal passage. An air control valve used in a storage tank configured to open and close the ventilation opening (13f).