JPH06272785A - Opening/closing device of automatic valve - Google Patents

Abstract

PURPOSE:To prevent generation of the hunting by communicating a first chamber and a second chamber of a valve opening/closing cylinder with each other through a first orifice, and communicating the second chamber and the secondary side flow passage with each other through a second orifice respectively, and making the diameter of the first orifice smaller than the diameter of the second orifice to suppress rapid opening/closing operation. CONSTITUTION:In a cylinder 13, when the liquid is poured from the inlet 20 of a first chamber 18, the air and the liquid present in the space between of a piston 15 and a bottom 14 in the first chamber is moved through a first communicating hole, a second chamber 19, a second communicating hole 26 and the secondary side in this order. As the air and the liquid is moved in such manner, and when the second chamber 19 is filled, the pressure in the first chamber 18 is larger than the pressure in the second chamber 19 because a first orifice 251 is designed smaller than a second orifice 261. However, the difference in size of the orifice does not affect much, and the movement of the piston 15 becomes extremely slow. Thus, a main valve 7 and auxiliary valve 9 are gradually released, preventing the hunting.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic valve suitable for use as fluid control means for various industries, and also as an automatic valve for extinguishing a fire.

[0002]

2. Description of the Related Art When a fluid such as water or a chemical is fed, various valve devices are known for controlling the feeding in the form of interrupting or releasing the interruption in the middle of feeding.

In the event of a fire, various valve devices are also known, which open the valve for controlling the discharge of fire extinguishing water or chemicals by various starting means and deliver the fire extinguishing water or chemicals to necessary places. .

[0004]

In such a valve device, hunting occurs due to a sudden operation when the valve is opened and closed, which adversely affects not only the valve device but also the fluid delivery system or the automatic fire extinguishing system as a whole. There is.

In particular, the automatic fire extinguishing system does not operate on a daily basis, but it operates for the first time in the event of a fire,
If, for example, hunting occurs as a result of operation for regular inspection, and the valve device or other parts of the fire extinguishing system malfunction, there is a risk that the purpose of extinguishing the fire cannot be achieved when a fire that actually requires operation occurs. Therefore, there is a demand for an automatic valve that can perform a quick and gentle operation.

[0006]

According to the present invention, a valve seat is installed on a partition wall separating a primary side having an inflow port and a secondary side having an exhaust port, and a main valve is mounted on the valve seat. A sub-valve seat is provided in which a sub-valve is installed in part of the main valve.

Further, the end of the pressing rod for pressing and opening the sub valve and the main valve from the secondary side is fixed to a piston that slides in a cylinder separately installed, and a starting fluid such as water from the primary side is fixed. It was decided to supply the starting fluid from the second chamber to the secondary side by sequentially supplying the first chamber and the second chamber of the cylinder partitioned by the piston.

In the meantime, the piston is moved by the difference in the internal pressures of the two chambers, whereby the sub valve is first opened and then the main valve is opened, so that the inflow of water or the like from the primary side to the secondary side can be rapidly performed. However, it was done gently.

Even when the valve is closed, the sliding of the piston is buffered by the fluid so that the main valve is first closed and then the sub valve is closed gradually and gently.

[0010]

An embodiment of the present invention will be described with reference to the drawings.
Reference numeral 1 denotes a main body whose inside is partitioned by a partition wall 2 into a primary side 5 having an inflow port 3 and a secondary side 6 having a discharge port 4.

Reference numeral 7 denotes a valve seat 8 installed on the partition wall 2 and a primary side 5
Is a main valve installed through the partition wall 2. Reference numeral 9 is a sub valve that is installed in the sub valve seat 10 installed in the main valve 7 from the primary side 5 through the main valve 7.

The sub valve 9 is provided with an extension cylinder portion 9a in the primary side 5, and the end portion of the adjusting support rod 12 screwed into the lid body 11 of the primary side 5 is inserted into the extension cylinder portion 9a. .

A cylinder 13 is airtightly installed on the secondary side 6 of the main body 1. The open end of the cylinder 13 is closed by a bottom plate 14, and a piston 15 is slidably accommodated inside.

Reference numeral 16 denotes a pressing rod having one end fixed to the piston 15, which extends through the cylinder 13 into the secondary side 6 in parallel with the sliding direction of the piston 15 and has the other end at the valve seat 8
And penetrates the sub valve seat 10 and faces the surface of the sub valve 9 facing the secondary side 6.

Reference numeral 17 is a pressing plate for pressing the main valve 7,
The end portion is fixed on the pressing rod 16 which is located at a certain distance from the end portion of the pressing rod 16 facing the sub valve 9.

The cylinder 13 has a first chamber 18 formed between the piston 15 and the bottom plate 14, and a second chamber 19 formed between the piston 15 and the wall surface of the cylinder 13 through which the pressing rod 16 penetrates. It is equipped.

The cylinder 13 is provided with inlets 20 and 22 for supplying a necessary fluid to the first chamber 18 and the second chamber 19 for sliding the piston 15, and an outlet 21,
23 are provided respectively.

The cylinder 13 is hermetically enclosed by the main body 1 and the bottom plate 14, and the main passage 1 has an inlet passage 24 so that fluids required for the inlets 20 and 22 and the outlets 21 and 23 can flow in and out. , 26 and the exit passage 25,
27 is provided.

In the figure, 28 is a branch opening opened on the primary side 5, and 29 is a confluence opening opened on the secondary side 6. Reference numeral 30 denotes a cap that protects the end of the adjustment support rod 12,
Is screwed to. Reference numeral 31 indicates a spring stretched between the lid 11 and the sub valve 9.

An inlet 3 on the primary side 5 of the main body 1 is connected to a pressurized water supply pipe (not shown), and an outlet 4 on the secondary side 6 is connected to a fire extinguishing pipe (not shown).

Although the control flow circuit for opening and closing the automatic valve is not shown in the drawing, the control fluid such as water flows from the branch port 28 of the primary side 5 through a valve (not shown) or the like. From the inlet passage 24 of the first chamber 18 to the first chamber 1 of the cylinder 13.
8 and is depressurized from the outlet passage 25 through an orifice (not shown) or the like, and the inlet passage 2 of the second chamber 19
6 is supplied to the second chamber 19 and is discharged from the outlet passage 27 to the secondary side 6 of the main body 1 through the confluence 29.

To explain the operation, in order to open the valve from the closed state of FIG. 1, it is sufficient to supply the fluid from the branch port 28 of the primary side 5 to the first chamber 18 of the cylinder 13 as described above.

When the fluid is supplied, since the pressure in the second chamber 19 of the cylinder 13 is lower than that in the first chamber 18, the piston 15 moves in the direction of reducing the volume of the second chamber 19. Accordingly, the pressing rod 16 moves to separate the sub valve 9 from the sub valve seat 10 of the main valve 7.

As a result, inflow of pressurized water from the primary side 5 to the secondary side 6 is started. The state is as shown in FIG.

Then, as the piston 15 continues to move, the pressing plate 17 of the pressing rod 16 presses the main valve 7 and separates it from the valve seat 8. The state in which the operation is completed is as shown in FIG.

When the main valve 7 is separated from the valve seat 8, the pressurized water flows from the primary side 5 to the secondary side 6 through the valve seat 8, and the water is discharged from the discharge port 4 to the sprinkler head (not shown) or the like. Supplied for fire extinguishing.

To close the main valve 7 and the sub valve 9, a valve (not shown) or the like is closed and the first chamber 18 of the cylinder 13 is closed.
It suffices to stop the supply of fluid to the. The first chamber 18 of the cylinder 13 communicates with the merging port 29 of the secondary side 6 via the second chamber 19, and the first chamber 18 is connected to the second chamber 19 via an orifice (not shown). Therefore, when the supply of the fluid is stopped, the pressure in the first chamber 18 becomes equal to the pressure in the second chamber 19.

Since the pressurized water is supplied to the primary side 5 and the water is discharged from the secondary side 6 to the sprinkler head, the pressure on the secondary side 6 is lower than the pressure on the primary side 5. Become.

Therefore, when the supply of water to the first chamber 18 is stopped, the main valve 7 is pressed by the pressure on the primary side 5 and the pressing rod 16 is pressed.
While pressing the pressing plate 17, the valve seat 8 is moved in the closing direction. The state where this operation is completed is as shown in FIG.

However, the first chamber 1 of the cylinder 13
Since the fluid of No. 8 is sent to the second chamber 19 via the orifice (not shown) as described above, the piston 15
The fluid in the first chamber 18 gradually flows into the second chamber 19 without rapidly compressing the first chamber 18, and the second chamber 19 is gradually expanded.

Therefore, the movement of the piston 15 becomes extremely gentle.

Accordingly, the sub valve 9 moves in the direction of closing the sub valve seat 10 installed in the main valve 7 by the action of the spring 31 and the water pressure on the primary side 5. The state in which this operation is completed is as shown in FIG.

The movement of the main valve 7 and the auxiliary valve 9 promotes the movement of the piston 15 in the direction of the bottom plate 14, but the first chamber 18 is filled with water, and the water flows through the second chamber 19 to the bottom chamber. Since the piston 15 moves as it is discharged to the secondary side 6, the main valve 7 and the auxiliary valve 9 that move integrally with the piston 15 and the pressing rod 16 also operate in the same gentle operation as the piston 15. The seat 8 and the sub valve seat 10 will be closed.

A series of these opening and closing operations can be performed stepwise, gently and surely by manual or automatic operation of a valve (not shown). Therefore, even when the automatic valve of the present invention is inspected, it can be opened and closed quickly and gently, so that hunting or the like does not occur.

The degree of opening of the main valve 7 and the sub valve 9 is
The adjustment support rod 12 can be easily adjusted by rotating the adjustment support rod 12 to adjust the movement amount of the auxiliary valve 9. At the same time, the adjustment support rod 12 also serves as a guide for the movement of the auxiliary valve 9.

In FIG. 4, the primary side pressure A, the secondary side pressure B, the first chamber of the cylinder 13 from the state where the automatic valve of the present invention is opened to the state where the main valve 7 and the sub valve 9 are closed. The changes in the pressure C and the second chamber pressure D are shown by the graph.

Pressure is plotted on the vertical axis of the graph and elapsed time is plotted on the horizontal axis. When a valve (not shown) is closed at point P on the horizontal axis, the main valve 7 is closed at point Q. The auxiliary valve 9 is closed at point R.

Even when these valves are closed, as is clear from the graph showing the primary pressure A, the primary pressure A does not increase sharply with the closing of the valves. This means that hunting due to valve closure does not occur.

Incidentally, in the present invention, the opening and closing of the main valve 7 and the auxiliary valve 9 are performed in the horizontal direction, but by determining the opening and closing direction in this way, the moving direction of the piston 15 can also be determined horizontally. it can.

Therefore, the inlets 20 and 22 and the outlets 21 and 23 for supplying the fluid to the cylinder 13 can be installed in the vertical direction, so that the air in the first chamber 18 and the second chamber 19 can be smoothly removed.

[0041]

As described above, according to the present invention, the sub valve 9 and the main valve 7 are opened and closed stepwise and gradually by the action of the piston 15, so that an automatic valve which does not cause hunting and is free from failure is obtained. There is an effect that can be.

[Brief description of drawings]

FIG. 1 is an internal explanatory view of the automatic valve of the present invention in a closed state.

2 is a drawing similar to FIG. 1 with only the sub-valve opened.

FIG. 3 is a drawing similar to FIG. 1 with both the sub-valve and the main valve fully open.

FIG. 4 is a graph showing changes in pressure inside the device when the main valve and the sub valve are closed.

[Explanation of symbols]

 1 Main body 2 Partition wall 3 Inlet port 4 Discharge port 5 Primary side 6 Secondary side 7 Main valve 8 Valve seat 9 Secondary valve 10 Secondary valve seat 11 Lid body 12 Adjustment support rod 13 Cylinder 14 Bottom plate 15 Piston 16 Push rod 17 Push plate 18 1st chamber 19 2nd chamber 20 Inlet 21 Outlet 22 Inlet 23 Outlet 24 Inlet passage 25 Outlet passage 26 Inlet passage 27 Outlet passage 28 Branching port 29 Confluence port 30 Cap 31 Spring A Primary side pressure B Secondary side pressure C First chamber Pressure D Second chamber pressure P Valve closed position Q Main valve closed position R Sub valve closed position

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[Procedure amendment]

[Submission date] November 25, 1991

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction content]

[Document name] Statement

Title: Automatic valve opening / closing device

[Claims]

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic valve opening / closing device.

[0002]

2. Description of the Related Art When supplying a liquid such as water, it is already known to open and close a valve at an intermediate stage of the supply.

In particular, in a fire disaster prevention facility, a valve for shutting off / opening the supply of water or chemicals for extinguishing a fire should be shut off not only at the time of a fire accident but also at a daily inspection. Although it is opened, hunting occurs due to a rapid change in liquid pressure due to water or chemicals in the supply device when shutting off / opening, which causes surrounding facilities (automatic valve is installed in the building In that case, it was unavoidable to give a great impact to the building, the tunnel, etc. if installed in the tunnel.

FIG. 1 shows a main body 1 of a liquid supply apparatus.
Primary side 5 with inlet 3 and secondary 6 with outlet 4.
A valve seat 8 is provided on the partition wall 2 which isolates the main valve 7, a main valve 7 which is slidably installed on the partition 2 and is opened and closed, and a sub valve seat 10 is provided on the main valve 7. It shows a configuration by providing a sub valve 9 which is slid and opened and closed, which has already been developed by the present applicant, Oguma Machine Co., Ltd.

In such a structure in which the main valve 7 and the sub valve 9 are provided, when the valve is opened and the liquid is supplied, the piston 15 and the pressing rod 16 are moved from the position of the cylinder 13 to 2
By moving in the direction of the next side and the tip of the pressing rod 16 moves the sub valve 9 to the primary side, the sub valve is first opened, and then the pressing plate 17 moves the main valve 7 to the primary side. By opening it.

On the contrary, when shutting off the valve, the pushing rod 16
And the piston 15 moves to the cylinder 13 side, the state where the pressing plate 17 presses the main valve 7 first ends and the main valve 7 is shut off, and then the tip of the pressing rod 16 presses the sub valve 9. The state that has been completed is completed, and the sub valve 9 is shut off.

As described above, since the opening and closing of the valve are performed by the two steps of the auxiliary valve and the main valve, the primary side 5 and 2
The sudden change in the pressure of the liquid on the secondary side 6 is alleviated.

However, even if such a main valve and a sub valve are adopted, hunting at the time of opening and closing of the valve and the generation of impact accompanying this can be alleviated, but
It was impossible to escape these completely.

This is because in the structure of the cylinder and the piston used in the prior art, the movement of the piston at the time of opening and closing the main valve and the auxiliary valve is not always slow, so that the pressure Because it was not possible to prevent sudden changes.

The structure of the piston and the cylinder in the prior art will be described with reference to FIG.

In the prior art, the cylinder 13 has the first
An orifice (small hole) 151 is provided in the piston 15 which is divided into the chamber 18 and the second chamber 19, and the secondary side 6 of the second chamber 19 is provided.
The boundary surface between the liquid and the liquid is allowed to pass by being perforated, and in order to move the piston 15, the liquid is passed from the primary side of the main body 1 through a control valve (not shown) or the like to the first chamber. When the air flows into the first chamber 18 through the inlet 24, the air in the first chamber 18 flows into the second chamber 19 through the orifice 151, and the liquid that subsequently flows into the first chamber 18 also flows into the second chamber 19. Further, the air and the fluid flow from the second chamber 19 to the secondary side 6 through the hole 191 bored.

However, in the conventional structure of the piston 15 and the cylinder 13 as described above, the main valve 7 and the sub valve 9 are arranged.
Since the liquid does not exist or does not exist sufficiently on the secondary side 6 when opening the, the diameter of the analogy orifice 151 is designed to be large so that the liquid is quickly moved from the first chamber 18 to the second chamber 19. Even if so, the pressure in the second chamber is weak.

Therefore, when the liquid for moving the piston 15 flows into the first chamber 18, the pressure difference between the first chamber 18 and the second chamber 19 is extremely large.

Even if the second chamber is filled with the liquid through the orifice 151, the hole 191 extending from the second chamber to the secondary side is provided.
Therefore, there is almost no flow resistance from the second chamber to the secondary side.

Therefore, even if the liquid is filled on the secondary side, the pressure difference between the first chamber and the second chamber is still large.

Due to such a pressure difference, the speed at which the piston moves in the direction of opening the main valve 7 and the sub valve 9 is extremely high, the opening of the main valve 7 and the sub valve 9 is also rapid, and the main valve 7 and the sub valve 9 are opened rapidly. That is, the hunting could not be escaped when the sub valve 9 was opened.

On the contrary, by closing the control valve (not shown), the inflow of the liquid from the primary side 5 to the cylinder 13 is stopped, and thereby the pressurization of the main valve 7 and the auxiliary valve 9 by the piston 15 is stopped. In case of piston 15
Moves toward the first chamber due to the pressing force of the liquid on the primary side, and as the first chamber becomes narrower in sequence, the liquid existing in the first chamber flows into the second chamber through the orifice 151 provided in the piston 15. Orifice 15
The diameter of 1 is necessary to move the gas and the liquid from the first chamber 18 to the second chamber 19 when the main valve 7 and the sub valve 9 are opened.
Cannot be designed smaller than a certain size. For this reason, the piston 15 is likely to move to the first chamber side at a high speed even when shutting off, and a sudden shutoff is performed. Therefore, hunting cannot be escaped.

[0018]

DISCLOSURE OF THE INVENTION The present invention employs a mechanism in which the structure of the piston and cylinder is completely different from the conventional one in a device which uses a two-stage shutoff / opening of a main valve and an auxiliary valve. Moreover, it is an object of the present invention to prevent the occurrence of the hunting by opening / closing the liquid to be supplied to the cylinder for moving the piston also by preventing the abrupt opening / closing operation.

[0019]

[Means for Solving the Problems] In order to solve the above problems,
The present invention relates to a liquid supply apparatus main body having an inflow port 1
A main valve and a sub valve for opening and closing the secondary side and the secondary side having a discharge port are provided, and the sub valve and the main valve are opened and closed from the secondary side via the tip and the pressing plate, respectively. A pressing rod, a piston fixed to the pressing rod and moving integrally with the pressing rod,
The first of a closed type cylinder partitioned by the piston
An outlet of the chamber and an inlet of the second chamber are communicated with each other by a first communication hole, and a first orifice (small hole) is provided in the first communication hole;
The outlet of the second chamber and the secondary side are communicated by a second communication hole, and a second orifice (small hole) is provided in the first communication hole, and the first orifice is designed to be smaller than the second orifice. It adopts the automatic valve configuration.

[0020]

FIG. 2 shows an embodiment of the construction of the automatic valve used in the present invention.

In the present invention, the piston 15 is not provided with an orifice as in the prior art, and in the cylinder 13, the second chamber is perforated at the boundary surface with the secondary side as in the prior art. It is not closed and is closed by disconnecting from the secondary side.

[0022] Also, the inlet 20 of the first chamber 18 communicates with via the primary-side control valve, the outlet 21 is in communication via the inlet and the first communication hole 25 of the second chamber 22 , Second chamber 19
The outlet 23 communicates with the secondary side 6 through the second communication hole 26.

In the embodiment, the first communication hole 25 and the second communication hole 25
Although the communication hole 26 is shown as an elongated pipe shape, the shape of the communication hole is not necessarily limited to the above-described pipe, and for example, a facility of a type having an automatic valve (when installed in a building , The building, if installed in the tunnel, the shape by providing a hole in the tunnel is also considered).

A first orifice 251 is provided in the first communication hole 25, a second orifice 261 is provided in the second communication hole 26, and the size of the first orifice is designed to be smaller than the size of the second orifice. To do.

When the cylinder 13 and the piston 15 are constructed as described above and the liquid is injected from the inlet 20 of the first chamber through the control valve (not shown) from the primary side, in the first chamber The air and the liquid existing between the piston 15 and the bottom plate 14 are in the first chamber 18 → first communication hole → second chamber 19 →
It moves from the second communication hole 26 to the secondary side.

At the stage immediately after the liquid has been injected into the first chamber, air remains in the second chamber, so that the first chamber 18
The pressure difference between the second chamber 19 and the second chamber 19 is large, and the piston moves at a relatively high speed in the direction in which the main valve 7 and the sub valve 9 are present.

When the liquid moves to fill the second chamber as described above, the first orifice 251 is designed to be smaller than the second orifice 261. The liquid in the chamber is compressed more than the liquid in the second chamber by the inflow pressure from the primary side.

As a reaction, the pressure in the first chamber 18 is greater than the pressure in the second chamber 19 and, therefore, after the liquid has filled the second chamber, the piston will follow the pressure difference between the two. The main valve 7 and the sub valve 9 are sequentially moved in the direction in which they are present.

The pressure difference is the first orifice 25.
1 depends on the difference in flow resistance between the first communication hole 25 having the No. 1 and the second communication hole 26 having the second orifice 261. This is mainly due to the size of the first orifice 251 and the size of the second orifice 261. The difference in pressure between the first chamber and the second chamber is extremely small as compared with the conventional example shown in FIG. 1 because the difference is not so large.

Therefore, the movement of the piston 15 is extremely slow, and the main valve 7 and the sub valve 9 are gradually opened.

In FIG. 3, the supply of liquid from the primary side 5 to the first chamber 18 of the cylinder 13 is stopped by a control valve (not shown), and the primary side is added to the main valve 7 and the sub valve 9. The main valve 7 and the sub valve 9 are moved to the cylinder 13 side by the pressure of 1, and the pressing rod 16 and the piston 15 are moved to the first chamber accordingly.

In this case, the first chamber 18 gradually becomes smaller, while the second chamber 19 gradually becomes larger.

Therefore, the liquid existing in the first chamber moves to the second chamber through the first communication hole 25, but the movement of the liquid causes the piston to move toward the first self-chamber side. It becomes a resistance against the movement, and as a result, the movement of the piston when the main valve 7 and the auxiliary valve 9 are closed is also extremely slow as compared with the conventional example.

[0034]

As described above, according to the present invention, in addition to the structure for opening and closing the main valve and the sub-valve, the movement of the piston as described above is made extremely slow.
The opening and closing of the secondary side and the secondary side will be performed very slowly.

Incidentally, the primary side pressure A, the secondary side pressure B, the first chamber of the cylinder 13 in the state in which the main valve 7 and the sub valve 9 are closed from the state in which the automatic valve of the present invention shown in FIG. 4 is opened. Pressure C
And the change in the second chamber pressure D is shown by a graph.

Pressure is plotted on the vertical axis of the graph and elapsed time is plotted on the horizontal axis. When a valve (not shown) is closed at point P on the horizontal axis, the main valve 7 is closed at point Q. The auxiliary valve 9 is closed at point R.

Even when these valves are closed, as is clear from the graph showing the primary pressure A, the primary pressure A does not increase sharply with the closing of the valves. This means that hunting due to valve closure does not occur.

As described above, the present invention is epoch-making in that it can achieve the age-old problem of preventing hunting in the industry.

[Brief description of drawings]

FIG. 1 is a side sectional view showing the structure of an automatic valve according to the prior art.

FIG. 2 is a side sectional view showing a situation in which the piston moves in a direction of opening the sub valve and the main valve in the configuration of the embodiment of the automatic valve of the present invention. The white arrow indicates the moving direction of the piston and the pressing rod, and the black arrow indicates the moving direction of the liquid.

FIG. 3 is a side sectional view showing a situation in which the piston moves in a direction to shut off the main valve and the sub valve in the present invention.

FIG. 4 is a graph showing a state of change in pressure of each part when the valve is closed in the automatic valve opening / closing device of the present invention.

[Description of attachment] 1 main body 2 partition wall 3 inflow port 4 discharge port 5 primary side 6 secondary side 7 main valve 8 valve seat 9 auxiliary valve 10 auxiliary valve seat 11 lid 12 adjustment support rod 13 cylinder 14 bottom plate 15 piston 151 Orifice in Piston 16 Pressing Rod 17 Pressing Plate 18 First Chamber 19 Second Chamber 191 Second Chamber Hole 20 Inlet 21 Outlet 22 Inlet 23 Outlet 24 Inlet Passage 25 1st Communication Hole 251 1st Orifice 26 2nd Communication Hole 261 Second orifice 27 Outlet passage 28 Branching port 29 Confluence port 30 Cap 31 Spring A Primary pressure B Secondary pressure C First chamber pressure D Second chamber pressure P Valve closing position Q Main valve closing position R Sub valve Closed position

Claims (2)

[Claims] 1. A main valve mounted for closing a valve seat by installing a valve seat on a partition wall that separates a primary side having an inlet of a main body and a secondary side having a discharge port. A secondary valve seat installed on a part of the secondary valve seat to close the secondary valve seat, an adjustment support rod for guiding and adjusting the movement of the secondary valve and the main valve inside the primary side, and a secondary support valve from the secondary side. A pressing rod provided with a pressing plate for pressing the valve and the main valve, a piston fixed to the end of the pressing rod, and a cylinder for the piston to slide inside thereof.
The first chamber of the cylinder, which is partitioned by the piston, supplies the fluid from the branch port on the primary side, sends the fluid in the first chamber to the second chamber, and joins the fluid in the second chamber to the secondary side. An automatic valve characterized in that a pressure difference is provided to the internal pressure between the first chamber and the second chamber while discharging the gas to the mouth. 2. The first chamber and the second chamber of the cylinder are installed so as to move the piston in the horizontal direction, and the air in the cylinder is automatically discharged from the confluence on the secondary side. The automatic valve according to claim 1.