JP3341198B2 - Pilot type back pressure valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a back pressure valve for maintaining a primary side, that is, an inlet side of a valve at a predetermined pressure state, and more particularly to a pilot type back pressure valve combined with a pilot valve.

[0002]

2. Description of the Related Art As a conventional back pressure valve, for example,
What was shown in Unexamined-Japanese-Patent No. 9-108912 was used. This is done by connecting a piston and a diaphragm to the valve body, and detecting the pressure on the primary side with the diaphragm, when the predetermined pressure is reached, the valve body opens and the pressure fluid on the primary side flows down to the secondary side. , To maintain the primary side of the valve at a desired pressure state.

[0003]

SUMMARY OF THE INVENTION In the above prior art,
The size of the valve body cannot be made larger than the size of the diaphragm, and there is a problem that the size of the valve body is limited.

Conventionally, various pilot-type valves have been used as a mechanism capable of opening a larger valve body. However, the pilot-type valve has a complicated structure and a large shape as a back pressure valve. There was a problem.

Accordingly, a technical problem of the present invention is to form a valve body having a size larger than the size of a diaphragm,
An object is to obtain a pilot-type back pressure valve having a simple structure and a small size.

[0006]

Means for Solving the Problems The technical means of the present invention taken to solve the above technical problem is to form an inlet, a valve port, and an outlet in a valve body and to control the primary pressure of the valve port by the pressure. A piston valve which operates by utilizing the pressure energy of the controlled fluid detected by the response member and maintains the primary pressure in a predetermined pressure state, wherein a piston valve which opens and closes the valve port is disposed opposite to the valve port. , The piston valve is slidably slid inside a cylinder member attached to the valve body and urged in the valve closing direction by an elastic member to form an inlet communication passage communicating with the inlet inside the cylinder member. the forms a pilot valve port communicating with the outlet cylinder member, thereby opening and closing the pilot valve which is connected <br/> the pressure responding member the pilot valve port, the cylinder member
For inflow of fluid into and discharge of fluid from inside the cylinder member
Piston valve with small diameter orifice for time delay
Is provided inside .

[0007]

The operation of the above technical means is as follows.
When the primary pressure of the valve port becomes higher than the predetermined pressure, the pressure responsive member is displaced, and the pilot valve connected thereto opens the pilot valve port to communicate the inside of the cylinder member with the outlet. No fluid stays inside. Therefore, the piston valve slides in the cylinder member by the fluid pressure from the inlet and separates from the valve port to open the valve port, whereby the fluid on the inlet side flows down to the outlet side to reduce the primary pressure.

When the pressure on the primary side of the back pressure valve decreases to a predetermined pressure, the displacement of the pressure responsive member returns to its original state, and the serially connected pilot valve closes the pilot valve port. The fluid flowing in through the stagnation stays at approximately the same pressure as the inlet side. Therefore, the pressure state before and after the piston valve becomes substantially the same, and the piston valve is displaced in the valve port direction by the elastic force of the elastic member to close the valve port, so that the flow of the primary fluid to the secondary side is stopped. .

The opening and closing of the pressure responsive member and thus the pilot valve are automatically performed in response to the fluctuation of the primary pressure, and the primary pressure of the valve opening of the back pressure valve is maintained at a predetermined pressure value.

[0010]

An embodiment showing a specific example of the above technical means will be described (see FIG. 1). The body 1 and the lid 2 form a valve casing. An inlet 3, a valve port 4 and an outlet 5 are formed in the main body 1.
An annular main valve seat 19 is provided around the valve port 4. The piston valve 6 is arranged so as to face the valve port 4. The piston valve 6 connects the cylindrical portion 7 with the valve port 4 side in a conical shape. A substantially cylindrical cylinder member 8 fixed by valve casing around the cylindrical portion 7 is attached. The upper surface of the cylinder member 8 is covered with a partition 9 formed on the lid 2, and the inner periphery of the cylinder member 8 is slidably disposed by the cylindrical portion 7 of the piston valve 6. At the lower end of the piston valve 6, there is provided an inlet communication passage 10 that communicates the inlet 3 with the inside of the cylinder member 8.

A disk-shaped pilot valve 11 is disposed inside the partition wall 9 inside the cylinder member 8, and a diaphragm 13 as a pressure responsive member is connected to an upper portion of the pilot valve 11 via a connecting rod 12. The lower surface space of the diaphragm 13 communicates with the inlet 3 through an opening 27 formed in the main body 1, a communication pipe 28, and an opening 29 formed in the lid 2. Pilot valve 11
A pilot valve port 18 is formed in the partition wall 9 below and communicates with the outlet 5 through the communication passage 20. A pressure setting spring 15, a spring seat 16 and a pressure adjusting screw 17 are attached to the upper surface of the diaphragm 13 via a disk-shaped diaphragm retainer 14.

The piston valve 6 is connected to the main valve seat 1 between the lower surface of the partition 9 and the conical portion of the piston valve 6 inside the cylinder member 8.
A coil spring 22 as an elastic member that urges in nine directions is attached.

A small diameter orifice 2 is provided inside the piston valve 6.
Orifice plates 25, 26 provided with 3, 24 are attached. The orifices 23 and 24 fill the inside of the cylinder member 8 with the fluid flowing from the inlet communication passage 10 with a time delay, and the fluid in the cylinder member 8 has a time delay even when the pilot valve port 18 is opened. This is to prevent the sudden opening and closing of the piston valve 6 to prevent the valve portion from being damaged due to an impact, and to eliminate the instantaneous opening and closing valve of the fluid. -It prevents the hammer phenomenon.

Next, the operation will be described. The state shown in FIG.
The state in which the pressure on the primary side, that is, the inlet 3 side is higher than the set pressure value set by the pressure adjusting screw 17, the diaphragm 13 is displaced obliquely upward by the primary side pressure, and the pilot valve 11 opens the pilot valve port 18. By doing so, a state where the inside of the cylinder member 8 communicates with the outlet 5 is shown. Since the fluid from the inlet 3 and the inlet communication passage 10 does not flow down to the outlet 5 and stays in the cylinder member 8, the piston valve 6 is displaced obliquely upward by the fluid pressure from the inlet 3, and By opening 4, the fluid on the inlet 3, that is, the fluid on the primary side is discharged to the outlet 5 side, and the pressure on the primary side decreases.

When the pressure on the inlet 3 side decreases, the diaphragm 13 is displaced obliquely downward by the spring force of the pressure setting spring 15, so that the pilot valve body 11 closes the pilot valve port 18 and the inside of the cylinder member 8 and the outlet 5 are closed. Cut off between. When shut off, the inlet communication passage 1 is provided inside the cylinder member 8.
When the fluid on the inlet 3 side is supplied via the pressure valve 0, the pressure in the cylinder member 8 becomes substantially the same as the pressure on the inlet 3, the piston valve 6 is displaced toward the valve port 4 by the elastic force of the coil spring 22, and the main valve seat 19, the valve port 4 is closed, and the discharge of the inlet fluid to the outlet 5 is stopped.

On the basis of the spring force of the pressure setting spring 15,
The diaphragm 13 is automatically displaced in accordance with the level of the pressure on the inlet 3 side, so that the pilot valve 11 is also automatically opened and closed to maintain the pressure on the primary side, that is, the inlet 3 side at a predetermined value.

[0017]

The present invention has the following specific effects. According to the present invention as described above, in order to transmit the displacement of the pressure responsive member to the piston valve via the pilot valve, it is possible to open and close a main valve, that is, a piston valve that is larger than the size of the pressure responsive member, By arranging the pilot valve inside the piston or cylinder member, the structure can be simplified and the shape can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of an embodiment of a pilot back pressure valve of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main body 2 Lid 3 Inlet 4 Valve port 5 Outlet 6 Piston valve 8 Cylinder member 10 Inlet communication path 11 Pilot valve 13 Diaphragm 15 Pressure setting spring 17 Pressure adjusting screw 19 Main valve seat 22 Coil spring

Claims (1)

(57) [Claims] An inlet, a valve port, and an outlet are formed in a valve body, a primary pressure of the valve port is detected by a pressure responsive member, and the valve is operated by using pressure energy of a controlled fluid, and a primary pressure is set to a predetermined value. A piston valve for opening and closing the valve port is disposed opposite to the valve port, and the piston valve is slidably closed in a cylinder member attached to the valve body and closed by an elastic member. And a pilot valve port communicating with the outlet is formed in the cylinder member, and the pilot valve port is connected to the pressure responsive member. with opening and closing the pilot valve which is connected to the inflow and cylinder of the fluid into the cylinder member
To delay the discharge of fluid from inside
A pilot back pressure valve characterized in that a small diameter orifice is provided inside a piston valve.