JP2665822B2 - Pressure reducing valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a pressure reducing valve that changes an opening degree of a valve body by the energy of a passing fluid itself to reduce a primary pressure to a predetermined secondary pressure.

<Related Art> Pressure reducing valves include a direct-acting type and a pilot-type pressure reducing valve as shown in Japanese Utility Model Laid-Open No. 59-150065.

<Problems to be Solved by the Invention> The direct acting pressure reducing valve has a simple structure but is used for a small flow rate.
On the other hand, the pilot-type pressure reducing valve is suitable for a large flow rate, but has a problem that the structure is complicated and the shape is large, so that maintenance is difficult. This is a pilot type pressure reducing valve, a pilot valve portion, a driving portion such as a piston to which a driving force is given by fluid from the pilot valve portion, and a main valve which opens and closes by a force from the driving portion to control a flow rate of the fluid. This is because these members are inevitably enlarged in shape.

Accordingly, it is an object of the present invention to provide a pressure reducing valve having a simple structure, a small shape, and a large flow rate.

<Means for Solving the Problems> The technical problem of the present invention taken to solve the above problems is to provide a variable pressure chamber in which an inflow hole communicating with an inlet and a discharge hole communicating with an outlet are both opened. A disc valve that opens and closes the discharge chamber and the discharge chamber at the same time is arranged in the transformer chamber, a communication hole that constantly communicates the inlet chamber with the transformer chamber is opened, and a communication path that communicates with an outlet that communicates with the transformer chamber on the secondary side is provided. A pilot valve that allows the fluid in the variable pressure chamber to flow to the outlet side by opening and closing on the road is arranged.The elastic force of the pressure setting spring acts on the upper end of the pressure responsive member such as the bellows and diaphragm, and the secondary pressure is applied to the lower surface. The pilot valve is opened and closed by the displacement force of the pressure responsive member caused by the balance of the two forces.

<Operation> The operation of the above technical means is as follows. The pilot valve is opened and closed by the displacement force of the stress response member due to the balance between the elastic force of the pressure setting spring and the secondary pressure. Therefore, when the secondary pressure is lower than the set pressure, the pilot valve is opened, and when it is higher, the pilot valve is closed.

On the other hand, the high-pressure fluid on the primary side always acts in the variable-pressure chamber through the communication port, and the pressure acts on the opening surface of the discharge hole in the low-pressure region to generate a valve closing force of the disk valve. Therefore, when the secondary pressure is low and the pilot valve is open, the pressure in the variable pressure chamber does not increase, and the disc valve is opened by the primary pressure from the inlet, and as a result, the fluid at the inlet opens the outlet. Go through to the exit. When the pressure on the secondary side reaches the desired pressure and the pilot valve closes in balance with the elastic force of the pressure setting spring, the pressure in the variable pressure chamber reaches the primary side pressure, and the pressure is reduced to the opening surface of the discharge hole in the low pressure region. , The disc valve closes both the inflow hole and the discharge hole to stop the fluid from flowing to the outlet side.
The above operations are continuously performed to perform a smooth decompression operation.

<Example> An example showing a specific example of the above technical means will be described.
(See FIG. 1) The main body 2, the valve case 4, and the spring case 6 constitute a casing of the pressure reducing valve. An inlet 8 and an outlet 10 are formed in the main body 2, and an inflow hole 12 and an outflow hole 14 that communicate with each other are opened in the upper surface of the main body. The outflow hole 12 is formed by an annular inner ring valve seat 18, and the discharge hole 14 is connected to an annular groove 16 formed between the inner ring valve seat 18 and the outer ring valve seat 20. Inner ring valve seat 18 and outer ring valve seat 20
Is formed into a plane having the same height, and the valve case 4 is arranged so as to cover both the valve seats 18 and 20 to form the transformation chamber 22. Transformer room
A disk-shaped disc valve 24 is disposed in the inside 22 so as to abut the two valve seats 18, 20, and is elastically urged by the coil spring 28 against the two valve seats 18, 20. A communication hole 26 is opened at a portion corresponding to the inflow hole 12 of the disk valve 24 so that the fluid on the primary side always flows into the variable pressure chamber 22.

The valve case 4 is provided with a communication passage 44 for communicating the variable pressure chamber 22 with an outlet (secondary side), and a pilot valve 30 for opening and closing the passage 44 is provided. The pilot valve 30 is urged in the valve closing direction by an urging spring 32, and is opened and closed by the operating force of the pilot valve rod.

The lower portion of the bellows 36 is mounted between the valve case 4 and the spring case 6, and the lower surface of the bellows 36 is brought into contact with the upper end of the pilot valve rod 34, and the bellows retainer 38 is placed on the upper surface. A secondary pressure always acts on the lower surface of the bellows 36 via the detection hole 46. A pressure setting spring 40 is disposed on the bellows retainer 38, and the elastic force of the pressure setting spring generated by the advance and retreat of the pressure adjusting screw 42 screwed to the spring-case 6 is transmitted to the pilot valve rod 34 via the bellows 38. .

The operation is as follows. The pilot valve 30 is a bellows by balancing the elastic force of the pressure setting spring 40 and the secondary pressure.
It is opened and closed with 36 displacement forces. Therefore, when the secondary pressure is low due to the urging force of the pressure setting spring 40 set by operating the pressure adjusting screw, the pilot valve 30 is opened, and when the secondary pressure is high, the pilot valve 30 is closed.

On the other hand, the high-pressure fluid on the primary side always flows into the variable pressure chamber through the communication port 26 of the disk valve 24, and the pressure in the variable pressure chamber 22 acts on the annular groove 16 in the low-pressure region, thereby generating the valve closing force of the disk valve 24. I do. That is, the valve opening force acting on the disc valve 24 is
And the primary pressure, this force does not change unless the primary pressure fluctuates. On the other hand, the valve closing force acting on the disc valve 24 is a product of the area of the annular groove 16 and the pressure in the variable pressure chamber 22, and is changed by the pressure in the variable pressure chamber 22. However, in the case of the present embodiment, it is necessary to take into account that the urging force of the coil spring 28 acts as a valve closing force at all times. Therefore, when the secondary pressure is low and the pilot valve 30 is open, the pressure in the variable pressure chamber 22 does not increase, and the opening force of the disk valve 24 due to the primary pressure from the inflow hole 12 is the closing force. The superior disc valve 24 is opened, so that the inlet flow exits through the outlet hole 14 to the outlet 10.

If the secondary pressure approaches the set pressure, the pressure
The bellows 36 is raised via the valve to move the pilot valve 30 in the valve closing direction. If the fluid flowing out of the pilot valve 30 decreases, the pressure in the variable pressure chamber 22 increases, and the valve closing force acting on the disk valve 24 exceeds the valve opening force. To close the valve. When the secondary pressure rises to the set pressure, the pilot valve 30 closes, and the disc valve 24 also completely closes. If the secondary pressure decreases, the pilot valve 30 starts to open and repeats the above operation. As described above, the disc valve 30 opens and closes in a state of balance between the pressure in the variable pressure chamber 22 and the primary side pressure acting on the primary inflow hole 12, so that a smooth pressure reducing operation can be realized.

In the above-described embodiment, the coil spring 28 is provided to provide a stronger valve closing force of the disk valve, but the coil spring 28 operates normally even without it. In addition, in the above embodiment, even if the inlet 8 and the outlet 10 are mounted in reverse, they function normally as pressure reducing valves. However, in this case, the inflow hole (in this case, reference number 1
A communication hole communicating between 4) and the transformation chamber 22 opens to the outer ring valve seat 20.

<Effect of the Invention> According to the present invention, by sharing the piston and the main valve in the pilot type pressure reducing valve, the structure is simple, the shape is small, and a large flow rate can be discharged. Further, if the member on the main body is removed, the valve seat is exposed on the upper surface, so that the sealing property can be maintained by simple maintenance such as wrapping.

[Brief description of the drawings]

 FIG. 1 is a sectional view of a pressure reducing valve according to an embodiment of the present invention. 2: Body, 8: Inlet, 10: Outlet 12: Inlet, 14: Outlet, 18: Inner ring valve seat 20: Outer ring valve seat, 22: Transformer chamber 24: Disc valve, 30: Pilot valve 36: Bellows, 40 : Pressure setting spring

Claims (1)

(57) [Claims] 1. A variable pressure chamber having an inflow hole communicating with an inlet and an exhaust hole communicating with an outlet are both provided, and a disc valve for simultaneously opening and closing the inflow hole and the exhaust hole is disposed in the variable pressure chamber. A communication valve communicating with an outlet communicating with the transformation chamber and the secondary side is provided, and a pilot valve is arranged on the communication passage to allow the fluid in the transformation chamber to flow to the outlet side. , The elastic force of the pressure setting spring is applied to the upper end of the pressure responsive member such as a bellows or a diaphragm, and the secondary pressure is applied to the lower surface, and the pilot valve is opened and closed by the displacement force of the pressure responsive member due to the balance between the two forces. A pressure reducing valve characterized in that: