JP2510852Y2 - Pressure reducing valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a pressure reducing valve for adjusting the pressure of a fluid, that is, a pressure reducing valve for controlling a fluid on the upstream side so as to maintain the fluid system on the downstream side at a predetermined pressure. The present invention relates to a valve that automatically adjusts the flow to the downstream side.

<Prior Art> A pressure reducing valve applies an elastic force of a pressure setting spring to one surface of a pressure receiving wall such as a diaphragm and uses this as a reference value,
Apply the secondary side (downstream side of the pressure reducing valve) fluid pressure to the other surface, bend the diaphragm according to the deviation from the reference value, and directly or through the valve member connected to this to open the main valve. It is driven to open and close the valve port.

The pressure reducing valve includes a direct-acting type in which a main valve is directly driven by a diaphragm and a pilot type in which a pilot valve is driven by a diaphragm to control a fluid pressure acting on a main valve such as a piston. In any case, the main valve receives a displacement force only in the valve opening direction. The displacement (return) in the valve closing direction of the main valve utilizes the fluid pressure and the elastic biasing action of the spring. The main valve is biased by a spring to achieve the desired seal even when the fluid pressure acting on the main valve in the valve closing direction is small, that is, when the set pressure on the secondary side is high and the differential pressure with the primary side is small. This is to obtain the effect.

This spring-biased valve structure is disclosed, for example, in Japanese Utility Model Laid-Open No. 59-150065. Here, a coiled main valve spring arranged between the valve casing and the fixed wall is used to urge the main valve in the valve closing direction to close the valve port.

<Problems to be solved by the present invention> In this case, a member for displacing a main valve such as a diaphragm or a piston valve in a valve opening direction needs to be capable of exerting a large force, which causes a problem of becoming large. This is because the member that displaces these main valves in the valve opening direction has a low set pressure on the secondary side and a large differential pressure with the primary side, and the fluid pressure in the valve closing direction that acts on the main valve is large. Even if it exists, it must be able to exert the force that displaces the main valve.

Therefore, the technical problem of the present invention is to make it possible to displace the main valve in the opening direction by using a small diaphragm, a piston valve or the like.

<Means for Solving the Problems> The technical means of the present invention taken to solve the above technical problems is to apply the elastic force of the pressure setting spring to one surface of the pressure receiving wall such as a diaphragm. The main valve, which is made to actuate the secondary side fluid pressure on the other surface and is elastically biased in the valve closing direction by the main valve spring that is arranged between the casing and the fixed wall of the casing, either directly by the deflection of the diaphragm or by a member such as a piston valve. In order to open and close the valve opening provided between the inlet and the outlet by displacing it in the valve opening direction via a spring receiver, a spring receiver is arranged between the main valve and the fixed wall of the casing. The main valve spring is placed between the bearing and the bellows between the spring bearing and the fixed wall of the casing, and the casing has a through hole that connects the inside of the bellows with the secondary side of the valve opening. is there.

<Operation> The operation of the above technical means is as follows.

A spring bearing is disposed between the main valve and the fixed wall of the casing, a main valve spring is disposed between the main valve and the spring bearing, and a bellows is disposed between the spring bearing and the fixed wall of the casing. Since the casing has a through hole that connects the inside with the secondary side of the valve opening, the bellows moves away from the valve disc when the pressure difference between the inlet and the outlet is large, and when the pressure difference is small. Is displaced toward the main valve. This displacement of the bellows reduces the elastic force of the main valve spring that elastically biases the main valve in the closing direction when the differential pressure is large, and the elastic force of the main valve spring when the differential pressure is small. Power increases. Therefore, regardless of the differential pressure between the inlet and the outlet, the main valve can be urged in the valve closing direction with the minimum elastic force of the main valve spring that achieves the desired sealing effect. Therefore, a member that exerts a small force can be used as a member that displaces the main valve such as the diaphragm or the piston valve in the valve opening direction.

<Effect of Invention> The present invention has the following unique effects.

As described above, according to the present invention, the member for displacing the main valve such as the diaphragm or the piston valve in the valve opening direction may be a member that can exert a small force, so that a small member can be used. Therefore, the valve itself can be made small.

<Example> An example showing a specific example of the above technical means will be described (see FIG. 1).

The main body 1 forms an inlet 2, a valve opening 3, and an outlet 4. The inlet 2 is connected to the high pressure fluid source on the primary side, and the outlet 4 is connected to the low pressure region on the secondary side. The valve port 3 is formed by a valve seat member 5 and is opened and closed by a main valve 6 arranged on the inlet 2 side.

A coil-shaped main valve spring 8 is provided between the bottom surface of the main valve 6 and the bottom member 7.
Arrange the spring bearing 9 and the bellows 10. The main valve 6 has a main valve shaft slidably fitted on a spring bearing 9. The coiled main valve spring 8 has its upper end in contact with the lower surface of the main valve 6 and its lower end in contact with the upper surface of the spring receiver 9. The bellows 10 has its upper end welded to the lower surface of the spring bearing 9 and its lower end welded to the upper surface of the bottom member 7. A through hole that connects the outlet 4 side with the inside of the bellows 10.
11 is formed on the main body 1 and the bottom member 2.

The piston 12 is slidably arranged in the cylinder 13, and the piston rod of the piston 12 is brought into contact with the main valve 6 through the valve port 3. The member number 14 is a piston ring for maintaining airtightness between the piston 12 and the cylinder 13, and the reference number 15 is an orifice that connects the upper surface and the lower surface of the piston 12 to each other.

Primary pressure passage that connects the inlet 2 and the space above the piston 12
A pilot valve 18 biased in a valve closing direction by a biasing spring 17 is arranged at 16. The diaphragm 19 is attached with its outer peripheral edge sandwiched between the flanges 20 and 21. The space below the diaphragm 19 communicates with the outlet 4 through the secondary pressure detection passage 22.
The head of the valve rod 23 of the pilot valve 18 contacts the lower surface of the diaphragm 19.

The lower end of the pressure setting spring 25 is brought into contact with the upper surface of the diaphragm 19 via the spring seat 24. The lower end of an adjusting screw 29 screwed to a spring case 28 abuts on the upper end of the pressure setting spring 25 via a ball 26 and a spring seat 27.

When the adjusting screw 29 is turned to the left or right, the elastic force of pushing down the diaphragm 19 of the pressure setting spring 25 changes. This pressure setting spring
With the elastic force of 25 as a reference value, the diaphragm 19 bends according to the secondary pressure acting on the lower surface of the diaphragm 19, and the valve rod 23 is displaced to open and close the pilot valve 18. As a result, the primary side fluid pressure is introduced above the piston 12, the piston 12 is driven and the main valve 6 is displaced, and the fluid at the inlet 2 flows through the valve port 3 to the outlet 4. This automatically operates so that the valve port 3 opens when the fluid pressure on the secondary side drops and closes when the fluid pressure rises.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of a pressure reducing valve showing an embodiment of the present invention. 1: Main body, 2: Inlet 3: Valve port, 4: Outlet 6: Main valve, 7: Bottom member 8: Main valve spring, 10: Bellows 11: Through hole, 19: Diaphragm 25: Pressure setting spring

Claims (1)

(57) [Scope of utility model registration request] 1. An elastic force of a pressure setting spring is applied to one surface of a pressure receiving wall such as a diaphragm, and a fluid pressure on the secondary side is applied to the other surface of the diaphragm, which is arranged between the casing and a fixed wall. The main valve, which is elastically urged in the valve closing direction by the main valve spring, is displaced in the valve opening direction by the deflection of the diaphragm directly or through a member such as a piston valve, and the valve port provided between the inlet and the outlet is opened and closed. In this case, a spring bearing is arranged between the main valve and the fixed wall of the casing, a main valve spring is arranged between the main valve and the spring bearing, and a bellows is arranged between the spring bearing and the fixed wall of the casing. A pressure reducing valve in which a casing is provided with a through hole that connects the inside of the bellows with the secondary side of the valve opening.