JPH03186906A - Cylinder structure for pressure reducing valve - Google Patents

Abstract

PURPOSE:To improve reliability as a pressure reducing valve by controlling a main valve body by means of the slide of a cylinder and a mainbody inner wall so as to open/close a main valve port even if chattering occurs and a piston and the cylinder are caught. CONSTITUTION:When chattering occurs and the piston 20 and the cylinder 22 are caught, the sliding resistance of both considerably becomes large, it becomes larger than the energizing force of a spring 54 and the cylinder 22 is vertically displaced in the state where the piston 20 and the cylinder 22 are caught. Consequently, the piston 20 energizes the main valve body 18 and the main valve port 14 can be opened and closed in a usual way, whereby it functions as the pressure reducing valve. Then, the cylinder 22 vertically slides in the state where the piston 20 and the cylinder 22 are caught. The upper end surface of the piston is impulsively abutted on the lower end surface of a spacer 27, a piston rod 20b on the projecting part of the main valve body, or the upper end of the cylinder 22 on the lower end of the spacer 27. Consequently, the piston and the cylinder which are inclined and are caught are released. Thus, reliability as the pressure reducing valve improves.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a pressure reducing valve that is attached to a fluid piping system to reduce the fluid pressure on the primary side and maintain the fluid pressure on the secondary side at a predetermined set pressure. Concerning improvement of a part of the cylinder of a pilot type pressure reducing valve.

<Prior Art> A conventional Pirota 1-type pressure reducing valve is shown in FIG. Main body 10
Entrance 12. Valve port 14. An outlet 16 is formed, with the inlet 12 connecting to a source of high pressure fluid on the primary side and the outlet 16 connecting to a low pressure region on the secondary side. The main valve 18 is disposed at the inlet side end of the valve port 14 and is elastically biased by a main valve spring 19.

The piston 20 is slidably disposed within the cylinder 22, and the piston rod 20b is brought into contact with the central protrusion of the main valve 18 through the valve port 14. The lower surface of the piston 20 and the piston rod 2
0b through a substantially hemispherical surface, and an orifice 20G is opened that communicates the upper space and the lower space.

The space above the inlet 12 and the piston 20, that is, the piston chamber 2
08@ A pilot valve portion 26 is arranged in the communicating primary pressure passage 24. The outer peripheral edge of the diaphragm 28 is attached to the flange 3.
The space below the diaphragm 28 communicates with the outlet 16 through the secondary pressure detection passage 34.

The pilot valve portion 26 is composed of a sudem guide 36, a pilot stem 38, and a pilot valve body 40. The pilot valve body 50 is pushed in the valve closing direction (=J force) by the pilot spring 42 from below.
4, a coil spring 46 for pressure setting is brought into contact with the coil spring 46. The adjusting screw 4B is screwed and attached to the sp1 non-gang case 50.

By turning the adjustment screw 48 left and right, the elastic force of the pressure setting spring 46 that pushes down the diaphragm 28 changes.

Using the elastic force of the pressure setting spring 46 as a reference value, the diaphragm 28 curves in response to the secondary pressure acting on its lower surface, displacing the pilot stem 38 and opening and closing the pilot valve body 40. As a result, the primary fluid is introduced into the piston chamber 20a, the piston 20 is driven, the main valve 1B is displaced, and the fluid at the inlet 12 flows through the valve port 14 to the outlet 16. When the secondary pressure rises, the pressure acts on the lower surface of the diaphragm 28 through the secondary pressure detection passage 34, causing the valve body 40 to act on the pilot 1 in the valve closing direction.

<Problems to be Solved by the Invention> In the general pressure reducing valve described above, a phenomenon occurs in which the piston 20 gets caught in the cylinder 22 and becomes unable to slide. This is because when the piston 20 vibrates significantly up and down due to the occurrence of a V-cylinder, the piston 20 tilts and the diagonal corners of its cross section bite into the inner wall of the cylinder 22. In addition to this, since the piston rod 20b is tilted by the high-speed fluid flowing out from the main valve port 14, the white body of the piston 20 is also tilted as a whole and is pulled against the cylinder 22. Conceivable.

If the piston becomes unable to rotate, the main valve body will maintain its open or closed state, and will no longer be able to perform its basic movements as a pressure reducing valve. If the piston and cylinder become stuck, it is impossible to recover unless a large impact is applied from the outside or the cylinder is disassembled to release the stuckness.

Therefore, the technical problem of the present invention is to provide a pressure reducing valve that can act as a pressure reducing valve even if the piston is tilted and caught in the cylinder, and the tension can be automatically released. It is.

Means for Solving the Problems> The technical means of the present invention taken to solve the above technical problems is that the technical means of the present invention is provided between an inlet connected to the primary side and an outlet connected to the secondary side. The main valve body is installed to open and close the main valve port and is biased by a valve-closing spring, and the elastic force of the pressure setting spring is applied to the upper surface, and the secondary pressure is applied to the lower surface by the deflection of the diaphragm. A pilot valve is installed to open and close the valve when the pilot valve is opened, and a primary pressure fluid is introduced into the pressure chamber when the pilot valve is opened, and the main valve body is moved by the pressure to open the main valve body. In the pressure reducing valve, the cylinder containing the screw 1 is disposed in the pressure reducing valve body so as to be movable, and the cylinder is connected to the piston or the main valve by means of an elastic part (A). The body is constantly biased in the opposite direction to the valve opening direction, and with a force greater than the surrounding resistance of the piston and cylinder.

Effect〉 The operation of the above technical means is as follows.

During normal operation of the pressure reducing valve, the screws 1 to 1 and the cylinder slide smoothly, and at this time, the sliding resistance between them (the elasticity that forces the cylinder) is smaller than J, so the cylinder itself does not move.Chattering. If this occurs and the cylinder is pulled by the cylinder, the cylinder and the inner wall of the main body slide to control the main valve body and open and close the main valve port.

<Example> An example showing a specific example of the above technical means will be described. (
(See FIG. 1) This embodiment is not shown in FIG. 2, and is a modification of a part of the cylinder of a conventional pressure reducing valve, so a detailed explanation of the pressure reducing valve will be omitted. The gap between the cylinder 22 and the main body is made slightly larger than the conventional one shown in FIG. 1 to enable IH operation of the main body. An annular groove is formed on the circumferential side of the cylinder 22, and cylinder rings 52a and 52b are arranged in the groove to improve the circumferential movement a3J of the gap with the inner wall of the main body and the airtightness. Reference numbers 25a and 25b are piston rings arranged between the piston 20 and the cylinder 22. The spacer 27 is made shorter to raise the cylinder 22 accordingly, and a spring 5 is formed between the lower end of the cylinder 22 and the protrusion 56 from the main body.
4 and force the cylinder 22 upward. The biasing force of the spring 54 is greater than the surrounding resistance between the piston 20 and the cylinder 22.

Explain the action. When the piston and cylinder are acting normally, the sliding resistance between them is smaller than the biasing force J of the spring 54, so the cylinder 22 is always raised as shown in FIG. Next, chattering occurred and screws 1 to 20
When the cylinder 22 is caught, the surrounding resistance between them becomes significantly large and becomes greater than the biasing force of the spring 54, and the cylinder 22 slides up and down while the piston 20 and cylinder 22 remain caught. Therefore, the screw 20 can energize the main valve body 18 to open and close the main valve port 14 as usual, and functions as a pressure reducing valve.

Resync-22 slides up and down with the piston 20 and cylinder 22 engaged, and the upper end surface of the piston, the lower end surface of the spacer 27, the piston rod 20b and the protrusion of the main valve body,
Alternatively, when the upper end of the cylinder 22 and the lower end of the spacer 27 come into contact with each other with an impact, the piston and cylinder, which have been tilted and hooked, are released.

<Effects of the Invention> Therefore, according to the present invention, even if the piston is tilted and gets caught in the cylinder, it can function as a pressure reducing valve, and the tension can be automatically released, so that the pressure can be reduced. Reliability as a valve is significantly improved. Also,
Since the period for maintenance and inspection can be set over a long period of time, costs can be reduced accordingly.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a part of a cylinder showing an embodiment of the present invention;
FIG. 2 is a sectional view of a conventional pressure reducing valve. 10: Main body 16 2 outlets 22 Niji cylinder 28: Diaphragm 2 0 6 4: Inlet: Screw 1 - N: Pilot 1 - Valve part: Biasing spring

Claims (1)

[Claims] 1. A main valve body provided to open and close the main valve port provided between an inlet connected to the primary side and an outlet connected to the secondary side and biased by a valve closing spring, and the upper surface. A pilot valve is installed to open and close the valve based on the deflection of a diaphragm that applies the elastic force of a pressure setting spring to the lower surface of the diaphragm, and when the pilot valve opens, the primary pressure fluid is adjusted to the above pressure A pressure reducing valve comprising a piston introduced into a chamber and moved by the pressure thereof to open the main valve body, wherein the cylinder housing the piston is slidable within the pressure reducing valve body. The cylinder is always biased by an elastic member in a direction opposite to the direction in which the piston opens the main valve body, and with a biasing force greater than the sliding resistance between the piston and the cylinder. The cylinder structure of the pressure reducing valve.