JPH01314316A - Relief mechanism for pressure reducing valve - Google Patents

Abstract

PURPOSE:To accurately hold a secondary side at constant set pressure without any delay by coupling an energizing force adjusting means with a 2nd pressure driven member in the direction wherein a 2nd communication hole is opened and coupling a pressure adjusting means which adjusts the set pressure with a 1st pressure driven member through a coupling member. CONSTITUTION:When the secondary pressure rises, the pressure reaches the pressure space 4 formed of the 2nd pressure driven member 2 and coupling members 106 and 1 through the 1st communication hole 7. The 2nd pressure driven member formed of bellows 2 extends by the pressure in the pressure space 4 against the energizing force of the energizing force adjusting means 8 to open the 2nd communication hole 5, thereby releasing the secondary-side pressure to the atmosphere. The extension of the 2nd pressure driven member 2 can be adjust4d optionally by the energizing force adjusting means 8 and becomes large because the member is formed of the bellows. Consequently, the secondary-side rising pressure of the pressure reducer valve can be released speedily even when the pressure is extremely low.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a pressure reducing valve that is attached to a fluid piping system for compressed air or the like to maintain fluid pressure on the secondary side at a constant set pressure, and in particular, it relates to a pressure reducing valve that is attached to a fluid piping system for compressed air or the like to maintain fluid pressure on the secondary side at a constant set pressure. This invention relates to a relief mechanism i structure for releasing.

BACKGROUND ART For example, as shown in FIG. 2, a conventional pneumatic pressure reducing valve has a casing formed by a main body 101 having an inlet 90 and an outlet 91, and a bonnet member 109 containing a pressure adjustment spring 108. The main valve body 102 biased toward the valve seat 92 at 104 is disposed, and the main valve body 102 and the stem 10
3 and connect the upper end of the stem 103 to the diaphragm 10
5 is a part that is brought into contact with a relief valve seat 107 that is screwed together via a diaphragm receiver 106.

When setting the pressure, the spring force of the pressure adjustment spring 108 is adjusted by rotating the handle 111, and the secondary pressure acting on the lower surface of the daicephragm 105 is adjusted to balance this spring force.

When the secondary side pressure increases due to wear of the sealing surface of the valve seat 92 or the main valve element 102, foreign matter getting caught, or a delay in closing the main valve element 102, the diaphragm 105 is caused to reduce the pressure by the increased secondary side pressure. The stem 103 is displaced to the adjustment spring 108 side, and the stem 103 is separated from the relief valve seat 107, so that the secondary pressure is released from the casing through the relief holes 93 in the relief valve seats 1 to 107 and the relief hole 9711 in the bonnet member 109. is released.

By releasing the secondary side pressure, the secondary side pressure of the pressure reducing valve is maintained at a predetermined constant pressure.

Problems to be Solved by the Invention In this case, there was a problem in that the secondary boost pressure could not be released quickly. In other words, even if the secondary pressure rises slightly due to leakage from the valve or a delay in closing the main valve, the displacement on the pressure adjustment spring side of the diaphragm will be extremely small because it is receiving a downward load from the pressure adjustment spring. Therefore, the degree of opening between the stem and the relief valve seat is also very small, making it impossible to quickly release the pressure on the secondary side.

In addition, an elastic member such as synthetic rubber is generally used for the seal part of a pneumatic valve, but when the degree of opening is extremely small, the displacement is absorbed by the elastic region of the elastic member, so the actual opening becomes even more difficult. The degree becomes small. The release of the secondary side pressure rise becomes a problem especially when even a slight increase in the secondary side pressure must be accurately controlled without delay.

Therefore, a technical object of the present invention is to obtain a relief mechanism that can quickly release the increased pressure on the secondary side of a pressure reducing valve even if the pressure is minute.

Technical means for solving the problems The technical means of the present invention taken to solve the above-mentioned technical problems is a first pressure for detecting the secondary side pressure of a direct acting or pilot type pressure reducing valve. A second pressure responsive member formed by a responsive member and a bellows are connected via a connecting member, a pressure space is formed by the second pressure responsive member and the connecting member, and the pressure space is communicated with the secondary side pressure section. A first communication hole is provided, and a second communication hole is provided that communicates the pressure space with the atmosphere. A valve member is provided at one end of the pressure responsive member and integrally formed with the connecting member at a position facing the second communication hole,
A biasing force adjusting means is connected to the second pressure responsive member in the direction of closing the second communication hole, and a pressure adjusting means for adjusting the set pressure is connected to the first pressure responsive member via the connecting member. .

When the working secondary pressure increases, the increased pressure passes through the first communication hole,
It reaches into the pressure space formed by the second pressure-responsive member and the connecting member. Due to the pressure in the pressure space, the second pressure responsive member formed of a bellows overcomes the biasing force of the biasing force adjusting means and expands, thereby opening the second communication hole and releasing the secondary boost pressure to the atmosphere. Ru. The extension of the second pressure-responsive member can be arbitrarily adjusted by the biasing force adjusting means, and is large because it is formed of a bellows.

When the second communication hole is closed, the first pressure-responsive member detects the secondary pressure and keeps it constant, similar to a conventional pressure reducing valve.

Effects of the Invention The opening degree of the valve that releases the increased secondary side pressure is sufficiently large, and even a slight increase in secondary side pressure can be released quickly, and the secondary side pressure is maintained accurately and without delay. Can be maintained at the set pressure.

Embodiment An embodiment illustrating a specific example of the above technical means will be described (see FIG. 1).

In this embodiment, the same members as in the conventional example shown in FIG. 2 are denoted by the same reference numerals, and a detailed explanation of the pressure reducing valve will be omitted.

The upper diaphragm receiver 106 and the lower diaphragm receiver 1 are screwed together to form a connecting member, which holds the diaphragm 105 as the first pressure responsive member, and a cylindrical bellows 2 is welded to the upper end of the upper diaphragm receiver 106. Attach it. The bellows 2 and the connecting member 106.1 form a pressure space 4. A disk-shaped relief spring receiver 3 is welded and attached to the upper end of the bellows 2, and a second communication hole 5 is provided in the center to communicate with the atmosphere via a pressure space 4 and a relief hole 94 provided in the bonnet member 109. . A valve member 6 is disposed integrally with the lower diaphragm receiver 1 on the lower surface of the second communication hole 5 within the bellows 2, and the second communication hole 5 is opened and closed by expansion and contraction of the bellows 2. The lower diaphragm receiver 1 is provided with a linear-shaped first communication hole 7 that communicates the downward secondary side pressure of the diaphragm 105 with the pressure space 4 . A relief spring 8 is disposed above the relief spring receiver 3 to bias the relief spring receiver 3 toward the valve member 6 side. The biasing force of the relief spring 8 is adjusted via the upper spring receiver 11 by rotating the relief handle 9 and moving the adjusting screw 10 up and down. The set pressure can be set by rotating the handle 111 to adjust the spring force of the pressure adjustment spring 108.

When the secondary side pressure increases, the bellows 2 overcomes the spring force of the relief spring 8 and expands, thereby opening the second communication hole and releasing the bellows 2 to the atmosphere. The bellows 2 can extend a large amount, and the increased pressure can be quickly released to the atmosphere.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a pressure reducing valve according to an embodiment of the present invention, and FIG. 2 is a sectional view of a conventional pneumatic pressure reducing valve. 1: Lower diaphragm receiver 2: Bellows 3: Relief spring receiver C block 4: Pressure space 5: Second communication hole 6
:Valve member

Claims (1)

[Claims] 1. A first pressure responsive member for detecting the secondary side pressure of the pressure reducing valve and a second pressure responsive member formed of a bellows are connected via a connecting member, and the second pressure responsive member and the connecting member create a pressure space. a first communication hole communicating the pressure space with the secondary pressure section, a second communication hole communicating the pressure space with the atmosphere at one end of the second pressure responsive member; A valve member integrally formed with the connecting member is disposed at a position facing the two communicating holes, and a biasing force adjusting means is connected to the second pressure responsive member in a direction to close the second communicating hole, and the connecting member is connected to the second pressure responsive member. A relief mechanism for a pressure reducing valve, in which a pressure adjusting means for adjusting a set pressure is connected to a first pressure responsive member.