JPH0528845B2 - - Google Patents

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. Relating to a relief mechanism for releasing.

Prior Art For example, as shown in FIG. 2, a conventional pneumatic pressure reducing valve has a main body 101 having an inlet 90 and an outlet 91.
A casing is formed by a bonnet member 109 housing a pressure adjustment spring 108, and a main valve body 102 is attached to the main body 101 and biased toward the valve seat 92 by a valve spring 104.
to connect the main valve body 102 and the stem 103, and connect the upper end of the stem 103 to the diaphragm 105.
There is also one in which the relief valve seat 107 is brought into contact with a screw-connected relief valve seat 107 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 diaphragm 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. When the stem 103 is displaced toward the adjustment spring 108 and separated from the relief valve seat 107, the secondary pressure is released from the casing through the relief hole 93 in the relief valve seat 107 and the relief hole 94 in the bonnet member 109. be done.

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 side 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, and the secondary side pressure cannot be released quickly.

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, the technical problem 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 it is a very small pressure.

Technical means for solving the problems The technical means of the present invention taken to solve the above-mentioned technical problems are as follows: A response member, a second pressure response member, a pressure space formed by the second pressure response member, and a first communication path integrally formed with the first pressure response member, which communicates the pressure space with the secondary pressure section. and the first communication path of the first communication path.
a stem disposed with one end facing the end of the pressure-responsive member; a second communication passage having a smaller diameter than the first communication passage and communicating the pressure space with the atmosphere; It consists of a valve means for communicating and cutting off communication between the next side pressure section and the atmosphere, and a pressure adjusting means connected to the first pressure responsive member and adjusting the set pressure.

Operation When the secondary side pressure increases, the first pressure responsive member is displaced to the opposite side of the stem, thereby opening the first communication passage. The secondary pressure passes through the first communication path and accumulates in the pressure space formed by the second pressure responsive member. The pressure in the pressure space causes the second pressure-responsive member to open the valve means for communicating and shutting off communication between the secondary pressure section and the atmosphere, thereby increasing the secondary pressure by communicating the secondary pressure section with the atmosphere. is rapidly released into the atmosphere.

When the increased pressure is released to the atmosphere, the pressure within the pressure space is also released to the atmosphere from the second communication path, and the first pressure responsive member is displaced toward the stem, closing the first communication path.

When the secondary pressure is not increasing, the first communication passage is closed by the stem and the pressure space becomes equal to atmospheric pressure, so the first pressure responsive member is Detects the next side pressure and keeps it constant.

Since the valve opening area and valve opening degree of the valve means are determined by the pressure-receiving area and displacement amount of the second pressure-responsive member, by appropriately designing the size and shape of the second pressure-responsive member, the release of the secondary side pressure can be improved. The required valve area and valve opening can be obtained.

Effects of the Invention The valve opening area and valve opening degree of the valve means for releasing the increased secondary side pressure can be made sufficiently large, and even a slight increase in the secondary side pressure can be quickly released. Therefore, the pressure on the secondary side can be maintained at a constant set pressure accurately and without delay.

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

A main body 3 provided with an inlet 1 and an outlet 2, a first holding member 5 holding a first pressure responsive member 4, a second holding member 7 holding a second pressure responsive member 6, and a coil spring 8 as a pressure adjusting means. The valve casing is formed by connecting the valve casing with the cover member 9 that accommodates the valve casing with bolts 60. The second pressure responsive member 6 is formed of a cylindrical bellows and defines a pressure space 50 within the bellows.

A valve seat 10 is provided on the inlet 1 side of the main body 3, and a main valve body 11 is biased against the valve seat 10 by a spring 12 and placed at an opposing position. One end of the stem 13 is inserted into the center of the main valve body 11 and engaged with the snap ring 14, and the upper part is guided through the guide hole 15 penetrating the main body 3, so that the upper end portion 16 serves as a pilot valve body of the relief mechanism. .

The first holding member 5 is clamped and fixed between the main body 3 and the second holding member 7. One end of a cylindrical first bellows 4 as a first pressure responsive member is attached to the first holding member 5 by welding. The other end of the first bellows 4 is similarly welded to the bottom surface of a connecting member 17 having an inverted T-shaped cross section. A first communicating path 19 is provided inside the connecting member 17 to communicate the secondary side pressure section 18 and the pressure space 50. The upper end portion 16 of the stem 13 is disposed at the end of the secondary side pressure portion of the first communicating path 19 (the first
In the figure, the first communicating path 19 is connected to the upper end 16 of the stem 13.
(indicates a state where the mouth is closed). 61 is a communication hole for secondary side pressure.

Valve means 51 is provided on the first holding member 5 side of the second pressure responsive member 6. The valve means 51 has a valve stem 20 that cooperates with the downward movement of the second pressure responsive member 6;
The valve body 21 fixed to the tip of the valve stem 20 and the valve stem 20
A spring 23 urges the valve body 21 toward the second pressure responsive member 6 via the valve plate 22, and a valve port 24 provided in the first holding member 5. In this embodiment, two valve means 51 are provided on the left and right sides, but if necessary, one valve means 51 is provided.
It is also possible to use two or more. The second holding member 7 is provided with a relief hole 25 that releases the secondary pressure released from the valve means 51 to the atmosphere, and a first communication path that releases the pressure in the pressure space 50 to the atmosphere after the secondary side increased pressure is released. The second communication passage 26 has a smaller diameter than 19.
will be established.

When the secondary pressure increases due to leakage from the valve, etc., the first pressure responsive member 4 overcomes the spring force of the coil spring 8 and is slightly displaced toward the coil spring 8, causing the first communication passage 19 and the upper part 16 of the stem 13 to separate. By sitting, the secondary pressure reaches the inside of the pressure space 50 through the first communication path 19. The second communication path 26 is the first communication path 19
Because the pressure on the secondary side is smaller than that, the secondary side pressure accumulates in the pressure space 50, and the second pressure responsive member 6 opens the valve means 51 to quickly release the secondary side pressure to the atmosphere, thereby reducing the secondary side pressure. is maintained at a constant set pressure precisely and without delay.

[Brief explanation of drawings]

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...Entrance, 2...Exit, 3...Main body, 4...
First pressure responsive member, 6...Second pressure responsive member, 8
... Coil spring, 9 ... Cover member, 10 ... Valve seat, 13 ... Stem, 17 ... Connection member, 19 ...
...First communication path, 26...Second communication path, 50...Pressure space, 51...Valve means.

Claims (1)

[Claims] 1. A first pressure responsive member and a second pressure responsive member for detecting the secondary side pressure of the pressure reducing valve, a pressure space formed by the second pressure responsive member, and communication between the pressure space and the secondary side pressure section. and a first communicating passage formed integrally with the first pressure responsive member, a stem disposed with one end facing the first pressure responsive member side end of the first communicating passage, and a stem having a diameter smaller than that of the first communicating passage. a second communication path that communicates the pressure space with the atmosphere; a valve means that communicates and cuts off communication between the secondary pressure section and the atmosphere in response to a response of the second pressure responsive member; A pressure reducing valve relief mechanism consisting of a pressure adjusting means connected to each other and adjusting a set pressure.