JPH0528842B2 - - 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 second pressure-responsive member, which has a larger diameter than the first pressure-responsive member and is connected to the first pressure-responsive member via a connecting member;
a pressure responsive member, a pressure space formed by the first pressure responsive member, the second pressure responsive member, and the valve casing, and a first pressure responsive member that communicates the pressure space with the secondary side pressure section.
a communicating hole; a stem disposed with one end facing the secondary pressure portion end of the first communicating hole; a second communicating hole having a smaller diameter than the first communicating hole and communicating the pressure space with the atmosphere; and a pressure adjusting means connected to the first pressure responsive member and adjusting the set pressure via the second pressure responsive member.

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 hole. The secondary pressure passes through the first communication hole and accumulates in a pressure space formed by the first pressure responsive member, the second pressure responsive member, and the valve casing. Due to the pressure in the pressure space, the second pressure responsive member having a larger diameter than the first pressure responsive member further displaces the first pressure responsive member to the opposite side of the stem and offsets the load of the pressure adjusting means on the stem side. By doing so, the degree of opening between the stem and the first communication hole becomes sufficiently large, and the secondary side rising pressure quickly reaches the pressure space and is released through the second communication hole.

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

Effects of the invention The valve opening of the relief valve formed by the first communication hole, the connecting member, the pressure space, and the second communication hole is sufficiently large, and even a slight increase in pressure on the secondary side can be quickly released. The side pressure 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 holding member 6 that holds diaphragms 4 and 5 as two pressure-responsive members, and a cover member 8 that accommodates a coil spring 7 as a pressure adjusting means are connected with bolts 60. to form the valve casing.

A valve seat 9 is provided on the inlet 1 side of the main body 3, and a main valve body 10 is placed at an opposing position, biased against the valve seat 9 by a spring 11. One end of the stem 12 is inserted into the center of the main valve body 10 and engaged with a snap ring 13, and the upper part is guided by a guide hole 15 penetrating the main body 3, so that the upper end part 14 is used as a valve body of a relief mechanism.

A first diaphragm 4 is provided between the main body 3 and the holding member 6 to detect fluid pressure on the secondary side. Similarly,
A second diaphragm 5 having a larger diameter than the first diaphragm is provided between the holding member 6 and the cover member 8. First diaphragm 4 and second diaphragm 5
is a connecting member formed by screwing together an upper diaphragm retainer 16, an intermediate diaphragm retainer 17, and a lower diaphragm retainer 18, respectively. 1st
A pressure space 20 is formed below the coil spring 7 by the diaphragm 4, the second diaphragm 5, and the valve casing. The secondary side pressure acts on the lower surface of the first diaphragm 4 through the through hole 61 provided on the outlet 2 side of the main body 3. A through hole is provided in each of the intermediate diaphragm holder 17 and the lower diaphragm holder 18 to create a pressure space 2.
A first communication hole 19 is formed that communicates the pressure section 0 and the secondary side pressure section. The secondary side pressure part end of the first communication hole 19 and the upper end 14 of the stem 12 are arranged on the same axis.

A second communication hole 21 is provided in the second diaphragm 5 to communicate the pressure space 20 with the inside of the cover member 8 . It is assumed that the second communication hole 21 has a smaller diameter than the first communication hole 19. The cover member 8 is provided with a hole 62 communicating with the atmosphere.

The secondary side pressure is determined by the magnitude of the pressure on the lower surface of the first diaphragm 4 and the spring force of the coil spring 7.
0 opens and closes to adjust the degree of opening with respect to the valve seat 9, thereby maintaining the pressure on the secondary side at the set value.

When the secondary pressure increases due to leakage in the valve section, the first diaphragm 4 overcomes the spring force of the coil spring 7 and is slightly displaced toward the second diaphragm 5, causing the first diaphragm 4 to move toward the second diaphragm 5.
When the communicating hole 19 and the stem 12 are separated from each other, the secondary pressure reaches the inside of the pressure space 20. Second communication hole 2
Since the hole diameter of the first communication hole 19 is smaller than the hole diameter of the first communication hole 19, secondary side pressure accumulates in the pressure space 20. The second diaphragm 5 located on the upper surface of the pressure space 20
has a larger diameter and a larger pressure receiving area than the first diaphragm 4, so the first diaphragm 4 is attached to the stem 1.
2 and offset the spring force of the coil spring 7 to make the degree of opening between the stem 12 and the first communication hole 19 sufficiently large to increase the pressure on the secondary side to the pressure space 20. By quickly discharging to the atmosphere via the outlet, the pressure on the secondary side can be maintained precisely at the set pressure without delay.

[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...Entrance, 2...Exit, 3...Main body, 4...
First diaphragm, 5...Second diaphragm, 7
... Coil spring, 12 ... Stem, 15 ... Guide hole, 16, 17, 18 ... Connection member, 19 ...
First communication hole, 20... pressure space, 21... second communication hole, 61... through hole.

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 that has a larger diameter than the first pressure responsive member and is connected to the first pressure responsive member via a connecting member. , a pressure space formed by the first pressure responsive member, the second pressure responsive member, and the valve casing, a first communication hole that communicates the pressure space with the secondary pressure section, and a secondary side of the first communication hole. a stem disposed with one end facing the end of the pressure section; a second communication hole having a smaller diameter than the first communication hole and communicating the pressure space with the atmosphere; and a second communication hole connected to the first pressure responsive member and connected to the first pressure responsive member.
A relief mechanism for a pressure reducing valve comprising a pressure adjusting means for adjusting a set pressure via a pressure responsive member.