JPH01193473A - Relief valve - Google Patents

Abstract

PURPOSE:To improve sealing property by pressing a seat ring against a seat surface with the upstream side pressure in closing a relief valve. CONSTITUTION:A seal ring 9 is removably fitted in a seal ring holding portion 27 provided on the inside surface upstream of a casing 20. The seal ring 9 is urged toward the upstream side (inlet 21 side) by a valve body 31 which is urged to the upstream side by an elastic body 13. Thus, the seal ring is pressed against a seat surface by the upstream side pressure in closing the valve. Also, in opening the valve, fluid grazes and passes through only exposed surface of seal ring 9, so that dust in the fluid is not deposited on the seal ring.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a relief valve provided immediately before a fuel injection valve in, for example, an additive fuel gas turbine.

(Conventional technology) In additive fuel gas turbines, fuel injection, fuel addition at stop,
A relief valve is used to eliminate the Shinshiro phenomenon. This relief valve has a structure as shown in FIG. That is, in FIG. 6, reference numeral 1 indicates a casing, and this casing 1 is made up of an upstream casing member 2 and a downstream casing member 3 joined together. A fluid inflow hole 4 is formed in the upstream casing member 2, and a seat portion 5 is formed to protrude from the inner surface of the upstream casing member 2 along this inflow hole. On the other hand, the end of the downstream casing member 3 is closed by an end plate 3a, and a fluid outflow hole 6 is formed in the end plate 3a. A valve body 8 having a valve rod 7 inserted into the inflow hole 4 is provided within the casing 1 . A ring socket 10 into which a seal ring 9 is fitted is formed in the valve body 8.

Further, a seat plate 12 having a ventilation hole 11 is provided at the tip of the valve body 8.
is arranged, and this seat plate 12 is pressed by an elastic body 13 made of, for example, a coil spring.

The elastic body 13 is inserted and held in the elastic body holder 14. A ventilation hole 16 is formed in the end plate 15 of the elastic body holder 14, and a screw 17 is cut on the outer peripheral surface of this boulder 14. There is. This screw 17 is screwed into a screw 18 cut on the inner peripheral surface of the casing 1 to fix the elastic body holder 14 inside the casing 1. Note that the reference numeral 19 in the figure is a ring retainer screwed onto the outer periphery of the valve stem 7.

In the above conventional relief valve, the left side is the upstream side, the right side is the downstream side, and the fluid flows in the direction of the arrow.

Therefore, the sealing structure between the valve body 8 and the seat portion 5 by the seal ring 9 is not the ring of the valve body 8 which is a movable part. 1!1
0, the seal ring 9 is fitted into the ring holder 19, and the valve body 8 is inserted through the seat plate 12 by the elastic body 13 held by the elastic body holder 14, as shown in an enlarged view in FIG. It is pushed upstream. This pressing forces the seal ring 9 against the seat portion 5 and seals the fluid. When the upstream pressure of the fluid increases, the valve body 8 is pushed downstream by this pressure, and when it overcomes the upstream force of the elastic body 13, the seal ring 9 and seat portion 5 are separated as shown in FIG. A gap is created between them, and fluid flows in the direction shown by the arrow in FIG.

That is, the fluid flows from the ventilation hole 11 of the seat plate 12 to the elastic body 13.
It flows through the center of the elastic body holder 14 through the ventilation hole 16 and is discharged from the outflow hole 6. This relief pressure can be adjusted by changing the amount by which the elastic body holder 14 is screwed into the casing 1 and by changing the shrinkage margin of the elastic body 13.

(Problems to be Solved by the Invention) In the conventional relief valve, the flow of fluid near the seat portion due to the seal ring 9 is as shown in FIG. That is, after the fluid collides with the seal ring 9, the fluid enters the ring groove 10.
It flows out downstream by going around the brim. Therefore, the g & fine dust contained in the fluid tends to adhere to the ring groove 10 portion, and once the dust is removed from the seal ring 9.
If it adheres to the ring groove 10, it is formed in a shape that is difficult to remove when viewed from the direction of fluid flow. Therefore, when dirt accumulates in the ring groove 10, the sealing performance with the seat portion 5 deteriorates, causing a problem that fluid leakage occurs.

The present invention has been made to solve the above problems,
It is an object of the present invention to provide a relief valve in which sealing performance is not deteriorated due to dirt in a fluid adhering to the vicinity of a seal ring or a ring groove.

[Structure of the Invention] (Means for Solving the Problems) The present invention includes a casing having a fluid inflow hole formed on the upstream side and a fluid outflow hole formed on the downstream side, and a casing provided on the upstream inner surface of the casing. The seal ring holding part, the seal ring removably fitted into the seal ring holding part, and the upstream inner surface of the casing are made airtight by pressing this seal ring from the downstream side to the upstream side. a valve body formed with a contact surface to seal; an elastic body that presses the valve body from the downstream side to the upstream side via the seat plate; and a screwed-on movement of the elastic body to the inner peripheral surface of the casing while holding the elastic body. It is characterized by comprising an elastic body holder that is freely attached.

(Function) When the fluid passes through the inside of the casing from the inflow hole, the fluid passes through the notch formed in the valve stem, collides with the seat portion of the valve body, and moves the valve body downstream. Due to this movement of the valve body, fluid passes through the vent hole in the valve seat, flows through the center of the elastic body, and flows out from the vent hole in the elastic body holder through the outflow hole formed in the cap at the end of the casing.

Therefore, the fluid passes through only the exposed surface of the seal ring fitted in the seal ring holding part provided on the inner wall surface of the upstream end of the casing, so dirt in the fluid does not accumulate on the seal ring, reducing sealing performance. does not occur.

(Example) Hereinafter, an example of a relief valve according to the present invention will be described with reference to FIGS. 1 to 4.

In FIG. 1, reference numeral 20 indicates a casing, the left side of this casing 20 is the upstream side of the fluid, and the right side is the downstream side. That is, a fluid inlet hole 21 is formed at the upstream end of the casing 20, and a screw 22 formed on the casing 20 and a screw 23 formed on the cap are formed on the downstream side.
A cap 24 is detachably attached by screwing.

This cap 24 has a fluid outflow hole 25 formed therein. A tapered inclined wall 26 that expands toward the downstream side is formed on the upstream inner surface of the casing 20, that is, on the inner surface of the end portion, and this inclined wall 26 has a seal ring holding portion that holds the seal ring 9. 27 are provided. This seal ring holding portion 27 is made up of a protruding strip member 29 having a slit 28 and a cylindrical member 30 with a narrow end.
It is inserted between. Further, as shown in an enlarged view in FIG. 2, the outer periphery of the seal ring 27 is pressed into contact with a seat portion 32 formed on the valve body 31, so that a seal is formed between the upstream inner surface of the casing 20 and the valve body 31. The ring 27 keeps it airtight. The valve stem 33 of the valve body 31 has a notch 34 on its outer surface, as shown only in cross section in FIG.
It is a cross-shaped rod with . Fluid passes along this notch 34 . A seat plate 12 and an elastic body 13 having the same shape as shown in FIG. A thick part 36 is formed on the outer peripheral surface of the open end of the elastic body holder 35, and this thick part 36 has a screw 17 on the inner surface of the casing 25.
A screw 37 is formed to be screwed into. This screw 3
The repulsive force of the elastic body 13 is determined by how well the screw 7 is screwed into the screw 17 of the casing 20. These two screws 17
．． 37 are screwed together, the position of the elastic boulder 35 is fixed with a lock nut 38. A ventilation hole 16 is formed in the other end plate 15 of the elastic body holder 35 in which the lock nand 38 has a screw 39 that is screwed into the screw 17.

The relief pressure can be adjusted by the amount by which the elastic boulder 35 is screwed into the casing 20.

Therefore, when the upstream pressure is lower than the relief pressure, the force of the elastic body 13 pushing the valve body 31, which is a movable part, upstream through the seat plate 12 is greater than the force pushing the valve body 31 downstream due to the pressure. Therefore, the seat portion 32 of the valve body 31 is pressed against the seat ring 9, and the fluid is sealed and does not flow.Furthermore, looking at the force applied to the seat ring 9 in this state,
Since the slit 28 is cut in the convex strip member 29 as shown in FIG. 1, fluid pressure is applied to the seat ring 9.

This pressure generates a force that presses the seat ring 9 against the downstream side, that is, against the seat portion 32. As a result, when the upstream pressure is lower than the relief pressure, as the pressure increases, the force that presses the seat ring 9 against the seat portion 32 increases, so that the sealing performance is improved. When the upstream pressure exceeds the relief pressure, the force pushing the valve body 31 of the movable part toward the downstream side overcomes the reaction force of the elastic body 13, and the valve body 31 moves downstream. Seat ring 9 and seat part 32
A gap is created between the two, and the fluid flows out along the path shown by the arrow in FIG.

As can be seen from the fluid flow in FIG. 4, the fluid flow around the valve body 31 is smoother than in the conventional example, and the seat ring 9 is also positioned at a position that blocks the fluid flow. Therefore, the seat ring 9 and seat part 3
There is no possibility of dust adhering to the vicinity of 2, and the sealing effect will not deteriorate due to dust. Also, seat ring 9
The sealing performance of the seat portion 32 is also improved compared to the conventional example.

FIG. 5 is a partial sectional view showing only the main parts of another embodiment of the present invention, in which the same parts as in FIG. 2 are designated by the same reference numerals, and other parts are omitted because they are the same as in the previous embodiment. In the embodiment shown in FIG. 5, the shapes of the seal ring holding part 27 and the seat part 32a are slightly different from those of the previous embodiment. That is,
A seal ring 9 is formed by forming an angle at the tip of the cylindrical member 30.
In addition, by forming a slant in the seat portion 32a, the valve body 3 is further prevented from coming off due to fluid force.
The flow near the first seat portion 32a can be maintained in a smoother state.

[Effects of the Invention] According to the present invention, when the upstream pressure is equal to or lower than the relief pressure,
The seat ring is pressed against the seat surface by the upstream pressure, and as the pressure increases, the sealing performance improves. Furthermore, since the flow of fluid is smoother than in the conventional example, it is difficult for dust to adhere to the vicinity of the seat portion, and there is an effect that the sealing performance is not deteriorated due to dust.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing one embodiment of a relief valve according to the present invention, FIG. 2 is a partial sectional view showing an enlarged main part of FIG. 1, and FIG. 3 is a line A-A in FIG. 2. 4 is a cross-sectional view taken in the direction of the arrow, FIG. 4 is a cross-sectional view showing the operating state of FIG. 1, and FIG.
The figure is an enlarged vertical sectional view showing only the essential parts of another embodiment of the present invention, and FIG. 6 is a MIFli showing a conventional relief valve.
7 is a partially sectional view showing an enlarged main part of FIG. 6, and FIG. 1 is a sectional view showing the operating state of FIG. 6. 1.20...Casing 2...Upstream casing member 3...
...Downstream casing member 4.21...Inflow hole 5.32...Seat portion 6.25...Outflow hole 7.33...Valve rod 8.31...Valve body 9 ......Seal ring 10...Ring arm 11...Vent hole 12...Seat plate 13... ...... Elastic body 14.35... Elastic body holder 15... End plate 16... Ventilation hole 17.18.22.23. 37;...Screw 19...
...Ring retainer 24 ... Cap 26 ... Slanted wall 27 ... Seal ring holding part 28 ...
...... Slit 29 ...... Convex strip member 30 ...... Cylindrical member 34 ...... Notch portion 36 ... ...Thick part 38...Lock nut

Claims (1)

[Claims] A casing having a fluid inflow hole formed on the upstream side and a fluid outflow hole formed on the downstream side, a seal ring holding portion provided on the upstream inner surface of the casing, and a seal ring holding portion that is removably fitted into the seal ring holding portion. with a sealed seal ring,
A valve body is formed with a contact surface that presses the seal ring from the downstream side toward the upstream side and airtightly seals between the seal ring and the upstream inner surface of the casing, and the valve body is connected to the downstream side through a seat plate. 1. A relief valve comprising: an elastic body that presses from the side toward the upstream side; and an elastic body holder that holds the elastic body and is movably attached to the inner peripheral surface of the casing by screwing.