JPS5847334Y2 - High pressure operated pilot valve - Google Patents

Description

[Detailed explanation of the invention] This invention is a high-pressure operation pilot that opens the main relief valve and releases pressurized fluid when the pressure reaches a certain level or higher in containers, pipes, or equipment that handles fluid. It concerns valves.

High-pressure operating pilot valves are well known which include a single pressure detection member such as a mutton, diaphragm, etc., which applies fluid pressure in the valve opening direction and a spring force in the valve closing direction.

FIG. 5 shows an example of this, in which a valve body 105 is inserted into the outlet side of a valve body 104 having an inlet 101 connected to a back pressure chamber of the main valve, a valve seat 102, and an outlet 103. A valve rod 106 that moves together with the body 105 is fixed to the center of a diaphragm 107, and a pressure fluid chamber 108 surrounded by the valve body 104 and the diaphragm 107 is connected to the inlet side of the main valve by a passage 109, and the inlet 101 and discharge channel 11
Further, an adjustable spring 111 acting in the valve closing direction is applied to the diaphragm 107 by the connecting member 0.

The fluid on the main valve inlet side is introduced into the pressure fluid chamber 108 from the passage 109 through the throttle 112 and acts on the diaphragm 107 in the valve opening direction. When this fluid is below the set pressure, the force of the spring 111 acts on the valve body. 105 is seated on the valve seat 102.

The fluid pressure P1 on the main valve inlet side increases and the set pressure Pla
When the pressure is reached, the valve body 105 separates from the valve seat 102 and releases the fluid in the main valve back pressure chamber to the outlet 103, reducing the main valve back pressure P3 to the minimum pressure p3bt.

When the main valve opens and the fluid pressure P1 on the main valve inlet side decreases, the force of the spring 111 overcomes and moves the valve body 105 in the valve closing direction, and the valve is completely closed and the back pressure P3 is applied to the main valve inlet side. Fluid pressure P
Recover to ie.

This conventional pilot valve cannot avoid chattering, but this is because the valve operating speed is determined by the force of the spring 111 acting on the diaphragm 107 and the fluid pressure, and since the spring load is constant, it is proportional to the fluid pressure. This is due to the valve opening or closing at a certain speed, and the valve does not operate quickly.As a countermeasure to this problem, attempts have been made to drastically reduce the valve opening speed or, on the contrary, to fully open the valve at the same speed. The same operation cannot be performed during valve operation.

The orifice 112 shown in Fig. 5 is one such example; when the diameter is made large, the valve opens at a high speed, but the valve closing speed decreases; when the diameter is made small, the valve can be closed at a high speed, but the valve opening speed decreases, and eventually This causes a chattering phenomenon.

This project was devised for the purpose of solving the above-mentioned problems and providing a high-pressure operating pilot valve that can perform stable opening and closing operations without worrying about chattering when opening or closing the valve. It is something.

In order to achieve this purpose, the high-pressure operating pilot valve according to the present invention includes a valve body having a fluid inlet and a valve seat connected to a back pressure chamber of the main valve, and a fluid outlet, and a valve body seated on the valve seat. or a valve body separated from the valve body, two pressure detection members added to this valve body and movable in the valve opening/closing direction and having different effective areas, and a pressure detection member formed between these two pressure detection members on the main valve inlet side. A passage chamber to which a fluid introduction passage and a discharge passage opening to the inlet are connected, an adjustable flow rate control valve provided in the introduction passage, and a first pressure detection member having a larger effective area are sandwiched therebetween. A pressure fluid chamber is provided on the opposite side of the passage chamber, and fluid on the main valve inlet side is constantly introduced to act in the valve opening direction, and a second pressure detection member having a smaller effective area acts in the valve closing direction. It is characterized by being constructed with a spring that acts on the body.

According to this configuration, one of the two pressure detection members performs the valve opening movement, and the other performs the valve closing operation, and depending on the effective area difference of the pressure detection members, the spring load, the opening degree of the flow rate control valve, etc. The valve opens and closes quickly depending on the set fluid pressure.

That is, when the fluid pressure on the main valve inlet side becomes high, the first pressure detection member is opened, and the spring load is constant and the effective area of the first pressure detection member is large, so that the valve is closed. The body fully opens rapidly, and conversely, when the fluid pressure on the main valve inlet side decreases, the opening force of the first pressure detection member decreases, and the valve body quickly seats on the valve seat due to the spring load. .

Next, an embodiment of the present invention will be described with reference to the drawings. A valve body 4 is inserted into the outlet side of a valve body 4 which has a fluid inlet 1 and an outlet 2 and has a valve seat 3 between them. A valve stem 6 that moves together with the valve body 5 is fixed to the center of a pressure detection member 7°8 consisting of two parallel diaphragms, and the free end side of the bellows 9 for sealing is attached to the valve stem 6. A pressure fluid chamber 10, which is airtightly or liquidtightly fixed to the valve body and surrounded by the first pressure detection member 7 on the valve body side, the bellows 9, and the valve body 4, is connected to, for example, a pressure vessel 12A through a passage 11.

The bellows 9 is a back chamber 1 between the outlet 2 of the valve body 4 and the valve seat 3.
3 and the pressure fluid chamber 10 are isolated from each other.

The second pressure detecting member 8/I′i has a smaller effective area than the first pressure detecting member 7, and the flat gap between them forms a passage chamber 14 through which the pressure fluid passes, and the discharge passage 15 Said passage 1 is controlled by an inlet 17 which is open to the inlet 1 and has an adjustable flow control valve 16 with a non-return valve.
1 is connected.

A coiled spring 18 is pressed against the side of the second pressure detection member 8 opposite to the passage chamber 14.
Numeral 9 has a screw cap 20 and a bundle 21, and the screw cap 20 is screwed into a stand 22 fixed to the valve body 4 so that the spring force can be adjusted.

The flow rate control valve 16 has a tapered valve seat 24 formed in the valve body 23 and a spherical valve body 25 built therein, and a threaded stopper 26 for adjusting the opening stroke of the valve body 25.
The threaded stopper 26 defines the maximum clearance between the valve seat 24 and the valve body 25, so that the common valve seat 24 and valve body 25 serve as both a flow rate control valve and a check valve. .

However, as shown in FIG.
8 to adjust the gap with the valve seat 29, and the flow rate control valve and the check valve may be provided in one valve body 23, and in either case, the valve body of the check valve 25 is made of a light specific gravity material so that it floats away from the valve seat 24 with a slight positive pressure of the pressure fluid.

In this embodiment configured in this way, the inlet 1 is connected to the pressure vessel 12.
The main valve 12B is connected to the back pressure chamber of the main valve 12B of A, and when the fluid pressure in the pressure vessel 12A exceeds a certain level, the main valve 12B is opened to release pressurized fluid. 18 and the opening degree of the flow rate control valve 16 is adjusted in advance.

The pressure fluid in the pressure vessel 12A is introduced into the pressure fluid chamber 10 through the passage 11 and into the passage chamber 1 through the introduction passage 17.
4, and further passes through the discharge passage 15 and the inlet 1 to the main valve 12.
It acts as a back pressure on B.

Therefore, the same pressure acts on both sides of the first pressure detection member 70, and fluid pressure in the valve opening direction and spring force in the valve closing direction act on the second pressure detection member 3.

The bellows 9 works to prevent the fluid in the pressure fluid chamber 10 from being released into the back chamber 13, and at the same time reduces or cancels out the fluid pressure that acts on the valve body 5 as a valve opening force. It is designed to be sufficiently smaller than the difference in effective area between members 7 and 8.

When the pressure fluid is lower than the set pressure, the pressure fluid chamber 10 and passage chamber 14 are at the same pressure, and only the second pressure detection member 8 receives the pressure fluid in the valve opening direction, but this valve opening force Since the force of the spring 18 is greater than that of the valve body 5, the valve body 5 is seated on the valve seat 3.

When the pressure of the pressurized fluid rises close to the set pressure and overcomes the valve opening force or spring load acting on the second pressure detection member 8, the valve body 5 slightly separates from the valve seat 3, causing fluid to flow from the inlet 1 to the outlet 2. will be released.

At this time, the flow rate of the pressure fluid discharged from the discharge passage 15 through the inlet 1 to the outlet 2 is greater than the flow rate of the pressure fluid entering the passage chamber 14 through the introduction passage 17 throttled by the flow rate control valve 16. The pressure decreases, creating a pressure difference with the pressure fluid chamber 10, and a valve opening force is generated in the first pressure detection member 7.

The load of the spring 18 acting as a valve opening force on the second pressure detection member 8 is constant, and since the first pressure detection member 7 has a larger effective area, it overcomes the spring load and opens the valve body 5.
It opens at full speed.

Therefore, the back pressure of the main valve 12B is released all at once, and the main valve 12B
The valve B quickly opens to release the pressure fluid in the pressure vessel 12A.

When the fluid pressure on the main valve inlet side decreases, the pressure in the pressure fluid chamber 10 also decreases, so the valve opening force of the first pressure detection member 7 decreases, and the force of the spring 18 moves the valve body 5 in the valve closing direction. When the flow rate of fluid enters the passage chamber 14 from the introduction passage 17 is larger than the flow rate of the fluid discharged from the discharge passage 15 to the outlet 2 via the inlet 1, The pressure is restored and the pressure difference between the pressure fluid chamber 10 and the passage chamber 14 becomes small, and the valve opening force generated by the first pressure detection member 7 becomes extremely small, and the fluid pressure itself becomes low. Together, the force of the spring 18 causes the valve body 5 to be seated on the valve seat 3 at a rapid speed.

Figures 3 and 4 show the fluid pressure P1 on the main valve inlet side using the conventional pilot valve and the pilot valve of the present invention.
4 is a graph showing the results of measuring the back pressure P3 of the main valve. In FIG. 4, when Pl reaches the set pressure PIA and the pilot valve opens, P3 is the lowest pressure 43.
When P□ decreases and the pilot valve closes, P3 changes from P3C to fluid pressure p1Dt on the main valve inlet side.
to recover.

Regarding the conventional product shown in FIG. 5, the Pla-+P3.
.

PIA due to this product compared to pressure change of P3b-+PIC
It can be seen from these graphs that the pressure changes of →P3B and P3cm+PID occur in a very short time, and it is understood that the pilot valve according to the present invention opens and closes at a higher speed than conventional products.

The pressure detection members 7 and 8 may be constructed of a bellows housing or a piston, or a suitable shaft sealing device may be used in place of the bellows 9 to block the passage between the pressure fluid chamber 10 and the back chamber 13 of the valve stem 6. Furthermore, the check valve attached to the flow rate control valve 16 is not necessary in the case of a fluid system in which the pressure fluid is always at or above atmospheric pressure.

As is clear from the above explanation, the present invention involves attaching two pressure detection members that are movable in the valve opening and closing directions and having different effective areas to the valve body, and supplying the pressure fluid for control purposes to the passage chamber between them using a flow rate control valve. The pressure fluid is adjusted and introduced, and the pressure fluid is discharged to the inlet side or outlet side of the valve body, and also to the side opposite to the passage chamber of the first pressure detection member having a larger effective area in the valve opening direction. In addition to applying the working pressure fluid at all times, a spring acting in the valve closing direction is applied to the second pressure detection member having a smaller effective area, and when the pressure of the pressure fluid increases, the pressure in the passage chamber is reduced and the first pressure detection member is activated. It is possible to generate a large valve opening force in the pressure detection member of the valve and open the valve body all at once at a rapid speed.
Furthermore, when the pressure of the pressure fluid decreases, the valve opening force generated by the first pressure detection member is reduced, and the valve can be closed all at once by the force of the spring acting on the second pressure detection member.

That is, according to the present invention, the two pressure detection members share the valve opening action and the valve closing action, so that sudden opening and closing can be performed reliably.
Therefore, not only the pilot valve itself but also the main valve open suddenly.
This allows stable operation without the worry of sudden closing and chattering.

Additionally, by adjusting the opening degree of the flow control valve, the valve opening/closing operating pressure can be arbitrarily and precisely adjusted, and the optimum operating pressure can be set depending on the type of pressure fluid to be handled and the place of use.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view showing an embodiment of the present invention, Fig. 2 is a longitudinal sectional view showing different embodiments of the flow control valve, and Figs. 3 and 4 are performance tests of the conventional product and the proposed product. The graph showing the results, FIG. 5, is a vertical cross-sectional view showing →0 of the conventional product. 1...Entrance, 2...Exit, 3...
...Valve seat, 4... Valve body, 5... Valve body, 7, 8... Pressure detection member, 10...
Pressure fluid chamber, 14... Passage chamber, 15...
・Discharge path, 16...Flow rate control valve, 17...
...Introduction path, 18... Spring.

Claims (1)

[Claims for Utility Model Registration] Fluid inlet 1 connected to the back pressure chamber of the main valve and valve seat 3
and a valve body 4 having an outlet 2 for the fluid; a valve body 5 seated on the valve seat 3 or separated therefrom; two pressures added to the valve body 5 and movable in the valve opening/closing direction and having different effective areas; Detection members 7, 8; passage chamber 14 formed between the two pressure detection members 7, 8 and connected to a fluid introduction path 17 on the main valve inlet side and a discharge path 15 that opens to the inlet 1; An adjustable flow rate control valve 16 provided in the introduction passage 17; provided on the opposite side of the passage chamber 14 with the first pressure detection member 7 having a larger effective area in between, so that the fluid on the main valve inlet side is always supplied. A high pressure operating pilot valve comprising: a pressure fluid chamber 10 that is introduced and acts in the valve opening direction; and a spring 18 that acts in the valve closing direction and acts on the second pressure detection member 8 having a smaller effective area.