JPS6151191B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pressure control device, which directly introduces fluid from an upstream piping of a pressure control valve into one pressure introduction chamber of a valve body drive part of a normally open pressure control valve; By introducing the output fluid from the output fluid chamber of the pilot valve into the other pressure introduction chamber of the valve body drive section, the fluid discharged from the pilot valve during control operation is directed to the downstream side of the pressure control valve. When the pressure control valve is closed, no fluid is released from the pilot valve to the downstream piping, which reduces wasteful consumption of fluid, and when the pressure control valve is closed, the fluid is discharged into the downstream piping. It is an object of the present invention to provide a pressure control device configured to prevent the pressure from increasing abnormally.

For example, a pressure control device used in city gas distribution equipment supplies gas before and after a pressure control valve installed in a gas supply pipe to a pilot valve, and controls the valve opening of the pressure control valve based on the output of the pilot valve. The pressure control valve is configured such that the pressure in the downstream piping of the pressure control valve is kept constant. The pressure control valves used in this type of pressure control device are of the so-called normally closed type, which opens when the valve body drive section is supplied with gas pressure, and vice versa, when the valve body drive section is supplied with gas pressure. There are two types of pressure control valves: a normally open type that closes when the valve closes, and which type of pressure control valve to use is determined on a case-by-case basis.

FIG. 1 shows a schematic configuration diagram of an example of a conventional pressure control device using a normally open type pressure control valve. In Fig. 1, the pilot valve 2 of the pressure control device 1
is a spring mounting chamber 2 in which a spring 3 for pressure setting is fitted;
A and the output fluid chamber 2b are always in communication via an orifice, and the gas bled into the spring mounting chamber 2a due to the control operation of the pilot valve 2 is dangerous if released into the atmosphere, so the pressure control valve is used. It is necessary to release the gas into a pipe 6 which is separate from the pipe 5 in the pipe 4. Therefore, all the gas in the pipe 5 must be effectively discharged into the pipe 5.
It had the disadvantage that it could not flow downstream.

The present invention eliminates the above drawbacks, and the second
An example will be described below with reference to the drawings. FIG. 2 is a schematic diagram of an embodiment of the pressure control device of the present invention, and FIG. 3 is a vertical sectional view of an embodiment of the pilot valve.

In FIG. 2, the pressure control device 7 is the conventional device 1.
Similarly, a normally open type pressure control valve 4 is provided in the supply pipe 5 for city gas, etc., and the pressure control valve 4 is driven by a pilot valve 11, which will be described later, to control the fluid pressure in the downstream supply pipe 5. The configuration is such that the constant control is achieved. Valve body drive section 4a of pressure control valve 4
has a pair of diaphragm chambers 8a and 8b as first and second pressure introduction chambers, and a diaphragm membrane 10 is caused to close the valve of the valve portion 4b by a spring 9 fitted in one diaphragm chamber 8a. The body is always energized in the valve opening direction. This spring 9 determines the minimum operating pressure of the pressure control valve 4, and this minimum operating pressure can be adjusted as desired by changing the screwing position of the setting screw 9a.

As shown in FIG. 3, the pilot valve 11 has diaphragm membranes 13 and 14 interposed on both end faces of a short-axis hollow cylindrical body 12, respectively, and end faces of bottomed cylindrical bodies 15 and 16. They are configured so that they match each other and are fixed. Inside the pilot valve 11, a spring mounting chamber 17, an output fluid chamber 18, and an input fluid chamber 19 are defined. Reference numeral 20 denotes an output port, which is bored through the circumferential surface of the body 12 at an appropriate location. A protrusion 21 extends from the circumferential side of the body 12 at a position facing the output port 20 to the center of the body 12 . A communicating conduit 22 is bored inside the protrusion 21 , and one end of the conduit 22 serves as a supply port 23 and opens on the circumferential side of the body 12 . The other end of the conduit 22 communicates with a through hole 47 in a nozzle 46 attached to the tip of the protrusion 21 . Reference numeral 24 denotes an input port, which is bored in the upper part of the body 16.

A yoke 25 includes a disk-shaped head 26, a pair of cylindrical bodies 27, and a disk-shaped bottom 28.
The bottom portion 28 is fixed to the diaphragm membrane 13 by fixing bolts 29. A ring-shaped protrusion 30 having a male thread is formed on the outer circumferential surface of the head 26 in the axial direction of the upper surface thereof. This protrusion 30 is inserted through a through hole 31 of the diaphragm membrane 14, and is attached to an O-ring 33 and a reinforcing member 3 by a holder 32, which will be described later.
4 and is airtightly fixed to the diaphragm membrane 14.

The holder 32 is made of a stepped cylindrical body, and female threads are threaded on the inner periphery of a small diameter through hole 35 and a large diameter through hole 36 that coaxially pass through the inside of the holder 32. The part 30 is screwed.

Reference numeral 37 denotes a hollow cylindrical adjustment nut for adjusting the gain of the pilot valve 11, which has a valve seat/spring receiving protrusion 38 and a spring guide protrusion 39 formed on one end surface, and is attached to the holder 32. Small diameter through hole 3
It is screwed into 5. In order to prevent the output fluid from the output fluid chamber 18 from leaking into the input fluid chamber 19 from the threaded portion of the adjustment nut 37, an O-ring 40 is attached to the circumferential surface of the protrusion 39.

The bleed valve 41 includes a first valve body 42 and a second valve body 43, and the second valve body 43 is coaxially screwed into a part of the outer peripheral surface of the first valve body 42. First valve body 4
2 and the second valve body 43 are both chamfered several times in the axial direction, so that the bleed valve 41
The output fluid chamber 18 and the input fluid chamber 19 are always in communication with each other when they are fitted as shown in the figure. Further, in the above state, the tapered seat surface 42 of the first valve body 42
a is in contact with the protrusion 38 of the adjusting nut 37, and a disk-shaped elastic disk 45 fitted into the lower end of the second valve body 43 is in contact with the upper surface of the nozzle 46. The spring 44 is attached to the protrusion 3 of the nut 37.
8 and the second valve body 43, and urges the bleed valve 41 downward in FIG.

Reference numeral 48 denotes a pressure setting spring, which is installed in the spring mounting chamber 1.
It is stretched between a pair of spring receivers 49 and 50 provided in 7, and normally urges the diaphragm membranes 13 and 14 upward. One spring receiver 49 is locked to the tip of an adjustment screw 51 inserted through the bottom of the body 15, and the other spring receiver 50 is fixed to a spring force transmitting member 52. This spring force transmission member 52 is in contact with a reinforcing member 53 fixed to the diaphragm membrane 13 using a fixing bolt 29,
The spring force of the pressure setting spring 48 is transferred to the spring force transmitting member 5.
2 to the diaphragm membranes 13 and 14.

The more the adjustment screw 51 is screwed into the body 15, the more the spring 48 is compressed and the spring force increases, and the set pressure for the pressure control valve 4 increases accordingly. The more the spring 48 is screwed out, the more the spring 48 stretches and the spring force becomes smaller, and the set pressure for the pressure control valve 4 becomes smaller accordingly. In this way, the set pressure for the pressure control valve 4 is determined according to the spring force of the spring 48.

Here, the input port 24 of the pilot valve 11 is connected to the feed pipe 5 on the downstream side of the pressure control valve 4 via a pipe line 54. The supply port 23 of the pilot valve 11 is connected to the diaphragm chamber 8b of the pressure control valve 4 via a conduit 55,
Further, the diaphragm chamber 8b is connected to the feed pipe 5 on the upstream side of the pressure control valve 4 via a pipe line 56. Further, the output port 20 of the pilot valve 11 is connected to the other diaphragm chamber 8a of the pressure control valve 4 via a conduit 57, and the diaphragm chamber 8a connects the conduits 57 and 54. It is connected to the feed pipe 5 on the downstream side of the pressure control valve 4 via a pipe line 58 .

Reference numeral 59 denotes a pressure reducing valve provided in the pipe line 56, which supplies upstream fluid reduced to a constant pressure to the diaphragm chamber 8b of the pressure control valve 4.

Reference numeral 60 denotes a variable restrictor provided in the pipe line 58, which limits the flow rate of fluid discharged from the output fluid chamber 18 and the diaphragm chamber 8b to the downstream side of the pressure control valve 4 to an appropriate value.

Now, when the fluid pressure in the piping 5 on the downstream side of the pressure control valve 4 decreases below the set value, the pressure of the gas in the input fluid chamber 19 communicating with the downstream piping 5 via the pipeline 54 also decreases. As a result, the diaphragm membranes 13 and 14 move upward, and the adjustment nut 3
The protruding portion 38 of No. 7 comes into contact with the seat surface of the bleed valve 41. On the other hand, the disk 45 of the bleed valve 41 is separated from the tip of the nozzle 46, and the nozzle 4
No. 6 opening 47a is opened. Therefore, the pressure reducing valve 5
The upstream fluid that has been depressurized and supplied into the diaphragm chamber 8b by 9 flows into the output fluid chamber 18 through the pipe line 55, the supply port 23, the communication pipe line 22, and the nozzle 46, and the output fluid The pressure of the fluid within chamber 18 increases. As a result, the pressure within the diaphragm chamber 8a of the pressure control valve 4, which communicates with the output fluid chamber 18 via the conduit 57, increases. As a result, the differential pressure between the two diaphragm chambers 8a and 8b becomes smaller, the opening degree of the pressure control valve 4 increases due to the spring force of the spring 9, and the pressure of the fluid in the downstream feed pipe 5 increases and recovers. do.

Here, since the opening speed of the pressure control valve 4 is mainly determined by the inflow speed of fluid into the diaphragm chamber 8a, by changing the pressure setting value of the pressure reducing valve 59, the opening speed can be varied.
Also, in this case, since a part of the fluid supplied from the output fluid chamber 18 to the diaphragm chamber 8a flows out to the downstream side of the pressure control valve 4 via the pipe line 58, the magnitude of the throttle resistance value of the variable throttle 60 The opening speed of the pressure control valve 4 can also be varied by changing .

Contrary to the above, when the pressure of the fluid in the downstream feed pipe 5 becomes higher than the set pressure, the input fluid chamber 1
The pressure of the fluid within 9 increases. As a result, the diaphragm membranes 13 and 14 are displaced downward, and the disk 45 of the bleed valve 41 comes into contact with the tip of the nozzle 46 to close the opening 47a. On the other hand, the protrusion 38 of the adjustment nut 37 is separated from the seat surface 42a of the bleed valve 41. Therefore, the supply of upstream fluid through the nozzle 46 is cut off, and at the same time, the input fluid chamber 19 is largely communicated with the output fluid chamber 18 through the opening of the protrusion 38, so that the output in the output fluid chamber 18 is reduced. Fluid flows through pipes 54, 57, 58
It flows out to the downstream side of the pressure control valve 4 via the like. At the same time, the fluid in the diaphragm chamber 8a of the pressure control valve 4 also flows out to the downstream side of the pressure control valve 4 via the conduit 58. As a result, both diaphragms 8a,
The differential pressure between the valves 8b and 8b increases, the opening degree of the pressure control valve 4 decreases, and the pressure of the fluid in the downstream feed pipe 5 also decreases.

Here, since the opening speed of the pressure control valve 4 is mainly determined by the discharge speed of the fluid in the diaphragm chamber 8a, the closing speed can be arbitrarily varied by changing the throttle resistance value of the variable throttle 60. I can do it.

Furthermore, when the input pressure is equal to the set pressure, the pressure discharged from the bleed valve 41 to the input fluid chamber 19 and the output fluid chamber 18 from the orifice member 46 are
Since the pressures supplied to the diaphragm membranes 13 and 14 are balanced, the diaphragm membranes 13 and 14 maintain their positions and the opening degree of the pressure control valve 4 does not change.

Next, the operation when no fluid is consumed and the flow rate in the feed pipe 5 becomes almost zero will be described. In this case, similarly to the above, the feed pipe 5 on the downstream side
Since the pressure of the fluid inside becomes higher than the set pressure, the opening degree of the pressure control valve 4 decreases. However, even if the opening degree of the pressure control valve 4 decreases, the fluid is not consumed, so the pressure of the fluid in the downstream feed pipe 5 does not decrease, and therefore the pressure control valve 4 becomes fully closed, and the pressure The upstream and downstream sides of the control valve 4 are shut off. At this time, the nozzle 46 of the pilot valve 11 is closed, and the fluid on the upstream side is not discharged downstream through the pilot valve 11.

In this way, the pressure control device 7 having the above configuration
Since all the fluid discharged from the pilot valve 11 into the pipes 54 and 57 is finally discharged into the supply pipe 5, unlike the conventional device 1, a part of the fluid flowing inside the pipe 5 is diverted to other parts. There is no inconvenience caused by having to release the product into the piping system. Therefore, all the fluid flowing inside the pipe 5 is consumed on the downstream side of the pipe 5, and even a small amount of fluid is not wasted. Further, when the pressure control valve 4 is fully closed, the nozzle 46 of the pilot valve 11 is closed, so the fluid on the upstream side is not discharged downstream, and the pressure control valve 4 is closed. Abnormal pressure increase in the downstream piping when fully closed can be prevented.

In addition, the diaphragm chamber 8b of the pressure control valve 4 includes:
Since the fluid upstream of the valve section 4b is supplied after being reduced to a constant pressure by the pressure reducing valve 59, the fluid pressure within the diaphragm chamber 8b does not fluctuate, and thus stable pressure control is always possible. .

Further, the opening/closing speed of the pressure control valve 4 is controlled by a variable throttle 60.
It can be adjusted extremely easily by
Thereby, it is possible to always set the optimum opening/closing speed commensurate with load fluctuations on the downstream side of the pipe 5.

In the above embodiment, the pilot valve 11 is configured to communicate with the upstream piping 5 via the diaphragm chamber 8b as the second pressure introduction chamber of the pressure control valve 4, but the pressure control shown in FIG. device 61
As shown, the nozzle 46 of the pilot valve 11 is connected to the pipe 5.
5' may be configured to be directly connected to the conduit 56.

Furthermore, in the above embodiments, the fluid to be controlled is not limited to city gas, but may be other gases or liquids such as oil.

As described above, the pressure control device of the present invention directly introduces the fluid upstream of the valve portion of the pressure control valve into the second pressure introduction chamber of the valve body drive portion of the normally open pressure control valve. By introducing the output fluid from the output fluid chamber, which is always in communication with the input fluid chamber of the pilot valve, which is connected downstream of the valve part of the pilot valve, into the first pressure introduction chamber of the valve body driving part, The fluid that is no longer needed due to the control operation can be discharged into the same piping system as the pressure control valve, and as a result, the fluid that is no longer needed due to the control operation of the pilot valve can be discharged from the same piping system as the pressure control valve. It is possible to reliably prevent inconveniences such as always wasting a part of the fluid by discharging it into a piping system separate from the pressure control valve, and also to ensure that the pressure control valve is not in a fully closed state. Since the pilot valve nozzle is closed when the pressure is exhausted, the fluid on the upstream side is not released to the downstream side, which prevents abnormal pressure rise in the downstream piping when the pressure control valve is fully closed. It has the following features.

Furthermore, the pressure control device of the present invention is configured to introduce fluid upstream of the valve portion of the pressure control valve into the second pressure introduction chamber of the valve body drive portion of the pressure control valve via the pressure reducing valve. The fluid pressure in the second pressure introduction chamber of the pressure control valve does not fluctuate, and as a result, stable pressure control is always possible. Furthermore, by providing a variable throttle in the pipeline connecting the first pressure introduction chamber of the pressure control valve and the downstream side of the valve, the opening and closing speed of the pressure control valve can be varied at will. It has the following features.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of an example of a conventional pressure control device, FIG. 2 is a schematic configuration diagram of an embodiment of the pressure control device of the present invention, and FIG. 3 is a vertical sectional view of an embodiment of the pilot valve. FIG. 4 is a schematic diagram of a modified example of the pressure control device of the present invention. 4...Pressure control valve, 4a...Valve element drive unit, 4b
...Valve section, 5...Feeding piping, 7, 61...Pressure control device, 8a, 8b...Diaphragm chamber, 9...
Spring, 11... Pilot valve, 18... Output fluid chamber, 19... Input fluid chamber, 46... Nozzle, 5
4, 55, 56, 57, 58, 55'...pipe.

Claims (1)

[Claims] 1. A pressure control valve disposed in a fluid supply pipe;
a valve body drive unit that drives the valve body of the pressure control valve to open and close; and a first pressure introduction unit that is formed in the valve body drive unit and accommodates a spring that biases the valve body of the pressure control valve in the valve opening direction. a second pressure introduction chamber to which the primary side pressure of the pressure control valve is supplied, an input fluid chamber and an output fluid chamber, and an opening of a nozzle provided in the output fluid chamber is configured to supply the input fluid. a pilot valve that is opened and closed according to the pressure in the chamber and controls fluid flowing into the output fluid chamber through the nozzle; a downstream piping of the pressure control valve; the first pressure introduction chamber and the input fluid chamber; a pipe line that communicates with the upstream pipe of the pressure control valve and the second pressure introduction chamber and the nozzle; a pipe line that communicates the output fluid chamber with the first pressure introduction chamber; A pressure control device comprising: 2. A pressure reducing valve is provided in the pipe connecting the upstream pipe of the pressure control valve and the second pressure introducing chamber, so that the pressure of the fluid introduced into the second pressure introducing chamber can be variably set. A pressure control device according to claim 1, characterized in that the pressure control device comprises: 3. A variable throttle is provided in the pipe line communicating the downstream pipe of the pressure control valve and the first pressure introduction chamber,
2. The pressure control device according to claim 1, wherein the pressure control device is configured to be able to variably set the flow path resistance of the conduit.