JPH08227321A - Pressure controller - Google Patents

Abstract

PURPOSE: To shorten the time to be required from the open of a pilot valve up to the arrival of difference pressure between primary pressure and working pressure at a prescribed value and to shorten the time to be required for controlling secondary pressure at objective pressure. CONSTITUTION: This pressure controller is provided with a diaphragm 38 for reducing the feeding quantity of gas to a pressure room 20, a pilot valve 33 executing valve opening operation in accordance with the reduction of secondary pressure, increasing the quantity of bleeding and driving a valve body 5 in a valve driving direction and a pressure reducing valve 36 for reducing pressure supplied to the diaphragm 38. Since the valve body 5 can be driven in a small bleeding quantity area when the pilot valve 33 is opened, the valve body 5 can be stably and quickly displaced, secondary pressure on the downstream side can be controlled and responsiveness for the adjustment of pressure can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure control device, and more particularly to a pressure control device configured to drive a valve element with high responsiveness so that a secondary pressure in a downstream side pipeline maintains a target pressure.

[0002]

2. Description of the Related Art For example, a pipeline for feeding city gas or the like is provided with a pressure control device for controlling the pressure so that the secondary pressure on the downstream side becomes a preset target pressure.
Generally, a pressure control device includes a pilot valve that adjusts an operating pressure (also referred to as a jacket pressure) that is supplied to a valve drive unit according to a pressure fluctuation on the downstream side, and a valve that is based on the operating pressure that is supplied to the valve drive unit. And a pressure control valve that controls the secondary pressure on the downstream side to a target pressure by changing the opening degree. And
The pressure control valve includes an "unloading type" in which the primary pressure acts on the valve body in the valve closing direction and a "loading type" in which the primary pressure acts on the valve body in the valve opening direction.

In the above-mentioned unloading type pressure control valve, the operating pressure supplied to the valve drive section and the valve body 1 are applied.
The valve body is driven in the opening or closing direction by the pressure difference from the next pressure to change the valve opening degree, and pressure control is performed so that the secondary pressure becomes a predetermined target pressure. Then, when the operating pressure is equal to the primary pressure, the valve body is held at the valve closing position. for that reason,
When the amount of gas used on the downstream side increases and the secondary pressure decreases, the pilot valve opens and the operating pressure is reduced, which causes the valve element to open and the amount of gas supplied to the downstream side pipeline. Increase. Further, when the operating pressure is reduced to a pressure close to the secondary pressure, the valve body is displaced to the fully open position, and the amount of gas supplied to the downstream side pipeline further increases.

Further, when the amount of gas used on the downstream side decreases and the secondary pressure in the downstream pipeline increases above the target pressure, the operating pressure increases due to the closing operation of the pilot valve, which causes the pressure control valve to operate. The valve opening is throttled, and the amount of gas supplied to the downstream pipe is reduced. Therefore, the secondary pressure of the downstream side pipeline is maintained at the target pressure.

In this way, when the secondary pressure fluctuates, the operating pressure changes due to the opening / closing operation of the pilot valve, and the valve opening of the pressure control valve is adjusted. As a result, the secondary pressure in the downstream side pipe line becomes the target pressure. Controlled by.

[0006]

However, in the above-mentioned conventional structure, when the secondary pressure decreases, the pilot valve opens and the operating pressure of the valve drive section begins to decrease. When the pressure difference with the pressure becomes equal to or higher than a predetermined pressure difference, the pressure control valve opens to control the secondary pressure to the target pressure. Therefore, after the pilot valve opens, the primary pressure and the working pressure It takes time for the differential pressure of
Therefore, there is a problem that it takes time to control the secondary pressure to the target pressure.

Further, in order to solve the above problem, a pressure reducing valve may be provided in a conduit for supplying the primary pressure as an operating pressure to the pressure chamber of the pressure control valve to lower the operating pressure by the opening operation of the pilot valve. Although considered, in that case, when the pressure conditions of the primary pressure and the secondary pressure are changed, the pressure reduction value by the pressure reduction valve must be adjusted each time. Further, the adjustment work of the pressure reducing valve is troublesome, and for example, when the pressure condition is changed without adjusting the pressure reducing valve, the pressure control valve may open even though the pilot valve is not operating. There is.

Therefore, an object of the present invention is to provide a pressure control device that solves the above problems.

[0009]

In order to solve the above problems, the present invention has the following features. Claim 1
In the invention, the valve main body provided between the upstream side pipeline and the downstream side pipeline to which the fluid is fed, and the valve opening degree so that the secondary pressure downstream from the valve main body becomes a target pressure value. And a valve body to change
A valve that drives the valve element in a valve closing direction or a valve opening direction by a pressure difference between an operating pressure supplied through a communication conduit communicating with the upstream conduit and a primary pressure upstream of the valve body. A drive unit, a throttle provided in the communication conduit and configured to reduce a fluid supply amount to the valve drive unit, and a valve opening operation to supply the valve drive unit when the secondary pressure becomes a predetermined pressure value or less. A pilot valve for releasing the operating pressure to the downstream side, and a pressure reducing means provided in the communication pipe line upstream of the throttle for reducing the pressure supplied to the throttle to a predetermined pressure. It is what

Therefore, according to the first aspect, the maximum value of the operating pressure supplied from the throttle to the valve drive unit is set in the pressure reducing means by reducing the primary pressure supplied to the throttle by the pressure reducing means. Since the pressure is reduced to a predetermined pressure, 2
When the next pressure drops and the pilot valve opens, the pressure difference between the primary pressure and the operating pressure becomes less than or equal to a predetermined pressure difference for driving the valve body. Therefore, the responsiveness of the pressure adjustment of the secondary pressure is enhanced.

According to a second aspect of the present invention, in the pressure control device according to the first aspect, the depressurizing means displaces in accordance with fluctuations in the primary pressure and the secondary pressure, and the displacement member. And a working pressure adjusting valve that adjusts the working pressure supplied to the throttle according to a displacement.

Therefore, according to claim 2, the pressure reducing means is 1
Since the working pressure is adjusted according to the fluctuation of the secondary pressure and the secondary pressure, even if the primary pressure and the secondary pressure are changed, the depressurizing means automatically adjusts the working pressure, thereby eliminating the troublesome work of adjusting the working pressure. In addition, even if the pressure conditions of the primary pressure and the secondary pressure are changed, it is possible to prevent the valve body provided in the valve body from opening without permission regardless of the operation of the pilot valve.

[0013]

1 and 2 show a first embodiment of a pressure control device according to the present invention. 1 is a schematic configuration diagram of the pressure control device, and FIG. 2 is an enlarged vertical sectional view showing the inside of the pressure control valve.

The pressure control device comprises a pressure control valve 1 and a pressure control section 30 which will be described later. The pressure control valve 1 is provided, for example, in a gas supply line, and the flow path 3 in the valve body 2 is provided.
The secondary pressure on the downstream side is controlled to a predetermined target pressure by operating the valve body 5 in the valve opening and closing directions with respect to the valve seat 4 provided in the.

The valve body 2 has an upstream side flange 2a to which the upstream side pipeline 6 is connected on the left side, and a downstream side pipeline 7 on the lower side.
Is connected to the downstream side flange 2b. An inlet 2c that communicates with one end of the flow path 3 in the center of the upstream flange 2a.
Is opened, and an outlet 2d communicating with the other end of the flow path 3 is opened at the center of the downstream side flange 2b.

The flow path 3 is divided into an upstream flow path 3a communicating with the inflow port 2c and a downstream flow path 3b communicating with the outflow port 2d by a partition wall 8 formed so as to cross the inside of the valve body 2. Well defined. Here, the pressure in the upstream flow path 3a is represented as a primary pressure P ₁ , and the pressure in the downstream flow path 3b is represented as a secondary pressure P ₂ . In this embodiment, for example, the primary pressure P ₁ = 70 kg / cm ²
And is set to a fairly high pressure.

The valve seat 4 is formed in a ring shape, is fitted in a central hole 9 formed in the partition wall 8, and is fixed to the partition wall 8 by tightening a bolt 10. Further, when the valve body 5 descends due to the valve closing operation, the piston 12
The seat portion 12a of the above contacts the upper surface of the valve seat 4.

A cage guide 11 is provided below the valve seat 4. The cage guide 11 is formed in a cylindrical shape, and a plurality of elongated holes 11a penetrating the inner circumference and the outer circumference are formed in this cylindrical portion. Further, in the cage guide 11, the perforated plate 15 is fixed to the upper end flange portion with a bolt 15b.

A plurality of elongated holes 1 are provided around the entire circumference of the cage guide 11.
Since 1a is provided at regular intervals, it also functions as a throttle, and when the valve body 5 opens, it throttles the flow of fluid and reduces the flow velocity. Therefore, even if the primary pressure P ₁ is set to a high pressure, the flow velocity passing through the valve seat 4 is decelerated and the pressure control in the small flow rate range is facilitated.

The valve body 5 has a piston 12 slidably provided above the valve seat 4 in a vertical direction and a cage 13 integrally provided below the piston 12 integrally formed by a bolt 14. Combined. The piston 12 has a seat portion 12a on its lower surface, which comes into contact with the valve seat 4 when the valve is closed, and an O-ring 12b is fitted in the groove on the outer circumference. The cage 13 is fitted to the inner circumference of the cage guide 11 described above to guide the sliding movement of the piston 12.

A plurality of openings 13a through which the fluid passes are formed on the peripheral surface of the cage 13. The opening 13a is formed in a trapezoidal shape, and the opening area increases according to the amount of movement of the valve body 5. That is, when the valve body 5 starts the valve opening operation, the opening area is small and the flow rate passing through the valve seat 4 is narrowed. As the valve opening degree of the valve body 5 increases, the opening area increases and the flow rate increases. Will increase.

Therefore, when the valve body 5 starts the valve opening operation, the flow rate does not suddenly increase, but the flow rate gradually increases with the valve opening operation of the valve body 5, and the pressure control in the small flow rate region is performed. It is easy to remove. A cylindrical perforated plate 15 is arranged around the cage guide 11. The perforated plate 15 has a large number of holes on its outer peripheral surface. Therefore, the fluid (gas in this embodiment) that has passed through the valve seat 4 from the upstream side flow passage 3 a passes through the holes of the perforated plate 15, flows out to the downstream side flow passage 3 b, and passes through the holes of the perforated plate 15. Is rectified in the process.

A position detecting rod 16 extending in the vertical direction is fixed to the center of the piston 12 with a bolt 17. The position detection rod 16 has a lid 1 with an upper end 16a.
8, the amount of movement of the valve body 5, that is, the valve opening is known from the sliding height position of the upper end 16a.

The lid 18 for closing the upper opening 2e of the valve body 2 is
It is fixed to the valve body 2 with bolts 19. Valve body 5 and lid 1
A pressure chamber 20 is formed between the pressure chamber 20 and the pressure chamber 8, and a pressure introducing hole 18a for introducing pressure to the pressure chamber 20 is formed on the outer periphery of the lid 18. Since the valve element 5 operates in the valve opening or valve closing direction depending on the pressure value supplied to the pressure chamber 20,
The pressure chamber 20 and the piston 12 form a valve drive section.

Reference numeral 21 is a piston guide, which projects radially from the outer periphery and is fitted into the upper opening 2e of the valve body 2 to form a step 2f.
21a that abuts on the piston 12 and the piston 12 formed on the inner circumference.
And a guide surface 21b on which the outer circumference of the slides. The piston guide 21 has a hole 21d through which a bolt 37 is inserted in the flange 21a. The bolt 37 is screwed into the screw hole of the step 2f and fixed to the valve body 2. An O-ring 21c that seals between the valve body 2 and the lid 18 is arranged in a groove on the outer circumference of the piston guide 21.

Reference numeral 24 denotes a spring retainer, which comes into contact with the upper end portion of a coil pressing coil spring 25 for pressing the piston 12 against the valve seat 4. The spring retainer 24 is fitted in the central hole 18b of the lid 18, has a recess 24a on the bottom against which the upper end of the coil spring 25 abuts, and a bearing 27 for bearing the position detection rod 16 is fitted in the center. ing. Further, the lower end of the coil spring 25 has a concave portion 12c of the piston 12.
Is in contact with Therefore, the valve body 5 is the coil spring 2
It is urged in the valve closing direction by the pressing force of 5.

Reference numeral 28 denotes a valve opening display member, which is screwed to the upper surface of the lid 18 so that the upper end flange portion of the spring retainer 24 is covered with the lid 18.
Press on the upper surface of. The valve opening display member 28 includes a scale 28a for displaying the valve opening and a window 28 for viewing the scale 28a.
b and. The upper end 16 of the position detection rod 16 described above
a can be visually recognized from the window 28b of the valve opening degree display member 28. Therefore, the valve opening degree of the valve body 5 can be known by reading the scale 28a corresponding to the sliding position of the upper end 16a.

Reference numeral 30 denotes a pressure control unit, primary pressure supply pipe lines (communication pipe lines) 31, 40, a bleed pipe line 32 for releasing the bleed pressure to the downstream side, a pilot valve 33, and an operating pressure for the pressure chamber 20. An operating pressure introducing line 34 for introducing P _L (also referred to as jacket pressure) and a detecting line 35 for supplying the downstream side detected pressure (secondary pressure P ₂ ) to the pilot valve 33.
And consists.

Further, one end of the primary pressure supply pipeline 31 is connected to the primary side connection port 6a of the upstream pipeline 6, and the other end is connected to the branch point 41 of the primary pressure supply pipelines 31, 40. Has been done. The upstream pressure line 6 is connected to the primary pressure supply line 31.
Pressure reducing valve (pressure reducing means) 36 for reducing the primary pressure P ₁ from
And a throttle 38 that limits the flow rate of the gas whose pressure is reduced by the pressure reducing valve 36.

Furthermore, one end of the operating pressure introducing pipe 34 is connected to a branch point 41 between the primary pressure supplying pipe 31 and the primary pressure supplying pipe 40, and the other end is connected to the pressure introducing hole 18a of the lid 18. It is connected. Accordingly, the pressure chamber 20 is supplied with the working pressure P _L whose pressure is reduced by the pressure reducing valve 36 and whose flow rate is restricted by the throttle 38.

One end of the primary pressure supply conduit 40 is a branch point 41 between the primary pressure supply conduit 31 and the working pressure introducing conduit 34.
, And the other end is connected to the nozzle 33f of the pilot valve 33. The pilot valve 33 is divided into an upper chamber 33c, a middle chamber 33d, and a lower chamber 33e by a pair of diaphragms 33a and 33b. A nozzle 33f connected to the secondary pressure supply pipe 40 is provided in the middle chamber 33d, and the lower chamber 3d
3e is a coil spring 33 for pressing the diaphragm 33b.
g intervenes. In addition, the coil spring 33g is an adjusting screw 33h.
By rotating, the magnitude of the spring force is changed and the pilot set pressure P ₀ is adjusted.

Therefore, the secondary pressure P ₂ downstream of the pressure control valve 1 is set to a desired target pressure by changing the pilot set pressure P ₀ . Also, a pair of diaphragms 3
3a and 33b are connected to each other and are displaced in the same direction. The diaphragm 33a restricts the flow rate outflow from the nozzle 33f due to the pressure rise in the upper chamber 33c, and increases the flow rate outflow from the nozzle 33f due to the pressure drop in the upper chamber 33c. Let

One end of the bleed conduit 32 is connected to the inner chamber 33d of the pilot valve 33, and the other end of the bleed conduit 32 is located at 2 of the downstream conduit 7.
It is connected to the secondary side connection port 7a. Therefore, the inner chamber 33d
The gas that has been supplied to the downstream side passes through the bleed line 32 and escapes to the downstream side line 7. One end of the detection conduit 35 is connected to the upper chamber 33c of the pilot valve 33, and the other end is connected to the downstream conduit 7.
Is connected to the secondary side connection port 7b. Therefore, the upper chamber 33c of the pilot valve 33 has a pressure corresponding to the change in the secondary pressure P ₂ on the downstream side.

The pressure reducing valve 36 has a working pressure equal to or higher than the working pressure such that the pressure difference between the primary pressure P ₁ and the working pressure P _L becomes the pressure difference required to open the valve body 5, and The primary pressure P ₁ is reduced so that the following pressure (reduced pressure value) is obtained. The pressure reducing valve 36 includes a valve drive portion 36b having a diaphragm 36a, a valve body 36c connected to the diaphragm 36a, an upper chamber 36d and a lower chamber 36e defined by the diaphragm 36a, and a diaphragm provided in the upper chamber 36d. Coil spring 36f for urging 36a in the valve opening direction
And.

When the diaphragm 36a is displaced upward, the valve body 36c comes close to the valve seat 36g, and the diaphragm 36a
Is displaced downward, it is separated from the valve seat 36g. Further, the pressure supplied to the diaphragm 38 is set to an arbitrary pressure by the spring force of the coil spring 36f, and the spring force of the coil spring 36f is adjusted by the adjusting screw 36h. The upper chamber 36d is at atmospheric pressure.

Reference numeral 39 denotes a primary pressure detection pipe, one end of which is connected to the lower chamber 36e of the pressure reducing valve 36 and the other end of which is connected to the primary pressure supply pipe 31 between the pressure reducing valve 36 and the throttle 38. There is.
Therefore, the pressure reduced by the pressure reducing valve 36 is supplied to the lower chamber 36e of the pressure reducing valve 36.

Therefore, the working pressure P _L supplied to the pressure chamber 20 of the pressure control valve 1 having the above structure is reduced to a predetermined pressure value (reduced pressure value) by the pressure reducing valve 36, and the flow rate is limited by the throttle 38. At the same time, it is determined by the difference between the flow rate discharged from the throttle 38 and the flow rate discharged from the pilot valve 33 to the downstream side pipeline 7 via the bleed pipeline 32.

Further, since the gas whose pressure is reduced by the pressure reducing valve 36 is supplied to the throttle 38, the primary pressure P ₁ is not directly supplied as the operating pressure P _L , and the secondary pressure P ₂ is lowered. When the pilot valve 33 increases the gas outflow amount (bleed amount) to the bleed conduit 32, the pressure difference between the primary pressure P ₁ and the operating pressure P _L is the pressure difference required to open the valve body 5. It is possible to shorten the time required for the operating pressure P _L to decrease until it becomes lower than before. Therefore, the valve opening can be stably controlled so that the secondary pressure P ₂ always maintains the target pressure.

Here, the pressure control operation of the pressure control device having the above configuration will be described. The upstream-side primary pressure P ₁ is supplied to the upstream-side flow path 3 a upstream of the valve seat 4 and also to the primary-pressure supply pipe line 31. The primary pressure P ₁ is the pressure reducing valve 3 provided in the primary pressure supply line 31.
After the pressure is reduced to the set pressure by 6, the flow rate is reduced by the throttle 38.

Further, the gas discharged from the diaphragm 38 is
The operating pressure P _L is supplied into the pressure chamber 20 via the operating pressure introducing pipe 34, and a part of the operating pressure P _L is supplied to the nozzle 33 f of the pilot valve 33 via the primary pressure supply pipe 40. Therefore, the primary pressure P ₁ of the upstream pipe line 3a acts on the lower portion of the piston 12 of the valve body 5, and the operating pressure P _L of the pressure chamber 20 acts on the upper portion of the piston 12 (the pressure reducing valve 36 when closed). The set pressure reduced by) acts.

Therefore, when the pressure difference between the working pressure P _L of the pressure chamber 20 and the primary pressure P ₁ does not reach the pressure difference that allows the valve body 5 to open, the valve body 5 is operated at the working pressure P _L and the spring. The piston 12 is seated on the valve seat 4 by being pressed downward by the pressing force of 25. That is, the valve body 5 is closed and the flow path 3 is shut off.

When the amount of gas used on the downstream side increases, the secondary pressure P ₂ becomes lower than the target pressure. In this way, since the secondary pressure P ₂ is lower than the target pressure,
Since the pressure in the upper chamber 33c of the pilot valve 33 decreases, the diaphragms 33a and 33b are displaced upward. As a result, the diaphragm 33a of the pilot valve 33 is separated from the nozzle 33f.

As a result, the gas supplied through the primary pressure supply conduit 40 is discharged from the nozzle 33f into the middle chamber 33d and flows out into the bleed conduit 32. Since the primary pressure supply conduit 31 is provided with the throttle 38, the nozzle 33f
The gas in the pressure chamber 20 is released by opening the valve of the working pressure supply pipe 3
4 and the primary pressure supply line 40 to pass the pilot valve 3
3 flows out into the inner chamber 33d. Further, the gas in the inner chamber 33d flows out to the downstream side pipeline 7 via the bleed pipeline 32.

Therefore, the gas in the working pressure introducing line 34 and the gas in the pressure chamber 20 flows out to the bleed line 32 and the working pressure P
_L decreases. As a result, as shown in FIG.
The resultant force of the operating pressure P _{L of} 0 and the pressing force of the spring 25 becomes smaller than the pressing force of the primary pressure P ₁ of the upstream side flow path 3a, and this pressure difference causes the valve body 5 to move upward and the piston 12 Moves away from the valve seat 4.

Since the cylindrical cage 13 is attached to the lower portion of the valve body 5, the valve body 5 is displaced in the valve opening direction while the lower cage 13 is guided by the cage guide 11. Therefore, the valve body 5 is not subjected to the swinging vibration of the fluid pressure and is not inclined with respect to the valve seat 4, and the valve opening operation is stably performed.

As described above, the working pressure P _L is reduced by the pressure reducing valve 36.
Since the pressure is reduced by and the flow rate is limited by the throttle 38 to be supplied to the pressure chamber 20, the amount of bleed flowing out from the nozzle 33f to the bleed conduit 32 can be reduced as compared with the conventional case as shown in FIG. Therefore, in the region where the lift amount of the diaphragm 33a that opens and closes the nozzle 33f of the pilot valve 33 is 50% or less, the bleed amount is variable in the low flow rate region.

[0047] Therefore, the diaphragm 33a 2 primary pressure P ₂ on the downstream side conduit 7 is lower than the target pressure nozzle 33f
When the valve is separated from and the valve is open, the secondary pressure P
_{Even if 2} is lowered, the diaphragm 33a is displaced from the nozzle 33f in the separating direction, so that the bleed amount can be increased and the valve body 5 can be driven in the valve opening direction.

Therefore, in the pressure control valve 1, the pilot valve 33 is opened / closed according to the fluctuation of the secondary pressure P ₂ , and the bleed amount can be adjusted in proportion to the displacement of the diaphragm 33a of the pilot valve 33. Therefore, the pressure control valve 1 can always perform pressure control so that the secondary pressure P ₂ becomes the target pressure.

Since the cage 13 is provided with the trapezoidal opening 13a as described above, the opening area does not increase rapidly even if the valve body 5 is separated from the valve seat 4, and the downstream side The flow rate to will gradually increase. That is, it is possible to change the capacitance or the characteristic by the shape of the opening 13a provided in the cage 13. Therefore, when the valve starts to be opened, the rate of increase in flow rate can be suppressed to be small, and the rate of increase in flow rate can be increased when the valve body 5 rises over a certain distance.

The fluid from the upstream flow passage 3a is rectified by the valve opening operation of the valve body 5 by the long hole 11a of the cage guide 11 and the perforated plate 15, and simultaneously with the valve opening, the downstream flow passage 3a.
It is prevented that the fluid flows to b. Therefore, the valve body 5
Is displaced in the valve opening direction and comes out from the valve seat 4
The flow rate according to the total opening area of a is supplied to the downstream side flow path 3b, and the control is stable especially in the small flow rate range. Therefore, the inconvenience that the flow rate rapidly increases during the valve opening operation of the valve element 5 and the small flow rate region cannot be controlled is solved.
Therefore, the secondary pressure P ₂ gradually rises and hunting is prevented from occurring.

Next, the operation of the pressure control valve 1 when the secondary pressure P _{2 in} the downstream pipe 7 increases will be described.
When the amount of gas used on the downstream side decreases, the secondary pressure P ₂ rises above the set pressure P ₀ , and the pressure is supplied to the upper chamber 33c of the pilot valve 33 via the detection pipe line 35. Then, in the pilot valve 33, the diaphragm 33a moves downward due to the pressure increase in the upper chamber 33c, and the amount of outflow from the nozzle 33f is reduced.

When the amount of gas used on the downstream side decreases and the secondary pressure P ₂ in the downstream side pipeline 7 rises to a pressure higher than the target pressure, the diaphragm 33a of the pilot valve 33 is displaced downward and the nozzle 33f is closed. Therefore, the amount of bleed that flows out from the pilot valve 33 to the bleed conduit 32 becomes zero, and as a result, all the pressure supplied from the primary pressure supply conduit 31 passes through the working pressure introduction conduit 34. Is supplied to. Therefore, since the operating pressure of the pressure chamber 20 rises, the valve body 5 is displaced in the valve closing direction and throttles the flow rate to the downstream side pipeline 7 to reduce the secondary pressure P ₂ to the target pressure.

Although the piston 12 defines the space between the pressure chamber 20 and the upstream flow passage 3a in the first embodiment, the invention is not limited to this. It goes without saying that a diaphragm may be defined between the passage 3a and the passage 3a. FIG. 5 shows a second embodiment of the present invention.

In the figure, reference numeral 51 denotes a motor-driven pressure reducing valve (pressure reducing means) which is arranged in the primary pressure supply pipe line 31. The pressure reducing valve 51 adjusts the pressure supplied to the throttle 38 by changing the valve opening degree according to a signal from the control device 52. The pressure reducing valve 51 includes a motor 51a, a valve shaft 51b driven by the motor 51a in a valve opening or closing direction, and a valve shaft 5
It is composed of a valve body 51c provided at an end of 1b and a valve seat 51d on which the valve body 51c is separated or seated. A worm gear is formed on the rotary shaft 51e of the motor 51a and is screwed in a state intersecting the valve shaft 51b.

Reference numeral 52 denotes a control device, which normally outputs a valve opening signal to the motor 51a of the pressure reducing valve 51. When the secondary pressure P ₂ on the downstream side becomes lower than the target pressure, the valve opening is reduced and the throttle 3 is opened.
The pressure supplied to 8 is reduced. 53 is a pressure sensor,
The secondary pressure P _{2 in} the downstream pipe line 7 is detected, and the detection signal is output to the control device 52. Therefore, the control device 52 controls the rotation amount of the motor 51a based on the detection signal from the pressure sensor 53 to change the valve opening degree of the electromagnetic valve 51.

Therefore, the operating pressure P is set by the solenoid valve 51.
_{Since the} primary pressure P ₁ supplied as _L is reduced, it becomes possible to change the operating pressure P _L with a small flow rate change of the bleed amount as in the embodiment shown in FIGS. 1 to 3 described above. The body 5 can be quickly operated according to the change in the secondary pressure P ₂ . Therefore, the offset during the pressure control operation can be reduced, and the secondary pressure P ₂
Can stably control the valve opening so that the target pressure is maintained.

6 to 8 show a third embodiment of the present invention. 6 is a schematic configuration diagram of the second embodiment of the pressure control device, FIG. 7 is an enlarged vertical sectional view showing the inside of the pressure reducing valve, and FIG. 8 is taken along line VIII-VIII in FIG. FIG. Further, in FIG. 6, the same components as those in FIG. 1 described above are designated by the same reference numerals and the description thereof will be omitted.

The pressure reducing valve (pressure reducing means) 61 has a primary pressure P ₁
And the pressure difference between the secondary pressure P ₂ and the operating pressure P _L becomes a desired pressure (decompression value) by depressurizing the operating pressure or more so as to become the pressure difference required to open the valve body 5. Thus, the primary pressure P ₁ is reduced.

The pressure reducing valve 61 has a primary pressure supply line 31.
a is connected to the primary pressure introduction port 62, the working pressure supply line 31b having the throttle 38 is connected to the working pressure discharge port 63, and the upstream side line 6 is connected to the primary side connection port 6b. A primary pressure detection port 65 to which the primary pressure supply pipeline 64 is connected and a secondary pressure detection port 67 to which a secondary pressure supply pipeline 66 branched from the detection pipeline 35 is connected.
And.

The pressure reducing valve 61 has a piston (displacement member) 69 that is displaced inside the pressure reducing valve body 68 in response to fluctuations in the primary pressure and the secondary pressure, and a throttle 38 in accordance with the displacement of the piston 69. And a pressure adjusting valve 70 for adjusting the supplied throttle valve upstream pressure P _LO . The pressure reducing valve main body 68 is composed of first to fourth blocks 71 to 74, and the first to fourth blocks 71 to 74 are integrally connected by tightening bolts 75 and 76.

The first block 71 is provided with the working pressure discharge port 63, and the second block 72 is provided with the operating pressure discharge port 63.
A primary pressure introducing member 77 having a secondary pressure introducing port 62 is laterally inserted. Then, the third block 73
Is provided with the primary pressure detection port 65, and the fourth block 74 is provided with the secondary pressure detection port 67. The primary pressure introducing member 77 is provided with a passage 77a communicating with the primary pressure introducing port 62, and an intermediate portion of the primary pressure introducing member 77 has a valve seat 85 communicating with the passage 77a.
Is stuck.

The piston 69 is slidably inserted in a space 68a formed in the pressure reducing valve main body 68, and has the pressure of the throttle valve upstream pressure P _LO and the primary pressure P ₁ and the secondary pressure P _2. It slides in the Ya and Yb directions according to the balance. Also,
A coil spring 78 for pressing the piston 69 in the Ya direction is incorporated in the space 74a provided in the fourth block 74.

The piston 69 has a third block 73.
Has a large-diameter portion 69a that slides in the large-diameter cylinder 73a and a small-diameter portion 69b that slides in the small-diameter cylinder 73b of the third block 73. Sealing members 79 and 80 are provided to seal the inner walls of the diameter cylinder 73a and the small diameter cylinder 73b.

Further, a valve portion 81 formed in an inverted U shape so as to straddle the primary pressure introducing member 77 is fixed to the upper end of the piston 69 by tightening a bolt 82. A seat portion 83 of the operating pressure adjusting valve 70 is inserted into a hole 81a provided at the center of the valve portion 81, and the seat portion 83 is fixed in the hole 81a by fastening a screw 84. Therefore, in the seat portion 83, the piston 69 is Y
By sliding in the a and Yb directions, it moves toward or away from the valve seat 85 provided at the intermediate portion of the primary pressure introducing member 77. As a result, the working pressure adjusting valve 70
Operates to open or close the valve.

In the piston 69, below the large diameter portion 69a
The pressure receiving area ratio between the surface and the lower end of the small diameter portion 69b is determined by the pressure control valve.
Primary pressure acting on piston 12 provided inside 1
P₁And secondary pressure P₂To be the same as the pressure receiving area ratio of
Is set. Therefore, the primary pressure P₁, Secondary pressure P₂
Pressing force in the Ya direction due to and throttle valve front stage pressure P_LOby
When the pressing force in the Yb direction is equal, the piston 69
It moves in the Ya direction by the spring force of the le spring 78.
Also, the primary pressure P₁, Secondary pressure P ₂The total value of
Ri valve front stage pressure P_LOIs greater than a specified value,
The ton 69 moves in the Yb direction.

When the piston 69 slides in the Ya direction, the operating pressure adjusting valve 70 opens and the throttle valve front stage pressure P _LO discharged from the pressure reducing valve 61 rises, and the piston 69 moves to Yb.
When the valve slides in the direction, the operating pressure adjusting valve 70 closes and the throttle valve upstream pressure P _LO discharged from the pressure reducing valve 61 decreases. In this way, the opening / closing operation of the operating pressure adjusting valve 70 adjusts the pressure P _LO discharged from the operating pressure discharge port 63 to the throttle 38.

Here, the action of pressure balance between the piston 12 of the pressure control valve 1 and the piston 69 of the pressure reducing valve 61 having the above-mentioned structure will be described. The pressure receiving area of the piston 12 on which the primary pressure P ₁ supplied from the upstream flow passage 3a acts is A _1, and the pressure receiving area of the piston 12 on which the secondary pressure P ₂ of the downstream flow passage 3b acts is A ₂ . To do. When the pressure receiving area of the lower surface of the large diameter portion 69a of the piston 69 is A _p1 and the pressure receiving area of the lower end of the small diameter portion 69b is A _p2 , the piston 12 of the pressure control valve 1 and the piston 69 of the pressure reducing valve 61 are The area ratio relationship can be expressed as the following equation.

A ₁ : A ₂ = A _p1 : A _p2 (1) Then, in the piston 69, the large diameter portion 69 a and the small diameter portion 69.
The pressure receiving area ratio with b is set to be the same as the pressure receiving area ratio between the primary pressure P ₁ and the secondary pressure P ₂ acting on the piston 12 of the pressure control valve 1. The ratio can be X ₁ and X ₂ .

A ₁ / (A ₁ + A ₂ ) = A _p1 / (A _p1 + A _p2 ) = X ₁ (2) A ₂ / (A ₁ + A ₂ ) = A _p2 / (A _p1 + A _p2 ) = X ₂ (3) Further, considering the balance between each pressure acting on the piston 69 and the spring force F _p of the coil spring 78, the following equation is established.

(A _p1 + A _p2 ) P _LO = A _p1 · P ₁ + A _p2 · P ₂ + F _p (4) From this equation (4), P _LO = A _p1 · P ₁ / (A _p1 + A _p2 ) + A _p2 · P ₂ / (A _p1 + A _p2 ) + F _p / (A _p1 + A _p2 ) ... (5) Substituting the formulas (2) and (3) into the formula (5) gives the following formula.

P _LO = X ₁ · P ₁ + X ₂ · P ₂ + F _p / (A _p1 + A _p2 ) ... (6) The pressure reducing valve 61 responds to changes in the primary pressure P ₁ and the secondary pressure P _2. The throttle valve front stage pressure P _LO is set so that the expression (6) is established. Next, considering the balance between each pressure acting on the pressure control valve 1 and the spring force F _v of the coil spring 25, the following equation holds.

(A ₁ + A ₂ ) · P _L + F _v = A ₁ · P ₁ + A ₂ · P ₂ (7) From this equation (7), P _L = A ₁ · P ₁ / (A ₁ + A ₂ ). + A ₂ · P ₂ / (A ₁ + A ₂ ) −F _V / (A ₁ + A ₂ ) ... (8) Substituting the equations (2) and (3) into the equation (8) gives the following equation.

P _L = X ₁ · P ₁ + X ₂ · P ₂ −F _V / (A ₁ + A ₂ ) ... (9) In the pressure control valve 1, the operating pressure P _L is calculated from the pressure value that is established by the equation (9). When the pressure becomes low, the piston 12 opens. From the above (6) and (9), the difference between the throttle valve upstream pressure P _LO and the operating pressure P _L can be expressed as the following equation.

[0074] _{P LO -P L = F p /} (A p1 + A p2) + F V / (A 1 + A 2) ... (10) than the (10), P _LO -P _L is primary pressure P _1, 2 It can be seen that it can be set regardless of the next pressure P ₂ . Therefore, the pressure reducing valve 61 can automatically set the throttle valve upstream pressure P _LO to a pressure value corresponding to the primary pressure P ₁ and the secondary pressure P ₂ by the operation of the piston 69, and at the same time, the throttle valve upstream pressure can be set. The primary pressure P ₁ and the secondary pressure P ₂ are P _LO and the operating pressure P _L.
It can be adjusted so that it is not affected by.

Next, the operation of the pressure reducing valve 61 when the pressure conditions of the primary pressure and the secondary pressure are changed will be described. For example, when the primary pressure P ₁ or the secondary pressure P ₂ rises, the force that tries to lift the piston 12 of the pressure control valve 1 from the lower side increases, and the working pressure that acts on the upper side of the piston 12 in balance with this increases. P _L also increases from before the pressure condition was changed. However, when the pressure reduction amount of the pressure reducing valve 61 is not adjusted after the pressure condition is changed, the throttle valve front stage pressure P _LO has not risen, so that the piston 12 is below the working pressure P _L acting on the piston 12 above. Pressure P acting on
_The primary pressure P ₂ becomes larger than the secondary pressure P ₂ . In this case, the pressure control valve 1 uses the secondary pressure P ₂ of the pilot valve 33.
Even if the bleeding operation for reducing the operating pressure P _L is not performed by the valve opening operation by the detection, the piston 12 arbitrarily moves up and the valve opening operation is performed.

If this is replaced with the relationship between the bleed amount and the lift amount of the pilot valve 33 shown in FIG. 4, the control region becomes the same as when it is shifted to 50% or less, and the piston 12 is moved even if the bleed amount is zero. It means that the valve body 5 has a valve opening operation. However, in the pressure reducing valve 61 of the present embodiment, the piston 69 is slidably displaced according to the magnitudes of the primary pressure P ₁ and the secondary pressure P ₂ , and the valve opening (pressure reducing amount) of the pressure regulating valve 70 is adjusted. Therefore, such a problem can be solved.

That is, in the pressure reducing valve 61, the primary pressure P ₁
Or, when the secondary pressure P ₂ rises, the piston 69 moves to Ya.
Seat portion 8 provided on the valve portion 81 for sliding in the direction
3 separates from the valve seat 85 to open the operating pressure adjusting valve 70. At that time, the piston 69 is displaced in the Ya direction to a position where the primary pressure P ₁ and the secondary pressure P ₂ , the spring force of the coil spring 78 and the throttle valve upstream pressure P _LO are balanced.

As a result, the primary pressure P ₁ supplied through the primary pressure supply conduit 31a is reduced to a depressurizing pressure corresponding to the sliding displacement of the piston 69, and the depressurized throttle valve front stage pressure P _LO is From the valve seat 85 of the operating pressure adjusting valve 70 to the piston 69.
It is discharged to the upper part. Therefore, the operating pressure supply line 31b
The throttle valve pre-stage pressure P _LO supplied to the throttle 38 via the valve is increased.

The flow rate of the throttle valve upstream pressure P _LO is throttled by the throttle 38 to become the working pressure P _L , and is further introduced into the pressure chamber 20 through the working pressure introducing pipe line 34, so that the pressure chamber 2
The pressure of 0 is increased. Therefore, the operating pressure P _L that presses the piston 12 downward is also increased in accordance with the increase in the primary pressure P ₁ or the secondary pressure P ₂ that presses the piston 12 upward, so that the pilot valve 33 does not bleed. It is possible to prevent the piston 12 from moving upward without permission, and the secondary pressure P ₂
Is controlled to maintain a preset set pressure.

The pressure receiving area ratio between the lower surface of the large diameter portion 69a of the piston 69 and the lower end of the small diameter portion 69b is the same as the pressure receiving area ratio of the primary pressure P ₁ and the secondary pressure P ₂ acting on the lower surface of the piston 12. Therefore, the throttle valve pre-stage pressure P _LO reduced by the pressure reducing valve 61 has a spring force of the coil spring 78 higher than the working pressure P _L balanced with the primary pressure P ₁ and the secondary pressure P ₂ acting on the lower surface of the piston 12. Therefore, the pressure increases to the area of the large diameter portion 69a regardless of the primary pressure P ₁ and the secondary pressure P ₂ . As a result, even if the primary pressure P ₁ and the secondary pressure P ₂ increase, the control area of the pressure control valve 1 is secured in the control area of this embodiment shown in FIG.

Next, the primary pressure P₁Or secondary pressure P₂Is low
If it is lowered, the force acting on the lower side of the piston 12 decreases
Operation that acts on the upper side of the piston 12 that balances with this
Pressure P _LIs smaller than before the pressure condition was changed. By the way
However, the pressure reduction amount of the pressure reducing valve 61 should not be adjusted after the pressure condition is changed.
If it does, the throttle valve front stage pressure P_LODoes not decrease,
Working pressure P acting on the upper side of the stone 12_LThan the power of
Pressure P acting on the lower side of the piston 12₁, Secondary pressure
Power P₂Will be less powerful. So the pie
Increase the bleed amount of the lot valve 33 more than before changing the pressure condition.
Otherwise, the valve body 5 of the pressure control valve 1 will not open.
become.

When this is replaced with the relationship between the bleed amount and the lift amount of the pilot valve 33 shown in FIG. 4, the control region becomes the same as when it is shifted to 50% or more, and the pressure control is performed unless the bleed amount is increased. the valve 1 does not open, it means that the response of the pressure regulating operation of the secondary pressure P ₂ decreases, also gas consumption of the downstream side is increased secondary pressure P ₂ is reduced The valve body 5 of the pressure control valve 1 will not open and gas supply will be delayed.

However, the pressure reducing valve 61 of this embodiment is
The piston 69 is slidably displaced according to the magnitudes of the primary pressure P ₁ and the secondary pressure P ₂ , and the valve opening degree (pressure reduction amount) of the pressure regulating valve 70.
Is adjusted so that such a problem can be solved. That is, in the pressure reducing valve 61, the primary pressure P ₁ or the secondary pressure P ₂
Is decreased, the piston 69 slides in the Yb direction, so that the seat portion 83 provided on the valve portion 81 approaches the valve seat 85 to close the operating pressure adjusting valve 70. At that time, the piston 69 is displaced in the Yb direction to a position where the primary pressure P ₁ and the secondary pressure P ₂ , the spring force of the coil spring 78 and the throttle valve upstream pressure P _LO are balanced.

As a result, through the primary pressure supply line 31a
Supplied primary pressure P₁To the sliding displacement of piston 69
Decompressed to the appropriate decompression pressure
Pressure P_LOIs the piston from the valve seat 85 of the working pressure regulating valve 70.
69 is discharged to the upper part. Therefore, the working pressure supply line 3
Throttle valve pre-stage pressure P supplied to the throttle 38 via 1b _LO
Is decompressed.

By this pressure reducing operation, the operating pressure P _L acting on the upper side of the piston 12 is also reduced in accordance with the decrease in the primary pressure P ₁ or the secondary pressure P ₂ acting on the piston 12 on the lower side. The bleed amount of the valve 33 is increased to prevent the valve body from opening, and the secondary pressure P ₂ is controlled so as to maintain the set pressure.

Further, as in the case where the primary pressure P ₁ and the secondary pressure P ₂ are increased as described above, even if the primary pressure P ₁ and the secondary pressure P ₂ decrease, the pressure control valve 1 The control area is secured in the control area of this embodiment shown in FIG. As described above, the pressure reducing valve 61 generates the throttle valve upstream pressure P _LO having a magnitude corresponding to the fluctuations of the primary pressure P ₁ and the secondary pressure P ₂ only by adjusting the pilot set pressure P ₀ of the pilot valve 33. Therefore, it is possible to prevent troublesome adjustment work of the pressure reducing valve and prevent the pressure control valve 1 from malfunctioning even if the pressure reducing valve is forgotten to be adjusted.

In the pressure reducing valve 61, the piston 69 is displaced according to the change of each pressure, but the invention is not limited to this. For example, the diaphragm is displaced according to the change of each pressure, and the displacement of the diaphragm is changed. Throttle valve front pressure P
_{The LO} may be adjusted.

In each of the above-mentioned embodiments, the pressure of the gas is controlled, but the pressure of gas other than gas or liquid may be controlled.

[0089]

As described above, according to the first aspect of the present invention, the primary pressure supplied to the throttle is reduced by the pressure reducing means so that the maximum value of the operating pressure supplied from the throttle to the valve drive section is reached. Is reduced to a predetermined pressure set in the pressure reducing means, so when the secondary pressure decreases and the pilot valve opens, the pressure difference between the primary pressure and the operating pressure drives the valve element in a short time. The pressure difference is less than or equal to a predetermined pressure difference. Therefore, when the pilot valve is opened, the valve element can be driven in a small bleed amount region, so that the valve element can be displaced stably and quickly to control the secondary pressure on the downstream side. The responsiveness of adjustment can be improved. further,
It is possible to stably change the working pressure to the valve drive unit to reduce the offset during the working pressure adjustment operation, and to perform stable control so that the secondary pressure always maintains the target pressure.

Further, according to the second aspect of the invention, since the pressure reducing means adjusts the operating pressure according to the fluctuations of the primary pressure and the secondary pressure, the pressure reducing means even if the primary pressure and the secondary pressure fluctuate. Since the operating pressure can be automatically adjusted, the troublesome work of adjusting the operating pressure becomes unnecessary. Further, the valve body provided in the valve body is arbitrarily opened when the primary pressure and the secondary pressure are increased, or the pilot valve is opened when the primary pressure and the secondary pressure are decreased to reduce the bleed amount. It is possible to prevent the valve body from failing to open even though it is increased, and even if the pressure conditions of the primary pressure and the secondary pressure are changed, it is independent of the primary pressure and the secondary pressure. Moreover, the secondary pressure can be controlled to the set pressure.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a first embodiment of a pressure control valve according to the present invention.

FIG. 2 is an enlarged vertical cross-sectional view showing the inside of a pressure control valve.

FIG. 3 is a vertical sectional view showing a valve opening operation.

FIG. 4 is a graph showing a relationship between a lift amount of a pilot valve and a bleed amount.

FIG. 5 is a vertical sectional view of a second embodiment of the present invention.

FIG. 6 is a schematic configuration diagram of a third embodiment of the pressure control device.

FIG. 7 is a vertical cross-sectional view showing the interior of the pressure reducing valve in an enlarged manner.

8 is a vertical cross-sectional view taken along the line VIII-VIII in FIG.

[Explanation of symbols]

 1 Pressure Control Valve 2 Valve Body 5 Valve Body 12 Piston 20 Pressure Chamber 30 Pressure Control Unit 31 Primary Pressure Supply Pipeline 32 Bleed Pipeline 33 Pilot Valve 34 Working Pressure Introduction Pipeline 36,51 Pressure Reduction Valve 38 Throttle 52 Control Device 61 Pressure reducing valve 62 Primary pressure introducing port 63 Operating pressure discharge port 64 Primary pressure supply line 65 Primary pressure detecting port 66 Secondary pressure supply line 67 Secondary pressure detecting port 69 Piston 70 Operating pressure adjusting valve

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Takashi Komiya 4-1-2, Hirano-cho, Chuo-ku, Osaka City, Osaka Prefecture Osaka Gas Co., Ltd. (72) Moriatsu Kobayashi 1-chome, Fujimi, Kawasaki-ku, Kanagawa Prefecture No. 6-3 Tokico Co., Ltd. (72) Inventor Akio Ishii 1-6-3 Fujimi, Kawasaki-ku, Kawasaki-shi, Kanagawa Tokiko Co., Ltd. (72) In-house Yasio Ozawa 1-6 Fujimi, Kawasaki-ku, Kawasaki-shi, Kanagawa No. 3 Tokico Corporation

Claims (2)

[Claims] 1. A valve main body provided between an upstream side pipeline and a downstream side pipeline to which a fluid is fed, and a valve opening so that a secondary pressure downstream from the valve main body reaches a target pressure value. The valve body in the valve closing direction due to the pressure difference between the operating pressure supplied through the valve body for changing the degree of pressure and the communication line communicated with the upstream side pipe line and the primary pressure upstream of the valve body. Alternatively, a valve drive unit that drives in the valve opening direction, a throttle that is provided in the communication conduit and reduces a fluid supply amount to the valve drive unit, and a valve opening operation when the secondary pressure becomes equal to or lower than a predetermined pressure value. And a pilot valve for releasing the working pressure supplied to the valve drive unit to the downstream side, and a pressure reducing valve provided in the communication pipe upstream of the throttle for reducing the pressure supplied to the throttle to a predetermined pressure. A pressure control device comprising: 2. The pressure control device according to claim 1, wherein the depressurizing means includes a displacement member that displaces in response to fluctuations in the primary pressure and the secondary pressure, and a diaphragm that responds to displacement of the displacement member. An operating pressure adjusting valve for adjusting the supplied operating pressure, and a pressure control device comprising: