JP2000213665A - Pilot-operated flow control valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a pressure loss of fluid by arranging a leak passage connecting one of fluid passages on the upstream side and downstream side beyond a heat exchanger to the inside of a pressure regulation chamber via a narrow cross sectional area and a constant differential pressure control valve controlling a differential pressure between a fluid pressure inside the other passage and a fluid pressure inside the pressure regulation chamber at an optional constant pressure. SOLUTION: In fluid passages 1 on the upstream side and the downstream side beyond a heat exchanger 2, a downstream side passage 1b is connected to the inside of a pressure regulation chamber 13 by a leak passage 17 via a narrow cross sectional area. An upstream side passage 1a is connected to the pressure regulation chamber 13 by a pilot flow passage 3, and in the middle of the pilot flow passage 3, a constant differential pressure control valve 20 is inserted and connected in series. The pilot flow passage 3 is formed so as to be provided with a cross sectional area greatly larger than that of the leak passage 13. The constant differential pressure control valve 20 controls a differential pressure between a fluid pressure on the upstream side beyond the heat exchanger 2 and a fluid pressure inside the pressure regulation chamber 13. In this way, a pressure loss inevitably generated by the heat exchanger 2 can be used for operating a main valve 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pilot-actuated flow control valve which regulates the flow rate of a fluid while maintaining the differential pressure across the valve at an arbitrary constant pressure.

[0002]

2. Description of the Related Art Generally, a flow control valve adjusts a differential pressure across the valve by an electromagnetic solenoid, and controls a flow rate in accordance with the set differential pressure, and is operated with a small driving force. For this purpose, a pilot-actuated flow control valve is used.

[0003] Such a pilot operated flow control valve is generally provided with a pressure regulating chamber which is separated from a flow path located downstream of the main valve by a movable pressure receiving member connected to the main valve. The flow rate is controlled by controlling the pressure in the pressure regulation chamber by the constant differential pressure control valve which is energized by.

[0004]

In the above-described pilot operated flow control valve, when the main valve is completely closed, the fluid pressure does not act in the direction of opening and closing the main valve. A spring is provided to maintain the fully closed state.

[0005] However, as a result, in order to open the main valve, it is necessary to create an operating differential pressure greater than the urging force of the spring in the fluid line, and accordingly, the fluid pressure is lost for the flow control valve (pressure). Loss), and there is a drawback that the operation cannot be performed unless the original pressure of the fluid is so high.

Accordingly, an object of the present invention is to provide a pilot-operated flow control valve with high pressure efficiency that does not cause fluid pressure loss.

[0007]

In order to achieve the above object, a pilot operated flow control valve according to the present invention is provided with a valve upstream of the heat exchanger for flowing fluid to a heat exchanger in which a pressure loss of a passing fluid occurs. The main valve for adjusting the flow rate of the fluid pipeline connected to the side and the downstream side on either the upstream side or the downstream side of the heat exchanger, and the movable pressure receiving member connected to the main valve. In the vicinity of the main valve, a pressure regulating chamber partitioned from the fluid conduit, one of the fluid conduits upstream and downstream of the heat exchanger and the pressure regulating chamber communicate with a small cross-sectional area. A leak path for controlling a pressure difference between a fluid pressure in the other one of the fluid pipes upstream and downstream of the heat exchanger and a fluid pressure in the pressure regulation chamber to an arbitrary constant pressure. A constant pressure control valve is provided. It may be one that controls the differential pressure to an arbitrary constant pressure by.

[0008] The constant differential pressure control valve is provided between the pressure control chamber and the one of the fluid lines upstream and downstream of the heat exchanger where the main valve is not provided. The leak path may be formed in the movable pressure receiving member so as to be connected in series.

Alternatively, the pressure regulation chamber communicates with the fluid line upstream and downstream of the heat exchanger, which is not provided with the main valve, via the leak passage. ,
The constant differential pressure control valve may be connected between the fluid line near the main valve and the pressure regulation chamber.

In addition, a second pilot operated flow control valve having a flow path in which a pressure loss equivalent to that of the heat exchanger is generated in place of the heat exchanger is connected in parallel with the pilot operated flow control valve. It may be.

[0011]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a pilot operation flow control valve according to a first embodiment of the present invention, for example, water (hot water).
A heat exchanger 2 that is heated by a heat source (not shown) is inserted and connected in the middle of the fluid pipeline 1 of the hot water supply device through which the water flows.

The pressure of the fluid passing through the fluid pipe 1 decreases due to the pressure loss caused by passing through the flow path in the thin and long heat exchanger 2, and the fluid in the downstream pipe 1 b of the heat exchanger 2 is reduced. The pressure is, for example, 0.2 to 0.5 higher than the fluid pressure in the upstream pipeline 1a.
kg / cm ² .

In this embodiment, a flow control valve 10 is inserted and connected to such a downstream pipe 1b, and
The main valve 11 facing from upstream toward the fluid line 1
It is arranged to open and close. The fluid line 1 immediately upstream of the main valve 11 is referred to as a main valve upstream portion 1p, and the downstream side thereof is referred to as a main valve downstream portion 1q.

A pressure regulating chamber 13 partitioned by a main valve downstream portion 1q and a diaphragm 15 is formed, and the main valve downstream portion 1q and the pressure regulating chamber 13 are communicated only by a leak passage 17 having a small cross-sectional area. . The diaphragm 15 is formed of a flexible material, and the movable pressure receiving member 14 integrally attached to the diaphragm 15 is formed in a hard disk shape.

The movable pressure receiving member 14 is arranged so that the central axis thereof coincides with that of the valve seat 12, and the main valve 11 and the movable pressure receiving member 14 are integrally connected by a connecting member 18 arranged at the axial position. ing.

Further, the movable pressure receiving member 14 is always urged in the direction in which the main valve 11 comes into contact with the valve seat 12 by the valve closing compression coil spring 16 disposed between the valve seat 12 and the movable pressure receiving member 14. Have been.

Therefore, in the direction in which the main valve 11 is closed, the fluid pressure in the downstream pipes 1b (1p, 1q) and the urging force of the valve closing compression coil spring 16 act to open the main valve 11 in the opening direction. , The fluid pressure in the pressure regulating chamber 13 acts, and the main valve 11 stops at a position where they are balanced.

The pressure regulating chamber 13 is connected to the upstream pipeline 1a by a pilot flow path 3. An electromagnetically driven constant differential pressure control valve 20 is inserted and connected in series in the pilot flow path 3. I have. 21 is an electromagnetic coil, 22 is a fixed iron core, 2
3 is a movable iron core. The pilot flow path 3 is formed to have a much larger cross-sectional area than the leak path 17.

A compression coil spring 24 for differential pressure is disposed between the fixed iron core 22 and the movable iron core 23, and the spherical pilot valve body 25 is moved from the low pressure side to the high pressure side (ie, from the low pressure side toward the valve seat 26). The pressure is urged from the pressure adjustment chamber 13 side to the upstream pipe line 1a).

With such a configuration, the constant differential pressure control valve 20
In the state where the electromagnetic coil 21 is not energized in
Pilot valve body 25 is strongly pressed against valve seat 26 by the urging force of compression coil spring 24 for differential pressure, and pilot flow path 3 is closed.

Therefore, on the flow regulating valve 10 side, the inside of the pressure regulating chamber 13 becomes equal in pressure to the main valve downstream portion 1q of the downstream pipe line 1b through the leak passage 17, and the main valve 11 is connected to the compression coil spring 16 for valve closing. It is pressed against the valve seat 12 only by the urging force and is closed.

When the electromagnetic coil 21 is energized, the urging force applied from the movable iron core 23 to the pilot valve body 25 decreases as the current increases, and the upstream pipeline 1a
The pilot valve element 25 is separated from the valve seat 26 by a pressure difference between the fluid pressure on the pressure side and the fluid pressure on the pressure regulation chamber 13 side.

In such a state, the upstream pipeline 1
The differential pressure between the fluid pressure on the a side and the fluid pressure on the pressure regulation chamber 13 balances the urging force applied from the movable iron core 23 to the pilot valve body 25, and the pressure difference corresponding to the current value flowing through the electromagnetic coil 21. The pressure is kept constant. Specifically, as the current value increases, the pressure in the pressure regulating chamber 13 increases in the upstream pipe line 1a.
Approach pressure inside.

Then, since the fluid pressure on the downstream pipe line 1b side is lower than the upstream pipe line 1a side by a fixed pressure due to the passage through the heat exchanger 2, the differential pressure control of the constant differential pressure control valve 20 is performed. In response, the movable pressure receiving member 14 moves, and the main valve 11 moves to the valve seat 1.
2 and the flow control valve 10 is opened.
The flow rate of the fluid passing through the fluid line 1 is controlled to be constant.

As described above, the flow control valve 10 is provided downstream of the heat exchanger 2 to control the differential pressure between the fluid pressure upstream of the heat exchanger 2 and the fluid pressure in the pressure regulating chamber 13 by a constant differential pressure control. With the configuration in which the control is performed by the valve 20, the pressure loss inevitably generated by the heat exchanger 2 can be used for the operation of the main valve 11.

As a result, pressure loss for operating the flow control valve 10 does not occur, so that flow control can be reliably performed even in an environment where the original pressure on the upstream side of the fluid pipeline 1 is low.

FIG. 2 shows a pilot-operated flow control valve according to a second embodiment of the present invention. In contrast to the above-described first embodiment, the upstream side of the heat exchanger 2 is the upstream side. Pipe line 1a
And a constant pressure control valve 20 connected in series between the downstream pipe line 1 b downstream of the heat exchanger 2 and the inside of the pressure regulation chamber 13.

Since the pressure direction is opposite to that of the first embodiment, the valve closing compression coil spring 16 is disposed in the pressure regulating chamber 13 and the pilot valve body 25 is moved from the downstream pipe line 1b side. It faces the valve seat 26 toward the pressure regulation chamber 13 side. Other configurations are the same as those of the first embodiment, and operate in the same manner as in the first embodiment to obtain the same functions and effects.

FIG. 3 shows a pilot-operated flow control valve according to a third embodiment of the present invention, and a flow control valve 10 is connected downstream of the heat exchanger 2. A leak passage 17 is provided between the upstream pipe 1a and the pressure control chamber 13, and a constant pressure difference control valve 20 is connected between the pressure control chamber 13 and the main valve downstream portion 1q of the downstream pipe 1b. Have been.

The main valve 11 of the flow regulating valve 10 is arranged so as to face the valve seat 12 from the downstream side, and the valve opening compression coil spring 16 'is arranged so as to urge the main valve 11 in the opening direction. Have been. Other configurations are the same as those of the first embodiment.

As a result, in a state in which the electromagnetic coil 21 is not energized in the constant differential pressure control valve 20, the pressure in the pressure regulating chamber 13 becomes equal to the pressure in the upstream pipe 1a, which is higher than the pressure in the downstream pipe 1b. As a result, the main valve 11 is pressed against the valve seat 12 by the differential pressure received by the movable pressure receiving member 14 from both sides, and the valve is closed.

When the electromagnetic coil 21 is energized and the urging force from the movable iron core 23 on the pilot valve body 25 is reduced, the pressure inside the pressure regulating chamber 13 is maintained at a constant pressure difference with the inside of the main valve downstream portion 1q. The main valve 11 is opened by the balance between the differential pressure applied to both surfaces of the movable pressure receiving member 14 and the valve opening compression coil spring 16 ′, and the flow rate of the fluid passing through the flow control valve 10 is controlled to be constant.

As described above, in the third embodiment, the full closing force of the main valve 11 is obtained by utilizing the pressure loss in the fluid pipe 1 which is inevitably generated by the heat exchanger 2. As a result, pressure loss for operating the flow control valve 10 does not occur, so that it can be reliably operated even in an environment where the original pressure on the upstream side of the fluid pipeline 1 is low.

FIG. 4 shows a pilot-operated flow control valve according to a fourth embodiment of the present invention. In contrast to the above-described third embodiment, an upstream pipe on the upstream side of the heat exchanger 2 is shown. The flow control valve 10 is connected to the passage 1 a, and a leak passage 17 is formed between the downstream pipe 1 b downstream of the heat exchanger 2 and the inside of the pressure regulation chamber 13. It is connected between the most upstream side of the pipeline 1 (the upstream portion 1p of the main valve) and the pressure regulating chamber 13.

Since the pressure direction is opposite to that of the third embodiment, the valve opening compression coil spring 16 ′ is disposed in the pressure regulating chamber 13, and the pilot valve body 25 of the constant differential pressure control valve 20 is provided. Is opposed to the valve seat 26 from the pressure regulation chamber 13 side.
Other configurations are the same as those of the third embodiment, and operate in the same manner as in the third embodiment to obtain the same functions and effects.

FIG. 5 shows a pilot-operated flow control valve according to a fifth embodiment of the present invention. This is one in which a pilot operation flow control valve B is arranged.

However, the second pilot operated flow control valve B
Is connected to a bypass pipe 50 that does not pass through the heat exchanger 2 so as to control the flow rate of cold water, and a throttle flow that causes the same pressure loss as the heat exchanger 2 is provided at a position corresponding to the heat exchanger 2. A passage 51 is formed in the bypass line 50.

With this configuration, the mixing ratio and flow rate of hot water and water can be controlled by applying the pilot operation flow control valve of the present invention to both the hot water and hot water systems of the hot water supply apparatus. When the two sets of pilot operation flow control valves A and B are combined in this way, the invention is not limited to the pilot operation flow control valve of the third embodiment, and any type may be used.

FIG. 6 shows a pilot operated flow control valve according to a sixth embodiment of the present invention, which is similar to the pilot operated flow control valve according to the second embodiment, but is different from the pilot operated flow control valve according to the second embodiment. The main valve downstream portion 1q is disposed in reverse (the main valve 11 faces the valve seat 12 from the downstream side), and a leak passage 17 is formed at a position corresponding to the main member 11 to penetrate the connecting member 18 in the axial direction. The second embodiment is different from the second embodiment in that the movable pressure receiving member 14 is formed in a piston shape to be fitted in the pressure regulating chamber 13 and the diaphragm 15 is not provided.

FIG. 7 shows a pilot operated flow control valve according to a seventh embodiment of the present invention, in which the opening and closing direction of the main valve 11 is reversed as compared with the sixth embodiment. .
As a result, in the pilot operated flow control valve of this embodiment, the main valve 11 is opened when the constant differential pressure control valve 20 is closed, and the opening of the main valve 11 is opened when the constant differential pressure control valve 20 is opened. Gradually become smaller.

As described above, the pilot operated flow control valve of the present invention can take various forms, and may be other than the above-described embodiment. Also, the application of the present invention,
The present invention can be applied not only to a water heater but also to various other devices such as a refrigerant flow control in a refrigeration cycle.

[0042]

According to the present invention, the leak path is connected between one of the upstream and downstream fluid pipes connected to the heat exchanger and the pressure regulating chamber, and the other is connected to the pressure control chamber. By connecting the constant differential pressure control valve between the pipeline and the pressure regulating chamber, the pressure loss inevitably generated by the heat exchanger can be used for operating the flow control valve. Therefore, pressure loss for operating the flow control valve does not occur, and the operation can be reliably performed even in an environment where the upstream source pressure given to the fluid is low.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a pilot operated flow control valve according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of a pilot operated flow control valve according to a second embodiment of the present invention.

FIG. 3 is a longitudinal sectional view of a pilot operation flow control valve according to a third embodiment of the present invention.

FIG. 4 is a longitudinal sectional view of a pilot operation flow control valve according to a fourth embodiment of the present invention.

FIG. 5 is a longitudinal sectional view of a pilot operation flow control valve according to a fifth embodiment of the present invention.

FIG. 6 is a longitudinal sectional view of a pilot operated flow control valve according to a sixth embodiment of the present invention.

FIG. 7 is a longitudinal sectional view of a pilot operated flow control valve according to a seventh embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fluid pipe 1a Upstream pipe 1b Downstream pipe 2 Heat exchanger 3 Pilot flow path 10 Flow control valve 11 Main valve 12 Valve seat 13 Pressure regulation chamber 14 Movable pressure receiving member 15 Diaphragm 16 Compression coil spring for valve closing 16 ′ Valve opening compression coil spring 17 Leak path 18 Connecting member 20 Constant differential pressure control valve 23 Moving iron core 24 Differential pressure compression coil spring 25 Pilot valve body 26 Valve seat

Claims (5)

[Claims] The flow rate of a fluid line connected upstream and downstream of the heat exchanger for flowing the fluid to a heat exchanger in which a pressure loss of a passing fluid occurs is determined by an upstream flow rate of the heat exchanger. A main valve for adjustment on either the side or the downstream side, a pressure regulating chamber partitioned from the fluid pipe near the main valve by a movable pressure receiving member connected to the main valve, and A leak path for communicating one of the upstream and downstream fluid pipes with the pressure regulating chamber with a small cross-sectional area; and a leak path for the other of the upstream and downstream fluid pipes from the heat exchanger. A pilot operation flow control valve, comprising: a constant differential pressure control valve for controlling a differential pressure between a fluid pressure in a pipeline and a fluid pressure in the pressure regulation chamber to an arbitrary constant pressure. 2. The pilot operated flow control valve according to claim 1, wherein said constant differential pressure control valve controls said differential pressure to an arbitrary constant pressure by electromagnetic force. 3. The pressure regulating chamber according to claim 1, wherein the constant differential pressure control valve is provided between the pressure regulating chamber and a fluid line upstream or downstream of the heat exchanger, where the main valve is not provided. 3. The pilot-actuated flow control valve according to claim 1, wherein the valve is connected in series, and the leak path is formed in the movable pressure receiving member. 4. The pressure regulating chamber communicates with the fluid line upstream and downstream of the heat exchanger, which is not provided with the main valve, via the leak passage. 3. The pilot operation flow control valve according to claim 1, wherein the constant differential pressure control valve is connected between the fluid line near the main valve and the pressure regulating chamber. 5. A second pilot-operated flow control valve having a flow path in which a pressure loss equivalent to that of the heat exchanger is generated in place of the heat exchanger, is connected in parallel with the pilot-operated flow control valve. 4. The pilot operated flow control valve according to claim 1, wherein the pilot operated flow control valve is provided.