JP4049909B2 - Pilot operated flow adjustment valve - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pilot-actuated flow rate adjusting valve that adjusts the flow rate of a fluid while keeping the differential pressure across the valve constant.
[0002]
[Prior art]
In general, the flow rate adjusting valve is configured such that the flow rate is controlled in accordance with the set differential pressure by adjusting the differential pressure across the valve with an electromagnetic solenoid.
[0003]
However, if the differential pressure is very large, for example, 50 to 100 atmospheres, a huge solenoid is required compared to the cross-sectional area of the flow path, which is impractical. Used.
[0004]
Such a pilot-operated flow rate adjusting valve is different from a simple pilot-operated on-off valve in that a valve for opening and closing the pilot passage needs to be a constant differential pressure valve. Therefore, conventionally, the pilot passage formed between the downstream flow path of the main valve and the pressure regulation chamber is opened and closed from the downstream side by a constant pressure valve energized by a solenoid, and the upstream flow path and the pressure regulation chamber are regulated. The room communicated with a narrow leak path.
[0005]
[Problems to be solved by the invention]
However, with the above-described configuration, when the pilot passage is closed when the valve is closed, the pressure regulating chamber communicating with the upstream side through the narrow leak passage becomes high pressure. Then, as described above, when the differential pressure from the downstream side is very large, the fluid flows from the pressure regulating chamber to the downstream side through the pilot passage and its surroundings, and there is a disadvantage that a flow rate of a certain level is always generated. is there.
[0006]
Therefore, an object of the present invention is to provide a pilot-actuated flow rate adjusting valve that can reliably stop the flow of fluid downstream even when the pilot passage is closed even when the upstream fluid pressure is high.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the pilot operated flow rate adjusting valve of the present invention is arranged so as to be in a closed state by contacting a valve seat formed in a flow path through which a high-pressure fluid is sent from the upstream side. The main valve, the pressure regulating chamber formed by branching from the flow path on the downstream side of the valve seat, the pressure in the flow path on the downstream side of the valve seat, and the pressure in the pressure regulating chamber on both sides The pressure receiving member connected to the main valve by a connecting member so as to move integrally with the main valve, and a small cross-sectional area between the flow path on the downstream side of the valve seat and the pressure regulating chamber. A leak passage for leaking, a pilot passage communicating between the flow path upstream of the valve seat and the pressure regulating chamber, and opens when the differential pressure between the inlet and outlet of the pilot passage exceeds a certain level. Providing a pilot passage constant differential pressure valve that maintains a constant pressure difference between the inlet and outlet And features.
[0008]
The pilot passage constant differential pressure valve may be an electromagnetically operated valve, and the differential pressure value may be controlled by an energization current to the electromagnetic coil. An on-off valve that opens and closes the pilot passage may be the pilot passage constant pressure valve. It may be connected and arranged in series with the differential pressure valve.
[0009]
Further, the pilot passage may be formed from the connecting member to the pressure receiving member, and the pilot passage constant differential pressure valve may be disposed in that portion.
[0010]
In that case, the pilot passage constant differential pressure valve is an electromagnetically operated valve that urges the pilot valve body by a movable iron core driven by an electromagnetic coil, and the movable iron core disposed in the pilot passage is disposed outside. Alternatively, it may be driven by an electromagnetic coil.
[0011]
And the said movable iron core urges | biases the said pilot valve body toward the upstream of the said pilot channel | path, and the on-off valve for opening and closing the said pilot channel | path is connected with the downstream end part of the said movable iron core. Also good.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings.
The pilot operating flow rate adjusting valve of the present invention is supplied with a high-pressure fluid such as an expansion valve of a refrigeration cycle using carbon dioxide gas as a refrigerant, a direct injection fuel control valve of an internal combustion engine, or a high water pressure flow control valve. Used for valves that need to be operated under large differential pressures.
[0013]
FIG. 1 shows a pilot operating flow rate adjusting valve according to a first embodiment of the present invention. For example, a valve seat 1 is annularly formed in the middle of a pipe line to which a high-pressure fluid of 50 to 100 atm is sent. Is formed.
[0014]
The pipe line 2 on the upstream side of the valve seat 1 and the pipe line 3 on the downstream side are bent at a right angle, and the valve seat 1 is formed in the pipe line 2 on the upstream side.
The main valve 4 is formed in a cylindrical shape whose end face on the upstream side is closed, and is fitted and placed in the valve seat 1 so as to be movable back and forth in the axial direction. A slit 5 for adjusting the flow rate is formed on the side wall surface of the main valve 4. Is formed.
[0015]
A stop valve portion 6 is formed in a flange shape at the upstream end of the main valve 4 so that when the stop valve portion 6 is pressed against the valve seat 1, the main valve 4 is fully closed. It has become.
[0016]
A cylindrical pressure regulating chamber 8 having a diameter larger than the diameter of the valve seat 1 is formed by branching from the downstream line 3 at the extended line position of the axis of the upstream line 2. A piston disk-shaped pressure receiving member 9 is fitted and inserted in the axial direction so as to be movable back and forth. Reference numeral 17 denotes an outer partition wall of the pressure regulating chamber 8, which is formed in a lid shape in this embodiment.
[0017]
The pressure receiving member 9 is integrally connected to the main valve 4 by a connecting rod 10 arranged at a position connecting the axis of the upstream pipe line 2 and the axis of the pressure regulating chamber 8 in a straight line. Therefore, the main valve 4 and the pressure receiving member 9 move together. Reference numerals 12 and 13 denote compression coil springs that are biased from both sides so that they do not rattle.
[0018]
The main valve 4 receives the pressure in the upstream pipe line 2 on one surface and receives the pressure in the downstream pipe line 3 from the opposite side. Further, the pressure receiving member 9 receives the pressure in the pressure regulating chamber 8 on one surface, and receives the pressure in the downstream pipe 3 on the opposite surface.
[0019]
The pressure receiving area of the pressure receiving member 9 (= the cross-sectional area of the pressure regulating chamber 8) is formed wider (for example, about 2 to 10 times wider) than the pressure receiving area of the main valve 4 (= the cross-sectional area of the valve seat 1). Therefore, the state of the main valve 4 is controlled through the pressure receiving member 9 and the connecting rod 10 by controlling the pressure in the pressure regulating chamber 8.
[0020]
There is provided a pilot passage 15 that does not pass through the valve seat 1 and the downstream pipe 3 but leads from the upstream pipe 2 to the pressure regulating chamber 8. The pilot passage constant differential pressure valve 20 and the stop valve 30 are connected to the pilot passage. In the middle of 15, they are connected in series.
[0021]
15A is a portion of the pilot passage 15 upstream of the constant differential pressure valve seat 21, 15B is a portion between the constant differential pressure valve seat 21 and the pilot open / close valve seat 31, and 15C is downstream of the pilot open / close valve seat 31. The side part. Further, the inside of the pressure regulating chamber 8 and the downstream pipe line 3 communicate with each other through a leak path 16 having a narrow cross-sectional area. However, the leak path 16 may be formed in the pressure receiving member 9.
[0022]
The stop valve 30 is an electromagnetic on-off valve that simply opens and closes a pilot on-off valve seat 31 formed in the middle of the pilot passage 15 with a pilot on-off valve body 32. When the electromagnetic coil 34 is not energized, the pilot on-off valve 30 Since the movable iron core 33 connected to the body 32 is not attracted to the fixed iron core 35, the valve is closed. A compression coil spring 36 is disposed between the movable iron core 33 and the fixed iron core 35. Hereinafter, description will be made on the assumption that the stop valve 30 is in an open state.
[0023]
The pilot passage constant differential pressure valve 20 is a movable iron core in which a conical pilot valve body 22 disposed facing a pilot valve seat 21 formed on the inner surface of the pilot passage 15 from the downstream side is driven by an electromagnetic coil 24. 23 is an electromagnetically driven constant differential pressure valve having a structure connected to the motor 23. The movable iron core 23 is attracted to the fixed iron core 25 by the magnetic field generated from the electromagnetic coil 24 and biases the pilot valve body 22 in the closing direction.
[0024]
As a result, when the value of the energization current to the electromagnetic coil 24 is constant, the differential pressure between the upstream side and the downstream side of the pilot valve seat 21 (that is, the differential pressure between the inlet and the outlet of the pilot passage 15) becomes a certain level or more. When the pilot valve body 22 is opened and the differential pressure becomes smaller than a certain value, the pilot valve body 22 is closed, and the differential pressure between the inlet and the outlet of the pilot passage 15 is kept constant.
[0025]
Therefore, the differential pressure value between the inlet and the outlet of the pilot passage 15 that is kept constant can be controlled by selecting the value of the energization current to the electromagnetic coil 24. Pressure value is minimized.
[0026]
Since the pressure in the pressure regulating chamber 8 is the outlet pressure of the pilot passage 15, the pressure difference between the pressure in the upstream pipe 2 and the pressure in the pressure regulating chamber 8 is maintained constant by such a configuration. Thus, the opening of the main valve 4 is controlled, and the flow rate of the fluid flowing from the upstream pipe line 2 to the downstream pipe line 3 is controlled to be constant. Therefore, the flow rate of the fluid flowing from the upstream side pipe line 2 to the downstream side pipe line 3 can be arbitrarily controlled by changing the energization current value to the electromagnetic coil 24 of the pilot passage constant differential pressure valve 20.
[0027]
In such a pilot operation flow rate adjusting valve, if the stop valve 30 is turned off and closed, the pilot passage 15 is closed, so that the inside of the pressure regulating chamber 8 communicating with the downstream pipe 3 side through the leak passage 16 is formed. The pressure is the same as that in the downstream pipe 3.
[0028]
As a result, the stop valve portion 6 of the main valve 4 is pressed against the valve seat 1 by the differential pressure between the pressure and the pressure in the upstream pipe line 2, and the main valve 4 is fully closed. Since the pressure regulating chamber 8 has the same low pressure as that in the downstream pipeline 3, no matter how high the upstream pipeline 2 is, there is no leakage from the pressure regulating chamber 8 to the downstream pipeline 3 and the complete flow rate. A zero state can be obtained stably.
[0029]
FIG. 2 shows a pilot operating flow rate adjusting valve according to a second embodiment of the present invention, in which a pilot passage 15 is formed so as to extend from the connecting rod 10 to the pressure receiving member 9, and the pilot passage constant differential pressure valve is formed. 20 pilot valve seats 21, pilot valve body 22, movable iron core 23 and fixed iron core 25 are arranged therein. The electromagnetic coil 24 is arranged outside in a state of surrounding them.
[0030]
In the second embodiment, parts having the same functions as those in the first embodiment are given the same reference numerals. The new code is 19 only, and in order to reduce the pressure loss of the leak path 16 formed by the gap of the fitting portion between the outer wall partition wall 17 and the fixed iron core 25 formed in the closed end, the fixed iron core is reduced. These are three circumferential grooves formed on the outer peripheral surface of 25.
[0031]
Also in the second embodiment, the positional relationship among the valve seat 1, the upstream pipe line 2, and the downstream pipe line 3 is the same as that of the first embodiment. However, the main valve 4 is disposed so as to face the valve seat 1 from the front side on the upstream pipe line 2 side. The stop valve portion 6 is a rubber disc.
[0032]
The pressure regulating chamber 8 is formed by a space behind the cylindrical outer partition wall 17 whose tip is closed, and the cylindrical pressure receiving member 9 and the fixed iron core 25 are integrally connected therein. And are inserted and arranged so as to freely advance and retract in the axial direction.
[0033]
As a result, the pressure in the pressure regulating chamber 8 is received by the end face of the pressure receiving member 9, and the pressure in the downstream pipe 3 is received by the end face of the fixed iron core 25. Therefore, the fixed iron core 25 also serves as the pressure receiving member 9 (or the fixed iron core 25 constitutes a half of the pressure receiving member 9).
[0034]
Thus, the connecting rod 10 that connects the fixed iron core 25 that also serves as a half of the pressure receiving member 9 and the main valve 4 has a pipe shape, and the hole portion becomes a part (15A) of the pilot passage 15 and is downstream. The mouth of the side end is a pilot valve seat 21 of the pilot passage constant differential pressure valve 20.
[0035]
The pressure receiving area of the pressure receiving member 9 (and the fixed iron core 25) is wider than the cross-sectional area of the valve seat 1 (for example, about 2 to 10 times wider). The pilot valve body 22 of the pilot passage constant differential pressure valve 20 is disposed in a hole formed at the axial position of the fixed iron core 25, and is disposed in a space within the pressure receiving member 9 by energization of the electromagnetic coil 24. When the movable iron core 23 is sucked to the fixed iron core 25 side, the pilot valve body 22 is pressed against the pilot valve seat 21.
[0036]
The internal space of the pressure receiving member 9 and the fixed iron core 25 is a part (15B) of the pilot passage 15. The inner opening of the hole (15C) through which the pressure receiving member 9 and the pressure regulating chamber 8 are passed is a pilot opening / closing valve seat 31 of a stop valve, and a pilot opening / closing valve body 32 is provided at the end of the movable iron core 23 facing it. Is protruding.
[0037]
In the pilot operating flow rate adjusting valve of the second embodiment configured as described above, the differential pressure between the upstream side and the downstream side of the pilot valve seat 21 (i.e., when the energization current value to the electromagnetic coil 24 is constant) When the differential pressure between the inlet and the outlet of the pilot passage 15) exceeds a certain value, the pilot valve body 22 opens. When the differential pressure becomes smaller than the certain pressure, the pilot valve body 22 closes, and the differential pressure between the inlet and the outlet of the pilot passage 15 Kept constant.
[0038]
Since the pressure in the pressure regulating chamber 8 is the outlet pressure of the pilot passage 15, the pressure difference between the pressure in the upstream pipe 2 and the pressure in the pressure regulating chamber 8 is maintained constant by such a configuration. Thus, the opening degree of the main valve 4 is controlled, and the flow rate of the fluid flowing from the upstream pipe line 2 to the downstream pipe line 3 is controlled to be constant.
[0039]
Therefore, the flow rate of the fluid flowing from the upstream side pipe line 2 to the downstream side pipe line 3 can be arbitrarily controlled by changing the energization current value to the electromagnetic coil 24 of the pilot passage constant differential pressure valve 20.
[0040]
When the electromagnetic coil 24 is turned off, the movable iron core 23 is not attracted at all to the fixed iron core 25 side, so that it is disposed between the movable iron core 23 and the fixed iron core 25 as shown in FIG. The pilot open / close valve body 32 is pressed against the pilot open / close valve seat 31 by the compression coil spring 36 and the pilot passage 15 is closed.
[0041]
At this time, as in the case of the first embodiment, the pressure regulating chamber 8 has the same low pressure as that in the downstream pipe 3, so no matter how high the upstream pipe 2 is, the pressure regulating chamber 8 There is no leakage to the downstream pipe 3 and a completely zero flow rate can be stably obtained.
[0042]
【The invention's effect】
According to the present invention, the pressure receiving member provided between the pressure regulating chamber formed by branching from the downstream flow path of the valve seat and the downstream flow path is connected so as to move integrally with the main valve. Since the pilot passage that connects the flow path upstream of the valve seat and the pressure regulating chamber is opened and closed by the constant differential pressure valve, the flow rate of the valve seat portion can be controlled by controlling the constant differential pressure valve. Since the pressure adjustment chamber has the same low pressure as the downstream flow path, no matter how high the upstream flow path side is, there is no leakage from the pressure adjustment chamber to the downstream flow path, and when the pilot passage is closed, The flow of fluid to the side can be stopped reliably.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a pilot operated flow rate adjusting valve according to a first embodiment of the present invention.
FIG. 2 is a longitudinal sectional view of a pilot operated flow rate adjusting valve according to a second embodiment of the present invention.
FIG. 3 is a longitudinal sectional view showing a fully closed state of a pilot operated flow rate adjusting valve according to a second embodiment of the present invention.
[Explanation of symbols]
1 Valve seat 2 Upstream pipe (flow path)
3 Downstream pipe (flow path)
4 Main valve 8 Pressure regulating chamber 9 Pressure receiving member 10 Connecting rod 15 Pilot passage 16 Leak passage 20 Pilot passage constant differential pressure valve 21 Pilot valve seat 22 Pilot valve body 23 Movable iron core 25 Fixed iron core 31 Pilot on / off valve seat 32 Pilot on / off valve body

Claims (4)

A main valve arranged so as to be in contact with the valve seat formed in the flow path through which the high-pressure fluid is sent from the upstream side and closed;
A pressure regulating chamber formed by branching from the flow path on the downstream side of the valve seat;
A pressure receiving member connected by the connecting member to the main valve so as to receive the pressure in the flow path downstream of the valve seat and the pressure in the pressure regulating chamber on both the front and back surfaces and move integrally with the main valve; ,
A leak path that leaks between the flow path on the downstream side of the valve seat and the pressure regulation chamber with a thin cross-sectional area;
A pilot passage for communicating between the flow path upstream of the valve seat and the pressure regulating chamber;
A pilot passage constant differential pressure valve that opens when the differential pressure between the inlet and outlet of the pilot passage exceeds a certain level, and maintains a constant differential pressure between the inlet and outlet of the pilot passage;
A pilot-actuated flow control valve provided with
The pilot passage is formed from the connecting member to the pressure receiving member, and the pilot passage constant differential pressure valve is disposed in that portion.
The pilot passage constant differential pressure valve is an electromagnetically actuated valve that urges the pilot valve body by a movable iron core driven by an electromagnetic coil, and an electromagnetic coil in which the movable iron core arranged in the pilot passage is arranged outside It is driven by the pilot-actuated flow control valve. The pilot operating flow rate adjusting valve according to claim 1, wherein the pilot passage constant differential pressure valve is an electromagnetically operated valve, and a differential pressure value can be controlled by an energization current to the electromagnetic coil. The pilot operating flow rate adjusting valve according to claim 1 or 2, wherein an on-off valve for opening and closing the pilot passage is connected in series with the pilot passage constant differential pressure valve. The movable iron core urges the pilot valve body toward the upstream side of the pilot passage, and an open / close valve for opening and closing the pilot passage is connected to a downstream end portion of the movable iron core. The pilot operated flow rate adjusting valve according to 1, 2 or 3 .

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