JP2004293695A - Flow control valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a large flow of tens to hundreds of liters per minute in a flow control valve for which voltage given to a solenoid and moving quantity of a valve element are continuously and linearly proportional. <P>SOLUTION: In a flow passage 4 in a body 1, a main valve 8 is provided to be energized in a closing direction. A branch passage 12a communicated with the inlet side of the flow passage is communicated with a pilot valve 25. For the valve 25, voltage and lift are proportional based on balance between electromagnetic force by the solenoid 33 and force of a plate spring 20. Fluid coming from the valve 25 is added to a diaphragm 45. The diaphragm is connected to the main valve by a connection means 46. As voltage is given to the solenoid, the valve 25 is opened by the lift proportional to the voltage. The fluid adds pressure to the diaphragm to move the main body in an opening direction against the spring by proportional force to pressure receiving area. Proportional flow control of large flow with a wide adjustable range can thus be realized by constant pressure. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a liquid flow control valve using a solenoid, and in particular, a voltage applied to the solenoid and a flow rate of the fluid are linearly proportional, and for example, a flow rate of several hundred liters per minute can be controlled, such as in a gas turbine. The present invention relates to a flow control valve applicable to a relatively large engine.
[0002]
[Prior art]
In the flow control of liquid fuel for the purpose of temperature control in a boiler or the like, a method has been adopted in which, for example, an operator manually operates a needle valve while watching the temperature of the boiler. As shown in FIG. 6, a plurality of valves V, which can be opened and closed by a pulse signal, are connected in parallel in the middle of the fuel pipe, and the opening and closing of each valve V are combined by an electric operation to thereby control the flow rate of the fuel. A multi-stage switching valve system for adjusting the pressure was also used.
[0003]
According to such a conventional method, there is a problem that the adjustment range of the flow rate is generally narrow, and the pressure of the fluid changes with the change of the flow rate. In particular, the multi-stage switching valve system has been configured to automatically control the flow rate of the fuel according to the temperature of the boiler because the electric switching operation can be performed, but each valve V is controlled to be on / off. The adjustment of the flow rate had to be stepwise, and fine control could not be performed. There is also a problem that a trouble is likely to occur in the opening / closing portion of each valve V.
[0004]
Therefore, the present applicant has proposed a flow control valve and a flow control method as disclosed in Patent Document 1 and Patent Document 2 in order to solve the above problems.
[0005]
[Patent Document 1]
Japanese Patent Publication No. Hei 7-26702
[Patent Document 2]
Japanese Patent Publication No. 7-26703
[0006]
The flow control valve disclosed by the present applicant in Patent Document 1 and Patent Document 2 is a flow control valve using a solenoid, and is constituted by an operating force of a solenoid for moving a valve element and a moving resistance plate attached to the valve element. By precisely balancing the resistance, the voltage applied to the solenoid and the amount of movement of the valve are continuously and linearly proportional, and the pressure is almost constant over a wide adjustment range, and the flow rate of the liquid can be proportionally controlled. Things.
[0007]
[Problems to be solved by the invention]
However, according to this flow control valve, the flow rate of the fluid that can be controlled is at most several liters per minute to about ten and several liters per minute, and it is not possible to proportionally control a larger flow rate than this. That is, this flow control valve is proportional to the voltage in a range where the opening degree of the valve is relatively small by applying each urging force of the solenoid and the resistance plate directly to the valve body for the fluid having a relatively small flow rate described above. It has been adjusted as follows. For this reason, when the size of the valve is increased, the displacement of the heavy valve must be controlled in a relatively wide range, and the voltage and flow rate are controlled by using a large solenoid and a large moving resistance plate. It was extremely difficult to adjust the ratio so as to be proportional.
[0008]
However, in the field of flow control, there has been a strong demand to perform continuous fine-grained control of the voltage and flow using a solenoid even in the large flow range described above.
[0009]
Therefore, an object of the present invention is to provide a flow control valve capable of proportionally controlling the flow rate of a liquid by continuously and linearly proportionalizing the voltage applied to a solenoid and the amount of movement of a valve body. An object of the present invention is to provide a flow control valve which can perform proportional control even at a large flow rate of about ten to several hundred liters.
[0010]
Further, another object of the present invention is to adjust the release valve in advance in the flow rate control valve, so that the flow rate of the fluid supplied through the pilot valve and the opening degree of the flow path by the main valve are adjusted. In order to reliably set the continuous and linear proportional relationship between the voltage applied to the solenoid and the amount of movement of the main valve in accordance with the flow rate and pressure of the fluid to be controlled.
[0011]
Another object of the present invention is to provide a flow control valve, comprising: amplifying a pressure of a fluid introduced from the inlet side of the flow path and transmitting the amplified pressure to a main valve to thereby increase a voltage and a valve applied to a solenoid. An object of the present invention is to surely set a continuous and linear proportional relationship of the amount of body movement.
[0012]
[Means for Solving the Problems]
The flow control valve according to claim 1, wherein a flow path of the fluid having an inlet and an outlet, a main valve provided in the middle of the flow path to open and close the flow path, and a direction in which the flow path is closed. Urging means for urging the main valve, a branch provided in communication with the inlet side of the flow path with respect to the main valve, and a pilot valve provided in the branch and opening and closing the branch. A leaf spring for urging the pilot valve moving in the direction to open the branch path in the opposite direction, a solenoid for urging the pilot valve in a direction to open the branch path when energized, and the main valve. A main valve operation that is mounted and moves when the fluid supplied from the branch path acts to move the main valve in a direction in which the flow path is opened when the pilot valve opens the branch path; Means.
[0013]
According to such a configuration, when a voltage is applied to the solenoid, the leaf spring is deformed to open the pilot valve. The fluid passes through the branch from the inlet side of the flow path and applies pressure to the main valve operating means via the pilot valve. The main valve operating means transmits the force due to the pressure of the applied fluid to the main valve and moves the main valve in the opening direction against the biasing means, so that the fluid flows through the main valve to the outlet.
[0014]
Further, the flow control valve according to claim 2 has a main body in which an upper main body and a lower main body are combined with each other in the flow control valve according to claim 1, wherein the flow path, the main valve, The biasing means is provided on the lower body, the pilot valve, the leaf spring, and the solenoid are provided on the upper body, and the branch path is provided on the upper body and the lower body for communication. And the branch passage of the upper body communicates with a first liquid chamber provided on the lower surface of the upper body, and the outlet side of the flow path for the main valve of the lower body is The main valve operating means communicates with a second liquid chamber provided on the upper surface of the lower main body, and the main valve operating means is sandwiched between the upper main body and the lower main body combined with each other. A diaphragm separating the liquid chamber and the second liquid chamber; It is characterized by having a coupling means disposed in the flow path of the body for connecting the main valve and the diaphragm.
[0015]
According to such a configuration, it is possible to realize a compact configuration in which a complicated structure in which the main valve, the pilot valve, and the diaphragm that amplifies and transmits the pressure are integrated as a whole is integrated into the main body. In addition, since the pressure of the fluid that has passed through the pilot valve can be reliably transmitted to the main valve by the diaphragm, a continuous and linear proportional relationship between the voltage applied to the solenoid and the opening of the main valve can be reliably set.
[0016]
The flow control valve according to claim 3, wherein in the flow control valve, a voltage applied to the solenoid and a fluid supplied from the branch passage by moving the pilot valve by the solenoid applied with the voltage. The elasticity of the leaf spring is set so that the flow rate is proportional to the flow rate.
[0017]
According to such a configuration, when a voltage is applied to the solenoid to open the pilot valve, the leaf spring becomes a resistance in a range where the driving force by the solenoid rapidly increases and regulates the movement of the pilot valve. Open by proportional lift. As a result, proportional control of the entire flow control valve is suitably performed.
[0018]
The flow control valve according to claim 4 is the flow control valve according to claim 2, wherein an adjustable relief valve that releases a part of the fluid is provided between the pilot valve and the diaphragm, It is characterized in that the pilot valve moves so that the flow rate of the fluid supplied from the branch passage is proportional to the opening degree of the flow passage by the main valve.
[0019]
According to this configuration, by adjusting the relief valve in advance, the continuous and linear proportional relationship between the voltage applied to the solenoid and the opening of the main valve can be reliably determined in accordance with the flow rate and pressure of the fluid to be controlled. Can be set to
[0020]
A flow control valve according to a fifth aspect of the present invention is the flow control valve according to the second aspect, wherein a through-hole communicating with the flow path is formed on a lower surface of the lower body, and the through-hole is freely retractable. The adjusting member is provided, and the urging means is provided between the inner surface of the adjusting member and the main valve.
[0021]
According to this configuration, by adjusting the mounting position of the adjusting member with respect to the lower body, the urging force applied to the main valve by the urging means can be appropriately adjusted. The flow rate adjusting operation for setting a continuous and linear proportional relationship between the valve openings can be performed more precisely and efficiently.
[0022]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described with reference to FIGS.
The flow control valve of this embodiment shown in FIG. 1 has a cylindrical main body 1 composed of a lower main body 2 and an upper main body 3. A fluid flow path 4 is formed inside the lower main body 2, and the flow path 4 has an inlet 5 and an outlet 6 opened on a side peripheral surface. An annular valve seat 7 is formed coaxially with the central axis of the cylindrical lower body 2 in the middle of the flow path 4 which is the center position of the lower body 2. A main valve 8 is provided in the flow path 4 below the valve seat 7, and is configured such that the main valve 8 abuts from below to close the opening of the valve seat 7. A guide shaft 9 is provided on the lower surface side of the main valve 8. A through-hole 2a communicating with the flow path 4 is formed at the bottom of the lower body 2, and a substantially disc-shaped adjusting member 10 is attached to the through-hole 2a by a screw structure so as to be position-adjustable. I have. A guide hole 10a is formed in the center of the inner surface of the adjusting member 10, and the guide shaft 9 of the main valve 8 is inserted into the guide hole 10a. It is configured such that the opening of the valve seat 7 can be opened and closed by being guided movably in the inside. A spring 11 as an urging member is provided between the locking step 8a on the lower surface of the main valve 8 and the annular holding groove 10b formed on the upper surface of the adjusting member 10, and the spring 11 is provided. The main valve 8 is biased in a direction to close the path 4.
The position of the adjusting member 10 can be adjusted by the screw structure because the spring 11 adjusts the urging force applied to the main valve 8 to arbitrarily adjust the force when the main valve 8 is moved in the opening direction. That's why.
[0023]
In the flow path 4, a branch path 12 is provided on the inlet 5 side of the flow path 4 that is located before the main valve 8. The branch path 12 is a path that bypasses a part of the fluid that has entered from the inlet 5 of the flow path 4, is also formed continuously with the upper body 3, and is provided at the center of the upper body 3. Connected to valve.
[0024]
The branch path 12 has a portion that is open to the side peripheral surfaces of the lower main body 2 and the upper main body 3 for the convenience of machining and maintenance, but this portion is a screw 13 or the like as a closing member during normal use. Is sealed by. At the time of maintenance or the like, if the screw 13 is removed, the inside of the branch path 12 can be cleaned.
[0025]
A cylindrical pilot valve seat 14 is provided at a mounting portion 3 a provided at the center of the upper main body 3. The pilot valve seat 14 has a male screw portion that is screwed into and fixed to a female screw hole of the mounting portion 3a. A communication hole 14 a is formed inside the pilot valve seat 14, and the communication hole 14 a is opened on the side peripheral surface and connected to the first half of the branch passage 12. The communication hole 14a is opened at the center of the upper surface of the pilot valve seat 14 by an oil passage hole 14b, and communicates with the branch passage 12b in the latter half of the upper body 3 through the oil passage hole 14b. A packing is interposed between the side peripheral surface of the pilot valve seat 14 and the mounting portion 3a so that fluid does not leak from the communication hole 14a.
[0026]
By rotating the pilot valve seat 14, the axial position of the pilot valve seat 14 with respect to the upper body 3 can be adjusted by the screw mechanism. By this adjusting mechanism, fine adjustment can be performed so that a voltage applied to a solenoid described later and a flow rate at the pilot valve seat 14 are proportional.
[0027]
A concave step 3b communicating with the oil passage 14b of the pilot valve seat 14 and the branch passage 12b is formed in the upper end surface of the upper body 3 so as to open. A fixing nut 15 is screwed into the concave step 3b. The fixing nut 15 is a substantially annular fixing member, and presses and fixes a movement resistance plate 20, which will be described later, to the concave step portion 3b. An O-ring is interposed between the bottom surface of the concave step portion 3b and the fixing nut 15 to seal the inside of the concave step portion 3b of the upper main body 3 from the outside.
[0028]
The lower end of the opening of the pipe 21 is fixed to the center of the fixing nut 15. A fixed core 22 is fixed to an upper end of the pipe 21, and a screw portion 22 a is formed at an upper end of the fixed core 22 protruding upward outside the pipe 21.
[0029]
Inside the pipe 21, a cylindrical moving core 23 is provided so as to be vertically slidable. A fixed resistive plate 24 made of a non-magnetic material is provided on the upper end surface of the movable core 23 in the pipe 21 so that the movable core 23 in the pipe 21 is sharp and strong against the fixed core 22. To prevent magnetic adhesion. The thickness of the fixed resistance plate 24 may be determined in consideration of the influence of the magnetic field applied to the moving core 23 and the like. The fixed resistance plate 24 may be provided at the lower end of the fixed core 22 described later.
[0030]
At the lower end of the moving core 23, the above-described moving resistance plate 20 and a valve body 25 as a pilot valve for opening and closing the oil passage hole 14b of the pilot valve seat 14 are attached. As shown in FIG. 2, the moving resistance plate 20 has a large-diameter annular frame portion 26 and a small-diameter annular mounting portion 27 provided concentrically, and is formed by three curved radial arms 28. The two parts are connected to each other. The outer diameter of the annular frame 26 is set so that it can be stably engaged with the concave step 3b.
[0031]
The valve body 25 has a structure in which a mounting screw portion 30 is formed at an upper end of a base portion 29, and a projection 31 that opens and closes the oil passage hole 14 b of the pilot valve seat 14 is formed at a lower end of the base portion 29. The mounting screw portion 30 of the valve body 25 is screwed into the lower end of the moving core 23 with the annular mounting portion 27 of the moving resistance plate 20 being inserted, and the moving core 23, the moving resistance plate 20, and the valve body 25 is assembled integrally. When the movable core 23 is at the lowermost position and the projection 31 closes the oil passage hole 14b, the movable resistance plate 20 is in a state where the annular frame portion 26 is in contact with the pressing surface of the fixing nut 15 from below. Has become. At this time, the moving resistance plate 20 is not deformed. Therefore, when the moving core 23 is raised by the action of a coil described later to open the oil passage hole 14b, the moving resistance plate 20 is configured to bend in a convex shape upward.
That is, the movement resistance plate 20 functions as a leaf spring that urges the valve body 25 that moves in the direction in which the branch path 12a is opened in the opposite direction.
[0032]
Next, on the upper surfaces of the upper main body 3 and the fixing nut 15, a coil 32 is provided by extrapolating the pipe 21. The magnetic field generated by the coil 32 causes the moving core 23 in the pipe 21 to move. A solenoid 33 is configured as a driving unit. The coil 32 is covered by a cylindrical coil case 34 whose lower part is open. A mounting hole is provided at the center of the circular upper wall of the coil case 34. The screw portion 22a of the fixed core 22 is inserted through the mounting hole, and a nut 35 is screwed into the screw portion 22a, so that a pipe is formed. A coil case 34 is mounted on the side of the upper body 21 and the upper body 3.
[0033]
That is, when the coil 32 is energized, the pilot valve (valve element 25) is urged in the direction in which the branch passage 12a is opened, but at the same time, the movement resistance plate 20 closes the branch passage 12a. Receive bias. As a result, both forces are antagonized, and the voltage applied to the solenoid 33 is proportional to the flow rate of the fluid supplied from the branch passage 12a by the movement of the valve body 25 by the solenoid 33 to which the voltage is applied. The resistance of the moving resistance plate 20 is set so as to have a relationship.
[0034]
At the center of the lower end surface of the upper main body 3, the diameter of the upper main body 3 is larger than the branch passage 12 and the valve seat 7 of the main valve 8 (therefore, the cross-sectional area in the cross section perpendicular to the central axis of the cylindrical main body 3 is larger) The first liquid chamber 40 is formed to be open. The latter branch 12 of the upper body 3 is connected and connected to the first liquid chamber 40. On the upper surface of the lower body 2, a second liquid chamber 41 having the same inner diameter as the first liquid chamber 40 is formed. The second liquid chamber 41 communicates with the outlet 6 side of the flow path 4 of the lower main body 2 (that is, the flow path 4 downstream of the main valve 8). Further, a diaphragm 45 as a main valve operating means is sandwiched and fixed between the upper body 3 and the lower body 2 which are connected to isolate the first liquid chamber 40 and the second liquid chamber 41. The diaphragm 45 is a pressure transmitting member made of an elastic material having a substantially circular outer shape as a whole. The diaphragm 45 has a substantially corrugated cross section so as to be easily deformed and moved. The central portion of the diaphragm 45 and the main valve 8 are connected by a rod-shaped connecting means 46. Therefore, according to the diaphragm 45, when the pilot valve (valve element 25) opens the branch passage 12a, the fluid supplied from the branch passage 12a acts, and thus the first and second liquid chambers 40, 41 are actuated. The main valve 8 is deformed and moved by receiving a liquid pressure over a large area corresponding to a large cross-sectional area of the main valve 8, and the main valve 8 can be moved in a direction in which the flow path 4 is opened by operating the main valve 8 with an increased large force. .
[0035]
In the upper main body 3, a relief valve 47 (balance port) is provided between the valve body 25 and the diaphragm 45, which allows a part of fluid to escape to an external system and is capable of adjusting a flow rate. In the present example, a hole communicating with the outside is formed in the latter half branch passage 12b downstream of the oil passage hole 14b of the pilot valve seat 14, and a relief valve 47 is provided in this hole. This position is advantageous in that it is easy to process and is not easily affected by howling that may occur in the diaphragm 45 during use. The relief valve 47 has a needle-shaped valve body, and the screw structure allows the valve body to move forward and backward to freely adjust the flow rate of the fluid discharged to the outside. By operating the relief valve 47, adjustment can be performed so that the flow rate of the fluid supplied to the diaphragm 45 of the first liquid chamber 40 and the opening degree of the flow path 4 by the main valve 8 are proportional. .
[0036]
Next, the operation of the flow control valve configured as described above will be described.
First, the relationship between the flow rate of the pilot valve and the voltage of the solenoid 33 is adjusted. This adjustment is performed only by the upper main body 3 before assembling the main body 1.
In a state where no voltage is applied to the coil 32, the origin position of the valve body 25 at which the flow rate becomes the minimum (for example, 0) is detected. At this time, the projection 31 of the valve body 25 closes the oil passage hole 14b with the weight of the valve body 25 and the moving core 23, and the movement resistance plate 20 is not deformed. When the test air at a predetermined pressure is supplied from the first half branch 12a of the upper body 3, the air enters the second half branch 12b from the gap with the projection 31 through the oil passage hole 14b of the pilot valve stem 14, and It goes out of the liquid chamber 40. Here, as the pilot valve seat 14 is gradually turned, the pilot valve seat 14 rises in the upper main body 3 and gradually lifts the valve body 25 and the moving core 23. Then, when the annular frame portion 26 of the moving resistance plate 20 abuts against the fixed nut 15 from below, resistance of the lifting of the valve body 25 by the moving resistance plate 20 is generated, and the projection 31 is surely provided with a predetermined force. Since the oil passage hole 14b is closed, air at a predetermined pressure does not come out.
[0037]
The pilot valve adjusted in this manner can perform control in which the flow rate and the voltage are linearly proportional by increasing or decreasing the voltage applied to the coil 32 when the fluid of the predetermined pressure is supplied. When raising the voltage applied to the coil 32 to raise the moving core 23 toward the fixed core 22, when the lift amount increases and the moving core 23 approaches the fixed core 22, the moving core 23 responds to the increase in the voltage. It is thought that the moving force increases rapidly. However, in the pilot valve of this embodiment, since the fixed resistance plate 24 made of a non-magnetic material is provided between the moving core 23 and the fixed core 22, most of the region where the force acting on the moving core 23 rapidly increases is the moving core 23. , The moving core 23 does not suddenly and strongly magnetize the fixed core 22 to be magnetized. In addition, the movement of the movable core 23 toward the fixed core 22 causes the movable resistance plate 20 to bend. However, the larger the amount of deflection, the harder the movable resistance plate 20 bends. That is, when the voltage is small and the lift of the moving core 23 is small, the moving resistance plate 20 bends relatively easily, but the voltage rises and the moving core 23 approaches the fixed resistance plate 24, and the force acting on the moving core 23 increases rapidly. When the movement resistance plate 20 begins to increase, the movement resistance plate 20 becomes hard to bend and restricts a sudden displacement of the movement core 23.
[0038]
Therefore, as shown in FIG. 3, the relationship between the voltage applied to the coil 32 and the lift of the movable core 23 becomes substantially linear, and the opening of the valve body 25 is detected from the load on the coil 32 and automatically controlled, The flow rate in the valve body 25 can be continuously and finely controlled. Therefore, the fluid pressure in the present flow control valve does not greatly change due to a sudden change in the flow rate, and a flow rate control with a wide adjustment range can be realized while the pressure is kept almost constant. Further, the valve element 25 is for changing the voltage applied to the coil 32 to slightly move the moving core 23 up and down to perform proportional control of the flow rate in the flow control valve. Must be reliably set to 0, and unnecessary bending of the moving resistance plate 20 at the origin position must be avoided. As described above, the adjustment of the origin position in the valve element 25 is extremely delicate. However, since the flow control valve of this embodiment uses the above-mentioned screw type pilot valve seat 14, the minimum flow rate can be easily and accurately adjusted. Can be detected.
According to the valve element 25 and the pilot valve seat 14, if the flow rate when the oil passage hole 14b is opened is 0.23 cc, the flow rate is 0.81 cc for the voltage applied to the coil 32 in the range of 0 to 24 V. It is directly proportional in the range of ４4 cc.
[0039]
The upper body 3 containing the valve element 25 and the pilot valve seat 14 adjusted as described above and the lower body 2 having the main valve 8 and the like as described above are assembled to obtain the flow control valve having the above-described configuration.
A fluid having a predetermined pressure is supplied to the inlet 5 of the flow control valve, and an appropriate voltage is applied to the coil 32 to perform control. From the outlet 6, a controlled and desired flow of fluid is obtained. That is, the fluid flowing from the inlet 5 is supplied to the pilot valve seat 14 through the branch passage 12a. The valve body 25 moves up and down in proportion to the voltage applied to the coil 32. Here, the valve body 25 is restricted from moving abruptly by the action of the moving resistance plate 20 which is a leaf spring having a special shape and the fixed resistance plate 24 which prevents rapid magnetic adhesion. The proportional flow rate is substantially linearly proportional to the load voltage of the valve 32, and the valve body 25 and the pilot valve seat 14 can realize proportional flow control with a constant pressure and a wide adjustment range.
[0040]
The fluid that has flowed out of the oil passage hole 14b reaches the liquid chamber 40 of the upper main body 3 via the latter half branch path 12b. Since the fluid in the liquid chamber 40 applies pressure to the diaphragm 45, a force corresponding to the area acts on the diaphragm 45. The diaphragm 45 bends downward in response to the force received from the fluid, and the main valve 8 connected to the diaphragm 45 by the connecting means 46 also moves downward in response to the force received by the diaphragm 45 from the fluid. As a result, the main valve 8 separates from the valve seat 7 by a size corresponding to the force received by the diaphragm 45 from the fluid, and opens the flow path 4.
[0041]
As described above, according to the flow control valve, a part of the fluid received from the inlet 5 is guided to the pilot valve whose voltage and the flow rate are proportional to each other through the branch path 12a, and the flow rate of the fluid supplied to the diaphragm 45 by the pilot valve. Is proportionally controlled, and the main valve 8 is operated by obtaining a large force by receiving the fluid pressure by the diaphragm 45 set to a predetermined pressure receiving area. As described above, according to the flow control valve of the present embodiment, although the flow rate of the pilot valve itself is small, the force caused by the pilot valve itself can be amplified by the diaphragm 45 and the movement amount of the main valve 8 can be increased. Proportional control could be realized.
[0042]
In practice, the relief valve 47 is operated in advance to adjust the flow rate of the fluid discharged to the outside so that the voltage applied to the coil 32 is proportional to the flow rate obtained at the outlet 6. When adjusting the relief valve 47, the elastic force of the spring 11, which biases the main valve 8 in the closing direction, may be adjusted by rotating the adjusting member 10. Even if the elastic force of the spring 11 varies, the error can be absorbed by adjustment by the adjusting member 10.
[0043]
FIG. 4 is a graph showing the relationship between the voltage applied to the coil 32 and the flow rate obtained by the flow control valve of the present example. Here, the fluid was air, the room temperature was 23 ° C., the flow rate when the main valve 8 was opened was 900 l / min, the pressure at the inlet 5 was 4 MPa, and the pressure at the outlet 6 was 3 MPa. As described above, the flow rate control almost in proportion to the voltage of the coil 32 in a wide range of 150 to 400 l / min was realized with the differential pressure at the entrance and exit of 1 MPa.
[0044]
Next, an example in which the flow control valve is used for controlling the flow rate of a fuel injection device in a boiler will be described. As shown in FIG. 5, the kerosene in the kerosene tank 100 is sent to the bypass nozzle 101 at a predetermined pressure by the electromagnetic pump P. Kerosene is sprayed at a predetermined pressure from the nozzle hole 101a into the combustion chamber and burned. Part of the kerosene that has not been sprayed by the bypass nozzle 101 flows through the flow control valve at the predetermined pressure and returns to the kerosene tank 100. Here, the temperature in the furnace of the boiler is constantly monitored by a sensor, and the deviation between the value and the target temperature is fed back to automatically adjust the coil voltage of the flow control valve, so that the flow rate of kerosene flowing in the system can be reduced. The pressure can be finely increased or decreased while the pressure is kept almost constant. That is, the proportional flow rate control with a wide adjustment range can be realized by the automatic control while the pressure is almost constant, and the temperature inside the furnace of the boiler can always be made to coincide with the set target value. Further, since the flow rate control valve has a flow rate as high as several hundred liters per minute, it can be applied to a large-sized boiler without difficulty, and can also be used for a natural gas turbine of a power generation apparatus of several hundred kilowatt scale.
[0045]
The present invention is not limited to the above-described embodiment, and can be widely used in general for proportional flow rate control of a large flow rate fluid in addition to a dryer having a combustion device, a temperature control facility, and the like.
[0046]
【The invention's effect】
According to the first aspect of the invention, the main valve operating means (diaphragm) amplifies the fluid force from the pilot valve, in which the voltage is proportional to the valve lift, to operate the main valve. It is possible to realize proportional flow rate control of a large flow rate with a constant pressure and a wide adjustment range.
[0047]
According to the flow control valve according to the second aspect, a complicated structure in which the main valve, the pilot valve, and the diaphragm for amplifying and transmitting the pressure are integrated as a whole is integrated into the main body 1. However, a compact configuration can be realized. Also, since the pressure of the fluid that has passed through the pilot valve can be amplified by the diaphragm and reliably transmitted to the main valve, the continuous and linear proportional relationship between the voltage applied to the solenoid and the opening of the main valve can be ensured. Can be set.
[0048]
According to the flow control valve described above, when a voltage is applied to the solenoid to open the pilot valve, the leaf spring acts as a resistor in a range where the driving force by the solenoid rapidly increases, thereby restricting the movement of the pilot valve. Therefore, the pilot valve opens by a lift amount proportional to the voltage. As a result, proportional control of the entire flow control valve is suitably performed.
[0049]
According to the flow control valve according to the fourth aspect, in the flow control valve according to the second aspect, by adjusting the relief valve in advance, a continuous and linear relationship between the voltage applied to the solenoid and the opening of the main valve is obtained. The proportional relationship can be reliably set according to the flow rate and pressure of the fluid to be controlled.
[0050]
According to the flow control valve described in claim 5, in the flow control valve according to claim 2, by adjusting the mounting position of the adjusting member with respect to the lower body, the urging means is provided to the main valve. Since the power can be appropriately adjusted, the flow rate adjusting operation for setting a continuous and linear proportional relationship between the voltage applied to the solenoid and the opening of the main valve can be performed more precisely and efficiently.
[0051]
[Brief description of the drawings]
FIG. 1 is a cross-sectional view illustrating an example of an embodiment of the present invention.
FIG. 2 is a plan view of a moving resistance plate according to an example of an embodiment of the present invention.
FIG. 3 is a diagram showing a relationship between a coil voltage and a pilot valve lift amount in an example of an embodiment of the present invention.
FIG. 4 is a diagram illustrating a relationship between a coil voltage and a flow rate according to an example of an embodiment of the present invention.
FIG. 5 is a configuration diagram of a fuel injection device using a flow control valve as an example of an embodiment of the present invention.
FIG. 6 is a configuration diagram of a conventional fuel injection device using a multi-stage switching method.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Body, 2 ... Lower body, 2a ... Through-hole, 3 ... Upper body, 4 ... Flow path,
5 inlet, 6 outlet, 8 main valve, 10 adjusting member,
11 ... springs as biasing means, 12, 12a, 12b ... branch paths,
20: moving resistance plate as a leaf spring; 25: valve body as a pilot valve;
33: solenoid, 40: first liquid chamber, 41: second liquid chamber
45: diaphragm as main valve operating means; 46: connecting means; 47: relief valve.

Claims (5)

A fluid flow path having an inlet and an outlet,
A main valve provided in the middle of the flow path to open and close the flow path,
Urging means for urging the main valve in a direction to close the flow path,
A branch path provided in communication with the inlet side of the flow path with respect to the main valve,
A pilot valve provided in the branch path to open and close the branch path;
A leaf spring for urging the pilot valve moving in a direction to open the branch path in an opposite direction,
A solenoid for energizing the pilot valve in a direction in which the branch path is opened when energized;
Attached to the main valve, when the pilot valve opens the branch passage, the fluid supplied from the branch passage acts to move and move the main valve in a direction in which the flow passage is opened. Main valve operating means for causing
Having a flow control valve. Having a main body in which the upper main body and the lower main body are combined,
The flow path, the main valve, and the urging means are provided in the lower body,
The pilot valve, the leaf spring, and the solenoid are provided on the upper body,
The branch path is provided and communicated with the upper body and the lower body,
The branch path of the upper body communicates with a first liquid chamber provided to be opened on the lower surface of the upper body,
The outlet side of the flow path with respect to the main valve of the lower body communicates with a second liquid chamber provided on the upper surface of the lower body.
A diaphragm interposed between the coupled upper body and the lower body to isolate the first liquid chamber and the second liquid chamber; and a diaphragm in the flow path of the lower body. 2. The flow control valve according to claim 1, further comprising a connecting means arranged to connect the diaphragm and the main valve. The elasticity of the leaf spring is set so that the voltage applied to the solenoid and the flow rate of the fluid supplied from the branch passage by the pilot valve moved by the solenoid to which the voltage is applied are in a proportional relationship. The flow control valve according to claim 1 or 2, wherein In the upper body, by providing an adjustable relief valve for releasing a part of the fluid between the pilot valve and the diaphragm, the pilot valve moves and is supplied from the branch passage to the diaphragm. 3. The flow control valve according to claim 2, wherein the flow rate of the fluid and the degree of opening of the flow path by the main valve are proportional. A through-hole communicating with the flow path is formed on the lower surface of the lower main body, and an adjusting member that is capable of moving forward and backward is provided in the through-hole, and between the inner surface of the adjusting member and the main valve. The flow control valve according to claim 2, wherein the urging means is provided.

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