Solenoid valve control device

Abstract

The current supplied to the electromagnetic coil when the valve is open is set to an appropriate value. [Solution] The second shut-off valve 22 comprises a valve body and an electromagnetic coil that opens the valve body by energizing it, and is installed in the fuel piping 40 of the internal combustion engine 10. The control device 100 controls the current supplied to the electromagnetic coil when the valve body is opened. The control device 100 performs a process that reduces the current supplied to the electromagnetic coil as the pressure of the fluid acting on the valve body in the opening direction increases.

Description

Technical Field

[0001] The present invention relates to a control device for a solenoid valve.

Background Art

[0002] For example, the fuel pipe of an internal combustion engine described in Patent Document 1 includes a valve that allows and blocks the flow of fuel.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When adopting the solenoid valve that opens the valve body by energizing the solenoid coil as the above valve, if the current supplied to the solenoid coil during valve opening is excessively large, the attractive force of the solenoid coil becomes excessively strong, and for example, there is a possibility of generating abnormal noise. Therefore, it is desirable to set the current supplied to the solenoid coil during valve opening to an appropriate magnitude.

Means for Solving the Problems

[0005] The control device for a solenoid valve that solves the above problems includes a valve body and a solenoid coil that opens the valve body by energization, and is a control device for a solenoid valve provided in a fluid flow path. This control device has a processing circuit that controls the current supplied to the solenoid coil when the valve body opens. The processing circuit executes a process of reducing the current supplied to the solenoid coil as the pressure of the fluid acting on the valve body in the valve opening direction is higher.

Effects of the Invention

[0006] This solenoid valve control device can set the current supplied to the electromagnetic coil to an appropriate level when the valve is open. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a schematic diagram showing an internal combustion engine, fuel supply system, and control device to which a solenoid valve control device in one embodiment is applied. [Figure 2] Figure 2 is a cross-sectional view showing the structure of the second shut-off valve in the same embodiment. [Figure 3] Figure 3 is a flowchart showing the procedure of processing performed by the control device of the same embodiment. [Modes for carrying out the invention]

[0008] Below, one embodiment of the control device for the solenoid valve will be described with reference to Figures 1 to 3. <Internal combustion engines, fuel supply systems, and control devices> The internal combustion engine 10 shown in Figure 1 is mounted on a vehicle and uses hydrogen gas, a fluid gaseous fuel, as its fuel. The vehicle is, for example, a hybrid vehicle equipped with the internal combustion engine 10 and an electric motor as prime movers. In such a hybrid vehicle, the internal combustion engine 10 is operated intermittently.

[0009] The intake passage 11 of the internal combustion engine 10 is provided with a throttle valve 12 for adjusting the amount of intake air. The fuel supply system 300 provided by the internal combustion engine 10 includes a fuel injection valve 15, a tank 20, fuel piping 40, a first shut-off valve 21, a second shut-off valve 22, a pressure reducing valve 30, and a delivery pipe 60.

[0010] The fuel injector 15 supplies fuel to the cylinder 10a of the internal combustion engine 10. The tank 20 stores hydrogen gas, a gaseous fuel, in a compressed state. The fuel piping 40 connects the tank 20 to the delivery pipe 60. The fuel injector 15 is connected to the delivery pipe 60. The fuel piping 40 and the delivery pipe 60 are fuel passages and fluid flow paths connecting the tank 20 and the fuel injector 15. The hydrogen gas stored in the tank 20 is supplied to the fuel injector 15 via the fuel piping 40 and the delivery pipe 60.

[0011] In the fuel piping 40, a first shut-off valve 21, a pressure reducing valve 30, and a second shut-off valve 22 are arranged in order in the direction of fuel flow. The first shut-off valve 21 is a solenoid valve and is located near the outlet of the tank 20. When the first shut-off valve 21 is open, fuel is supplied from the tank 20 to the fuel piping 40. When the first shut-off valve 21 is closed, the fuel supply from the tank 20 to the fuel piping 40 is stopped.

[0012] The pressure reducing valve 30 is a valve that reduces the fuel pressure, which is the fuel pressure of hydrogen gas stored in the tank 20 under high pressure, to a specified pressure (for example, about 4 MPa) and supplies it to the fuel injection valve 15.

[0013] The second shut-off valve 22 is a solenoid valve installed in the fuel supply system of the internal combustion engine 10, and is located near the delivery pipe 60 in the fuel piping 40. When the second shut-off valve 22 is open due to energization, fuel is supplied to the delivery pipe 60. When the second shut-off valve 22 is closed due to de-energization, the fuel supply to the delivery pipe 60 is stopped.

[0014] The first shut-off valve 21 and the second shut-off valve 22 are closed when the internal combustion engine 10 is stopped. On the other hand, the first shut-off valve 21 and the second shut-off valve 22 are basically open when the internal combustion engine 10 is running.

[0015] The first pressure sensor 81 provided in the fuel pipe 40 between the first shut-off valve 21 and the pressure reducing valve 30 detects the first pressure P1, which is the fuel pressure in the fuel pipe 40 between the first shut-off valve 21 and the pressure reducing valve 30.

[0016] The second pressure sensor 82 provided in the fuel pipe 40 between the pressure reducing valve 30 and the second shut-off valve 22 detects the second pressure P2, which is the fuel pressure in the fuel pipe 40 between the pressure reducing valve 30 and the second shut-off valve 22.

[0017] The third pressure sensor 83 provided in the delivery pipe 60 detects the third pressure P3, which is the fuel pressure of the delivery pipe 60. The temperature sensor 84 provided in the delivery pipe 60 detects the fuel temperature THF, which is the temperature of the fuel in the delivery pipe 60.

[0018] The control device 100 performs various controls such as fuel injection of the internal combustion engine 10 by controlling various controlled objects such as the throttle valve 12, the fuel injection valve 15, the first shut-off valve 21, and the second shut-off valve 22. The control device 100 includes a CPU 110 and a memory 120 composed of a ROM and a RAM, etc. The CPU 110 executes the program stored in the memory 120 to perform various controls. The CPU 110 and the memory 120 constitute a processing circuit.

[0019] The control device 100 refers to various values necessary for controlling the internal combustion engine 10. For example, the control device 100 refers to the detection values of the first pressure sensor 81, the second pressure sensor 82, the third pressure sensor 83, and the temperature sensor 84. Further, the control device 100 refers to the detection signal of the accelerator position sensor 71 that detects the accelerator operation amount ACCP, which is the operation amount of the accelerator pedal 27 operated by the driver of the vehicle equipped with the internal combustion engine 10. Further, the control device 100 refers to the detection signal of the speed sensor 72 that detects the vehicle speed SP of the vehicle equipped with the internal combustion engine 10. Further, the control device 100 refers to the detection signal of the air flow meter 73 that detects the intake air amount GA of the internal combustion engine 10 and the detection signal Scr of the crank angle sensor 74 that detects the rotation angle of the crankshaft of the internal combustion engine 10.

[0020] The control device 100 calculates the engine rotational speed NE based on the detection signal Scr of the crank angle sensor 74. Further, the control device 100 calculates the engine load factor KL based on the engine rotational speed NE and the intake air amount GA. The engine load factor KL represents the ratio of the current cylinder inflow air amount to the cylinder inflow air amount when the internal combustion engine 10 is in steady operation at the full load state at the current engine rotational speed NE. Note that the cylinder inflow air amount is the amount of air flowing into each cylinder in the intake stroke.

[0021] <Fuel pressure control> The control device 100 executes fuel pressure control for controlling the pressure of the fuel supplied to the fuel injection valve 15, that is, the third pressure P3 which is the fuel pressure in the fuel passage connected downstream of the second shut-off valve 22 in the fuel flow direction in the fuel passage. This fuel pressure control is a control that repeatedly performs opening and closing drive of the second shut-off valve 22 so that the fuel pressure in the fuel passage connected downstream of the second shut-off valve 22 becomes a pressure within the control range CR defined by the predetermined upper limit value PtU and the predetermined lower limit value PtL. The target pressure Pt of the fuel pressure in the fuel pressure control is a pressure lower than the second pressure P2 which is the fuel pressure after being decompressed by the decompression valve 30, and is preset. For example, the target pressure Pt is a pressure of about 1 Mpa. And the upper limit value of the allowable fuel pressure with respect to the target pressure Pt is set to the above upper limit value PtU. Also, the lower limit value of the allowable fuel pressure with respect to the target pressure Pt is set to the above lower limit value PtL.

[0022] Note that the fuel pressure control is executed, for example, when the operating state of the internal combustion engine 10 shifts to the idle operating state. When the injection amount of the fuel injection valve 15 decreases as in the idle operation or the like, by performing fuel pressure control for maintaining the third pressure P3 which is the fuel pressure in the delivery pipe 60 at a pressure lower than the second pressure P2, a small amount of fuel is accurately injected from the fuel injection valve 15.

[0023] On the other hand, when the internal combustion engine 10 transitions to a normal operating state with a higher engine load than the idle state, the fuel pressure control of the second shut-off valve 22 is stopped. As a result, the periodic opening and closing drive of the second shut-off valve 22 is stopped, and the second shut-off valve 22 is maintained in the open state. When the second shut-off valve 22 is maintained in the open state, the third pressure P3 becomes the same as the second pressure P2, which is the pressure during normal operation.

[0024] <Structure of the second shutoff valve> Figure 3 shows the structure of the second shut-off valve 22. In the following, the direction along the central axis L of the plunger 211 of the second shut-off valve 22 is referred to as the axial direction. The direction perpendicular to the axial direction is referred to as the radial direction.

[0025] The second shut-off valve 22 includes a housing 200, a stator 230, an electromagnetic coil 240, a first valve 210, a holder 250, a second valve 220, and the like. The housing 200 includes an inlet port 201 to which a fuel pipe 40 connected to a pressure reducing valve 30 is connected, and an outlet port 203 to which a fuel pipe 40 connected to a delivery pipe 60 is connected.

[0026] The inlet port 201 and the outlet port 203 are in communication via the first chamber 202, which is a space formed within the housing 200. The stator 230 is cylindrical and is located inside the housing 200.

[0027] The electromagnetic coil 240 is located on the outer circumference of the stator 230. The electromagnetic coil 240 opens the valve body when energized. The electromagnetic coil 240 is connected to a drive circuit 400 that supplies power. The drive circuit 400 adjusts the supply current Is, which is the current supplied to the electromagnetic coil 240 when the valve body of the second shut-off valve 22 is opened. The drive circuit 400 is connected to the control device 100. The control device 100 controls the supply current Is via the drive circuit 400. The greater the force biasing the valve body in the closing direction, the greater the value of the supply current Is required to open the valve body.

[0028] The drive circuit 400 detects the actual current Isr, which is the actual current value flowing through the electromagnetic coil 240, to the control device 100. It then outputs the detected value of the actual current Isr to the control device 100.

[0029] The first valve body, the first valve 210, includes a plunger 211 that moves axially within the stator 230, and a first sealing member 213 that opens and closes the first fuel passage 222 as the plunger 211 moves.

[0030] One end of the plunger 211 is a protruding portion 212 that extends from the stator 230. The tip of the protruding portion 212 is provided with the first sealing member 213. The protruding portion 212 is also equipped with a radially extending pin 214. Both ends of the pin 214 protrude from the outer circumferential surface of the protruding portion 212.

[0031] The holder 250 has a cylindrical portion 251 that is coaxial with the central axis L. The inner circumferential surface of the cylindrical portion 251 is spaced apart from the outer circumferential surface of the protrusion 212. The second valve body, the second valve 220, is slidably housed on the inner circumferential surface of the cylindrical portion 251. The second valve 220 has a hole 221 through which the outer circumferential surface of the projection 212 of the first valve 210 slides. The second valve 220 has an elongated hole 225 into which the pin 214 is inserted and which allows the pin 214 to move in the axial direction.

[0032] The tip of the second valve 220 has a first fuel passage 222 that extends in the axial direction. The first fuel passage 222 is connected to the outlet port 203 which constitutes the second fuel passage. The outlet port 203 is a fuel passage with a larger flow path cross-sectional area than the first fuel passage 222.

[0033] The tip of the second valve 220 is provided with a second sealing member 224 that opens and closes the outlet port 203. More specifically, the second sealing member 224 opens and closes a second valve seat 204 provided at one end of the outlet port 203.

[0034] A first valve seat 223 is formed at the tip of the second valve 220, in which the first fuel passage 222 is formed, and protrudes toward the protruding portion 212. The first fuel passage 222 is opened and closed by the opening and closing of the first valve seat 223 by the first sealing member 213. This first fuel passage 222 is a communication passage that connects the flow path upstream of the second valve 220, which is the second valve body, with the flow path downstream of the second valve 220. The flow path upstream of the second valve 220 is the pressure chamber 227, the communication passage 226, the first chamber 202, and the inlet port 201, which will be described later. The flow path downstream of the second valve 220 is the outlet port 203. The first valve 210 is a first valve body that opens prior to the opening of the second valve 220 and opens and closes the first fuel passage 222.

[0035] In the hole 221, the space enclosed by the wall surface around the first valve seat 223 and the tip surface of the projection 212 forms a pressure chamber 227 through which pressure acts to bias the second valve 220 in the closing direction. This pressure chamber 227 is connected to the first chamber 202 via a connecting passage 226.

[0036] A second chamber 255 is formed on the inner circumferential surface side of the cylindrical portion 251 of the holder 250, which is a space for securing the axial stroke amount of the second valve 220. The end face 228 of the second valve 220, which is opposite to the side on which the second sealing member 224 is disposed, and the restricting portion 253 of the holder 250, which is the surface facing the end face 228, come into contact with each other when the second valve 220 is fully open. By maintaining this contact between the end face 228 and the restricting portion 253, the position of the valve body is stabilized when the second valve 220 is fully open.

[0037] An end cap 280 is provided inside the stator 230, at the end opposite to the side into which the plunger 211 is inserted, to close that end. A third chamber 257, which is a space, is formed between the end cap 280 and the plunger 211. A spring 215 is also provided between the end cap 280 and the plunger 211 to bias the plunger 211 in a direction away from the end cap 280.

[0038] <Opening and closing operation of the second shut-off valve> When the electromagnetic coil 240 is energized, the plunger 211 is pulled into the stator 230, causing the first valve 210 to move in a direction that separates the first sealing member 213 from the first valve seat 223, thereby opening the first valve 210. When the first sealing member 213 separates from the first valve seat 223, the fuel that has flowed in from the inlet port 201 flows into the outlet port 203 via the first chamber 202, the communication passage 226, the pressure chamber 227, and the first fuel passage 222.

[0039] Then, as the first valve 210 moves in a direction that separates the first sealing member 213 from the first valve seat 223, the pin 214 of the first valve 210 strikes the wall surface 229 located in the axial direction of the elongated hole 225 of the second valve 220, in the direction of the opening of the first valve 210. As a result, an opening force Fop acts on the second valve 220 in the same direction as the movement of the first valve 210. This opening force Fop is an attractive force generated by the magnetic force of the electromagnetic coil 240 and acts in the direction that opens the second valve 220.

[0040] When the first valve 210 opens, the pressure chamber 227 and the outlet port 203 are connected, reducing the pressure difference between the pressure chamber 227 and the outlet port 203. As a result, the resistance force Fcl, which resists the opening of the second valve 220, decreases. The resistance force Fcl includes the force acting on the second valve 220 in the closing direction, as well as the sliding resistance of the second valve 220 and the holder 250. Furthermore, the force acting on the second valve 220 in the closing direction includes the differential pressure load generated by the pressure difference between the pressure chamber 227 and the outlet port 203, and the biasing force of the spring 215.

[0041] Then, when the valve opening force Fop becomes greater than the resistance force Fcl, the second valve 220 moves in a direction that separates the second sealing member 224 from the second valve seat 204, thereby opening the second valve 220. When the second sealing member 224 separates from the second valve seat 204, the fuel that has flowed in from the inlet port 201 flows mainly through the first chamber 202 to the outlet port 203.

[0042] When the second valve 220 is fully open, the end face 228 and the restricting portion 253 come into contact, stopping the axial movement of the second valve 220. The fuel that flows into the outlet port 203 is sent to the fuel injection valve 15 via the fuel piping 40 and the delivery pipe 60.

[0043] When the current to the electromagnetic coil 240 is cut off, the biasing force of the spring 215 causes the first valve 210 to move in a direction that causes the first sealing member 213 to strike the first valve seat 223. This causes the first valve 210 to close.

[0044] When the first sealing member 213 contacts the first valve seat 223, the biasing force of the spring 215 acts on the second valve 220. As a result, the second valve 220 moves in the direction in which the second sealing member 224 contacts the second valve seat 204. This causes the second valve 220 to close.

[0045] In this way, the second shut-off valve 22 opens the second valve 220, which opens and closes the outlet port 203, having a larger flow path cross-sectional area than the first fuel passage 222, using the pressure in the pressure chamber 227. That is, when the pressure difference between the pressure chamber 227 and the outlet port 203, which is the pressure difference between the upstream and downstream sides of the second valve 220, decreases to a predetermined value or less, the second valve 220 opens. Therefore, compared to the case where the magnetic force of the electromagnetic coil is directly used to open the second valve 220, the magnetic force required to open the valve can be reduced. Consequently, for example, the electromagnetic coil 240 can be miniaturized.

[0046] Furthermore, the second shut-off valve 22 uses the first valve 210 to perform small-flow fuel adjustment. The fuel pressure control described above is performed by opening and closing the first valve 210. In addition, under operating conditions with a higher engine load than idle operation, the second valve 220 is kept open.

[0047] <Control of the supply current of the electromagnetic coil> The second shut-off valve 22 is closed when the vehicle driver stops the engine or when the engine stops due to intermittent operation. If there is no fuel leakage from the fuel injector 15, the fuel pressure in the delivery pipe 60 does not change after the engine stops, so the third pressure P3 remains at approximately the same value as the second pressure P2. On the other hand, if there is fuel leakage from the fuel injector 15, the fuel pressure in the delivery pipe 60 decreases after the engine stops, so the third pressure P3 becomes lower than the second pressure P2. Therefore, the third pressure P3 when the first valve 210 is opened during engine startup will be a different value depending on the degree of fuel leakage from the fuel injector 15.

[0048] Furthermore, when the internal combustion engine 10 transitions from idle operation to normal operation, the first valve 210 is kept open, thereby discontinuing the fuel pressure control described above. During fuel pressure control, the third pressure P3 is controlled to be within the control range CR. Therefore, when the first valve 210, which was closed during fuel pressure control, is opened due to the discontinuation of fuel pressure control, the third pressure P3 will be a different value within the control range CR.

[0049] Here, the fuel pressure from the delivery pipe 60 side acts on the downstream surface of the closed first valve 210 via the first fuel passage 222. This fuel pressure is the fluid pressure acting on the first valve 210 in the opening direction, and in this embodiment, it is the third pressure P3. When opening the closed first valve 210, the higher the third pressure P3, the greater the force biasing the first valve 210 in the opening direction. Therefore, the higher the third pressure P3, the smaller the supply current Is of the electromagnetic coil 240 required to open the first valve 210 can be.

[0050] Therefore, the control device 100 sets the supply current Is when opening the first valve 210 as follows. Figure 3 shows the procedure performed by the control device 100 to set the supply current Is. The procedure shown in Figure 3 is carried out by the CPU 110 executing a program stored in the memory 120 of the control device 100.

[0051] The process shown in Figure 3 is initiated when there is a request to open the second valve 220. This request is made, for example, during engine startup. Engine startup includes both actions by the vehicle driver and intermittent operation. The request to open the second valve 220 is also made when the fuel pressure control described above is discontinued. In the following, step numbers are represented by numbers preceded by "S".

[0052] When this process is started, the control device 100 acquires the third pressure P3 (S100). Next, the control device 100 sets the supply current Is based on the third pressure P3 (S110). In S110, the control device 100 sets the supply current Is such that the supply current Is decreases as the acquired third pressure P3 increases. This setting of the supply current Is is performed based on a setting map, for example, stored in memory 120, which shows the correspondence between the third pressure P3 and the supply current Is. Once the supply current Is is set, the control device 100 controls the drive circuit 400 so that the set supply current Is is supplied to the electromagnetic coil 240. This process in S110 is a process that reduces the current supplied to the electromagnetic coil as the pressure of the fluid acting on the valve body in the opening direction increases.

[0053] Then, after executing the process in S110, the control device 100 terminates this process. <Operation and Effects of This Embodiment> (1) The higher the third pressure P3, which is the fuel pressure acting on the first valve 210 in the opening direction, the smaller the supply current Is of the electromagnetic coil 240. Therefore, the current supplied to the electromagnetic coil 240 when the first valve 210 is open can be set to an appropriate size.

[0054] (2) If the attractive force of the electromagnetic coil 240 is excessively large, the collision speed when the pin 214 and the wall surface 229 come into contact when the first valve 210 opens will be faster. As a result, the opening noise generated by the contact between the pin 214 and the wall surface 229 may become louder. In this embodiment, however, since the supply current Is of the electromagnetic coil 240 is set to an appropriate size, the attractive force of the electromagnetic coil 240 is suppressed from becoming excessively large. Therefore, the opening noise generated by the contact between the pin 214 and the wall surface 229 can be reduced.

[0055] (3) In this embodiment, the attractive force of the electromagnetic coil 240 is suppressed from becoming excessively large. Therefore, the collision load when the pin 214 and the wall surface 229 come into contact when the first valve 210 is in the open state is reduced. As a result, wear of the pin 214 and the wall surface 229 due to contact can be suppressed.

[0056] (4) If the attractive force of the electromagnetic coil 240 is excessively large, the collision speed when the end face 228 and the restricting portion 253 come into contact when the second valve 220 is fully open will be high. As a result, the valve opening noise generated by the contact between the end face 228 and the restricting portion 253 may become louder. In this embodiment, however, since the supply current Is of the electromagnetic coil 240 is set to an appropriate size, the attractive force of the electromagnetic coil 240 is suppressed to be excessively large. Therefore, the valve opening noise generated by the contact between the end face 228 and the restricting portion 253 can be reduced.

[0057] (5) In this embodiment, the attractive force of the electromagnetic coil 240 is suppressed from becoming excessively large. Therefore, the collision load when the end face 228 and the restricting portion 253 come into contact when the second valve 220 is fully open is reduced. As a result, wear of the end face 228 and the restricting portion 253 due to contact can be suppressed.

[0058] (6) The higher the third pressure P3, the smaller the supply current Is to the electromagnetic coil 240, and thus the heat generated in the electromagnetic coil 240 due to energization can be suppressed. (7) The heat generated by the electromagnetic coil 240 due to the energization is suppressed, thereby extending the lifespan of the electromagnetic coil 240.

[0059] <Example of changes> The above embodiment can be implemented with the following modifications. The above embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0060] The second shut-off valve 22 does not necessarily have to be equipped with the first valve 210. In this case, the second valve 220 may be directly opened and closed by the electromagnetic coil 240. Even in this modified example, the fuel pressure from the delivery pipe 60 side acts on the downstream side of the closed second valve 220 via the first fuel passage 222. This fuel pressure is the pressure of the fluid acting on the second valve 220 in the opening direction, and is the third pressure P3 described above. Therefore, by making the same settings as the supply current Is described above, the same effects as in the above embodiment can be obtained.

[0061] The second shut-off valve 22 was a solenoid valve applied to the fuel pressure control described above, but it does not have to be applied to such fuel pressure control. For example, the second shut-off valve 22 may be controlled to be held in an open state during engine operation and in a closed state when the engine is stopped.

[0062] • The setting of the supply current Is based on the third pressure P3 is done based on a map. In addition, the attractive force of the electromagnetic coil 240 required to open the first valve 210 is calculated based on the third pressure P3. The supply current Is that yields the calculated attractive force may then be determined from a predetermined map.

[0063] The supply current Is of the electromagnetic coil 240 is reduced according to the third pressure P3, thus reducing the power consumption of the electromagnetic coil 240. Therefore, when the vehicle is equipped with the internal combustion engine 10 and an electric motor as its power source, the following effects can be obtained: The power consumption of the battery that drives the electric motor is reduced, thus extending the driving range in electric motor-driven driving mode. In addition, the operation of the internal combustion engine to charge the battery can be reduced, thus reducing fuel consumption for battery charging.

[0064] The fuel for the internal combustion engine 10 was hydrogen gas, a gaseous fuel, but other gaseous fuels, such as compressed natural gas, may also be used. • The fuel for the internal combustion engine 10 was a gaseous fuel, but a liquid fuel may also be used.

[0065] The fluid passage was the fuel passage of the internal combustion engine 10, but other passages may also be used. [Explanation of Symbols]

[0066] 10...Internal combustion engine 15...Fuel injector 20...Tank 21...First shut-off valve 22...Second shut-off valve 30...Pressure reducing valve 40...Fuel piping 60...Delivery pipe 81...First pressure sensor 82...Second pressure sensor 83...Third pressure sensor 100...Control device 210...First valve 220...Second valve 240...Electromagnetic coil 300...Fuel supply device 400...Drive circuit

Claims

[Claim 1] A control device for a solenoid valve, comprising a valve body and an electromagnetic coil that opens the valve body by energizing it, is installed in a fluid flow path, The system has a processing circuit that controls the current supplied to the electromagnetic coil when the valve body is open. The processing circuit performs a process in which the current supplied to the electromagnetic coil decreases as the pressure of the fluid acting on the valve body in the valve-opening direction increases. A control device for solenoid valves.

Images