JP2019100220A - Device for controlling solenoid valve - Google Patents

Abstract

To solve such the problem that a capacitor of a booster circuit is not charged completely in time and an applied voltage to a solenoid valve decreases, and which may cause variation in injection amount under a split injection condition of performing injection multiple times in one combustion cycle.SOLUTION: A control device includes a low voltage source and a high voltage source and charges a capacitor of a booster circuit for boosting a voltage for the high voltage source that feeds a solenoid valve at a high voltage, thereby including a function for early restoration of a voltage for the booster circuit.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a control device for controlling a solenoid valve mounted on an internal combustion engine.

  In recent years, with the tightening of emission regulations, in engines, the total amount of unburned particles (PM: Particulate Matter) during mode travel and the number of unburned particles (PN: Particulate Number), HC (hydrocarbon), It is required to reduce NOx (nitrogen oxide). The PN and HC are generated by the fuel injected from the fuel injection device adhering to the piston and bore wall surfaces of the combustion chamber. Further, with regard to the number of unburned particles, the equivalence ratio which is the ratio of air to fuel immediately before ignition tends to increase if there is a large fuel ratio. That is, in order to suppress PN and HC, it is necessary to reduce fuel adhesion. As means for suppressing fuel adhesion, a method of reducing the penetration of the spray is effective by performing split injection in which the injection in one combustion cycle is divided into a plurality of parts.

  Generally, the control device of the electromagnetic fuel injection device boosts the battery voltage (for example, 14 V) by a booster circuit in the drive device to make a transition from the valve closing state to the valve opening state quickly, and the fuel injection pulse signal In response, the high power is supplied to the fuel injector in a short time. When performing split injection, boosting of the voltage in the boosting circuit is not in time, and the voltage applied to the fuel injection device may be reduced, and the injection amount may vary. As means for solving this problem, according to Patent Document 1, when the charge amounts of the first capacitor and the second capacitor are both less than or equal to a predetermined value, the output of the booster circuit is until the next scheduled fuel injection start. And a control means for switching the switch element so as to preferentially supply the capacitor with a shorter period of time.

JP, 2016-56693, A

  According to Patent Document 1, since boosting is given priority to a capacitor having a short period until the start of fuel injection, it is possible to suppress voltage drop at the time of fuel injection next time, but when the number of split injections increases, boosting is There is a concern that the injection amount may vary and the circuit cost may increase because it is necessary to mount a plurality of capacitors.

  An object of the present invention is to provide a control device of a solenoid valve that suppresses voltage drop and suppresses variation in injection amount in split injection in which a plurality of injections are performed in one combustion cycle.

  In order to solve the above problems, the present invention relates to a control device for a solenoid valve mounted on a combustion system having a low voltage source and a high voltage source that outputs a voltage higher than the voltage of the low voltage source. A control unit is provided for charging a capacitor of a booster circuit that boosts the voltage supplied to the solenoid valve with a voltage source.

  According to the present invention, it is possible to provide a control device of a solenoid valve that suppresses the voltage drop of the booster circuit and suppresses the injection amount variation even when the number of split injections in one combustion cycle increases. Other configurations, operations and effects of the present invention will be described in detail in the following embodiments.

It is the schematic at the time of mounting the fuel-injection apparatus described in Example 1, the pressure sensor, the control apparatus, and ECU in a cylinder direct injection type engine. FIG. 1 is a longitudinal sectional view of a fuel injection device according to a first embodiment of the present invention, and a diagram showing a configuration of a drive circuit and a CPU connected to the fuel injection device. It is the figure which showed the cross-sectional enlarged view of the drive part structure of the fuel-injection apparatus in 1st Example of this invention. It is the figure which showed the relationship of the general injection pulse which drives a fuel-injection apparatus, the timing of the drive voltage and drive current which are supplied to a fuel-injection apparatus, a valve body displacement amount, and time. FIG. 5 is a diagram showing details of a CPU and a drive circuit provided in the ECU of the fuel injection device in the first embodiment of the present invention. FIG. 5 is a diagram showing details of a CPU and a drive circuit provided in the ECU of the fuel injection device in the first embodiment of the present invention. FIG. 7 is a view showing injection timings of first, second, third and fourth cylinders in the first embodiment. A diagram showing the relationship among the boost voltage, the injection pulse width, the drive current, and the amount of displacement of the valve body and time when the battery voltage is used to charge the capacitor of the boost circuit in the first cylinder and the second cylinder in the first embodiment. It is. In the first cylinder and the second cylinder in the first embodiment, the relationship between the boost voltage, the injection pulse width, the drive current, the amount of displacement of the valve body and the time when the high voltage source is used to charge the capacitor of the booster circuit is shown. FIG. FIG. 7 is a diagram showing the configuration of a CPU and a booster circuit provided in an ECU according to a second embodiment. It is the figure which described the high voltage at the time of using the control method of the control apparatus in 2nd Example, the injection pulse, the drive current, and the valve body displacement amount. It is the figure which described the structure of the vehicle in 3rd Example.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Hereinafter, a fuel injection system including the fuel injection device, the pressure sensor, and the control device according to the present invention will be described with reference to FIGS. 1 to 5.
First, the configuration of the fuel injection system will be described using FIG. The fuel injection devices 101A to 101D are installed in each cylinder so that the fuel spray from the injection holes is directly injected to the combustion chambers 107A to 107D. The fuel is pressurized by the fuel pump 106 and delivered to the fuel pipe 105 via the high pressure pipe 120 and delivered to the fuel injection devices 101A to 101D. The fuel pressure (referred to as fuel pressure) fluctuates depending on the balance between the flow rate of the fuel discharged by the fuel pump 106 and the injection amount of the fuel injected into each combustion chamber by the fuel injection device provided to each cylinder of the engine. An engine control unit (ECU) 150 controls the discharge amount from the fuel pump 106 with a predetermined pressure as a target value based on information from the pressure sensor 102.

  The fuel injection of the fuel injection devices 101A to 101D is controlled by the injection pulse width sent from the CPU (control unit) 104 of the ECU (control device) 150. The injection pulse is input to the drive circuit 103 of the fuel injection device, and the drive circuit 103 determines a drive current waveform based on a command from the CPU 104, and the drive current is supplied to the fuel injection devices 101A to 101D for a time based on the injection pulse. It is designed to supply a waveform. Note that the drive circuit 103 may be mounted as a component or a substrate integrated with the CPU 104. In the present embodiment, a device in which the drive circuit 103 and the CPU 104 are integrated is referred to as an ECU 150.

  Next, the configuration and basic operation of the fuel injection device 101 and its ECU 150 will be described. FIG. 2 is a longitudinal sectional view of the fuel injection device 101 and a diagram showing an example of the configuration of the drive circuit 103 for driving the fuel injection device 101 and the ECU 150. As shown in FIG. In FIG. 2, the same symbols are used for parts equivalent to those in FIG. 1. The ECU 150 receives signals indicating the state of the engine from various sensors, and calculates the width and injection timing of the injection pulse for controlling the injection amount injected from the fuel injection device according to the operating conditions of the internal combustion engine. Further, the ECU 150 is provided with an A / D converter and an I / O port for taking in signals from various sensors. The injection pulse output from the CPU 104 is input to the drive circuit 103 of the fuel injector through the signal line 110. The drive circuit 103 controls the voltage applied to the solenoid 205 and supplies a current through the conductor 209. The CPU 104 communicates with the drive circuit 103 through the communication line 111, switches the drive current generated by the drive circuit 103 according to the pressure of the fuel supplied to the fuel injection device and the operating conditions, and sets the current and time It is possible to change

  Next, the configuration and operation of the fuel injection device will be described using the longitudinal cross-sectional view of the fuel injection device of FIG. 2 and the enlarged cross-sectional view of the vicinity of the mover 202 and the valve body 214 of FIG. In FIG. 3, the same symbols are used for parts equivalent to those in FIG. The fuel injection device shown in FIG. 2 and FIG. 3 is a normally closed solenoid valve (electromagnetic fuel injection device), and is fixed by attaching an insertion pipe 208 to the fuel pipe 105. The fuel in the fuel pipe 105 enters the fuel inlet 231 on the inner periphery of the insertion pipe 208. With the fuel injection device 101 in a state where the solenoid 205 is not energized, the valve body 214 is urged in the valve closing direction by the spring 210 which is the first spring so that the valve body 214 closely contacts the valve seat 218 and is closed. It becomes valve state. As shown in FIG. 3, in the valve closed state, a force from the return spring 212 which is a second spring acts on the mover 202 in the valve opening direction. At this time, the biasing force in the valve closing direction by the spring 210 (first spring) acting on the valve body 214 is larger than the biasing force in the valve opening direction by the return spring 212 (second spring). The upstream end surface 202 b of the element 202 is in contact with the downstream end surface of the convex portion 214 a of the valve body 214, and the mover 202 is at rest.

  The valve body 214 and the mover 202 are configured to be capable of relative displacement, and are contained in the nozzle holder 201. The nozzle holder 201 has an end face 201 a which is a spring seat of the return spring 212. The force by the spring 210 is adjusted at the time of assembly by the amount of depression of the spring retainer 224 fixed to the inner diameter of the fixed core 207 (magnetic core). The upper end of the nozzle holder 201 is positioned upstream of the upper end of the fixed core 207 (magnetic core), and the outer peripheral portion of the fixed core 207 is held by the inner peripheral portion of the upper portion of the nozzle holder 201.

  In addition, the fuel injection device 101 forms a magnetic circuit with the fixed core 207, the mover 202, the nozzle holder 201, and the housing 203, and has a gap 213 in the axial direction between the mover 202 and the fixed core 207. . The housing 203 is a cylindrical metal member, and is disposed so as to cover the entire area of the outer peripheral portion of the solenoid 205 and the bobbin 203. A mold portion 206 of synthetic resin is formed around the bobbin on the inner periphery of the housing 203. The mold portion 206 is integrally formed with a portion covering the outer periphery of the upper portion of the nozzle holder 201 and the outer periphery of the conductor 209. A magnetic diaphragm 211 is formed in a portion corresponding to the air gap between the mover 202 of the nozzle holder 201 and the fixed core 207. The solenoid 205 is attached to the outer peripheral side of the nozzle holder 201 in a state of being wound around the bobbin 204.

  A rod guide 215 is fixed to the nozzle holder 201 in the vicinity of the tip of the valve body 214 on the valve seat 218 side, and the outer periphery of the valve body 214 is slidably guided with the inner periphery of the rod guide 215. The movement of the valve body 214 in the axial direction of the valve is guided by the two sliding points of the spring seat 207 of the valve body 214 and the rod guide 215. An orifice member 216 in which a valve seat 218 and a fuel injection hole 219 are formed is fixed to an inner peripheral portion of a tip end portion of the nozzle holder 201. In the closed state, the orifice member 216 has a function of sealing the internal space (fuel passage) provided between the mover 202 and the valve body 214 from the outside.

  The fuel supplied to the fuel injection device 101 is supplied from a rail pipe 105 provided upstream of the fuel injection device 101, and flows toward the downstream end of the valve body 214 through the first fuel inlet portion 231. The fuel is sealed by the valve seat portion formed at the end of the valve body 214 on the side of the valve seat 218 and the valve seat 218. When the valve is closed, a pressure difference between the upper and lower portions of the valve body 214 is generated by the fuel pressure, and the valve body 114 is closed by the differential pressure obtained by multiplying the fuel pressure by the pressure receiving area of the seat inner diameter at the valve seat position. It is pushed in the valve direction. When a current is supplied to the solenoid 205 from the valve closed state, a magnetic field is generated in the magnetic circuit, a magnetic flux passes between the fixed core 207 and the mover 202, and a magnetic attraction force acts on the mover 202. At a timing when the magnetic attraction force acting on the mover 202 exceeds the pressure difference and the load by the set spring 210, the mover 202 starts to be displaced in the direction of the fixed core 207.

  After the valve body 214 starts the valve opening operation, the mover 202 moves to the position of the fixed core 207, and the mover 202 collides with the fixed core 207. After the mover 202 collides with the fixed core 207, the mover 202 receives a reaction force from the fixed core 207 and bounces, but the mover 202 is fixed core by the magnetic attraction force acting on the mover 202. It sucks at 207 and stops soon. At this time, since the force is applied to the mover 202 in the direction of the fixed core 207 by the return spring 212, the time until the rebounding converges can be shortened. The small bounce operation reduces the time during which the gap between the mover 202 and the fixed core 207 becomes large, and enables stable operation even for a smaller injection pulse width.

  Thus, the mover 202 and the valve body 214 which finished the valve opening operation stand still in the valve open state. In the open state, a gap is generated between the valve body 202 and the valve seat 218, and fuel is injected from the injection hole 219. The fuel flows through the central hole provided in the fixed core 207 and the fuel passage hole 202 a provided in the mover 202 in the downstream direction.

  When the solenoid 205 is deenergized, the magnetic flux generated in the magnetic circuit disappears, and the magnetic attraction force also disappears. As the magnetic attraction force acting on the mover 202 disappears, the mover 202 and the valve body 214 are pushed back to the valve closed position contacting the valve seat 218 by the load of the spring 210 and the differential pressure.

  In addition, when the valve body 214 closes from the open state, after the valve body 214 contacts the valve seat 218, the mover 202 separates from the valve body 214 and the mover 202 and moves in the valve closing direction. After exercising for a certain period of time, the return spring 212 returns the valve to the initial position in the valve closed state. The mover 202 separates from the valve body 214 at the moment when the valve body 214 is completely opened, thereby reducing the mass of the movable member at the moment when the valve body 214 collides with the valve seat 218 by the mass of the mover 202. Therefore, the collision energy when colliding with the valve seat 218 can be reduced, and the bounce of the valve body 214 caused by the collision of the valve body 214 with the valve seat 218 can be suppressed.

  In the fuel injection device 101 of the present embodiment, the valve body 214 and the mover 202 are the moment when the mover 202 collides with the fixed core 207 at the time of valve opening and the moment when the valve body 214 collides with the valve seat 218 at the valve closing time. By causing relative displacement for a short time, it is possible to suppress the bounce of the mover 202 against the fixed core 207 and the bounce of the valve body 214 against the valve seat 218.

  FIG. 4 illustrates the relationship between the injection pulse output from the CPU 104 in this embodiment, the drive voltage across the terminals of the solenoid 205, the drive current (excitation current), and the displacement of the valve body 214 (valve body behavior). Of the

  FIG. 5 is a diagram showing details of the drive circuit 103 and the CPU 104 of the fuel injection device 101. As shown in FIG. The CPU 104 is incorporated in, for example, the ECU 150, a pressure sensor 102 attached to the fuel pipe 105 upstream of the fuel injection device 101, an A / F sensor for measuring the amount of air flowing into the engine cylinders 107A to 107D, and the engine cylinders 107A to 107D. Signals indicating engine states from various sensors such as an oxygen sensor and a crank angle sensor for detecting the oxygen concentration of the exhaust gas discharged from the vehicle are taken in via the communication line 503. Then, the CPU 104 calculates the injection pulse width and the injection timing for controlling the injection amount injected from the fuel injection device 101 according to the operating condition of the internal combustion engine. The CPU 104 outputs the injection pulse width Ti to the drive IC 502 of the fuel injection device through the communication line 504 based on the calculation result. Thereafter, the drive IC 502 switches between energization and non-energization of the switching elements 505, 506, and 507 to supply a drive current to the fuel injection device 101.

  Switching element 505 is a high voltage source 516 (hereinafter referred to as a boosted voltage source) having a higher voltage than a low voltage source 500 (hereinafter referred to as a battery voltage source) input to the drive circuit and the high voltage side of fuel injection device 101 It is connected between the terminals of. The switching elements 505, 506, and 507 are formed of, for example, FETs or transistors, and can switch between energization and non-energization of the fuel injection device 101. The boosted voltage VH, which is the initial voltage value of the boosted voltage source 516, is 50 to 65 V, for example, and is generated by boosting the battery voltage VB of the battery voltage source 500 by the booster circuit 514. The voltage value of battery voltage VB is, for example, 11.0 to 14.0V.

The booster circuit 514 is constituted of, for example, a DC / DC converter or the like, or is constituted of a coil 530, a transistor 531, a diode 532, a capacitor 533 and a capacitor 536. In the case of the configuration of the latter booster circuit 514, when transistor 531 is turned on, the current due to battery voltage VB of battery voltage source 500 flows to the ground potential 534 side, but when transistor 531 is turned off, the high voltage generated in coil 530 Current is rectified through the diode 532 and charge is accumulated in the capacitor 533. The transistor 531 is repeatedly turned on and off until the boosted voltage VH is reached, and the voltage of the capacitor 533 is increased. The transistor 531 is connected to the drive IC 502 or the CPU 104, and the boosted voltage VH output from the booster circuit 514 is configured to be detected by the drive IC 502 or the CPU 104. In order to stabilize the voltage of the booster circuit 514, a capacitor 536 may be provided. The parasitic inductance of the wiring increases the impedance at high frequencies, but the capacitor 536 makes it possible to suppress the impedance.
Further, a diode 535 is provided between the power supply side terminal 590 of the solenoid 205 and the switching element 505 so that current flows in the direction from the boosted voltage source 516 to the solenoid 205 and the installation potential 515. The power supply side terminal 590 and the GND side terminal 591 constitute a connection terminal with the fuel injection device 101. Also between the power supply side terminal 590 of the solenoid 205 and the switching element 507, the switching element 506 is provided with the diode 511 so that current flows from the battery voltage source 500 in the direction of the solenoid 205 and the installation potential 515. During this period, current can not flow from ground potential 515 to solenoid 205, battery voltage source 500 and boosted voltage source 516. Further, a register and a memory are mounted on the CPU 104 in order to store numerical data necessary for control of the engine such as calculation of the injection pulse width. The register and the memory are contained in the ECU 150 or the CPU 104 in the ECU 150.

  Further, the switching element 507 is connected between the battery voltage source 500 and the high voltage terminal of the fuel injection device 101. The battery voltage source 500 is, for example, a general battery mounted on a car, and its voltage value is about 11 to 14V. The switching element 506 is connected between the low voltage side terminal 591 of the fuel injection device 101 and the ground potential 515. The drive IC 502 detects the value of the current flowing to the fuel injection device 101 by the resistors 508, 512, 513 for current detection, and switches between energization / non-energization of the switching elements 505, 506, 507 by the detected current value. , And generates a desired drive current. The diodes 509 and 510 are provided to apply a reverse voltage to the fuel injector solenoid 205 and to rapidly reduce the current supplied to the solenoid 205.

  The CPU 104 communicates with the drive IC 502 through the communication lines 503 and 504, and can switch the drive current generated by the drive IC 502 according to the pressure of the fuel supplied to the fuel injection device 101 and the operating conditions. Further, both ends of the resistors 508, 512, and 513 are connected to the A / D conversion port of the IC 502, and each voltage applied to both ends of the resistors 508, 512, and 513 is detected by the IC 502.

When an injection pulse is input to the drive IC 502 which is a part of the drive circuit 103, the drive IC 502 applies the high voltage 401 by the boosted voltage source 516 to the solenoid 205 by energizing the switching elements 505 and 506. Start supply of drive current. As shown in FIG. 4, when the current value reaches a peak current value I _peak preset in the CPU 104, the CPU 104 stops the application of the high voltage 401. That is, by deenergizing the switching element 505 and the switching element 507 and energizing only the switching element 506, the current is regenerated in the circuit, and a voltage of approximately 0 V is applied to the solenoid 205, and a peak current value is obtained like the current 402. It drops from I _peak . At this time, the switching element 505, the switching element 506, and the switching element 507 may be deenergized. In this case, the diode 509 and the diode 510 are energized by the back electromotive force due to the inductance of the coil 540, and the current is fed back to the boosted voltage source 516 side. As a result, the current supplied to the fuel injection device 101 rapidly decreases from the peak current value I _peak . In this case, the CPU 104 turns on the switching element 506 in the transition period from the peak current value I _peak to the holding current 403. As a result, the current due to the back electromotive force energy flows to the ground potential 515 side, the current is regenerated in the circuit, and a voltage of approximately 0 V is applied to the solenoid 205, so that the current gradually decreases.

When the current value becomes smaller than the set current value 404, the CPU 104 causes the switching element 506 to be energized via the drive IC 502, and the switching element 505 remains de-energized, and application of the battery voltage VB is performed by energizing / de-energizing the switching element 507. Then, a switching period is provided to control so that the set current value 403 is maintained. As the fuel pressure supplied to the fuel injection device 101 increases, the fluid force acting on the valve body 214 increases, and the time for the valve body 214 to reach the target lift amount becomes longer. As a result, the timing at which the target lift amount is reached may be delayed with respect to the arrival time of the peak current I _peak . As described above, when the drive current is rapidly reduced by the back electromotive force, the magnetic attraction force acting on the mover 202 is also rapidly reduced. For this reason, the behavior of the valve body 214 may become unstable, and the valve closing may be started regardless of energization. Therefore, when the switching element 506 is turned on and the switching elements 505 and 507 are turned off during transition of the peak current I _peak to the current 403 to gradually reduce the current, the decrease in magnetic attraction can be suppressed, and the fuel can be reduced at high fuel pressure. The stability of the valve body 214 can be secured, and injection amount variation can be suppressed.

The CPU 104 drives the fuel injection device 101 with such a profile of the supplied current. Between application of high voltage 401 and peak current value I _peak , mover 202 and valve body 214 start displacement at timing t ₄₁ , and thereafter mover 202 and valve body 214 move to the collision height position. To reach. At timing t ₄₂ when the mover 202 reaches the collision height position, the mover 202 collides with the fixed core 207, and then the mover 202 bounces to the opposite side of the fixed core 207. Since the valve body 214 is configured to be capable of relative displacement with respect to the mover 202, the valve body 214 is separated from the mover 202 after the mover 202 collides with the fixed core 207. For this reason, the displacement of the valve body 214 overshoots beyond the collision height position.

Thereafter, due to the magnetic attraction force generated by the holding current 403 and the force in the valve opening direction of the return spring 212, the mover 202 is stopped at the predetermined collision height position. Also, after reaching the maximum height position after overshooting, the valve body 214 starts to move in the downstream direction again by the biasing force of the spring 210 and the biasing force of the fuel pressure. The contact with the movable element 202 and the timing t ₄₃ to move back to the upstream direction after moving in a downstream direction by bouncing toward the collision height position at approximately the same motion. The stationary armature 202 and the valve body 214 are both at the location of impingement height position at the timing t _44, the valve opening state is maintained.

  In the case of a fuel injection device having a movable valve in which the valve body 214 and the mover 202 are integrated, the displacement amount of the valve body 214 does not become larger than the collision height position, and the movement after reaching the collision height position The displacement amounts of the element 202 and the valve body 214 are equal.

  Next, problems to be solved by the present embodiment will be described using FIGS. 7 and 8. FIG. 7 shows the fuels of the first to fourth cylinders in the case where the fuel injection is performed three times in the intake stroke and two in the compression stroke in one combustion cycle of the intake stroke, the compression stroke, the expansion stroke and the exhaust stroke. It is the figure which showed the relationship of the injection timing and the injection period. FIG. 7 shows an in-line four-cylinder engine in which the first cylinder, the third cylinder, the fourth cylinder, and the second cylinder are ignited in the order of the first cylinder, the first cylinder, the second cylinder, the third cylinder, and the fourth cylinder. It is a figure explaining.

  FIG. 8 shows the voltage value of the boosted voltage VH of the boosted voltage source 516, the injection pulse of the first cylinder and the third cylinder, the drive current, the valve body displacement amount, and the horizontal axis as time in the period 704 of FIG. It is the figure which showed the relationship of time. In FIG. 8, the drive current of the third cylinder is indicated by a solid line 810, and the amount of displacement of the valve body is indicated by a solid line 811. The driving current of the first cylinder is indicated by a broken line 812 and the amount of displacement of the valve body is indicated by a broken line 813 when the timing at which the injection pulse of the first cylinder is ON is aligned with the timing at which the injection pulse of the third cylinder is ON.

  The conditions under which the injection timings overlap between the cylinders will be described with reference to FIG. In a direct injection engine in which fuel is directly injected into a cylinder, fuel may be injected a plurality of times in the intake stroke and the compression stroke from the viewpoint of suppressing wall adhesion and improving homogeneity. In this case, in 701 of FIG. 7, the injection timing or injection period of the injection in the compression stroke of the third cylinder and the injection in the intake stroke of the fourth cylinder overlap. Further, at 702, the injection timing or injection period of the injection in the intake stroke of the second cylinder and the injection in the compression stroke of the fourth cylinder overlap. At 703, the injection timing or injection period of the injection in the intake stroke of the first cylinder and the injection in the compression stroke of the second cylinder overlap. Furthermore, there are cases where the injection timing or injection period of the injection in the compression stroke of the first cylinder and the injection in the intake stroke of the third cylinder overlap at 704, respectively.

  When one booster circuit 514 is disposed in each cylinder, if injection intervals in one cylinder are secured, even if fuel injection in the intake stroke and the compression stroke overlap between the cylinders, the boosted voltage It is unlikely that the next reinjection will be required when the voltage value of the source 516 is reduced. However, since the charge accumulated in the capacitor 533 of the booster circuit 514 is discharged after a predetermined time elapses, when the drive cycle of the booster circuit 514 is late, the voltage value of the boosted voltage source 516 may slightly decrease. Further, in order to reduce the heat generation and cost of the ECU 150 or the CPU 104, in the four-cylinder engine, one booster circuit 514 is provided for each of the first cylinder, the third cylinder, the odd cylinder, the second cylinder, and the fourth cylinder. In the case of arrangement, there is a case where one booster circuit 514 is shared by four cylinders. By reducing the number of boosting circuits 514, the number of transistors, switching elements, and capacitors that can discharge a high voltage can be reduced, so that the cost of the ECU 150 or the CPU 104 can be reduced.

  Further, in the booster circuit 514, in order to discharge the charge to the capacitor 533, the switching element 531 is controlled to repeat ON / OFF at high frequency. In this case, the booster circuit 514 may generate heat and be restricted by the time of high voltage application to the solenoid 205 or the current value which can be supplied to the solenoid 205. By reducing the number of boosting circuits 514, heat generation of the ECU 150 or the CPU 104 can be suppressed, and in particular, even when the fuel pressure supplied to the fuel injection device 101 becomes high, the time of high voltage application or the drive current value is restricted. Therefore, the current control of the fuel injection device 101 can be performed without receiving the signal. As a result, stable operation can be performed at high fuel pressure, and the accuracy of the injection amount in the high fuel pressure range can be enhanced.

A case where multistage injection is performed in a configuration using one shared boost circuit 514 for the first cylinder, the second cylinder, the third cylinder, and the fourth cylinder will be described using FIG. 8. The CPU 104 controls the voltage value of the boosted voltage source 516 to be the initial value, ie, the boosted voltage VH, at a time prior to the timing t ₈₁ at which the injection pulse is turned on in the intake stroke of the third cylinder. The CPU 104 sends a control signal to the drive IC 502 so as to energize the switching elements 505 and 506 at a timing t ₈₁ when the injection pulse of the third cylinder is turned on, thereby applying a voltage from the boosted voltage source 516 to the solenoid 205. Control. Therefore, the charge stored in capacitor 533 is reduced, whereby the voltage value of boosted voltage source 516 is reduced. At timing t ₈₂ when the current reaches the peak current I _peak , the CPU 104 de-energizes the switching element 505 and the switching element 507 and sends a control signal to the drive IC 502 so that only the switching element 506 is energized, whereby the current is a circuit. The interior is regenerated, and a voltage of approximately 0 V is applied to the solenoid 205, and the application of the boosted voltage source 516 to the solenoid 205 is stopped. At this time, control may be performed so that the voltage of the battery voltage source 500 is applied.

After the timing _{t 82,} the voltage value of the boost voltage source 516, to return toward the boosted voltage VH. When the injection pulse in the compression stroke of the first cylinder is energized at time t ₈₃ before returning to the boosted voltage VH, the voltage value of the boost voltage source 516 is reduced. Thereafter, when the current value of the first cylinder reaches timing t ₈₄ at which the peak current I _peak is reached, voltage application of the boosted voltage source 516 to the solenoid 205 is stopped, so the voltage of the boosted voltage source 516 elapses after a predetermined time has elapsed. The value returns to boosted voltage value VH.

Comparing the drive current 812, the valve body displacement amount 813 of the first cylinder, the drive current 810 of the third cylinder, and the valve body displacement amount 811 when the timing when the injection pulse is turned on is compared with the third cylinder. In the first cylinder, the voltage value applied to the solenoid 205 is low. For this reason, the current flowing to the solenoid 205 is reduced, and the rising of the current is delayed. As a result, rising of the magnetic attraction force generated in the mover 202 is also delayed. Therefore, the valve opening start timing of the valve body 214 and the valve closing force acting on the movable element 202 delays the timing at which the magnetic attraction force exceeds the valve body 214 is delayed from the timing t ₈₅ to the timing t _86. Since the voltage value of the boosted voltage source 516 does not affect the current after the current value flowing to the solenoid 205 reaches the holding current 821, the delay time from when the injection pulse is turned off until the valve body 214 is closed is The first and third cylinders are substantially equivalent. Therefore, comparing the injection amounts of the first cylinder and the third cylinder, the valve opening delay time until the valve body 214 reaches the target lift amount after the injection pulse of the first cylinder turns ON becomes longer There was a case where the amount decreased.

  Next, the configuration and control method of the control device according to the first embodiment of the present invention will be described with reference to FIGS. FIG. 6 is a view showing details of the drive circuit 103 and the CPU 104 of the fuel injection device 101 in the present embodiment, and the same symbols are used for parts equivalent to FIG.

  FIG. 9 shows the voltage value of the boosted voltage source 516 in the period 704 of FIG. 7 with time on the horizontal axis when the present embodiment is applied, the injection pulse of the first cylinder and the third cylinder, the drive current, and the valve body displacement amount It is the figure which showed the relationship of. In FIG. 9, the boost voltage VH of the boost voltage source 516, the drive current of the first cylinder, and the valve body displacement amount when the drive circuit 103 and the CPU 104 of FIG. 5 are used are shown by broken lines. Further, in FIG. 9, the high voltage, the drive current, and the valve body displacement amount in the case of using the drive circuit 103 and the CPU 104 of FIG. In FIG. 9, since the same reference numerals as those in FIG. 8 denote the same meanings, the description will be omitted.

  The control device for driving the solenoid valve according to the first embodiment includes a high voltage source (hereinafter referred to as high voltage battery 600) having a voltage higher than that of battery VB500, and capacitor 533 of step-up circuit 514 using high voltage battery 600. To charge. That is, in FIG. 6, when the transistor 531 is turned on, the current due to the high voltage of the high voltage battery 600 flows to the ground potential 534 side, but when the transistor 531 is turned off, the current due to the high voltage generated in the coil 530 is the diode 532 And charge is accumulated in the capacitor 533. The transistor 531 is repeatedly turned on and off until the boosted voltage VH is reached, and the voltage of the capacitor 533 is increased.

When the voltage applied to the booster circuit 514 is high, even when the voltage of the boosted voltage source 516 is lowered by the injection of the third cylinder, the timing at which the peak current I _peak of the third cylinder is stopped. After timing t _{82 at} which the use of 516 is stopped, as shown at 901, the return slope of the boosted voltage source 516 becomes large, and charging of the boosted voltage is completed in a period 902.

  As described above, the present embodiment includes the low voltage source (battery voltage source 500) and the high voltage source (high voltage battery 600) that outputs a voltage higher than the voltage of the low voltage source (battery voltage source 500). In a control device 150 of a solenoid valve (fuel injection device 101) mounted in a combustion system, a capacitor of a booster circuit 514 that boosts a voltage supplied to the solenoid valve (fuel injection device 101) by a high voltage source (high voltage battery 600). A control unit (CPU 104) for charging 533 is provided.

Thus, at a timing t ₈₃ for energizing the injection pulse of the first cylinder, since the voltage applied to the solenoid 205 is returned to the step-up voltage VH is the initial value of the boost voltage source 516, valve body 214 is desired lift amount The time delay until it reaches is reduced, and the accuracy of the injection amount can be secured. As a result, the injection amount variation at the time of divided injection can be suppressed, and the effect of the PN suppression is enhanced.

  As described above, in order to improve the responsiveness of the fuel injection device 101, the high voltage source (high voltage battery 600) should be a higher voltage than the low voltage source (battery voltage source 500), for example at 48 V It is desirable to have. In addition, when a battery whose operating voltage is higher than 60 V is mounted as high voltage battery 600, protection from the voltage source is required, so the voltage value of the high voltage source (high voltage battery 600) is more than 60 V. You should adopt a low one. By making the voltage value of the high voltage source (high voltage battery 600) smaller than 60 V, the cost of the isolation circuit necessary for protection from the voltage source can be suppressed.

  The voltage value of the high voltage source (high voltage battery 600) may be lower than the voltage of the boosted voltage source 516. Since the voltage of the booster circuit 514 contributes to the rise of the current of the fuel injection device 101, it directly affects the responsiveness of the fuel injection device 101. However, although the voltage value of high voltage source 600 contributes to the voltage recovery time of boosted voltage source 516, it can not directly contribute to the responsiveness of fuel injection device 101 if the voltage can be recovered to boosted voltage VH which is the initial value. Therefore, the voltage of boosted voltage source 516 may be higher than the voltage of high voltage source (high voltage battery 600).

  As described with reference to FIG. 4, the CPU 104 causes the switching element 506 to be energized via the drive IC 502, and the switching element 505 remains de-energized, applying the battery voltage VB by energizing / de-energizing the switching element 507, and setting current A switching period is provided to control to maintain the value 403 (holding current). In FIG. 6, when the CPU 104 energizes the switching element 506 via the drive IC 502, deenergizes the switching element 505, and generates the set current value 403 by the high voltage source 601 by energizing / deenergizing the switching element 507. Since the time from when the current decreases to when it reaches the current 404 is shortened, the number of ON / OFF operations of the switching element 507 is increased. On the other hand, by controlling so that the current 403 is maintained at the battery voltage VB, the number of ON / OFF of the switching element 507 can be reduced compared to the case of the high voltage source 601, so the heat generation of the circuit can be suppressed. There is.

  Further, in the present embodiment, the control device describes the configuration for controlling the fuel injection device, but in the case of a direct acting solenoid valve, the displacement amount of the valve body 214 when the boosted voltage decreases. An effect of suppressing the variation or suppressing an increase in time for the valve body 214 to reach the target lift amount can be obtained. Therefore, the control device of the present embodiment is effective even when the solenoid valve other than the fuel injection device is targeted.

  Although the effects in the case of targeting the fuel injection device have been described above, the electromagnetic valve having the solenoid has the same problem. Therefore, this embodiment can be applied not only to the fuel injection device 101 but also to a control device for controlling the solenoid valve.

  Hereinafter, the configuration of the control device according to the second embodiment of the present invention will be described with reference to FIG. FIG. 10 is a diagram describing the configuration of the booster circuit of the ECU 150 (control device) in the present embodiment. The same reference numerals in FIG. 10 as those in FIG.

  In FIG. 10 of the present embodiment and FIG. 6 of the first embodiment, an input switching portion (switching element 1001 in which high voltage source VH2 and battery voltage VB500 are arranged on the input voltage side of booster circuit 514 and switches these inputs. , Switching element 1002) is arranged. In FIG. 10, the drive circuit 103 such as the drive IC 502 and the switching elements 505 to 507 is omitted.

  As shown in FIG. 10, the ECU 150 in the present embodiment has a switching element 1001 and a switching element 1002. The switching element 1001 is connected to the CPU 104 at a terminal y104, and the switching element 1002 is connected to the CPU 104 at a terminal y103. The ECU 150 has an input switching unit 1000 that switches the switching element 1001 and the switching element 1002. That is, the ECU 150 of this embodiment controls the input switching unit 1000 to switch whether to energize the booster circuit 514 from the low voltage source (battery voltage source 500) or to energize the booster circuit 514 from the high voltage source 601. A control unit (CPU 104) is provided.

  The terminal y102 of the CPU 104 is connected to a boosted voltage source 516 which is an output voltage of the booster circuit 514, and detects a boosted voltage value VH of the boosted voltage source 516. When the detected voltage value VH is lower than the set threshold, the CPU 104 controls the input switching unit 1000 to charge the capacitor 533 from the high voltage source 601. That is, when the output voltage VH of the booster circuit 514 is lower than the set threshold, the control unit (CPU 104) controls the input switching unit 100 to charge the capacitor 533 from the high voltage source 601. Specifically, the CPU 104 controls the input switching unit 1000 to apply a voltage from the high voltage source 601 to the capacitor 533 to the solenoid 205 by turning on the switching element 1001 and turning off the switching element 1002. The terminal y101 of the CPU 104 is connected to the switching element 531, and the ON / OFF of the switching element 531 is repeated to charge the capacitor 533 from the high voltage source 601.

  The threshold may be set, for example, in the range of 0.1 to 10 V with respect to the initial value. On the other hand, when the output voltage VH of the booster circuit 514 is higher than the set threshold, the control unit (CPU 104) causes the input switching unit 1000 to charge the capacitor 533 from the low voltage source (battery voltage source 500). Control. As described above, when the voltage of the boosted voltage source 516 is low, the voltage application of the high voltage source 601 is performed to the booster circuit 514.

  FIG. 11 is a diagram showing the boosted voltage VH of the boosted voltage source 516, the injection pulse, the drive current, and the valve body displacement, with time on the horizontal axis, when the control method of the control device in this embodiment is used. In FIG. 11, the case where the battery voltage VB is used for charging the capacitor of the booster circuit is indicated by a broken line, and the case where a high voltage source is used is indicated by a solid line. When a voltage is charged to the capacitor 533 by the booster circuit 514 using the battery voltage VB when there is an interval 1103 between the first injection pulse 1101 and the second injection pulse 1102, the boosted voltage VH is as shown by a broken line in FIG. It took a long time to In this case, the inclination of the drive current becomes small as shown at 812 and as a result, there is a possibility that the valve body displacement amount will be delayed as shown at 813.

  On the other hand, according to the above-described control of this embodiment, the time until the voltage value of boosted voltage source 516 is restored to boosted voltage VH, which is the initial value, is from the period shown in 1103 of FIG. Since the drive current can be shortened, the inclination can be increased as shown by 812 to 810, and the drive current can be rapidly raised. As a result, since the valve body displacement amounts can be made to have no delay as shown in 813 to 811, it is possible to reduce the injection amount variation. As a result, it is possible to enhance the effect of suppressing PN.

  Also, the voltage of the high voltage source 601 may drop due to the use of the electronic device connected to the high voltage source 601. As described above, when the high voltage source 601 has a high usage rate, using the high voltage source 601 to charge the capacitor 533 of the booster circuit 514 further lowers the voltage of the high voltage source 601 and uses other electronic devices. May cause problems. Therefore, a terminal y 105 of A / D conversion for detecting the voltage VH 2 of the high voltage source 601 by the CPU 104 is provided, and the high voltage source usage rate is high or the voltage value of the high voltage source is set in advance in the control device 150 If less than the threshold value, the switching element 1001 may be turned off and the switching element 1002 may be turned on, and the CPU 104 of the ECU 150 may control so as to use the battery VB of the battery voltage source 500 for charging the capacitor 533 of the booster circuit 514.

  As a result, it is possible to stably drive the solenoid valve of the fuel injection device 101 while guaranteeing the operation of the electronic device connected to the high voltage source 601. Switching element 1001 and switching element 1002 are formed of, for example, an FET.

  A predetermined condition in which the high voltage source 601 can not be used is set in the control unit (CPU 104). The control unit (CPU 104) may control the input switching unit 1000 to charge a voltage from the high voltage source 601 to the capacitor 533 when the predetermined condition that the high voltage source 601 can not be used is satisfied. The predetermined condition in which the high voltage source 601 can not be used is, for example, the case where the high voltage source 601 fails and the voltage drops significantly. Specifically, control is made to use battery voltage VB for charging capacitor 533 to booster circuit 514 when high voltage source 601 fails and voltage VH2 drops significantly. As a result, the operation of the fuel injection device 101 at the time of fail safe can be ensured, and the traveling safety of the vehicle can be ensured.

  Next, a control method of the ECU 150 in the present embodiment will be described using 7, 8, 10, and 11. As shown in FIG. 7, in the period 704, the period of the injection pulse overlaps between the first cylinder and the third cylinder. In this case, for example, when battery voltage VB500 is used to charge capacitor 533 of booster circuit 514 of FIG. 10, the output voltage of booster circuit 514 does not return to boosted voltage VH which is the initial value as shown in FIG. The time until the valve body 214 reaches the target lift amount may increase and the injection amount may decrease.

  Therefore, in the present embodiment, the CPU 104 of the ECU 150 turns on the switching element 1001 shown in FIG. 10 and switches the switching element 1002 when the injection pulse width or the valve opening period of the valve body 214, ie, the injection period overlaps in two cylinders. Control is made to charge the capacitor 533 with the voltage VH2 of the high voltage source 601 by turning it off. That is, the CPU 104 of the ECU 150 is input so as to charge a voltage from the high voltage source 601 to the capacitor 533 when the period of the injection pulse for sending the drive voltage to the solenoid valve (fuel injection device 101) overlaps with two cylinders. The switching unit 1000 is controlled. By charging the capacitor 533 with the high voltage source 601, as shown in FIG. 11, the time to return to the boosted voltage VH, which is the initial value of the voltage of the boosted voltage source 516, becomes short as 1105. For this reason, the fall of the applied voltage to the solenoid 205 in the timing which performs the next fuel injection can be suppressed, and injection amount dispersion | variation can be suppressed. As a result, it is possible to improve the PN reduction effect.

  Further, as shown in FIG. 11, when the interval 1103 between the first injection pulse 1101 and the second injection pulse 1102 is short, the battery voltage VB of the battery voltage source 500 is used to charge the capacitor 533 of the booster circuit 514. Also, there is a possibility that the voltage does not return to the initial value VH at timing t111 when the injection pulse 1102 is energized. Then, the time 1104 until the valve body 214 reaches the target lift amount may be long, and the injection amount may be reduced. Therefore, when the interval 1103 of the injection pulse is short, control may be performed to apply the high voltage 601 to the charge to the capacitor 533 of the booster circuit 514.

  That is, when the solenoid valve (the fuel injection device 101) is controlled by multistage injection, the CPU 104 of the ECU 150 performs input so as to charge a voltage from the high voltage source 601 to the capacitor 533 when the injection interval in one cycle is less than the set interval. The switching unit 1000 is controlled. As a result, at the timing t111 at which the injection pulse 1102 is turned ON, the boosted voltage can be restored to the initial value VH. Therefore, the time until the valve body 214 reaches the target lift amount is equal to that in the case where the injection pulse 1101 is turned ON, and the injection amount variation can be suppressed. Further, when the solenoid valve (fuel injection device 101) is controlled by multistage injection, the CPU 104 of the ECU 150 controls the voltage from the low voltage source (battery voltage source 500) to the capacitor 533 when the injection interval in one cycle is equal to or greater than the set interval. It is preferable to control the input switching unit 1000 to charge. This makes it possible to realize multistage injection with power saving.

  Further, the injection interval 1103 becomes shorter as the number of injections of the fuel injection device 101 in one combustion cycle increases. Therefore, when the number of injections in one combustion cycle is the number (for example, 3 to 4 or more) previously set in the CPU 501 of the ECU, the CPU 104 uses the high voltage 601 to charge the capacitor 533 of the booster circuit 514. In this way, the input switching unit 1000 is controlled. When controlling the solenoid valve (the fuel injection device 101) by multistage injection, the CPU 104 of the ECU 150 performs input switching such that the high voltage source 601 charges the capacitor 533 when the number of injections in one cycle is equal to or greater than the set number. The unit 1000 is controlled.

  Furthermore, when the engine speed is high, the time for one combustion cycle is also shortened. Therefore, when the number of revolutions of the engine is a high number of revolutions equal to or higher than the set value, the CPU 104 turns on the switch 1001 so as to use the high voltage source 601 to apply voltage to the booster circuit 514 and turns off the switch 1002. You should control to do. Further, when the engine speed is lower than the set value, the CPU 104 lengthens the time of one combustion cycle, so the switch 1001 is turned off so that the battery voltage VB500 is used for voltage application to the booster circuit 514. And the switch 1002 may be controlled to be turned on. That is, the CPU 104 of the ECU 150 charges the voltage from the low voltage source (battery voltage source 500) to the capacitor 533 when the number of injections in one cycle of the solenoid valve (the fuel injection device 101) is less than the set number. Control.

  When the number of split injections is the number set in advance in ECU 150 (for example, 3 to 4 times or less), control may be performed to use battery VB for charging capacitor 533 of boosting circuit 514. In particular, by using the high voltage source 601 for the step-up circuit 514 under the condition that the number of split injections is large, the power reduction of the step-up circuit 514 is reduced while the power of the electronic device connected to the high voltage source 601 is reduced. Can be suppressed.

  The input switching unit 1000 may be inside the booster circuit 514 or outside the booster circuit 514 inside the ECU 150. Furthermore, the input switching unit 1000 may be external to the ECU 150. If there is a vehicle that does not have high voltage power supply 601, by configuring input switching unit 1000 outside the ECU, the ECU may or may not have high voltage power supply 601 installed in the vehicle. Since the same circuit configuration can be used, the cost of the ECU can be reduced.

  Although the effects in the case of targeting the fuel injection device have been described above, the electromagnetic valve having the solenoid has the same problem. Therefore, this embodiment can be applied not only to the fuel injection device 101 but also to a control device for controlling a solenoid valve.

  Hereinafter, the configuration of the vehicle according to the third embodiment of the present invention will be described with reference to FIG. FIG. 12 is a diagram describing the configuration of the vehicle in the third embodiment. Parts in FIG. 12 having the same reference numerals as those in FIGS. 1, 5, 6 and 10 mean the same parts, so detailed description will be omitted.

In the third embodiment, the configuration of a vehicle equipped with the ECU 150 in the first and second embodiments will be described.
As shown in FIG. 12, a power switching unit 1203 is disposed between the engine 1201 and the electric motor 1202. The power switching unit 1203 is configured to be able to select the driving power transmitted to the shaft 1206 from the engine 1201 and the electric motor 1202. When the shaft 1206 rotates, the driving force is transmitted to the tire 1207 of the vehicle, the tire 1207 rotates, and the vehicle travels. A power generator 1204 is provided between the power switching unit 1203 and the ECU 150, and the power of the engine and the rotational energy of the shaft 1206 can be revised and stored in the power generator 1204 as electric power. The ECU 150 is configured to communicate with a hybrid controller 1205 for controlling the hybrid system. The hybrid controller 1205 is configured to control the motor 1202 or to control ON / OFF of the power unit switching unit 1203 via the ECU 150 so that the power reduction transmitted to the shaft 1206 can be selected from the electric motor 1202 and the engine 1201. Ru.

  Also, the high voltage source 601 is connected to the electric motor 1202 via the hybrid controller 1205. Hybrid control device 1205 may be the same component as ECU 104 or may be configured as a separate component.

  As described above, the ECU 150 of the present embodiment controls the high voltage source 601 which outputs a voltage higher than 14 V, and the solenoid valve (fuel injection device 101) mounted on the vehicle having the electric motor 1202 and the engine 1201. Further, the solenoid valve (fuel injection device 101) is configured to inject fuel directly into the cylinder of the engine 1201. Although not shown in FIG. 12, the CPU 104 of the ECU 104 of FIG. 6 or 10 charges the capacitor 533 of the booster circuit 514 that boosts the voltage supplied to the solenoid valve (fuel injection device 101) by the high voltage source 601.

  The high voltage source 601 is effective when used in a hybrid vehicle equipped with an internal combustion engine and an electric motor, and in particular, the electric motor 1202 determines the output characteristics of the motor by the applied voltage and contributes to improvement of fuel consumption and cost reduction by compactness. Do. Further, in the engine 1201 of the internal combustion engine, the injection in one combustion cycle is divided in the case where the fuel injection device is mounted in the cylinder as compared with the case where the fuel injection device is mounted in the intake port. Therefore, the effect of suppressing the adhesion of fuel to the wall surface or the mixture injected into the cylinder is high. Therefore, the configuration in the first and second embodiments of the present invention reduces the variation in the injection amount by using for the vehicle of the third embodiment having the electric motor 1202 for driving the vehicle and the engine 1201 of the direct injection type. Effect can be increased, and PN can be suppressed.

  DESCRIPTION OF SYMBOLS 101 ... Fuel injection apparatus, 104 ... CPU, 150 ... ECU, 205 ... Solenoid, 500 ... Battery voltage source, 502 ... Drive IC, 505-507 ... Switching element, 515 ... Installation electric potential, 516 ... Boosted voltage source.

Claims (12)

In a control device of a solenoid valve mounted on a combustion system having a low voltage source and a high voltage source that outputs a voltage higher than the voltage of the low voltage source,
A control device for a solenoid valve comprising a control unit for charging a capacitor of a booster circuit that boosts a voltage supplied to the solenoid valve by the high voltage source. In the control device for a solenoid valve according to claim 1,
The control device of a solenoid valve which controls an input switching unit so as to switch whether the control unit energizes the booster circuit from the low voltage source or energizes the booster circuit from the high voltage source. In the control device for a solenoid valve according to claim 2,
The control unit for a solenoid valve controls the input switching unit to charge the capacitor from the high voltage source when the output voltage of the booster circuit is lower than a set threshold. In the control device for a solenoid valve according to claim 2 or 3,
The control unit for a solenoid valve controls the input switching unit to charge the capacitor from the low voltage source when the output voltage of the booster circuit is higher than a set threshold. In the control device for a solenoid valve according to claim 2,
The control device for a solenoid valve controls the input switching unit to charge the capacitor from the high voltage source when a predetermined condition that the high voltage source can not be used is satisfied. In the control device for a solenoid valve according to claim 2,
The control unit controls the input switching unit to charge the capacitor from the high voltage source when the period of the injection pulse for sending the drive voltage to the solenoid valve overlaps in two cylinders. Control device for solenoid valve. In the control device for a solenoid valve according to claim 2,
The control unit controls the input switching unit to charge the capacitor from the high voltage source when the number of injections in one cycle is equal to or greater than a set number when controlling the solenoid valve by multistage injection. Control device for solenoid valve. In the control device for a solenoid valve according to claim 7,
The control unit of a solenoid valve controls the input switching unit to charge the capacitor from the low voltage source when the number of injections in one cycle of the solenoid valve is equal to or less than a set number. In the control device for a solenoid valve according to claim 2,
The control unit controls the input switching unit to charge the capacitor from the high voltage source when the injection interval in one cycle is equal to or less than the set interval when controlling the solenoid valve by multistage injection. Control device for solenoid valve. In the control device for a solenoid valve according to claim 9,
The control unit controls the input switching unit to charge the capacitor from the low voltage source when the injection interval in one cycle is equal to or longer than the set interval when controlling the solenoid valve by multistage injection. Control device for solenoid valve. In the control device for a solenoid valve according to claim 1,
The control device, wherein a voltage of the booster circuit is higher than a voltage of the low voltage source, and a voltage of the booster circuit is higher than a voltage of the high voltage source. In a high voltage source that outputs a voltage higher than 14 V, and a control device of a solenoid valve mounted on a vehicle having an electric motor and an engine,
The solenoid valve is a control unit for a solenoid valve including a control unit that injects fuel directly into a cylinder of an engine and charges a capacitor of a booster circuit that boosts a voltage supplied to the solenoid valve by the high voltage source.

Images