JP2006336536A - Drive device of electric load - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drive device of an electric load including a function driving a fuel injection valve by electric power from an electric power supply means boosting and outputting power source voltage and a function driving on-vehicle electric load other than the fuel injection valve, and suitably suppressing enlargement of the drive device and increase of heating value. <P>SOLUTION: In the drive device of the electric load, discharge current of a capacitor 40 is supplied to electromagnetic solenoids 4a, 4b and discharge current of a capacitor 42 is supplied to electromagnetic solenoids 4c, 4d. The electromagnetic solenoid 70 provided on a pressure reducing valve or the like, and a change over circuit 80 changing over continuity to the capacitor 40 or the capacitor 42 is connected to a high electric potential side of the electromagnetic solenoids 4a-4d. The change over circuit 80 establishes continuity of the electromagnetic solenoid 70 to one of the capacitors 40, 42 not used for drive of the electromagnetic solenoids 4a-4d. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention has a function of driving an electronically controlled fuel injection valve of an in-vehicle internal combustion engine by power from a power supply means that boosts and outputs a power supply voltage, and a function of driving an in-vehicle electric load other than the fuel injection valve. The present invention relates to an electric load driving device.

  FIG. 7 shows an example of a fuel injection valve drive device. As shown in the figure, this drive device is configured as an electronic control device (ECU 101) including a microcomputer 102 and the like. The ECU 101 performs energization control on the electromagnetic solenoids 104a to 104d included in each of the fuel injection valves. The energization control of these electromagnetic solenoids 104a to 104d is performed by the microcomputer 102 driving the drive circuit that drives them. Hereinafter, this drive circuit will be described.

  This drive circuit includes a booster circuit 110 that boosts a battery voltage (eg, “12V”) to a predetermined voltage (eg, “100V”). The output of the booster circuit 110 is supplied to the electromagnetic solenoids 104a and 104b via the diode 116 and the drive start switch 120. The output of the booster circuit 110 is supplied to the electromagnetic solenoids 104 c and 104 d via the diode 118 and the drive start switch 122. The terminals on the low potential side of the electromagnetic solenoids 104a to 104d are grounded via the selection switches 124 to 130, respectively.

  A capacitor 140 that stores boosted power of the booster circuit 110 is connected between the diode 116 and the drive start switch 120 in such a manner that the other terminal is grounded. Further, a capacitor 142 for storing boosted power of the booster circuit 110 is connected between the diode 118 and the drive start switch 122 in such a manner that the other terminal is grounded.

  A current circuit 150 is connected to the electromagnetic solenoids 104a and 104b in order to continue energization started by discharging of the capacitor 140. In addition, a current circuit 160 is connected to the electromagnetic solenoids 104c and 104d in order to continue energization of the electromagnetic solenoids 104c and 104d started by discharging of the capacitor 142.

  The drive start switch 120 connects and disconnects the high-potential terminals of the electromagnetic solenoids 104a and 104b and the capacitor 140. The drive start switch 122 connects the high-potential terminals of the electromagnetic solenoids 104c and 104d and the capacitor 142. Conducted and interrupted. Therefore, by selectively turning on the selection switches 124 to 130 in a state where any one of the drive start switches 120 and 122 is turned on, any boosted power of the capacitor 140 or the capacitor 142 can be used. The electromagnetic solenoids 104a to 104d can be energized selectively.

  By the way, in recent years, the in-vehicle electronic control system has been increasingly complicated, and the number of actuators used for electronic control has been increasing. Under these circumstances, regarding the control of the internal combustion engine, it has been proposed to provide an electromagnetically driven pressure reducing valve for reducing the pressure inside the common rail that supplies high pressure fuel to the fuel injection valve of the diesel engine ( The number of electronically controlled actuators used, such as Patent Document 1), is steadily increasing.

Under such circumstances, by adding a drive circuit for driving an electronically controlled actuator, an increase in the size of a drive device for an electric load, an increase in the amount of heat generation, and the like have become serious problems.
JP 2003-176746 A

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to drive a fuel injection valve with electric power from a power supply unit that boosts and outputs a power supply voltage, and other than the fuel injection valve. An object of the present invention is to provide an electric load driving device that has a function of driving an in-vehicle electric load and can suitably suppress an increase in the size of the driving device and an increase in the amount of heat generated.

  Hereinafter, means for solving the above-described problems and the operation and effects thereof will be described.

  The means 1 has a function of driving an electronically controlled fuel injection valve of an in-vehicle internal combustion engine with electric power from a power supply means that boosts and outputs a power supply voltage, and a function of driving an in-vehicle electric load other than the fuel injection valve. The electric load driving device includes an energization circuit that supplies electric power of the power feeding means to the in-vehicle electric load.

  In the said structure, the electric power of a vehicle-mounted electric load is supplied by an electricity supply means. Thus, by sharing the power feeding means with the fuel injection valve, it is possible to configure the drive device without separately providing means for boosting and outputting the power supply voltage for driving the on-vehicle electric load. . For this reason, according to the said structure, the enlargement of a drive device and the increase in the emitted-heat amount can be suppressed suitably.

  Means 2 is characterized in that, in means 1, the energization circuit further comprises a switching element for opening and closing a loop circuit comprising the power feeding means and the in-vehicle electric load.

  According to the above configuration, since the power of the power feeding means is not supplied to the on-vehicle electric load when the loop circuit is opened by the switching element, it is possible to control whether the power feeding means supplies power to the on-vehicle electric load. .

  Means 3 is means 2, wherein the internal combustion engine comprises a plurality of the fuel injection valves, and the drive device comprises a plurality of the power feeding means, and each of the plurality of fuel injection valves comprises an electronic control type. The actuator further includes a selection switch that opens and closes a power supply path through which any one of the power supply units supplies power, and the energization circuit includes a switching circuit that selectively switches the power supply unit to be electrically connected to the in-vehicle electric load. It is characterized by becoming.

  In the above configuration, since a plurality of power feeding means are provided when driving the plurality of fuel injection valves, the electric system for supplying power to the electronically controlled actuator is multiplexed. For this reason, even if a specific electric system is short-circuited or disconnected, a limp home process for driving actuators of other electric systems can be performed as a fail-safe process.

  Further, in the above configuration, since the power feeding means to be electrically connected to the on-vehicle electric load is switched by the switching circuit, the on-vehicle electric load can be driven using the power feeding means that is not used for driving the fuel injection valve.

  The means 4 controls the power supply to the actuator by operating the selection switch in the means 3 and switches the power supply means not supplying power to the actuator and the in-vehicle electric load. Control means for controlling the circuit is further provided.

  According to the above configuration, when the selection switch is operated by the control means, the electronically controlled actuator of the fuel injection valve that is requested to drive is brought into conduction with the corresponding power supply means. Further, the power supply means that is not supplying power to the actuator and the in-vehicle electric load are conducted by the control of the switching circuit by the control means. For this reason, the vehicle-mounted electrical load can be driven by the control means using the power supply means that is not used for driving the fuel injection valve.

  The means 5 is characterized in that, in the means 3 or 4, the switching circuit is externally attached to the housing of the driving device.

  According to the above configuration, since the switching circuit is externally attached to the drive device, the amount of heat generated in the housing can be reduced by the amount of heat generated by the switching circuit.

  The means 6 is any one of the means 3 to 5, wherein the switching circuit includes a semiconductor relay.

  According to the above configuration, the switching responsiveness can be improved by using the switching circuit including the semiconductor relay.

  The means 7 is any one of the means 1 to 6, wherein the power supply means has a function of supplying electric power obtained by boosting the power supply voltage to the actuator, and in addition to supplying the electric power of the power supply to the actuator after the supply of the boosted electric power. It is further provided with the function to supply directly.

  According to the above configuration, by supplying the boosted power, the responsiveness at the start of the operation of the actuator is improved, and thereafter, the actuator is driven by the power of the power source to suppress the power consumption. be able to.

  The means 1 to 7 may be characterized in that, as with the means 8, the in-vehicle electric load is an actuator that performs a binary operation according to the presence or absence of energization.

  Here, if the means 8 has the structure of the means 7, by supplying the boosted power, the responsiveness at the start of the operation of the in-vehicle electric load is improved, and thereafter, the in-vehicle electric load is increased by the power of the power source. Power consumption can be suppressed by driving.

  The means 1 to 8 may be characterized in that, as with the means 9, the electronically controlled actuator of the fuel injection valve comprises an electromagnetic solenoid.

  Here, since an actuator provided with an electromagnetic solenoid requires a large electric power at the start of operation, when it has the configuration of the means 8, its effect can be achieved particularly suitably.

  As in means 10, the vehicle-mounted internal combustion engine stores the fuel pumped up from the fuel tank in a high pressure state and supplies the fuel injection valve with the pressure accumulation chamber and the fuel in the pressure accumulation chamber. A pressure reducing valve that returns to the tank, and at least one of a fuel addition valve that adds fuel to the exhaust system for regeneration of an aftertreatment device that is provided in the exhaust system of the internal combustion engine. It is desirable that the fuel addition valve is any one of the above.

  Hereinafter, an embodiment in which a drive device for an electric load according to the present invention is applied to a drive device for a fuel injection valve and a pressure reducing valve (fuel addition valve) of a diesel engine will be described with reference to the drawings.

  FIG. 1 shows the configuration of the drive device.

  In the present embodiment, the drive device is configured as a part of an electronic control device (ECU1) of the diesel engine.

  The ECU 1 includes a microcomputer 2 and the like, takes in detection values of various sensors of the engine, and operates various actuators of the engine based on the detection values. In particular, the ECU 1 performs energization control for a fuel injection valve that injects and supplies fuel to the combustion chamber of each cylinder (here, four cylinders are exemplified) of the engine that is a multi-cylinder internal combustion engine (more precisely, fuel injection) Energization control is performed on the electromagnetic solenoids 4a to 4d used for opening and closing the valve). In the figure, the first cylinder is # 1, the second cylinder is # 2, the third cylinder is # 3, and the fourth cylinder is # 4.

  The energization control to these electromagnetic solenoids 4 a to 4 d is performed by driving a drive circuit provided in the ECU 1 by the microcomputer 2. Hereinafter, this drive circuit will be described.

  The drive circuit includes a booster circuit 10 that boosts a battery voltage (eg, “12V”) to a predetermined voltage (eg, “100V”). The booster circuit 10 includes a series connection body of a coil 12 and a switching element 14, and boosts the voltage of the battery power supply when the switching element 14 is turned on / off by the microcomputer 2. The anodes of the diodes 16 and 18 are connected between the coil 12 of the booster circuit 10 and the switching element 14.

  The cathode side of the diode 16 is connected to the electromagnetic solenoids 4 a and 4 b via the drive start switch 20. The cathode side of the diode 18 is connected to the electromagnetic solenoids 4 c and 4 d via the drive start switch 22.

  The electromagnetic solenoids 4a to 4d have one terminal connected to the booster circuit 10 via the drive start switches 20 and 22, and the other terminal grounded via the selection switches 24 to 30.

  A capacitor 40 that stores boosted power of the booster circuit 10 is connected between the diode 16 and the drive start switch 20 in such a manner that the other terminal is grounded. Further, a capacitor 42 for storing boosted power of the booster circuit 10 is connected between the diode 18 and the drive start switch 22 in such a manner that the other terminal is grounded.

  The electromagnetic solenoids 4a and 4b and the capacitor 40 are electrically connected and disconnected by the drive start switch 20, and the electromagnetic solenoids 4c and 4d and the capacitor 42 are electrically connected and disconnected by the drive start switch 22. Therefore, when at least one of the drive start switches 20 and 22 is turned on, the selection switches 24 to 30 are selectively turned on while the corresponding terminals of the electromagnetic solenoids 4a to 4d are electrically connected to the booster circuit 10. Thus, the corresponding electromagnetic solenoids 4a to 4d can be energized using the boosted power of the capacitor 40 and the capacitor 42. For example, if the selection switch 24 is turned on while at least one of the drive start switches 20 and 22 is turned on and the terminals of the corresponding electromagnetic solenoids 4a to 4d are electrically connected to the booster circuit 10, the electromagnetic switch The solenoid 4a can be selectively energized.

  A current circuit 50 is connected to a node a between the drive start switch 20 and the electromagnetic solenoids 4a and 4b so as to continue energization of the electromagnetic solenoids 4a and 4b started by discharging of the capacitor 40. The current circuit 50 includes a diode 52 that outputs battery power to the node a, a switching element 54 that conducts and blocks the diode 52 and the battery, and a diode 56 that has a forward direction from ground to the node a. Configured.

  A current circuit 60 is connected to a node b between the drive start switch 22 and the electromagnetic solenoids 4c and 4d so as to continue energization of the electromagnetic solenoids 4c and 4d started by discharging of the capacitor 42. The current circuit 60 includes a diode 62 that outputs battery power to the node b, a switching element 64 that conducts and cuts off between the diode 62 and the battery, and a diode 66 that has a forward direction from ground to the node b. Configured.

  The voltages of the node c, which is a connection point downstream of the selection switches 24, 26, and the node d, which is a connection point downstream of the selection switches 28, 30, are monitored by the microcomputer 2, whereby the microcomputer 2 The amount of current flowing through the electromagnetic solenoids 4a to 4d is detected.

  Here, the energization control to the electromagnetic solenoids 4a to 4d by the microcomputer 2 will be described with reference to FIG.

  FIG. 2A shows the transition of the energization current of the electromagnetic solenoids 4a to 4d (one of them). FIG. 2B shows a transition of the operation mode of the drive start switches 20 and 22 (one of them). FIG. 2C shows the transition of the operation mode of the switching element 54 of the current circuit 50 or the switching element 64 of the current circuit 60. FIG. 2D shows the transition of the operation mode of the selection switches 24 to 30 (any one).

  The transition characteristics shown in FIG. 2 can be obtained by using any one of the electromagnetic solenoids 4a to 4d and any of the drive start switches 20 and 22, and further by the switching element 54 or the current circuit 60 of the current circuit 50. Therefore, the electromagnetic solenoid 4a, the drive start switch 20, and the switching element 54 of the current circuit 50 will be described below as an example.

  At time t1, the drive start switch 20 is turned on and the selection switch 24 is turned on, whereby a current flows through the electromagnetic solenoid 4a. The amount of current flowing through the electromagnetic solenoid 4a decreases with a peak (for example, “18A”) at time t2 when the drive start switch 20 is turned off. However, in the present embodiment, since the current circuit 50 is driven from time t3 to time t6, the current peaked at time t2 is the first intermediate current (for example, “8A”) from time t3 to t4. ) And between time t5 and time t6, the second intermediate current (for example, “4A” <first intermediate current) is controlled. After the energization of the electromagnetic solenoid 4a by the current circuit 50 is completed, the selection switch 24 is turned off at time t7.

  As described above, the ECU 1 can drive the fuel injection valve by performing energization control on the electromagnetic solenoids 4a to 4d.

  Further, the ECU 1 is equipped with a pressure reducing valve (or an engine exhaust system) for returning the fuel in the common rail (pressure accumulating chamber) that supplies the fuel pumped up from the fuel tank in a high pressure state and supplies the fuel injection valve to the fuel tank. A fuel addition valve for adding fuel to the exhaust system for regeneration of an aftertreatment device (for example, a diesel particulate filter) is driven. This will be described below.

  As shown in FIG. 1, a switching circuit 80 is connected to a high potential side terminal of an electromagnetic solenoid 70 provided in the pressure reducing valve (or fuel addition valve). The terminal on the low potential side of the electromagnetic solenoid 70 is grounded via the switching element 72.

  The switching circuit 80 switches whether the terminal on the high potential side of the electromagnetic solenoid 70 is connected to an electric system that supplies electric power to the electromagnetic solenoids 4a and 4b or an electric system that supplies electric power to the electromagnetic solenoids 4c and 4d. It is. The switching circuit 80 is formed by a semiconductor relay as shown in FIG.

  As shown in the figure, the switching circuit 80 includes an output terminal RT1 connected to a terminal on the high potential side of the electromagnetic solenoid 70 shown in FIG. The drains of N-channel MOS transistors 81 and 82 are connected to the output terminal RT1. The source of the transistor 81 is connected to the power supply terminal RT2 connected to the high potential side of the electromagnetic solenoids 4a and 4b shown in FIG. The source of the transistor 82 is connected to the power supply terminal RT3 connected to the high potential side terminals of the electromagnetic solenoids 4c and 4d shown in FIG. Further, the outputs of the driver circuits 83 and 84 are applied to the gates of the transistors 81 and 82. The driver circuit 83 converts the signal taken in from the control terminal RT4 into the power taken in from the power supply terminal RT2, and applies it to the gate of the transistor 81. On the other hand, the driver circuit 84 converts power obtained by logically inverting the signal fetched from the control terminal RT4 by the inverter 85 with the power fetched from the power supply terminal RT3, and applies it to the gate of the transistor 82. The driver circuits 83 and 84 are grounded via the ground terminal RT5.

  According to such a configuration, when the signal output from the microcomputer 2 to the control terminal RT4 is logic “H”, the power of the capacitor 42 and the current circuit 60 is supplied to the electromagnetic solenoid 70 via the power supply terminal RT2 and the transistor 81. Supplied. On the other hand, when the signal output from the microcomputer 2 to the control terminal RT4 is logic “L”, the power of the capacitor 40 and the current circuit 50 is supplied to the electromagnetic solenoid 70 via the power supply terminal RT3 and the transistor 82.

  With such a configuration, by using the electric power of the capacitors 40 and 42 and the electric power of the current circuits 50 and 60 together, energization control for the electromagnetic load can be performed while improving the responsiveness of the electromagnetic solenoid 70. Here, FIG. 4 shows an example of energization control of the electromagnetic load using both the power of the capacitors 40 and 42 and the power of the current circuits 50 and 60.

  FIG. 4A shows the transition of the energization current of the electromagnetic solenoid 70. FIG. 4B shows the transition of the operation mode of the drive start switches 20 and 22 (any one). FIG. 4C shows the transition of the operation mode of the switching element 54 of the current circuit 50 or the switching element 64 of the current circuit 60. FIG. 4D shows the transition of the operation mode of the switching element 72.

  The transition characteristics shown in FIG. 4 are the same regardless of which of the drive start switches 20 and 22 is used, and whether the switching element 54 of the current circuit 50 or the switching element 64 of the current circuit 60 is used. Hereinafter, the drive start switch 20 and the switching element 54 of the current circuit 50 will be described as examples. In other words, the case where the capacitor 40 and the current circuit 50 are selected by the switching circuit 80 will be described as an example.

  At time t11, the drive start switch 20 is turned on and the switching element 72 is turned on, whereby a current flows through the electromagnetic solenoid 70. The amount of current flowing through the electromagnetic solenoid 70 decreases with a peak at time t12 when the drive start switch 20 is turned off. However, in the present embodiment, since the current circuit 50 is driven from time t13 to time 14, the current peaked at time t12 is controlled to an intermediate current from time t13 to t14. Then, the switching element 72 is turned off at time t15 after the driving of the current circuit 50 is completed.

  Control of the switching circuit 80 is performed using one of the capacitors 40 and 42 and the current circuits 50 and 60 that are not used for energization of the electromagnetic solenoids 4a to 4d, as illustrated in FIG. In FIG. 5, three-stage pilot injection and one-stage main injection are performed in the first cylinder in the “0 to 180 ° CA” region, and three-stage in the third cylinder in the “180 to 360 ° CA” region. Pilot injection and one-stage main injection are performed. Therefore, the energization control of the electromagnetic solenoid 4a is performed using the capacitor 40 and the current circuit 50 in the “0 to 180 ° CA” region, and the capacitor 42 and the current circuit 60 are used in the “180 to 360 ° CA” region. The energization control of the electromagnetic solenoid 4c is performed. Further, in the region of “0 to 180 ° CA”, the electromagnetic solenoid 70, the capacitor 42, and the current circuit 60 are electrically connected by the switching circuit 80, and in the region of “180 to 360 ° CA”, the electromagnetic solenoid 70 is operated by the switching circuit 80. Are connected to the capacitor 40 and the current circuit 50.

  As described above, by using the capacitors 40 and 42 and the current circuits 50 and 60 which are not used for energization of the electromagnetic solenoids 4a to 4d, the capacitors 40 and 42 and the drive start switches 20 and 22 can be electromagnetically connected. The design may be based on the premise that either one of the solenoids 4a to 4d or the electromagnetic solenoid 70 is driven. For this reason, the enlargement of the capacitors 40 and 42 can be avoided.

  On the other hand, an example in which such a switching circuit 80 is not provided is shown in FIG. In FIG. 6, members having the same functions as those shown in FIG. 1 are given the same reference numerals for the sake of convenience.

  In FIG. 6, since the switching circuit 80 is not provided, the capacitor 40 and the current circuit 50 are used when the electromagnetic solenoids 4a to 4d are energized. In order to make this possible, it is required to increase the size of the capacitor 40 and to make the drive start switch 20 compatible with high power. When these requirements cannot be satisfied, the electromagnetic solenoid 70 is driven using only the current circuit 50, and the responsiveness of the actuator including the electromagnetic solenoid 70 (the actuator for the pressure reducing valve and the actuator for the fuel addition valve) is reduced. To do.

  Further, in this embodiment, since the switching circuit 80 is externally attached to the casing of the ECU 1, the amount of heat generated in the casing of the ECU 1 is reduced by the amount of heat generated by the switching circuit 80.

  According to the embodiment described in detail above, the following effects can be obtained.

  (1) An energization circuit for supplying the electric power of the capacitors 40 and 42 to the electromagnetic solenoid 70 is provided. In this way, in the energization control, the capacitors 40 and 42 are shared with the electromagnetic solenoids 4a to 4d, so that a circuit similar to the booster circuit 10 and the capacitors 40 and 42 is separately provided for driving the electromagnetic solenoid 70. The ECU 1 can be configured. For this reason, the enlargement of a circuit scale and the increase in the emitted-heat amount can be suppressed suitably.

  (2) By including the switching element 72 that opens and closes the loop circuit including the capacitors 40 and 42, the current circuits 50 and 60, and the electromagnetic solenoid 70, it is possible to control whether or not the electromagnetic solenoid 70 is energized.

  (3) A switching circuit 80 for selectively switching between the electromagnetic solenoid 70 and the capacitor 40 or 42 is provided. Thereby, among the capacitors 40 and 42, the electromagnetic solenoid 70 can be driven by using one that is not used for driving the electromagnetic solenoids 4a to 4d.

  (4) Since the switching circuit 80 is externally attached to the casing of the ECU 1, the amount of heat generated in the casing can be reduced by the amount of heat generated by the switching circuit.

  (5) Since the switching circuit 80 is configured by a semiconductor relay, the switching response can be improved.

(Other embodiments)
Each of the above embodiments may be modified as follows.

  The energization control of the electromagnetic solenoid 70 may be performed by operating the drive start switches 20 and 22 and the switching elements 54 and 64 of the current circuits 50 and 60 without providing the switching element 72.

  For example, also in the configuration shown in FIG. 6, if the capacitance of the capacitor 40 is increased and the drive start switch 20 has durability against a large current, the discharge of the capacitor 40 is used (the boosted power is reduced). Use of the electromagnetic solenoid 70 can be controlled.

  -Switching circuit 80 is not restricted to what is constituted using the above-mentioned semiconductor relay. However, at this time, it is desirable to have durability against frequent switching.

  -The on-board electric load is not limited to the electromagnetic solenoid that constitutes the actuator of the pressure reducing valve or the fuel addition valve. However, an actuator that performs a binary operation according to the presence or absence of energization is desirable. That is, in this case, after the energization control is started using the discharge current of the capacitor, the energization control is continued using the current circuit, so that the response of the actuator can be improved. Furthermore, the in-vehicle electric load may not be driven by a current circuit, and may be required to be driven by electric power obtained by boosting the voltage of the power source. In this case, the on-vehicle electric load is driven only by the discharge current of the capacitor without using the current circuit. Further, in this case, the on-vehicle electric load may be directly driven by the output of the booster circuit instead of using the discharge current of the capacitor.

  Even if the switching circuit 80 is housed in the casing of the ECU 1, the effects (1) to (3) and (5) of the previous embodiment can be obtained.

  -As a drive device of vehicle-mounted electric load, it is not restricted to the structure with which ECU1 is equipped. For example, the drive unit may be configured by unitizing as a dedicated driver circuit (EDU) not provided with a microcomputer, and the EDU may be operated by an ECU provided with a microcomputer separately from this.

  The fuel injection valve actuator is not limited to an electromagnetic solenoid, and may be a piezoelectric element, for example.

  In addition, the on-vehicle internal combustion engine is not limited to a diesel engine, and may be, for example, a direct injection gasoline engine. In this case, the on-vehicle electric load may be an electromagnetic solenoid provided in the actuator of the high-pressure fuel pump.

The figure which shows the structure of one Embodiment of the drive device of the vehicle-mounted electrical load concerning this invention. The time chart which shows transition of the energization current of the fuel injection valve concerning the embodiment. The circuit diagram which shows the circuit structure of the semiconductor relay concerning the embodiment. The time chart which shows transition of the conduction current of the vehicle-mounted electrical load concerning the embodiment. The figure which shows the control aspect of the switching circuit concerning the embodiment. The figure explaining the problem in case a switching circuit is not provided. The circuit diagram which shows the structure of the drive device of the conventional vehicle-mounted electrical load.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Electronic control unit (ECU), 2 ... Microcomputer (one embodiment of a control means), 4a-4d ... Electromagnetic solenoid, 40, 42 ... Capacitor, 50, 60 ... Current circuit, 70 ... Electromagnetic solenoid, 80 ... Switching circuit.

Claims (10)

An electric load having a function of driving an electronically controlled fuel injection valve of an in-vehicle internal combustion engine by power from a power supply means that boosts and outputs a power supply voltage, and a function of driving an in-vehicle electric load other than the fuel injection valve In the drive device,
An electric load driving device comprising an energization circuit for supplying electric power of the power feeding means to the in-vehicle electric load.   2. The electric load driving device according to claim 1, wherein the energization circuit further includes a switching element that opens and closes a loop circuit including the power feeding unit and the in-vehicle electric load. The internal combustion engine includes a plurality of the fuel injection valves,
The drive device includes a plurality of the power supply means, and
And further comprising a selection switch for opening and closing a power feeding path through which any of the power feeding means supplies power to an electronically controlled actuator provided in each of the plurality of fuel injection valves,
3. The electric load driving device according to claim 2, wherein the energization circuit includes a switching circuit that selectively switches the power feeding means to be electrically connected to the in-vehicle electric load.   Control means for controlling power supply to the actuator by operating the selection switch, and for controlling the switching circuit so that the power feeding means that is not supplying power to the actuator and the in-vehicle electric load are conducted. The electric load driving device according to claim 3, wherein the electric load driving device is provided.   5. The drive device for an electric load according to claim 3, wherein the switching circuit is externally attached to a housing of the drive device.   6. The electric load driving device according to claim 3, wherein the switching circuit includes a semiconductor relay.   The power supply unit further includes a function of directly supplying the power of the power source to the actuator after the supply of the boosted power, in addition to a function of supplying the power obtained by boosting the power supply voltage to the actuator. The electric load drive device according to claim 1.   The electric load driving device according to any one of claims 1 to 7, wherein the on-vehicle electric load is an actuator that performs a binary operation according to the presence or absence of energization.   9. The electric load driving device according to claim 1, wherein the electronically controlled actuator of the fuel injection valve is configured to include an electromagnetic solenoid. The on-vehicle internal combustion engine includes a pressure accumulation chamber that stores fuel pumped up from a fuel tank in a high pressure state and supplies the fuel injection valve with a pressure accumulation chamber, a pressure reduction valve that returns the fuel in the pressure accumulation chamber to the fuel tank, and an exhaust system of the internal combustion engine. Comprising at least one of fuel addition valves for adding fuel to the exhaust system for regeneration of the provided aftertreatment device;
The electric load driving device according to any one of claims 1 to 9, wherein the on-vehicle electric load is one of the pressure reducing valve and the fuel addition valve.

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