JP2006322324A - Drive device of fuel injection valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drive device of a fuel injection valve capable of properly performing a limp-home treatment when trouble occurs in an electric system for feeding electric energy to electronically controlled actuators installed in a plurality of fuel injection valves. <P>SOLUTION: Charges accumulated in capacitors 40 and 42 are discharged to controllably energize electromagnetic solenoids 4a to 4d through high-side terminals T1 and T2. A first relay 70 and a second relay 72 capable of selectively communicating the high-side terminals T1 and T2 with any one of the electromagnetic solenoids 4a to 4d are installed between the high potential side terminals of the electromagnetic solenoids 4a to 4d and the high-side terminals T1 and T2. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention selectively supplies electric energy of a power feeding means to an actuator of a fuel injection valve that is requested to be driven among electronic control actuators provided in each of a plurality of fuel injection valves that perform fuel injection supply in an internal combustion engine. The present invention relates to a fuel injection valve drive device that drives the fuel injection valve.

  FIG. 6 shows an example of this type of driving 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 the capacitor 140. Further, a current circuit 160 is connected to the electromagnetic solenoids 104c and 104d so as to continue energization of the electromagnetic solenoids 104c and 104d started by 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.

  The driving device has two electric systems: an electric system that supplies power to the electromagnetic solenoids 104a and 104b by the capacitor 140 and the current circuit 150, and an electric system that supplies power to the electromagnetic solenoids 104c and 104d by the capacitor 142 and the current circuit 160. Has a system. By dividing the electrical system in this manner, limp home processing using the other electrical system can be performed as fail-safe processing when an abnormality occurs in one electrical system.

  However, for example, when the terminal on the high potential side of the electromagnetic solenoid 104d is short-circuited to the ground, the limp home process using the electromagnetic solenoids 104a and 104b can be performed by turning off the drive start switch 122. In practice, there is a problem that even an electromagnetic solenoid 104c having no abnormality cannot be used. For this reason, at the time of limp home, the output of the internal combustion engine may not be sufficient. Particularly in a large-sized commercial vehicle or the like loaded to the maximum extent, there is a risk that the output of the internal combustion engine at the time of limp home processing may not be sufficient.

  On the other hand, it is conceivable that each of the electromagnetic solenoids 104a to 104d has a separate electric system, but problems such as an increase in the size of the ECU 101 and an increase in the amount of heat generated due to an increase in the number of capacitors and the like. There are also many.

As a conventional technique for grouping control systems for a plurality of cylinders of an internal combustion engine in order to perform fail-safe processing, there is, for example, the following Patent Document 1 in addition to the above driving device.
Japanese Utility Model Publication No. 6-12743

  The present invention has been made to solve the above-described problems, and an object of the present invention is to supply electric energy to an electronically controlled actuator provided in each of a plurality of fuel injection valves. An object of the present invention is to provide a fuel injection valve drive device that can perform limp home processing more appropriately when an abnormality occurs.

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

  The means 1 selectively supplies the electric energy of the power feeding means to the actuator of the fuel injection valve that is requested to drive among the electronically controlled actuators provided in each of the plurality of fuel injection valves that perform fuel injection supply in the internal combustion engine. In the fuel injection valve drive device that drives the fuel injection valve, the high potential side terminal that is electrically connected to the power supply means is connected between the high potential side terminals of the plurality of actuators and the power supply means. A high potential side switching circuit for selectively switching is provided.

  In the above configuration, since the high potential side switching circuit is provided between the high potential side terminals of the plurality of actuators and the power supply means, the same operation is performed when an abnormality occurs in the electrical system that supplies electrical energy to the specific actuator. The high potential side switching circuit can be switched so as to prohibit conduction between the high potential side terminal of the specific actuator and the power feeding means. For this reason, even if an abnormality occurs in the electric system used when supplying electric energy to a specific actuator, electric energy can be appropriately supplied to other actuators, and thus limp home processing can be performed. Can be done appropriately.

  Means 2 is characterized in that, in means 1, the high-potential side switching circuit is capable of selectively conducting the power feeding means and any one actuator.

  According to the above configuration, when an abnormality occurs in the electrical system used when supplying electrical energy to a specific actuator, all actuators other than the specific actuator can be continuously driven. For this reason, the output torque of the internal combustion engine can be increased as much as possible even during limp home.

  The means 3 further includes a low-potential side switching circuit that selectively switches the low-potential side terminal that is electrically connected to the ground between the low-potential side terminals of the plurality of actuators and the ground in the means 1 or 2. It is characterized by providing.

  In the above configuration, since the low potential side switching circuit is provided, the following effects can be obtained.

  a. In the case of a configuration in which any one actuator and power supply means are independently conducted by the low potential side switching circuit. In this case, by combining with the control of the high potential side switching circuit, one electric system used when supplying electric energy to a specific actuator can be accurately specified.

  b. When the group of actuators connected to the power supply means can be switched by the low potential side switching circuit. In this case, it is possible to further narrow down the actuators that are electrically connected to the power supply means by combination with the high potential side switching circuit (can be specified in more detail).

  Means 4 is characterized in that, in means 3, the low-potential side switching circuit is capable of selectively conducting the ground and any one actuator.

  In the above-described configuration, it is possible to selectively supply the electric energy of the power feeding means to the actuator of any one fuel injection valve that is requested to be driven without the high potential side switching circuit. For this reason, for example, when there is a request to secure the output torque of the internal combustion engine as much as possible during limp home, a high potential side switching circuit can be provided according to the request.

  The means 5 is characterized in that, in the means 3 or 4, the high potential side switching circuit is externally attached to a housing in which the low potential side switching circuit and the power feeding means are housed.

  In the above configuration, since the high-potential side switching circuit is externally attached to the casing, the high-potential side switching circuit is used and not used without increasing the size of the casing. And the housing can be shared. For this reason, the versatility of the member which consists of a housing | casing and the circuit inside it can be improved, without causing the enlargement of the dimension of a housing | casing. Furthermore, the amount of heat generated in the housing can be reduced by externally attaching a high potential side switching circuit.

  Means 6 is characterized in that in any one of means 1 to 5, control means for controlling the high potential side switching circuit in response to the drive request is provided.

  According to the above configuration, the high potential side switching circuit is controlled by the control means in response to the drive request. Incidentally, when the means 6 has the structure of the means 5, the control means may be housed in the housing, or may be housed in another housing.

  The means 7 further comprises diagnostic means for diagnosing the presence or absence of an abnormality in the electric system when supplying electric energy from the power supply means to the actuator in each of the plurality of fuel injection valves in the means 6, and the control means Is characterized in that the high-potential side switching circuit is controlled so as to prohibit conduction between the actuator corresponding to the electrical system determined to be abnormal by the diagnostic means and the power feeding means.

  In the above configuration, when there is an abnormality in the electrical system, the high potential side switching circuit is controlled so as to prohibit conduction between the actuator corresponding to the electrical system having the abnormality and the power feeding means. Incidentally, when this means 7 has the structure of means 5, the diagnostic means may be accommodated in the said housing | casing, and may be accommodated in another housing | casing.

  The means 8 is characterized in that, in any one of the means 1 to 7, the high potential side switching circuit is constituted by a semiconductor relay.

  In the said structure, the response of switching can be made favorable by using a semiconductor relay.

(First embodiment)
Hereinafter, a first embodiment in which a fuel injection valve driving device according to the present invention is applied to an electronic solenoid fuel injection valve driving device will be described with reference to the drawings.

  FIG. 1 shows the configuration of the drive device.

  The electronic control unit (ECU 1) includes a microcomputer 2 and the like, takes in detection values of various sensors of the internal combustion engine (diesel engine), and operates various actuators of the internal combustion engine based on the detection values. In particular, the ECU 1 performs energization control with respect to an electronically controlled actuator provided in each fuel injection valve that injects and supplies fuel to the combustion chamber of each cylinder (here, four cylinders are exemplified) of the internal combustion engine. More precisely, energization control is performed on the electromagnetic solenoids 4a to 4d. Incidentally, the electromagnetic solenoids 4a, 4b, 4c, and 4d are provided in the first cylinder, the fourth cylinder, the third cylinder, and the second cylinder (# 1, # 4, # 3, and # 2 in the drawing), respectively.

  The energization control to these electromagnetic solenoids 4 a to 4 d is performed by the microcomputer 2 operating a drive circuit that drives them. 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. The switching element 14 is turned on / off by the microcomputer 2 to boost the voltage of the battery. 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 a high side terminal T1 that supplies electric power to the electromagnetic solenoids 4a and 4b via a drive start switch 20. Further, the cathode side of the diode 18 is connected to a high side terminal T <b> 2 that supplies electric power to the electromagnetic solenoids 4 c and 4 d via the drive start switch 22.

  In the electromagnetic solenoids 4a to 4d, the high potential side terminals are connected to the high side terminals T1 and T2, and the low potential side terminals are connected to the low side terminals Ta to Td. The low side terminals Ta to Td are grounded via selection switches 24 to 30, respectively.

  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.

  A current circuit 50 is connected to a node Na 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 the discharge of the capacitor 40. The current circuit 50 includes a diode 52 that outputs battery power to the node Na, a switching element 54 that conducts and cuts off the diode 52 and the battery, and a diode 56 that has a forward direction from ground to the node Na. Configured.

  A current circuit 60 is connected to a node Nb 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 Nb, 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 Nb. Configured.

  The drive start switches 20 and 22, the selection switches 24 to 30, and the switching elements 14, 54 and 64 are operated by the microcomputer 2.

  The drive start switch 20 connects and disconnects the high side terminal T1 and the capacitor 40, and the drive start switch 22 connects and disconnects the high side terminal T2 and the capacitor 42. Therefore, when any one of the drive start switches 20 and 22 is turned on, the selection switches 24 to 30 are in a state where any one of the high side terminals T1 and T2 and the corresponding capacitors 40 and 42 are electrically connected. By selectively turning on, it is possible to selectively energize any of the electromagnetic solenoids 4a to 4d using the boosted power of the capacitor 40 or the capacitor 42.

  However, in the present embodiment, any one high potential side terminal is electrically connected to the high side terminals T1 and T2 between the high potential side terminals of the electromagnetic solenoids 4a to 4d and the high side terminals T1 and T2. Further, a switching circuit that can perform the above-described operation is further provided to provide redundancy to the electric system that supplies power to the electromagnetic solenoids 4a to 4d.

  This switching circuit includes a first relay 70 that selectively supplies power from the high-side terminal T1 to one of the electromagnetic solenoids 4a and 4b, and any one of the electromagnetic solenoids 4c and 4d that supplies power from the high-side terminal T2. And a second relay 72 that selectively supplies the crabs. The first relay 70 and the second relay perform the selective supply of power according to a control signal output from the microcomputer 2 via the control terminals T3 and T4, respectively. Both the first relay 70 and the second relay 72 are grounded by being connected to the ground terminal T5.

  Both the first relay 70 and the second relay 72 are semiconductor relays. As these specific structures, it is good also as what is illustrated by FIG. 2, for example.

  As shown in the drawing, the semiconductor relay includes two output terminals RT1 and RT2. The drains of N-channel MOS transistors 81 and 82 are connected to these output terminals RT1 and RT2. The sources of the transistors 81 and 82 are connected to the power supply terminal RT3. 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 captured from the control terminal RT4 into electric power using the power captured from the power supply terminal RT3, 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.

  In such a configuration, for example, the power supply terminal RT3 is connected to the high side terminal T1, the ground terminal RT5 is connected to the ground terminal T5, the output terminals RT1 and RT2 are connected to the electromagnetic solenoids 4a and 4b, and the control terminal RT4 is connected to the control terminal T3. If it is connected to, it operates as follows. That is, when a control signal of logic “H” is taken in via the control terminal RT4, the control signal is converted into power discharged from the capacitor 40 or power of the current circuit 50 by the driver circuit 83, and then the transistor 81. Applied to the gate. Thereby, the transistor 81 is turned on, and the electric power taken in via the power supply terminal RT3 is output from the output terminal RT1. Thereby, electric power is supplied to the electromagnetic solenoid 4b. At this time, since a logic “L” signal is applied to the gate of the transistor 82, the transistor 82 is turned off.

  On the other hand, when a control signal of logic “L” is taken in via the control terminal RT4, this control signal is logically inverted by the inverter 85 to become a signal of logic “H”. The logic-inverted signal is converted into power discharged from the capacitor 40 or power of the current circuit 50 by the driver circuit 84 and then applied to the gate of the transistor 82. Thereby, the transistor 82 is turned on, and the electric power taken in through the power supply terminal RT3 is output from the output terminal RT2. Thereby, electric power is supplied to the electromagnetic solenoid 4b. At this time, since a signal of logic “L” is applied to the gate of the transistor 81, the transistor 81 is turned off.

  As described above, when the semiconductor relay is used, either the output terminal RT1 or the output terminal RT2 is selectively selected depending on whether the signal received from the control terminal RT4 is logic “H” or logic “L”. In addition, power taken in from the power supply terminal RT3 is output (more precisely, this power is outputted at a timing when predetermined power is taken in from the power supply terminal RT3).

  In the present embodiment, the energization control of the electromagnetic solenoids 4a to 4d is performed by the electric system having redundancy by including the first relay 70 and the second relay 72 made of the semiconductor relay. For this reason, when conducting energization control for any one of the electromagnetic solenoids 4a to 4d, not only the selection switches 24 to 30, but also the first relay 70 and the second relay 72 are controlled. That is, for example, when energization control is performed on either the electromagnetic solenoid 4a or the electromagnetic solenoid 4b, either one of the selection switches 24 and 26 is selectively turned on and one of the above is selected by the first relay 70. This is selectively conducted to the high side terminal T1. Further, for example, when energization control is performed on either the electromagnetic solenoid 4c or the electromagnetic solenoid 4d, either one of the selection switches 28 and 30 is selectively turned on and one of the above is selected by the second relay 72. This is selectively conducted to the high side terminal T2.

  The redundancy of the electric system is effective during limp home processing performed as fail-safe control when an abnormality occurs in a part of the electric system. Here, the diagnosis of the presence or absence of abnormality in the electric system is performed by, for example, monitoring the voltage between the low-side terminals Ta to Td and the ground (specifically, the voltage downstream of the selection switches 24 to 30). It is done by. That is, for example, when the selection switch 24 is turned on and the electromagnetic solenoid 4a is selected by the first relay 70, the node a is turned on when the drive start switch 20 is turned on or when the current circuit 50 is activated. Diagnose the presence or absence of abnormality based on the voltage of. Specifically, in this case, if the voltage at the node a is different from that when the current flows through the electromagnetic solenoid 4a, it is determined that there is an abnormality in the electric system that supplies power to the electromagnetic solenoid 4a.

  Here, the control mode of the first relay 70 and the second relay 72 in the case where there is no abnormality in the electric system and in the case where there is no abnormality will be described based on FIG. 3A and FIG.

  FIG. 3A shows a control mode of the first relay 70 and the second relay 72 when there is no abnormality in the electrical system. In this figure, as fuel injection to the first cylinder (corresponding to the electromagnetic solenoid 4a), three-stage pilot injection and first-stage main injection in the region of “0 to 180 ° CA”, and “180 to 360” Post injection is performed in the “° CA” region. For this reason, in the range of “0 to 360 ° CA”, the first relay 70 is controlled so as to select the electromagnetic solenoid 4a. In addition, as fuel injection to the fourth cylinder (corresponding to the electromagnetic solenoid 4b), in the region of “360 to 540 ° CA”, three stages of pilot injection and one stage of main injection are used, and “540 to 720 ° CA”. The post injection is performed in the area of “”. For this reason, in the region of “360 to 720 ° CA”, the first relay 70 is controlled so as to select the electromagnetic solenoid 4b.

  On the other hand, FIG. 3B shows a control mode of the first relay 70 and the second relay 72 when there is an abnormality in the electrical system that supplies power to the electromagnetic solenoid 4b. In this case, even in the region of “360 to 720 ° CA”, the first relay 70 does not select the electromagnetic solenoid 4b. In other words, the electromagnetic solenoid 4a and the high side terminal T1 are electrically connected. As a result, even when the high-potential side terminal of the electromagnetic solenoid 4b is short-circuited to the ground, it is possible to avoid wasteful consumption of power flowing to the ground via the high-potential side terminal. . Such a short circuit between the high potential side terminal and the ground cannot be appropriately dealt with by turning off the selection switch 26 provided between the low potential side terminal of the electromagnetic solenoid 4b and the ground. The configuration for switching between conduction and interruption between the high-potential side terminal of the electromagnetic solenoid 4b and the high-side terminal T1 is particularly effective.

  In contrast, in the drive device shown in FIG. 6, even if the high-potential side terminal of the electromagnetic solenoid 104d is short-circuited, even the electromagnetic solenoid 104c cannot be used by turning off the drive start switch 122. . Further, in the drive device shown in FIG. 6, the abnormality diagnosis for specifying whether there is an abnormality on the electromagnetic solenoid 104c side or the electromagnetic solenoid 104d side cannot be performed (here, the voltage in the ECU 101, etc.). It is assumed that the presence or absence of an abnormality will be diagnosed using a monitor. On the other hand, in the present embodiment, the first relay 70 and the second relay 72 are provided at the high potential side terminals of the electromagnetic solenoids 4a to 4d, so that the selection switch is provided from the downstream of the first relay 70 and the second relay 72. As for the abnormality between 24 and 30 upstream, it is possible to specify which of the electromagnetic solenoids 4a to 4d is abnormal in the electric system that performs energization control.

  Further, in the present embodiment, the first relay 70 and the second relay 72 are externally attached to the ECU 1. Thereby, since ECU1 can be comprised only by adding control terminal T3, T4 with respect to ECU101 shown in previous FIG. 6, the housing | casing of ECU1 is substantially the same as the housing | casing of ECU101. can do. For this reason, the case of the ECU is shared between the case where the first relay 70 and the second relay 72 that selectively connect the terminals on the high potential side of the electromagnetic solenoids 4a to 4b to the capacitors 40 and 42 are not provided. In this case, the size of the housing can be made as small as possible. That is, when the ECU 1 (including the casing) is manufactured in advance as shown in FIG. 1 and there is a request to secure the output torque of the internal combustion engine as much as possible at the time of limp home, for example, a large commercial vehicle, In other cases, the first relay 70 and the second relay 72 are provided, and in other cases, the first relay 70 and the second relay 72 are not provided.

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

  (1) Capacitors 40, 42 and any one electromagnetic solenoid 4a-4d can be selectively conducted between the high-potential side terminals of the electromagnetic solenoids 4a-4d and the capacitors 40, 42. 1 relay 70 and 2nd relay 72 were provided. Thus, when an abnormality occurs in the electric system that supplies power to a specific one of the electromagnetic solenoids 4a to 4d, all other solenoids can be continuously driven. For this reason, the output torque of the internal combustion engine can be increased as much as possible even during limp home.

  (2) The first relay 70 and the second relay 72 are externally attached to the ECU 1. Thus, the casing can be shared between those using the first relay 70 and the second relay 72 and those not using the first relay 70 and the second relay 72 without increasing the size of the casing of the ECU 1. For this reason, the versatility of the member which consists of a housing | casing and the circuit inside it can be improved, without causing the enlargement of the dimension of a housing | casing. Furthermore, the amount of heat generated in the casing of the ECU 1 can be reduced by externally attaching the first relay 70 and the second relay 72.

  (3) The 1st relay 70 and the 2nd relay 72 were comprised with the semiconductor relay. Thereby, the responsiveness of conduction | electrical_connection and interruption | blocking with the capacitors 40 and 42 can be made favorable.

(Second Embodiment)
Hereinafter, the second embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  FIG. 4 shows the configuration of the drive device according to the present embodiment. In FIG. 4, members having the same functions as those shown in FIG. 1 are given the same reference numerals for the sake of convenience.

  This driving device includes only one high side terminal T1 that supplies power to the high potential side terminals of the electromagnetic solenoids 4a to 4d. Furthermore, the power storage means for storing the electric power of the booster circuit 10 is only one of the capacitors 40, and the circuit for continuing energization of the electromagnetic solenoids 4 a to 4 d started by the discharge of the capacitor 40 is also one of the current circuits 50. Only. In order to selectively conduct the high-side terminal T1 and any one of the electromagnetic solenoids 4a to 4d, three semiconductor relays including a first relay 90, a second relay 92, and a third relay 94 are provided.

  Here, the first relay 90 is a circuit that performs switching so that one of the second relay 92 and the third relay 94 is electrically connected to the high-side terminal T1. The second relay 92 switches one of the electromagnetic solenoids 4a and 4b so as to be electrically connected to the first relay 90. Further, the third relay 94 switches so that one of the electromagnetic solenoids 4 c and 4 d is brought into conduction with the first relay 90. The control terminal of the first relay 90 is connected to the microcomputer 2 via the control terminal T4, and the connection terminal of the second relay 92 is connected to the microcomputer 2 via the control terminal T6. The control terminal of the 3 relay 94 is connected to the microcomputer 2 via the control terminal T7. For this reason, the microcomputer 2 can control the first relay 90 to the third relay 94 to make the high-side terminal T1 and any one of the electromagnetic solenoids 4a to 4d conductive.

  Also in this embodiment, the first relay 90 to the third relay 94 are externally attached to the ECU 1. Therefore, when the ECU 1 is shared between the case where the first relay 90 to the third relay 94 are not used as shown in FIG. 5 and the case where the first relay 90 to the third relay 94 are used as in the present embodiment. Even so, an increase in the size of the housing can be suitably suppressed.

  Incidentally, when performing the fuel injection exemplified in FIG. 3A in this configuration, for example, the timing of the post injection of the first cylinder and the timing of the pilot injection of the third cylinder should be set so as not to overlap. Is desirable.

  Also according to the present embodiment described above, the same effects as the effects (1) to (3) of the first embodiment can be obtained.

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

  -The diagnostic method of the presence or absence of abnormality of the electric system used for supplying electric power to the electromagnetic solenoids 4a to 4d is not limited to the one exemplified in the first embodiment. For example, in FIG. 1, the diagnosis may be performed by monitoring the current and voltage between the high side terminals T1, T2 and the drive start switches 20, 22.

  -The fuel injection valve drive device is not limited to a configuration formed integrally with the ECU, but is operated as a dedicated driver circuit (EDU) and operated based on a command signal from the ECU including a microcomputer. It is good also as a thing. Even in this case, if the semiconductor relay is externally attached to the housing of the EDU, the effect (2) of the first embodiment can be obtained.

  Even if the selection switches 24 to 30 are not provided, for example, when a short circuit occurs in the electrical system between the high-potential side terminals of the electromagnetic solenoids 4a to 4d and the first relay 70 and the second relay 72 in FIG. In addition, limp home can be performed using an electrical system other than the electrical system in which the short circuit occurs.

  For example, in FIG. 4, the second relay 92 and the third relay are not used, and the first relay 90 is selected so that the high side terminal T1 is electrically connected to one of the electromagnetic solenoids 4a and 4b and the electromagnetic solenoids 4c and 4d. Even in the case of the configuration, the limp home can be appropriately performed as compared with the driving device shown in FIG. That is, in the example shown in FIG. 5, the limp home process cannot be performed when the high potential side of the electromagnetic solenoids 4a to 4d is short-circuited to the ground. On the other hand, even if only the first relay 90 is provided, for example, when the terminal on the high potential side of the electromagnetic solenoid 4c is short-circuited to the ground, the limp home process can be performed using the electromagnetic solenoids 4a and 4b.

  -Even if it has a structure which equips the housing | casing of ECU and the housing | casing of EDU, the effect of said (1) and (3) of previous 1st Embodiment can be acquired.

  The electronically controlled actuator provided in the fuel injection valve is not limited to the one provided with an electromagnetic solenoid, and may be provided with a piezo element.

  ・ The number of fuel injectors is not limited to four. In addition to a multi-cylinder internal combustion engine, a single cylinder may be provided with a plurality of fuel injection valves.

  The power supply means for supplying electric energy to the electronically controlled actuator provided in the fuel injection valve is not limited to the one provided with the capacitors 40, 42 and the current circuits 50, 60. For example, the structure provided only with the capacitors 40 and 42 may be sufficient. Further, the high-potential side switching circuit that selectively switches the high-potential side terminal of the electronically controlled actuator that is brought into conduction with the power feeding means is not limited to a semiconductor relay. However, it is desirable to have durability against frequent switching.

The circuit diagram which shows the structure of 1st Embodiment of the drive device of the fuel injection valve concerning this invention. The figure which shows the structure of the semiconductor relay of the embodiment. The time chart which shows the switching aspect of the semiconductor relay in the embodiment. The circuit diagram which shows the structure of 2nd Embodiment. The circuit diagram when not using a semiconductor relay in 2nd Embodiment. The circuit diagram which shows the circuit structure of the drive device of the conventional fuel injection valve.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Electronic control unit (ECU), 4a-4d ... Electromagnetic solenoid, 40, 42 ... Capacitor (one embodiment of power supply means), 50, 60 ... Current circuit (one embodiment of power supply means), 70 ... First relay (One Embodiment of High Potential Side Switching Circuit), 72... Second Relay (One Embodiment of High Potential Side Switching Circuit).

Claims (8)

By selectively supplying the electric energy of the power feeding means to the actuator of the fuel injection valve that is requested to drive among the electronically controlled actuators provided in each of the plurality of fuel injection valves that perform fuel injection supply in the internal combustion engine, In a fuel injection valve drive device for driving a fuel injection valve,
A fuel injection system comprising: a high-potential side switching circuit that selectively switches the high-potential side terminals connected to the power supply means between the high-potential side terminals of the plurality of actuators and the power supply means. Valve drive device.   2. The fuel injection valve drive device according to claim 1, wherein the high-potential side switching circuit is configured to selectively connect the power feeding unit and any one actuator. 3.   The low-potential-side switching circuit that selectively switches the low-potential-side terminal that is electrically connected to the ground between the low-potential-side terminals of the plurality of actuators and the ground. 3. The fuel injection valve drive device according to 2.   4. The fuel injection valve driving device according to claim 3, wherein the low potential side switching circuit is configured to selectively connect the ground and any one actuator.   5. The fuel injection valve drive according to claim 3, wherein the high-potential side switching circuit is externally attached to a housing in which the low-potential side switching circuit and the power feeding unit are housed. apparatus.   6. The fuel injection valve driving device according to claim 1, further comprising a control unit that controls the high potential side switching circuit in response to the driving request. For each of the plurality of fuel injection valves, further comprising diagnostic means for diagnosing the presence or absence of an abnormality in the electric system when supplying electric energy from the power supply means to the actuator,
The control means controls the high potential side switching circuit so as to prohibit conduction between the actuator corresponding to an electrical system determined to be abnormal by the diagnosis means and the power supply means. Item 7. The fuel injection valve drive device according to any one of Items 1 to 6.   The fuel injection valve driving device according to claim 1, wherein the high potential side switching circuit is configured by a semiconductor relay.

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