JP7673604B2 - Fuel injection control device - Google Patents

Description

The present invention relates to a fuel injection control device.

In a device that controls fuel injection in an internal combustion engine, interrupt processing is performed in synchronization with a predetermined crank angle or fuel injection associated with the rotation of the internal combustion engine, and the end timing of the current injection or the start timing of the next injection is calculated (see, for example, Patent Document 1).

JP 2001-234777 A

Conventionally, interrupt processing is performed in synchronization with the edge of the injector drive pulse to calculate the end timing of the current injection or the start timing of the next injection. In other words, when the injector drive pulse turns on, handler processing is started and processing is performed to calculate the injection period, and the end timing of the current injection is calculated. Also, when the injector drive pulse turns off, handler processing is started and processing is performed to calculate the pulse interval until the next injection or the pulse-on angle of the next injection, and the start timing of the next injection is calculated.

However, when multiple injections are performed in which fuel injections of two or more cylinders overlap, the following problem occurs. When an injector-on interrupt occurs, handler processing is started at the injector-on timing of the preceding injection, and before the handler processing of the preceding injection is finished, that is, while the handler processing of the preceding injection is being executed, an injector-on interrupt of the following injection may occur. In this case, because the handler processing of the preceding injection has not finished, the handler processing of the following injection cannot be started at the injector-on timing of the following injection. As a result, a wait time occurs between the occurrence of the injector-on interrupt of the following injection and the start of the interrupt processing, and the wait time causes a delay in the injector-off timing, which may result in the fuel injection amount being greater than requested.

In addition, when an injector-off interrupt occurs, a wait time occurs between the occurrence of the injector-off interrupt for the subsequent injection and the start of interrupt processing. This wait time causes a delay in the timing of turning on the injector, which may result in the injection timing differing from that requested.

This type of problem can be avoided by avoiding multiple injection, but avoiding multiple injection puts greater restrictions on the number of injection stages, making it difficult to improve exhaust emissions and making it impossible to properly control fuel injection.

The present invention was made in consideration of the above circumstances, and its purpose is to provide a fuel injection control device that can appropriately control fuel injection in a configuration that performs multiple injections.

According to the invention described in claim 1, interrupt processing is performed in synchronization with a predetermined crank angle or fuel injection accompanying the rotation of the internal combustion engine, and the end timing of the current injection or the start timing of the next injection is calculated. When multiple injection interrupt processing occurs within a predetermined period between cylinders with adjacent fuel injection orders, the control unit performs interrupt processing of the preceding injection and interrupt processing of the following injection together in the same handler processing when an interrupt occurs for the preceding injection.

Conventionally, the interrupt processing for the preceding injection and the interrupt processing for the following injection are performed in separate handler processes, and it is necessary to perform a startup process for each separate handler process to start the handler process. In contrast, by performing the interrupt processing for the preceding injection and the interrupt processing for the following injection together in the same handler process, it is possible to eliminate the need for a startup process for the interrupt processing for the following injection. In other words, since the startup process for the interrupt processing for the following injection is not required, when the interrupt processing for the preceding injection is terminated, the interrupt processing for the following injection can be started immediately, and there is no waiting time until the interrupt processing for the following injection is started. By eliminating the waiting time, there is no delay in the timing of turning the injector off or on due to the occurrence of the waiting time, and the fuel injection amount does not increase more than required, or the injection timing does not differ from the request. As a result, in a configuration that performs multiple injections, it is possible to appropriately perform fuel injection control.

Functional block diagram showing one embodiment. Electrical circuit diagram showing the internal configuration of the drive circuit Time chart explaining the basic operation of the drive circuit Timing Chart Flowchart showing injector on interrupt processing Flowchart showing injector on interrupt processing Timing Chart Flowchart showing injector off interrupt processing Flowchart showing injector off interrupt processing Timing Chart Timing Chart

An embodiment will be described below with reference to the drawings. This embodiment is embodied as a common rail fuel injection system for an on-board four-cylinder diesel engine. It is possible to apply the present invention to a direct injection fuel injection system for a gasoline engine, as well as to diesel engines. High-pressure fuel is stored in the common rail at a predetermined fuel pressure, and the high-pressure fuel is injected into each cylinder by an electromagnetically driven injector. In this embodiment, the requirement is that multi-stage injection and multiple injection are selectively performed, and the multiple injection is performed by pre-injection, pilot injection, main injection, and after-injection. Pre-injection is an injection performed mainly for in-cylinder activation. Pilot injection is an injection performed mainly for reducing NOx and combustion noise. Main injection is an injection performed mainly for determining engine output. After-injection is an injection performed mainly for re-burning soot. In addition, post-injection for realizing multiple injection is an injection performed mainly for catalyst activation. Each of these injections is appropriately performed according to the engine operating state, etc., for the purpose of improving exhaust emissions, etc.

As shown in FIG. 1, an electronic control unit (ECU: Electric Control Unit) 1 serving as a fuel injection control device includes a microcomputer (hereinafter referred to as a microcomputer) 2 serving as a control unit, and a drive circuit 3. The microcomputer 2 has a CPU, ROM, RAM, I/O, etc., and executes a computer program stored in a non-transient physical storage medium to execute processing corresponding to the computer program, thereby controlling the operation of the electronic control unit 1.

The microcomputer 2 inputs a rotation pulse signal (hereafter referred to as an NE pulse signal) generated at equal crank angle intervals (for example, every 10° CA) from a crank angle sensor (not shown), and also inputs an accelerator opening signal from an accelerator opening sensor (not shown). When the microcomputer 2 inputs the NE pulse signal and accelerator opening signal, it identifies engine operating information based on the input NE pulse signal and accelerator opening signal, determines the injection requirements for each instance, and calculates the optimal fuel injection amount and fuel injection timing.

The microcomputer 2 is provided with a first injection timer 2a through a fourth injection timer 2d for each of the first through fourth cylinders, and sets the start and end timings of each injection in the first injection timer 2a through the fourth injection timer 2d. The microcomputer 2 turns on the injector drive pulse when the start timing of the injection set in the first injection timer 2a through the fourth injection timer 2d for each cylinder is reached, and turns off the injector drive pulse when the end timing of the injection set in the first injection timer 2a through the fourth injection timer 2d for each cylinder is reached.

The drive circuit 3 has high-side terminals COM1 and COM2 and low-side terminals INJ1, INJ2, INJ3, and INJ4, to which the injectors 4a to 4d for each cylinder are connected. When the drive circuit 3 detects that the injector drive pulse input from the microcomputer 2 is on, it energizes the solenoids of the injectors 4a to 4d for each cylinder, driving the injectors 4a to 4d. When injecting fuel, the drive circuit 3 drives the injectors 4a to 4d with a large current at the start of injection, and then drives the injectors 4a to 4d with a constant current.

The drive circuit 3 is configured on the premise that multiple injection will be performed, and drives the four cylinder injectors 4a-4d in groups of two cylinders. In this case, injector 4a and injector 4c are connected to a common terminal COM1 of the drive circuit 3 as the same injection group, and injector 4b and injector 4d are connected to a common terminal COM2 of the drive circuit 3 as the same injection group. Each injection group only needs to be made up of injectors that are not driven simultaneously, and the grouping is determined by the engine design specifications, such as which cylinders are to be used for multiple injection. In addition, in the case of an engine with six cylinders, for example, instead of four cylinders, the injectors for each cylinder can be divided into injection groups of three cylinders.

Next, the internal configuration of the drive circuit 3 will be described. As shown in FIG. 2, a series circuit consisting of an inductor L11, a transistor T13, and a current detection resistor R00 is connected between the battery power line (+B) and GND. A self-excited oscillator circuit 5 is connected to the gate terminal of the transistor T13, and the drive of the transistor T13 is controlled by the oscillator circuit 5. One end of a capacitor C10 is connected between the inductor L11 and the transistor T13 via a backflow prevention diode D13, and one end of a capacitor C20 is connected via a backflow prevention diode D23. The other ends of these capacitors C10 and C20 are connected to the connection point between the transistor T13 and the current detection resistor R00. The inductor L11, the transistor T13, the current detection resistor R00, the oscillator circuit 5, the diodes D13 and D23, and the capacitors C10 and C20 form a DC-DC converter circuit. The capacitor C10 is an energy storage capacitor dedicated to the injectors 4a and 4c, which are the injection group on the common terminal COM1 side. Capacitor C20 is an energy storage capacitor dedicated to injectors 4b and 4d, which are in the injection group on the common terminal COM2 side.

When transistor T13 is turned on and off, capacitors C10 and C20 are charged through diodes D13 and D23, and capacitors C10 and C20 are charged to a voltage higher than the battery voltage +B. In this case, the charging current is monitored by current detection resistor R00, and transistor T13 is turned on and off by oscillator circuit 5, so that capacitors C10 and C20 are charged at an efficient cycle.

The input terminals of the first through fourth cylinders are connected to the driving IC 6. The driving IC 6 inputs the injector drive pulses for each cylinder from the microcomputer 2 through these input terminals.

The transistors T12 and T22 are transistors that temporarily turn on when the injector drive pulse for each cylinder is inverted from off to on, and supply the stored energy of the capacitors C10 and C20 to the injectors 4a to 4d. Specifically, the transistor T12 is connected between the capacitor C10 and the common terminal COM1, and when the transistor T12 is turned on by the driving IC 6, the stored energy of the capacitor C10 is supplied to the injectors 4a and 4c on the common terminal COM1 side. The transistor T22 is connected between the capacitor C20 and the common terminal COM2, and when the transistor T22 is turned on by the driving IC 6, the stored energy of the capacitor C20 is supplied to the injectors 4b and 4d on the common terminal COM2 side. The stored energy of the capacitors C10 and C20 is supplied to the injectors 4a to 4d, and a large current flows as the drive current for the injectors 4a to 4d, improving the valve opening response of the injectors 4a to 4d.

Transistors T10, T20, T30, and T40 are connected to the low side of injectors 4a to 4d via terminals INJ1 to INJ4 of drive circuit 3. When the injector drive pulse for each cylinder from drive IC 6 is turned on, transistors T10 to T40 are turned on. Transistors T10, T30 and transistors T20, T40 each constitute the same injection group, and each of these transistors T10, T20, T30, and T40 is grounded via current detection resistors R10 and R20 for each group. The drive current flowing through injectors 4a to 4d is detected by current detection resistors R10 and R20, and the detection result is input to drive IC 6.

The injectors 4a and 4c that make up one injection group of the injectors 4a to 4d are connected to the capacitor C10 via the diodes D10 and D30. The back electromotive force energy generated in the injectors 4a and 4c when the current is cut off is recovered in the capacitor C10 via the diodes D10 and D30. The injectors 4b and 4d that make up the other injection group of the injectors 4a to 4d are connected to the capacitor C20 via the diodes D20 and D40. The back electromotive force energy generated in the injectors 4b and 4d when the current is cut off is recovered in the capacitor C20 via the diodes D20 and D40.

Next, the basic operation of the drive circuit 3 will be described with reference to FIG. 3. FIG. 3 illustrates the operation of multi-stage injection and multiple injection. In FIG. 3, "#1" indicates the injector drive pulse of the first cylinder, and "#2" indicates the injector drive pulse of the second cylinder. For the multi-stage injection of the first cylinder, pre-injection is performed in period T1, pilot injection is performed in period T2, main injection is performed in period T3, and after-injection is performed in period T4. In addition, in period T5, post-injection of the second cylinder is performed overlapping with the main injection of the first cylinder. In the case of a four-cylinder engine, for example, signals for pre-injection, pilot injection, main injection, and after-injection (multi-stage injection) are output within 180° CA as the injector drive pulse of the first cylinder, and a signal for post-injection (multiple injection) is output as the injector drive pulse of the second cylinder overlapping with the injector drive pulse of the first cylinder.

First, we will explain multi-stage injection. Before pre-injection, capacitors C10 and C20 are fully charged, and when the injector drive pulse for the first cylinder is turned on during period T1, transistor T10 is turned on and, at the same time, transistor T12 is turned on, starting pre-injection by injector 4a. Transistor T12 is turned on for a fixed period at the beginning of pre-injection, and the stored energy in capacitor C10 is supplied to injector 4a. As a result, a large current flows through injector 4a at the beginning of pre-injection, accelerating the valve-opening response of injector 4a.

After the energy supply from the capacitor C10, the transistor T11 is controlled to be turned on and off according to the drive current (INJ1 current) detected by the current detection resistor R10, and a constant current is supplied to the injector 4a via the diode D11. That is, the driving IC 6 turns the transistor T11 on and off according to the drive current (INJ1 current) detected by the current detection resistor R10, the drive current is held at a predetermined value, and the injector 4a is held in an open state.

After that, when the injector drive pulse for the first cylinder is turned off, transistor T10 is turned off and the back electromotive force energy generated when the injector 4a is de-energized is collected in capacitor C10 through diode D10. At this time, the energy is collected by capacitor C10, which is the same one that supplied energy when injection started. After de-energization, when the drive current (INJ1 current) of injector 4a attenuates to a predetermined level that is overcome by the biasing force of the return spring, injector 4a closes and pre-injection ends. Then, when the collection of the back electromotive force energy at the end of pre-injection is completed, transistor T13 is turned on and off and capacitor C10 is charged.

The same operation is performed for the pilot injection in period T2, the main injection in period T3, and the after-injection in period T4. That is, at the beginning of each injection when the injector drive pulse for the first cylinder is turned on, the stored energy in capacitor C10 is supplied to the injector, and then the injector 4a is driven with a constant current. After that, when the injector drive pulse for the first cylinder is turned off and the INJ1 current decays, each injection by the injector 4a ends. In capacitor C10, after the stored energy is supplied to the injector 4a, the back electromotive force energy generated when the current is cut off is recovered, and then it is charged by the DC-DC converter circuit.

Next, multiple injection will be explained. In the example of FIG. 3, the injector drive pulse for the first cylinder (main injection during period T3) and the injector drive pulse for the second cylinder (post injection during period T5) are turned on at the same time, and injectors 4a and 4b are driven simultaneously. In this case, injectors 4a and 4b belong to different injection groups, so they are controlled independently of each other, and even if their injection times overlap, fuel injection is performed without being influenced by each other.

Specifically, when the injector drive pulse for the second cylinder is turned on during period T5, transistor T20 is turned on and, at the same time, transistor T22 is turned on for a fixed period of time, the stored energy in capacitor C20 is supplied to injector 4b, and at the beginning of the post-injection, a large current flows through injector 4b, accelerating the valve-opening response of injector 4b.

After the energy supply from the capacitor C20, the transistor T21 is controlled to be turned on and off according to the drive current (INJ2 current) detected by the current detection resistor R20, and a constant current is supplied to the injector 4b via the diode D21. That is, the driving IC 6 turns the transistor T21 on and off according to the drive current (INJ2 current) detected by the current detection resistor R20, holds the drive current at a predetermined value, and holds the injector 4b in an open state.

After that, when the injector drive pulse for the second cylinder is turned off, transistor T20 turns off and the back electromotive force energy generated when the injector 4b is de-energized is collected in capacitor C20 through diode D20. At this time, the energy is collected by capacitor C20, which is the same capacitor that supplied energy when injection started. After de-energization, when the drive current (INJ2 current) of injector 4b attenuates to a predetermined level that is overcome by the biasing force of the return spring, injector 4b closes and post-injection ends. Then, when the collection of the back electromotive force energy at the end of post-injection is completed, transistor T13 turns on and off and capacitor C20 is charged.

However, even if the injection timings of the injectors 4a, 4b belonging to different injection groups overlap, the following problems occur.
When the injector ON of the first cylinder and the injector ON of the second cylinder overlap, as shown in Fig. 4, the handler process may be started at the injector ON timing of the preceding injection (t1), and before the handler process of the preceding injection is completed, an interrupt of the injector ON of the following injection may occur (t2). In this case, since the handler process of the preceding injection is not completed, the handler process of the following injection cannot be started at the injector ON timing of the following injection. Therefore, a waiting time (period Ta from t2 to t3) occurs from the interrupt of the injector ON of the following injection to the start of the interrupt process of the following injection, and the timing of turning off the injector drive pulse is delayed due to the waiting time, resulting in a delay time (period Tb from t4 to t5), which may result in the fuel injection amount being greater than the request.

Also, although not shown, there are cases where the handler process is started when the injector of a preceding injection is turned off, and an injector-off interrupt for a subsequent injection occurs before the handler process for the preceding injection is finished. In this case, a wait time occurs between the occurrence of the injector-off interrupt for the subsequent injection and the start of the interrupt process for the subsequent injection, and the occurrence of the wait time causes a delay in the injector-on timing, which may result in the injection timing differing from that requested.

To address this issue, in this embodiment, when multiple injection interrupt processes occur within a specified period between cylinders with adjacent fuel injection orders, when the preceding injection interrupt occurs, the control unit 2 performs both the interrupt process for the preceding injection and the interrupt process for the following injection together within the same handler process.

Next, the operation of the above-mentioned configuration will be described with reference to Figures 5 to 11. The control unit 2 performs injector-on interrupt processing and injector-off interrupt processing. Each process will be described below in order.

(1) Injector ON interrupt process (see Figures 5 to 7)
When the injector drive pulse ON is established, the control unit 2 starts the handler process and judges whether or not the subsequent ON event process execution flag is OFF (S1). When the control unit 2 judges that the subsequent ON event process execution flag is OFF (S1: YES), it proceeds to the pulse ON event process for the current injection (S2). When the control unit 2 starts the pulse ON event process for the current injection, it calculates the injection period of the current injection (S11), sets the end timing of the current injection (S12), and ends the pulse ON event process for the current injection.

When the control unit 2 ends the pulse-on event processing, it determines whether or not there is an injector-on interrupt request for the subsequent injection within a predetermined period, for example, starting from the timing when the injector drive pulse is turned on (S3). If the control unit 2 determines that there is no injector-on interrupt request for the subsequent injection within the predetermined period (S3: NO), it ends the injector-on interrupt processing and waits for the establishment of the next start event of the injector-on interrupt processing.

When the control unit 2 determines that there is an injector-on interrupt request for the subsequent injection within the specified period (S3: YES), it transitions to pulse-on event processing for the subsequent injection (S4). When the control unit 2 starts pulse-on event processing for the subsequent injection, it calculates the injection period of the most recent injection for the subsequent injection (S11), sets the end timing of the most recent injection (S12), and ends pulse-on event processing for the subsequent injection.

When the control unit 2 finishes the pulse on event processing for the subsequent injection, it turns on the subsequent on event processing execution flag (S5), ends the injector on interrupt processing, and waits for the occurrence of the next start event of the injector on interrupt processing.

When the control unit 2 determines that the subsequent on-event processing execution flag is on and not off (S1: NO), it turns off the subsequent on-event processing execution flag (S6), ends the injector on interrupt processing, and waits for the occurrence of the next start event of the injector on interrupt processing.

As shown in FIG. 7, when the injector drive pulse for the preceding injection is turned on (t1), the control unit 2 starts handler processing and performs interrupt processing for the preceding injection, and if there is an injector-on interrupt request for the subsequent injection within a predetermined period from the occurrence of the injector-on interrupt for the preceding injection (t2), the control unit 2 performs interrupt processing for the subsequent injection within the handler processing started when the injector-on interrupt for the preceding injection occurred. That is, the control unit 2 calculates the end timing of the current preceding injection (t3) and calculates the end timing of the most recent subsequent injection (t4) within the handler processing started when the injector-on interrupt for the preceding injection occurred.

(2) Injector off interrupt process (see Figs. 8 to 11)
When the injector drive pulse OFF is established, the control unit 2 starts the handler process and determines whether or not the subsequent OFF event process execution flag is OFF (S21). When the control unit 2 determines that the subsequent OFF event process execution flag is OFF (S21: YES), it proceeds to the pulse OFF event process for the current injection (S22).

When the control unit 2 starts the pulse-off event processing for the current injection, it determines whether the previous injection stage number is smaller than the total injection stage number in the group (S31). If the control unit 2 determines that the previous injection stage number is smaller than the total injection stage number in the group (S31: YES), it calculates the pulse interval until the next injection (S32), sets the start timing of the next injection by setting the calculated pulse interval (S33), and ends the pulse-off event processing for the current injection.

When the control unit 2 determines that the number of previous injection stages is not smaller than the total number of injection stages in the group (S31: NO), it determines whether the group number of the previous injection is smaller than the total group number (S34). When the control unit 2 determines that the group number of the previous injection is smaller than the total group number (S34: YES), it calculates the pulse-on angle of the first injection in the group (S35), sets the start timing of the next injection by setting the calculated pulse-on angle (S36), and ends the pulse-off event processing.

When the control unit 2 ends the pulse-off event processing, it determines whether or not there is an injector-off interrupt request for the subsequent injection within a predetermined period, for example, starting from the timing when the injector drive pulse is turned off (S23). If the control unit 2 determines that there is no injector-off interrupt request for the subsequent injection within the predetermined period (S23: NO), it ends the injector-off interrupt processing and waits for the establishment of the next start event of the injector-off interrupt processing.

When the control unit 2 determines that there is an injector-off interrupt request for the subsequent injection within the specified period (S23: YES), it transitions to pulse-off event processing for the subsequent injection (S24).

When the control unit 2 starts the pulse-off event processing for the subsequent injection, it determines whether the current number of injection stages is smaller than the total number of injection stages in the group (S31). When the control unit 2 determines that the current number of injection stages is smaller than the total number of injection stages in the group (S31: YES), it calculates the pulse interval until the next injection (S32), sets the start timing of the next injection by setting the calculated pulse interval (S33), and ends the pulse-off event processing for the subsequent injection.

When the control unit 2 determines that the current number of injection stages is not smaller than the total number of injection stages in the group (S31: NO), it determines whether the current group number is smaller than the total group number (S34). When the control unit 2 determines that the current group number is smaller than the total group number (S34: YES), it calculates the pulse-on angle of the first injection in the group (S35), sets the start timing of the next injection by setting the calculated pulse-on angle (S36), and ends the pulse-off event processing for the subsequent injection.

When the control unit 2 finishes the pulse off event processing for the subsequent injection, it turns on the subsequent off event processing execution flag (S25), ends the injector off interrupt processing, and waits for the occurrence of the next start event of the injector off interrupt processing.

When the control unit 2 determines that the subsequent off event processing execution flag is on and not off (S21: NO), it turns off the subsequent off event processing execution flag (S26), ends the injector off interrupt processing, and waits for the occurrence of the next start event of the injector off interrupt processing.

As shown in Figures 10 and 11, when the injector drive pulse for the preceding injection is turned off (t11), the control unit 2 starts handler processing and performs interrupt processing for the preceding injection, and if there is an injector off interrupt request for the subsequent injection within a predetermined period from the occurrence of the injector off interrupt for the preceding injection (t12), the control unit 2 performs interrupt processing for the subsequent injection within the handler processing started when the injector off interrupt for the preceding injection occurred. That is, the control unit 2 calculates the next start timing of the immediately preceding injection and calculates the next start timing of the current subsequent injection within the handler processing started when the injector off interrupt for the preceding injection occurred (t13).

As described above, according to the embodiment, the following advantageous effects can be obtained.
In the fuel injection control device 1, the interrupt processing of the preceding injection and the interrupt processing of the following injection are performed together in the same handler processing. It is possible to eliminate the need for a startup process for starting the handler processing for the following injection interrupt processing. In other words, since the startup process for the following injection interrupt processing is not required, when the interrupt processing of the preceding injection is finished, the interrupt processing of the following injection can be started immediately, and there is no waiting time until the interrupt processing of the following injection starts. By eliminating the waiting time, there is no delay in the timing of turning the injector off or on due to the occurrence of the waiting time, and the fuel injection amount does not increase more than required, or the injection timing does not differ from the required amount. As a result, in a configuration that performs multiple injections, it is possible to appropriately perform fuel injection control.

By using the subsequent on-event processing flag in the injector on interrupt processing and the subsequent off-event processing flag in the injector off interrupt processing, the need to perform interrupt processing for the subsequent injection can be appropriately managed by the subsequent on-event processing flag and the subsequent off-event processing flag.

Although the present disclosure has been described with reference to the embodiment, it is understood that the disclosure is not limited to the embodiment or structure. The present disclosure also encompasses various modifications and modifications within the scope of equivalents. In addition, various combinations and forms, as well as other combinations and forms including only one element, more than one element, or less than one element, are also within the scope and concept of the present disclosure.

In the drawing, 1 is a fuel injection control device and 2 is a microcomputer (control unit).

Claims (7)

A fuel injection control device that performs interrupt processing in synchronization with a predetermined crank angle or fuel injection associated with the rotation of an internal combustion engine, and calculates an end timing of a current injection or a start timing of a next injection,
A fuel injection control device having a control unit (2) that, when multiple injection interrupt processes occur within a specified period between cylinders with adjacent fuel injection orders, performs, when an interrupt occurs for a preceding injection, the interrupt process for the preceding injection and the interrupt process for a subsequent injection together within the same handler process. The fuel injection control device according to claim 1, wherein if an injector-on interrupt request for the subsequent injection occurs within a predetermined period from the occurrence of an injector-on interrupt for the preceding injection, the control unit performs interrupt processing for the subsequent injection within the handler processing that occurs when an interrupt for the preceding injection occurs. The fuel injection control device according to claim 2, wherein the control unit turns on a subsequent on-event processing execution flag after performing the interrupt processing for the subsequent injection. The fuel injection control device according to claim 3, wherein the control unit turns off the subsequent on-event processing execution flag when an injector on interrupt occurs for the subsequent injection. The fuel injection control device according to claim 1, wherein if an injector-off interrupt request for the subsequent injection occurs within a predetermined period from the occurrence of an injector-off interrupt for the preceding injection, the control unit performs interrupt processing for the subsequent injection within the handler processing that occurs when an interrupt for the preceding injection occurs. The fuel injection control device according to claim 5, wherein the control unit turns on a subsequent off event processing execution flag after performing the interrupt processing of the subsequent injection. The fuel injection control device according to claim 6, wherein the control unit turns off the subsequent off event processing execution flag when an injector off interrupt occurs for the subsequent injection.

Images