fuel injection control device

Abstract

To appropriately execute fuel injection control in a configuration to execute multi-stage injections.SOLUTION: A fuel injection control device 1 executes interruption processing in synchronization with a predetermined crank angle involved in rotation of an internal combustion engine or the fuel injection; and calculates a timing to stop current injection or to start next injection. When the interruption processing of the fuel injection occurs multiple times within a predetermined period in adjoining cylinders where the fuel injections are performed in succession, a control section 2 collectively executes the interruption processing for both the preceding injection and succeeding injection within identical handler processing at the time of occurring the interruption of the preceding fuel injection.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a fuel injection control device. [Background technology]

[0002] 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). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2001-234777 A Summary of the Invention [Problem to be solved by the invention]

[0004] 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. That is, when the injector drive pulse is turned on, handler processing is started to calculate the injection period and the end timing of the current injection is calculated. Also, when the injector drive pulse is turned off, handler processing is started 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.

[0005] However, when multiple injections in which fuel injections of two or more cylinders overlap is performed, the following problem occurs. When an injector-on interrupt occurs, the handler process is started at the injector-on timing of the preceding injection, and before the handler process of the preceding injection is finished, that is, while the handler process of the preceding injection is being executed, an injector-on interrupt of the following injection may occur. In this case, since the handler process of the preceding injection is not finished, the handler process of the following injection cannot be started at the injector-on timing of the following injection. Therefore, a waiting time occurs between the occurrence of the injector-on interrupt of the following injection and the start of the interrupt process, and the occurrence of the waiting time may delay the timing of the injector-off, which may result in the fuel injection amount being larger than requested.

[0006] In addition, when an injector-off interrupt occurs, a waiting time occurs between the occurrence of the injector-off interrupt for the subsequent injection and the start of interrupt processing. This waiting time causes a delay in the timing of injector-on, which may result in the injection timing differing from that requested.

[0007] Such problems 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.

[0008] The present invention has been made in consideration of the above-mentioned circumstances, and its object is to provide a fuel injection control device that can appropriately perform fuel injection control in a configuration that performs multiple injections. [Means for solving the problem]

[0009] 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 adjacent in fuel injection order, 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 of the preceding injection occurs.

[0010] 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 start-up process for starting each of the separate handler processes. 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 start-up process for the interrupt processing for the following injection. In other words, since the start-up 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 there is no possibility that the fuel injection amount will be larger than the request or the injection timing will differ from the request. As a result, in a configuration that performs multiple injections, it is possible to appropriately perform fuel injection control. [Brief description of the drawings]

[0011] [Figure 1] Functional block diagram showing one embodiment. [Diagram 2] Electrical circuit diagram showing the internal configuration of the drive circuit [Diagram 3] Time chart explaining the basic operation of the drive circuit [Figure 4] Timing Chart [Diagram 5] Flowchart showing injector on interrupt processing [Figure 6]Flowchart showing injector on interrupt processing [Figure 7] Timing Chart [Figure 8] Flowchart showing injector off interrupt processing [Figure 9] Flowchart showing injector off interrupt processing [Figure 10] Timing Chart [Figure 11] Timing Chart DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] An embodiment will be described below with reference to the drawings. This embodiment is embodied as a common rail type fuel injection system for an on-board four-cylinder diesel engine. It is possible to apply the present invention to a direct injection type 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, it is required to selectively perform multi-stage injection and multiple injection, and the multi-stage injection includes 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. Moreover, 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.

[0013] 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 includes a CPU, a ROM, a RAM, an 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.

[0014] The microcomputer 2 receives a rotation pulse signal (hereinafter 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 receives an accelerator opening signal from an accelerator opening sensor (not shown). When the microcomputer 2 receives the NE pulse signal and the accelerator opening signal, it identifies engine operation information based on the received 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.

[0015] 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 through fourth injection timers 2a through 2d. When the start timing of the injection set in the first through fourth injection timers 2a through 2d for each cylinder is reached, the microcomputer 2 turns on the injector drive pulse, and when the end timing of the injection set in the first through fourth injection timers 2a through 2d for each cylinder is reached, the microcomputer 2 turns off the injector drive pulse.

[0016] The drive circuit 3 has high-side terminals COM1 and COM2 and low-side terminals INJ1, INJ2, INJ3, and INJ4, and the injectors 4a-4d of each cylinder are connected to these terminals. 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-4d for each cylinder to drive the injectors 4a-4d. When injecting fuel, the drive circuit 3 drives the injectors 4a-4d with a large current at the beginning of injection, and then drives the injectors 4a-4d with a constant current.

[0017] The drive circuit 3 is configured on the premise that multiple injection is performed, and the injectors 4a to 4d of the four cylinders are divided into two cylinders and driven. In this case, the injectors 4a and 4c are connected to a common terminal COM1 of the drive circuit 3 as the same injection group, and the injectors 4b and 4d are connected to a common terminal COM2 of the drive circuit 3 as the same injection group. Each injection group may be composed of injectors that are not driven simultaneously, and the grouping is determined by the design specifications of the engine, such as which cylinders are to be used for multiple injection. In the case of an engine with six cylinders, for example, other than four cylinders, the injectors of each cylinder may be divided into injection groups of three cylinders.

[0018] 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 diode D13 for preventing reverse current, and one end of a capacitor C20 is connected via a diode D23 for preventing reverse current. The other ends of the 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 in the injection group on the common terminal COM2 side.

[0019] When the transistor T13 is turned on and off, the capacitors C10 and C20 are charged through the diodes D13 and D23, and the capacitors C10 and C20 are charged to a voltage higher than the battery voltage +B. In this case, the charging current is monitored by the current detection resistor R00, and the transistor T13 is turned on and off by the oscillator circuit 5, so that the capacitors C10 and C20 are charged in an efficient cycle.

[0020] Input terminals for the first to fourth cylinders are connected to the driving IC 6. The driving IC 6 receives injector driving pulses for each cylinder from the microcomputer 2 via these input terminals.

[0021] 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.

[0022] The low sides of the injectors 4a-4d are connected to the transistors T10, T20, T30, and T40 via the terminals INJ1-INJ4 of the drive circuit 3, and when the injector drive pulse for each cylinder from the drive IC 6 is turned on, the transistors T10-T40 are turned on. The transistors T10, T30 and the transistors T20, T40 each constitute the same injection group, and the transistors T10, T20, T30, and T40 are grounded via current detection resistors R10 and R20 for each group. The drive current flowing through the injectors 4a-4d is detected by the current detection resistors R10 and R20, and the detection result is input to the drive IC 6.

[0023] The injectors 4a and 4c constituting one of the injection groups among the injectors 4a to 4d are connected to a capacitor C10 via diodes D10 and D30. The counter electromotive force energy generated in the injectors 4a and 4c when the power supply is cut off is recovered in the capacitor C10 via the diodes D10 and D30. The injectors 4b and 4d constituting the other injection group among the injectors 4a to 4d are connected to a capacitor C20 via diodes D20 and D40. The counter electromotive force energy generated in the injectors 4b and 4d when the power supply is cut off is recovered in the capacitor C20 via the diodes D20 and D40.

[0024] 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 of 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 of 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.

[0025] First, the multi-stage injection will be explained. Before pre-injection, the capacitors C10 and C20 are in a fully charged state, and when the injector drive pulse for the first cylinder is turned on during period T1, the transistor T10 is turned on and at the same time the transistor T12 is turned on, and pre-injection by the injector 4a is started. The transistor T12 is turned on for a certain period at the beginning of the pre-injection, and the stored energy of the capacitor C10 is supplied to the injector 4a. As a result, a large current flows through the injector 4a at the beginning of the pre-injection, and the valve opening response of the injector 4a is accelerated.

[0026] After the energy supply from the capacitor C10, the transistor T11 is controlled to be turned on and off in response 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 in response 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.

[0027] After that, when the injector drive pulse for the first cylinder is turned off, the transistor T10 is turned off, and the counter electromotive force energy generated when the injector 4a is de-energized is collected in the capacitor C10 through the diode D10. At this time, the energy is collected by the capacitor C10, which is the same one that supplied the energy when the injection started. After the de-energization, when the drive current (INJ1 current) of the injector 4a attenuates to a predetermined level that is overcome by the biasing force of the return spring, the injector 4a closes and the pre-injection ends. Then, when the collection of the counter electromotive force energy at the end of the pre-injection is completed, the transistor T13 is turned on and off, and the capacitor C10 is charged.

[0028] After this, 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 the capacitor C10 is supplied to the injector, and the injector 4a is subsequently 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. After the stored energy is supplied to the injector 4a, the counter electromotive force energy generated when the current is cut off is recovered in the capacitor C10, and then the capacitor is charged by the DC-DC converter circuit.

[0029] Next, multiple injection will be described. In the example of Fig. 3, the injector drive pulse of the first cylinder (main injection in period T3) and the injector drive pulse of the second cylinder (post injection in period T5) are turned on at the same time, and the injectors 4a and 4b are driven simultaneously. In this case, the injectors 4a and 4b belong to different injection groups, so they are controlled independently of each other, and even if their injection times overlap, the fuel injections are performed without being influenced by each other.

[0030] 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, so that the stored energy in capacitor C20 is supplied to injector 4b. At the beginning of post-injection, a large current flows through injector 4b, and the valve-opening response of injector 4b is accelerated.

[0031] After the energy supply from the capacitor C20, the transistor T21 is controlled to be turned on and off in response 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 in response 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.

[0032] After that, when the injector drive pulse for the second cylinder is turned off, the transistor T20 is turned off, and the back electromotive force energy generated when the injector 4b is de-energized is collected in the capacitor C20 through the diode D20. At this time, the energy is collected by the same capacitor C20 that supplied the energy at the start of injection. After the de-energization, when the drive current (INJ2 current) of the injector 4b attenuates to a predetermined level that is overcome by the biasing force of the return spring, the injector 4b closes and the post injection ends. Then, when the collection of the back electromotive force energy at the end of the post injection is completed, the transistor T13 is turned on and off, and the capacitor C20 is charged.

[0033] 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 is 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.

[0034] Also, although not shown, there are cases where a handler process is started at the injector-off timing of a preceding injection, and an injector-off interrupt occurs for a subsequent injection before the handler process for the preceding injection is completed. In this case, a waiting 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 waiting time causes a delay in the injector-on timing, which may result in the injection timing differing from the request.

[0035] To address this problem, in this embodiment, when multiple injection interrupt processes occur within a specified period between cylinders with adjacent fuel injection orders, when the interrupt for the preceding injection occurs, the control unit 2 performs the interrupt process for the preceding injection and the interrupt process for the following injection together within the same handler process.

[0036] Next, the operation of the above-mentioned configuration will be described with reference to Figures 5 to 11. The control unit 2 performs an injector-on interrupt process and an injector-off interrupt process. Each process will be described below in order.

[0037] (1) Injector-on interrupt processing (see Fig. 5 to Fig. 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.

[0038] When the control unit 2 ends the pulse-on event processing, it determines whether or not there is an injector-on interrupt request for a 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 a 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.

[0039] When the control unit 2 determines that there is an injector-on interrupt request for the subsequent injection within a predetermined period (S3: YES), it proceeds 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 the pulse-on event processing for the subsequent injection.

[0040] 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), finishes the injector on interrupt processing, and waits for the establishment of the next start event of the injector on interrupt processing.

[0041] 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.

[0042] 7, when the injector drive pulse for the preceding injection is turned on (t1), the control unit 2 starts the handler process and executes the interrupt process for the preceding injection, and if there is an interrupt request for the injector on of the succeeding injection within a predetermined period from the occurrence of the injector on interrupt for the preceding injection (t2), the control unit 2 executes the interrupt process for the succeeding injection within the handler process that 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 succeeding injection (t4) within the handler process that started when the injector on interrupt for the preceding injection occurred.

[0043] (2) Injector off interrupt processing (see Fig. 8 to Fig. 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).

[0044] When the control unit 2 starts the pulse-off event processing for the current injection, it judges whether the previous injection stage number is smaller than the total injection stage number in the group (S31). When the control unit 2 judges 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.

[0045] When the control unit 2 determines that the number of the 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 injection at the head of 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.

[0046] When the control unit 2 ends the pulse-off event processing, it determines whether or not there is an injector-off interrupt request for a 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 a 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.

[0047] When the control unit 2 determines that there is an injector-off interrupt request for the subsequent injection within the predetermined period (S23: YES), the control unit 2 proceeds to pulse-off event processing for the subsequent injection (S24).

[0048] When the control unit 2 starts the pulse-off event processing for the subsequent injection, it judges whether the current injection stage number is smaller than the total injection stage number in the group (S31). When the control unit 2 judges that the current 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 subsequent injection.

[0049] When the control unit 2 determines that the current injection stage number is not smaller than the total injection stage number 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 injection at the head of 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.

[0050] 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), finishes the injector off interrupt processing, and waits for the establishment of the next start event of the injector off interrupt processing.

[0051] 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 establishment of the next start event of the injector off interrupt processing.

[0052] 10 and 11, when the injector drive pulse for the preceding injection is turned off (t11), the control unit 2 starts the handler process and executes the interrupt process 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 executes the interrupt process for the subsequent injection within the handler process started at the occurrence of the injector-off interrupt for the preceding injection. 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 (t13) within the handler process started at the occurrence of the injector-off interrupt for the preceding injection.

[0053] 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 unnecessary, 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.

[0054] By using the subsequent on-event processing execution flag in the injector on interrupt processing and the subsequent off-event processing execution flag in the injector off interrupt processing, the need to execute interrupt processing for a subsequent injection can be appropriately managed by the subsequent on-event processing execution flag and the subsequent off-event processing execution flag.

[0055] Although the present disclosure has been described based on the embodiment, it is understood that the present disclosure is not limited to the embodiment or structure. The present disclosure also includes various modifications and modifications within the equivalent range. 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. [Explanation of symbols]

[0056] In the drawing, reference numeral 1 denotes a fuel injection control device, and 2 denotes a microcomputer (control unit).

Claims

1. 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.

2. 2. The fuel injection control device according to claim 1, wherein the control unit, if there is an injector-on interrupt request for the subsequent injection within a predetermined period from the occurrence of an injector-on interrupt for the preceding injection, performs interrupt processing for the subsequent injection within the handler processing that occurs when the interrupt for the preceding injection occurs.

3. 3. The fuel injection control device according to claim 2, wherein the control unit turns on a subsequent on-event processing execution flag after executing the interrupt processing for the subsequent injection.

4. 4. 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.

5. 2. The fuel injection control device according to claim 1, wherein if an injector-off interrupt request for the subsequent injection is received 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 the interrupt for the preceding injection occurs.

6. 6. The fuel injection control device according to claim 5, wherein the control unit turns on a subsequent off-event processing execution flag after executing the interrupt processing for the subsequent injection.

7. 7. 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 for the subsequent injection occurs.

Images