JP6369305B2 - Fuel injection control device - Google Patents

Description

  The present invention relates to a fuel injection control device for an internal combustion engine in which fuel is injected into a cylinder by an in-cylinder injector.

  In recent years, exhaust gas regulations have been strengthened, and minute injection using a region (hereinafter also referred to as “partial lift region”) in front of a region where the injector valve body is completely opened (hereinafter also referred to as “full lift region”) The corresponding technology is known. In the partial lift region, the injection characteristics are affected by fluctuations in individual injectors. In order to eliminate this fluctuation effect and ensure an accurate fuel injection amount, the injection characteristics in the partial lift region are learned, and the injection command value is corrected based on the learning result (see Patent Document 1 below). ).

US2003 / 0071613

  In the above-described conventional technology, the injector is controlled according to the required injection amount for normal control, so that the required injection amount may be small or high in many cases, and the injection using the partial lift region is not necessarily performed. Therefore, in some cases, injection in the partial lift region is not performed over a long period of time, and necessary learning may not be performed at a necessary timing.

  Therefore, for example, the required injection amount is divided into the first injection amount using the partial lift region and the remaining second injection amount, thereby increasing the injection frequency in the partial lift region and performing necessary learning. It is possible to do it.

  However, even if learning is performed in this way, if the injector deteriorates over time or if there is a deviation in the injection characteristics between the partial lift area and the full lift area, the injection characteristics of the partial lift area and the full lift area Therefore, in some cases, the air-fuel ratio correction may not be performed in the correct direction.

  The present invention has been made in view of such a problem, and the purpose of the present invention is to provide both a partial lift region and a full lift region when fuel injection is performed using both a partial lift region and a full lift region in an in-cylinder injector. It is another object of the present invention to provide a fuel injection control device capable of optimal air-fuel ratio correction.

In order to solve the above problems, a fuel injection control device according to the present invention is a fuel injection control device (28) of an internal combustion engine (11) in which fuel is injected into a cylinder (29) by an in-cylinder injector (19). The fuel injection amount is determined based on the air-fuel ratio detected by an injection control unit (281) that controls the fuel injection amount of the in-cylinder injector and an air-fuel ratio sensor (23) that detects the air-fuel ratio of the internal combustion engine. And a correction unit (282) that executes air-fuel ratio correction to be corrected. The injection control unit reflects the air-fuel ratio correction, and uses a full lift region in which the valve opening of the in-cylinder injector has a maximum opening, and performs fuel injection from the in-cylinder injector, and the cylinder Any of partial lift injection in which fuel injection from the in-cylinder injector is performed using a partial lift region from the opening at the start of energization to the in-cylinder injector to the maximum opening. It controls to do. The correction unit performs a first correction that is the air-fuel ratio correction when the full lift injection is performed and a second correction that is the air-fuel ratio correction when the partial lift injection is performed. When the correction unit determines that the correction value of the air-fuel ratio correction does not exceed the first threshold value in the first correction, and the correction value of the air-fuel ratio correction exceeds the second threshold value in the second correction. The injection control unit performs the full lift injection.

  According to the present invention, even when fuel injection is performed selectively using both the partial lift region and the full lift region in the in-cylinder injector, the air-fuel ratio correction is performed using the first correction for full lift injection and the partial lift. Since the second correction for injection is performed, optimal air-fuel ratio correction can be performed in both the partial lift region and the full lift region.

  According to the present invention, there is provided a fuel injection control device capable of performing an optimal air-fuel ratio correction in both a partial lift region and a full lift region when fuel injection is performed using both a partial lift region and a full lift region in an in-cylinder injector. can do.

It is a figure showing the schematic structure of the engine control system to which ECU (fuel injection control device) concerning the embodiment of the present invention is applied. It is a block diagram which shows the functional structure of ECU shown in FIG. It is a figure which shows schematic structure of the injector shown in FIG. It is a figure which shows the cumulative injection quantity at the time of making it change from a partial lift area | region to a full lift area | region. FIG. 3 is a flowchart for explaining processing of an ECU shown in FIG. 2. FIG. FIG. 3 is a flowchart for explaining processing of an ECU shown in FIG. 2. FIG. It is a flowchart for demonstrating the information stored in the memory | storage part shown in FIG. It is a figure for demonstrating the specific content of an air fuel ratio correction | amendment. It is a figure for demonstrating the specific content of an air fuel ratio correction | amendment. It is a figure for demonstrating the specific content of an air fuel ratio correction | amendment.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In order to facilitate the understanding of the description, the same constituent elements in the drawings will be denoted by the same reference numerals as much as possible, and redundant description will be omitted.

  An engine control system 10 to which an ECU (fuel injection control device) according to an embodiment of the present invention is applied will be described with reference to FIG. The engine control system 10 includes an engine 11 and an ECU 28, and the ECU 28 controls the behavior of the engine 11.

  The engine 11 will be described. The engine 11 is an internal combustion engine and includes an intake pipe 12, a throttle valve 13, a surge tank 14, an intake manifold 16, an intake port 17, an exhaust pipe 22, and a cylinder 29. In FIG. 1, only one cylinder 29 and a pipe system connected thereto are illustrated, but the engine 11 is an in-line four-cylinder engine having four cylinders 29.

  The intake pipe 12 is provided with a throttle valve 13 whose opening degree is adjusted by a motor (not shown). An air flow meter (not shown) for detecting the intake air amount is provided on the upstream side of the throttle valve 13. A surge tank 14 is provided on the downstream side of the throttle valve 13. An intake pipe pressure sensor 15 that detects the intake pipe pressure is provided on the surge tank 14 or on the downstream side of the surge tank 14. The surge tank 14 is provided with an intake manifold 16 that introduces air into each cylinder of the engine 11.

  The intake manifold 16 is connected to the intake port 17. A port injector 18 for injecting the intake port is attached to the intake port 17. The intake port 17 is connected to each cylinder 29. The intake port 17 is provided with an airflow control valve 20 that controls the airflow strength (the strength of the swirl flow and the tumble flow) in the cylinder 29 (the room defined by the piston 29a and the cylinder 29b, the same applies hereinafter). .

  The cylinder 29 includes a piston 29a and a cylinder 29b. The in-cylinder injector 19 is provided in the cylinder head 29c above the cylinder 29b. The in-cylinder injector 19 is a fuel injection device for in-cylinder injection that directly injects fuel into the cylinder 29. The cylinder head 29 c is provided with a spark plug 21 so as to correspond to each cylinder 29. The in-cylinder mixture of each cylinder 29 is ignited by the spark discharge of the spark plug 21.

  An exhaust pipe 22 is connected to each cylinder 29. The exhaust pipe 22 is provided with an air-fuel ratio sensor 23 for detecting the air-fuel ratio of the exhaust gas. A catalyst (not shown) such as a three-way catalyst for purifying exhaust gas is provided on the downstream side of the air-fuel ratio sensor 23.

  The cylinder block including each cylinder 29 is provided with a coolant temperature sensor 24. A crankshaft 25 is connected to each piston 29a. The crankshaft 25 converts the reciprocating motion of the piston 29a into a circular motion. A crank angle sensor 26 is provided outside the crankshaft 25. The crank angle sensor 26 outputs a pulse signal every time the crankshaft 25 rotates a predetermined crank angle. Based on the output signal of the crank angle sensor 26, the crank angle and the engine speed are detected. The engine control system 10 is provided with an accelerator sensor 27. Based on the output signal from the accelerator sensor 27, the accelerator operation amount (depressed amount of the accelerator pedal) is detected.

  Output signals from the intake pipe pressure sensor 15, the air-fuel ratio sensor 23, the coolant temperature sensor 24, the crank angle sensor 26, and the accelerator sensor 27 are input to the ECU 28. The ECU 28 is mainly composed of a microcomputer, and executes various engine control programs stored in a built-in ROM (storage medium). The ECU 28 outputs control signals to the throttle valve 13, the port injector 18, the in-cylinder injector 19, the airflow control valve 20, and the spark plug 21 in accordance with the execution of this program. As described above, the ECU 28 controls the fuel injection amount, the ignition timing, the throttle opening (intake air amount) and the like according to the engine operating state. At that time, the ECU 28 sets the required injection amounts Qp and Qs of the port injector 18 and the in-cylinder injector 19, the injection timing, and the like according to the engine operating state (for example, the engine speed and load).

  In the present embodiment, the ECU 28 adjusts the required injection amount Qp to the port injector 18 and the required injection amount Qs to the in-cylinder injector 19 while adjusting the air-fuel ratio calculated based on the output signal from the air-fuel ratio sensor 23. The injection amount of the in-cylinder injector 19 is corrected based on the fluctuation. A functional configuration of the ECU 28 from this viewpoint will be described with reference to FIG.

  As shown in FIG. 2, the ECU 28 includes an injection control unit 281, a correction unit 282, and a storage unit 283. Output signals from the air-fuel ratio sensor 23, the crank angle sensor 26, and the accelerator sensor 27 are input to the ECU 28. From these output signals, it is possible to grasp the driving state of the engine 11 (from idling state to normal traveling state, etc.) and the air-fuel ratio.

  The engine control system 10 includes an instruction receiving unit 284 in addition to the above-described components. When the user or maintenance staff operates the instruction receiving unit 284, the ECU 28 executes a flow for determining characteristics of the in-cylinder injector 19 as described later.

  The injection control unit 281 is a functional part that controls the fuel injection amounts of the in-cylinder injector 19 and the port injector 18. The injection control unit 281 outputs a control signal indicating the required injection amount Qp to the port injector 18 and the required injection amount Qs to the in-cylinder injector 19 and stores the information in the storage unit 283.

  The correction unit 282 is a functional part that corrects the fuel injection amount from the in-cylinder injector 19 based on the air-fuel ratio detected by the air-fuel ratio sensor 23 that detects the air-fuel ratio of the internal combustion engine. The correction unit 282 stores the correction result in the storage unit 283. The injection control unit 281 and the correction unit 282 perform a series of fuel injection control and air-fuel ratio correction in conjunction with each other while exchanging their operation information.

  In the present embodiment, the in-cylinder injector 19 is moved to a full lift region (a region where the needle lift amount of the in-cylinder injector 19 becomes the full lift amount) and a partial lift region (a portion before the needle lift amount of the in-cylinder injector 19 becomes the full lift amount). Both areas are used as the partial lift amount).

  A full lift injection using the full lift region of the in-cylinder injector 19 and a partial lift injection using the partial lift region will be described with reference to FIG. FIG. 3A shows a state in which the opening 196 of the in-cylinder injector 19 is fully closed. FIG. 3B shows that the in-cylinder injector 19 is in a partial lift state. FIG. 3C shows that the in-cylinder injector 19 is in a full lift state.

  The in-cylinder injector 19 includes a housing 191, a needle 192, a solenoid coil 193, a core 194, and a spring 195. In the housing 191, a needle 192, a solenoid coil 193, a core 194, and a spring 195 are disposed. The housing 191 is provided with an opening 196 that is a fuel injection port.

  The tip of the needle 192 has a tapered shape and is formed so as to enter the opening 196. A core 194 is provided at the rear end portion of the needle 192 and is disposed adjacent to the solenoid coil 193. The spring 195 is provided between the housing 191 and the needle 192. When no external force is applied, the spring 195 attracts the needle 192 to the housing 191, and the tip of the needle 192 enters the opening 196, and the (A) of FIG. ).

  When a current flows through the solenoid coil 193 from the state of FIG. 3A, the core 194 is attracted to the solenoid coil 193 side. Since the needle 192 is provided integrally with the core 194, the tip of the solenoid coil 193 is separated from the opening 196, resulting in a state as shown in FIG.

  When the current continues to flow through the solenoid coil 193 from the state of FIG. 3B, as shown in FIG. 3C, the needle 192 is completely lifted from the opening 196 (full lift region). . The state represented by (B) in FIG. 3 from (A) to (C) in FIG. 3 is referred to as a partial lift state (partial lift region).

  As shown in FIG. 4, in the partial lift region from when the solenoid coil 193 is energized until the maximum opening amount is reached, an increase in the injector opening amount (the opening amount of the gap between the needle 192 and the opening portion 196) is increased. Accordingly, the cumulative injection amount (total injection amount) increases exponentially. When the state of FIG. 3C in which the injector opening amount is maximum is maintained, the cumulative injection amount increases in a linear function.

  As described above, in the partial lift region, the stroke of the needle 192 changes (lifts), thereby increasing the injector opening amount, which is the gap between the opening 196 and the needle 192. The cumulative injection amount increases in an exponential function. At this time, since the injector opening amount is dynamically changed, it is easily affected by the dimensional variation of each part of the in-cylinder injector 19, so the estimated value of the cumulative injection amount and the actual As a result, the air-fuel ratio sensor value increases or decreases from the assumed value.

  On the other hand, in the full lift region, the stroke of the needle 192 does not change (full lift holding), and the injector opening amount that is the gap between the opening 196 and the needle 192 does not fluctuate, so that the cumulative injection amount becomes a linear function. Although it increases monotonously, it is difficult to be affected by the dimensional variation of each part of the in-cylinder injector due to the fact that the injector opening amount does not fluctuate dynamically.Therefore, the difference between the estimated value of the cumulative injection amount and the actual value is unlikely to occur. The air-fuel ratio sensor value does not increase or decrease with respect to the assumed value.

  In this embodiment, as fuel injection control (air-fuel ratio correction), correction associated with the air-fuel ratio sensor value (injection amount deviation value) is performed independently in each of the partial lift region and the full lift region. Specifically, in the partial lift region, air-fuel ratio correction is performed based on the air-fuel ratio sensor value in the partial lift region, and in the full lift region, air-fuel ratio correction is performed based on the air-fuel ratio sensor value in the full lift region. Thus, by performing air-fuel ratio correction in each region, appropriate fuel injection control (air-fuel ratio correction) can be performed in each of the partial lift region and the full lift region.

  In the partial lift region, the air-fuel ratio sensor value (injection amount deviation value) tends to increase or decrease due to the influence of the variation among the in-cylinder injectors. As a result, if the air-fuel ratio correction is performed in common for the partial lift region and the full lift region, it becomes difficult to fully perform the air-fuel ratio correction according to the injection amount deviation value in the partial lift region. In order to cope with this, the air-fuel ratio correction according to the injection amount deviation value in the partial lift region is performed by performing the air-fuel ratio correction dedicated to the partial lift region in the partial lift region and the air-fuel ratio correction dedicated to the full lift region in the full lift region. Can be fully performed.

  A specific air-fuel ratio correction method will be described with reference to FIG. The flowchart shown in FIG. 5 shows an example in which fuel injection is performed using only the in-cylinder injector 19. Although FIG. 1 illustrates the configuration including both the port injector 18 and the in-cylinder injector 19, it is also preferable to execute the flow shown in FIG. 5 in a configuration including only the in-cylinder injector 19. Is.

  In step S01, the correction unit 282 confirms the air-fuel ratio correction amount in the partial lift region and the air-fuel ratio correction amount in the full lift region. When the air-fuel ratio correction amount in the partial lift region does not exceed the second threshold value and the air-fuel ratio correction amount in the full lift region does not exceed the first threshold value, the process proceeds to step S02. If the air-fuel ratio correction amount in the partial lift region exceeds the second threshold and / or the air-fuel ratio correction amount in the full lift region exceeds the first threshold, the process proceeds to step S11.

  In step S <b> 02, the injection control unit 281 performs normal injection using the in-cylinder injector 19.

  In step S11, the correction unit 282 determines whether only the air-fuel ratio correction amount in the partial lift region exceeds the second threshold value. When only the air-fuel ratio correction amount in the partial lift region exceeds the second threshold value, the process proceeds to step S12. In addition to the air-fuel ratio correction amount in the partial lift region exceeding the second threshold value, the air-fuel ratio correction amount in the full lift region also exceeds the first threshold value, or the air-fuel ratio correction amount in the partial lift region is the second value. If the threshold value is not exceeded and the air-fuel ratio correction amount in the full lift region exceeds the first threshold value, the process proceeds to step S21.

  In step S <b> 12, the injection control unit 281 uses the in-cylinder injector 19 to execute fuel injection using only the full lift region.

  In step S21, the correction unit 282 determines whether only the air-fuel ratio correction amount in the full lift region exceeds the first threshold value. When only the air-fuel ratio correction amount in the full lift region exceeds the first threshold value, the process proceeds to step S22. If the air-fuel ratio correction amount in the partial lift region exceeds the second threshold value, and if the air-fuel ratio correction amount in the full lift region also exceeds the first threshold value, the process proceeds to step S31.

  In step S <b> 22, the correction unit 282 determines whether the fuel injection amount is insufficient by only fuel injection using the partial lift region of the in-cylinder injector 19. If it is determined that the fuel injection amount is not insufficient, the process proceeds to step S23. If it is determined that the fuel injection amount is insufficient, the process proceeds to step S24.

  In step S <b> 23, the injection control unit 281 performs fuel injection using only the partial lift region using the in-cylinder injector 19.

  In step S <b> 24, the injection control unit 281 performs fuel injection using the partial lift region and the full lift region using the in-cylinder injector 19.

  In step S31, the correction unit 282 determines that the injector is assembled by mistake. The correction unit 282 notifies that an erroneous assembly has occurred as necessary.

  In the present embodiment, the engine 11 includes a port injector 18 in addition to the in-cylinder injector 19. Therefore, it is also a preferable aspect to execute the flow in which the injection from the port injector 18 is woven into the above-described flow. This preferred embodiment will be described with reference to FIG. The flowchart shown in FIG. 6 is obtained by replacing step S12 of the flowchart shown in FIG. 5 with step S13 and replacing step S24 with step S25.

  In step S11 of FIG. 6, the correction unit 282 determines whether only the air-fuel ratio correction amount in the partial lift region exceeds the second threshold value. When only the air-fuel ratio correction amount in the partial lift region exceeds the second threshold value, the process proceeds to step S13.

  In step S <b> 13, the injection control unit 281 performs fuel injection using only the full lift region using the in-cylinder injector 19, uses fuel injection using the port injector 18, or uses the port injector 18 for fuel injection. Do one of the following.

  In step S <b> 22 of FIG. 6, the correction unit 282 determines whether or not the fuel injection amount is insufficient only by fuel injection using the partial lift region of the in-cylinder injector 19. If it is determined that the fuel injection amount is not insufficient, the process proceeds to step S23. If it is determined that the fuel injection amount is insufficient, the process proceeds to step S25.

  In step S <b> 25, the injection control unit 281 performs fuel injection using the partial lift region using the in-cylinder injector 19 and performs fuel injection using the fuel injection using the port injector 18 together.

  The storage history of the in-cylinder injector 19 is stored in the storage unit 283 in FIG. As shown in FIG. 7, as the injection history of the in-cylinder injector 19, the number of injections and the A / F correction value (air-fuel ratio) are associated with each injection timing ("1 (previous)" "2 (previous)"). Correction value) is stored. In calculating the air-fuel ratio correction value at the next timing of the injection history, it is preferable to refer to the injection history (pre-injection).

  For example, as shown in FIG. 8, it is preferable to use the air-fuel ratio correction value of the injection history “1 (previous)” or “2 (previous)” for the air-fuel ratio correction in the injection of the in-cylinder injector 19 this time. More specifically, as shown in FIG. 9, the latest air-fuel ratio correction value of the injection history “2 (previous times)” is the same as the number of injections (two times) of the in-cylinder injector 19 this time. It is preferable to use it. Further, as shown in FIG. 10, it is also a preferable aspect that the air-fuel ratio correction value of the latest injection history “1 (previous)” is applied in consideration of the difference in the number of injections.

As mentioned above, although each embodiment of this invention was explained in full detail, this invention is not limited to each said embodiment, A various change can be performed, without deviating from the meaning of this invention.

11: Engine (internal combustion engine)
17: Intake port 18: Port injector 19: In-cylinder injector 23: Air-fuel ratio sensor 28: ECU (fuel injection control device)
29: Cylinder 281: Injection control unit 282: Correction unit 283: Storage unit 284: Instruction receiving unit

Claims (8)

A fuel injection control device (28) for an internal combustion engine (11) for injecting fuel into a cylinder (29) by means of an in-cylinder injector (19),
An injection control unit (281) for controlling the fuel injection amount of the in-cylinder injector;
A correction unit (282) for performing air-fuel ratio correction for correcting the fuel injection amount based on an air-fuel ratio detected by an air-fuel ratio sensor (23) for detecting an air-fuel ratio of the internal combustion engine,
The injection control unit reflects the air-fuel ratio correction, and uses a full lift region in which the valve opening of the in-cylinder injector has a maximum opening, and performs fuel injection from the in-cylinder injector, and the cylinder Any of partial lift injection in which fuel injection from the in-cylinder injector is performed using a partial lift region from the opening at the start of energization to the in-cylinder injector to the maximum opening. Control to do something,
The correction unit performs a first correction that is the air-fuel ratio correction when performing the full lift injection and a second correction that is the air-fuel ratio correction when performing the partial lift injection ,
When the correction unit determines that the correction value of the air-fuel ratio correction does not exceed the first threshold value in the first correction, and the correction value of the air-fuel ratio correction exceeds the second threshold value in the second correction. ,
The fuel injection control device , wherein the injection control unit performs the full lift injection . A fuel injection control device (28) for an internal combustion engine (11) for injecting fuel into a cylinder (29) by means of an in-cylinder injector (19),
An injection control unit (281) for controlling the fuel injection amount of the in-cylinder injector;
A correction unit (282) for performing air-fuel ratio correction for correcting the fuel injection amount based on an air-fuel ratio detected by an air-fuel ratio sensor (23) for detecting an air-fuel ratio of the internal combustion engine,
The injection control unit reflects the air-fuel ratio correction, and uses a full lift region in which the valve opening of the in-cylinder injector has a maximum opening, and performs fuel injection from the in-cylinder injector, and the cylinder Any of partial lift injection in which fuel injection from the in-cylinder injector is performed using a partial lift region from the opening at the start of energization to the in-cylinder injector to the maximum opening. Control to do something,
The correction unit performs a first correction that is the air-fuel ratio correction when performing the full lift injection and a second correction that is the air-fuel ratio correction when performing the partial lift injection,
When the correction unit determines that the correction value of the air-fuel ratio correction exceeds the first threshold value in the first correction, and the correction value of the air-fuel ratio correction does not exceed the second threshold value in the second correction. ,
The injection control unit, said partial whether to lift injection, or the partial lift injection and fuel injection control apparatus you and performing combination with fuel injection the full lift injection. When the correction unit determines that the correction value of the air-fuel ratio correction exceeds a first threshold value in the first correction, and the correction value of the air-fuel ratio correction exceeds a second threshold value in the second correction, the fuel injection control device according to claim 1 or 2, characterized in that detecting the assembled abnormality of the in-cylinder injector. Wherein the correction unit is configured in the second correction, the fuel injection control apparatus according to any one of claims 1 to 3, the injection number of the in-cylinder injector and switches the air-fuel ratio correction. 5. The fuel injection control device according to claim 4 , wherein the correction unit performs the air-fuel ratio correction based on the latest fuel injection in the second correction. In the second correction, when the fuel injection of the same number of injections as the number of injections in the partial lift region has been performed in the second correction, the correction unit performs the air-fuel ratio correction based on the most recent partial lift injection of the same number of injections. The fuel injection control device according to claim 4 , wherein the fuel injection control device is performed. A fuel injection control device (28) for an internal combustion engine (11) for injecting fuel into a cylinder (29) by means of an in-cylinder injector (19),
An injection control unit (281) for controlling the fuel injection amount of the in-cylinder injector;
A correction unit (282) for performing air-fuel ratio correction for correcting the fuel injection amount based on an air-fuel ratio detected by an air-fuel ratio sensor (23) for detecting an air-fuel ratio of the internal combustion engine,
The injection control unit reflects the air-fuel ratio correction, and uses a full lift region in which the valve opening of the in-cylinder injector has a maximum opening, and performs fuel injection from the in-cylinder injector, and the cylinder Any of partial lift injection in which fuel injection from the in-cylinder injector is performed using a partial lift region from the opening at the start of energization to the in-cylinder injector to the maximum opening. Control to do something,
The correction unit performs a first correction that is the air-fuel ratio correction when performing the full lift injection and a second correction that is the air-fuel ratio correction when performing the partial lift injection,
The internal combustion engine has a port injector (18) for injecting fuel into the intake port (17),
The injection control unit controls the fuel injection amount of the in-cylinder injector and the port injector,
When the correction unit determines that the correction value of the air-fuel ratio correction does not exceed the first threshold value in the first correction, and the correction value of the air-fuel ratio correction exceeds the second threshold value in the second correction. ,
The fuel injection control device, wherein the injection control unit performs fuel injection from the port injector in addition to the full lift injection. A fuel injection control device (28) for an internal combustion engine (11) for injecting fuel into a cylinder (29) by means of an in-cylinder injector (19),
An injection control unit (281) for controlling the fuel injection amount of the in-cylinder injector;
A correction unit (282) for performing air-fuel ratio correction for correcting the fuel injection amount based on an air-fuel ratio detected by an air-fuel ratio sensor (23) for detecting an air-fuel ratio of the internal combustion engine,
The injection control unit reflects the air-fuel ratio correction, and uses a full lift region in which the valve opening of the in-cylinder injector has a maximum opening, and performs fuel injection from the in-cylinder injector, and the cylinder Any of partial lift injection in which fuel injection from the in-cylinder injector is performed using a partial lift region from the opening at the start of energization to the in-cylinder injector to the maximum opening. Control to do something,
The correction unit performs a first correction that is the air-fuel ratio correction when performing the full lift injection and a second correction that is the air-fuel ratio correction when performing the partial lift injection,
The internal combustion engine has a port injector (18) for injecting fuel into the intake port (17),
The injection control unit controls the fuel injection amount of the in-cylinder injector and the port injector,
When the correction unit determines that the correction value of the air-fuel ratio correction exceeds the first threshold value in the first correction, and the correction value of the air-fuel ratio correction does not exceed the second threshold value in the second correction. ,
The injection control unit, fuel injection control apparatus you and performs fuel injection from the port injector in addition to the partial lift injection.

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