JP5182207B2 - Fuel injection control device for spark ignition internal combustion engine - Google Patents

Description

  The present invention relates to a fuel injection control device for a spark ignition type internal combustion engine.

  There is known an internal combustion engine that includes two injectors, a port injection injector that injects fuel into an intake passage and an in-cylinder direct injection injector that injects fuel into a cylinder. As a technique related to such fuel injection control of an internal combustion engine, Patent Document 1 describes control for reducing the in-cylinder direct injection ratio to be smaller than the port injection ratio. Patent Document 2 describes a technique for controlling the injection timing by the in-cylinder direct injection injector so that the addition is performed in a state where the flow of the lean air-fuel mixture is enhanced by the fuel injection from the in-cylinder direct injection injector. Yes. Patent Document 3 describes control for limiting the fuel pressure of an in-cylinder direct injection injector. Patent Document 4 describes a technique for injecting fuel having different properties between a port injection injector and an in-cylinder direct injection injector.

  Further, in relation to an internal combustion engine including an in-cylinder direct injection injector, Patent Document 5 describes an in-cylinder direct injection injector that changes the spray reach distance by changing the spray shape.

JP 2005-226529 A JP-A-2005-337104 JP 2006-017059 A JP 2007-154881 A JP 2003-214296 A

  In low pressure environments such as high altitudes, the reach of fuel spray from the direct injection injector in the cylinder increases, so the air-fuel ratio becomes excessively lean in stratified combustion at start-up and combustion instability such as misfire occurs. Exhaust performance may be deteriorated.

  The present invention has been made in view of such circumstances, and suppresses a decrease in combustion stability and exhaust performance in a low pressure environment in a spark ignition internal combustion engine including an in-cylinder direct injection injector and a port injection injector. For the purpose.

In order to solve the above problems, a fuel injection control device for a spark ignition type internal combustion engine according to the present invention includes:
A port injection injector for injecting fuel into the intake passage of the internal combustion engine;
An in-cylinder direct injection injector for injecting fuel into a cylinder of the internal combustion engine;
When the internal combustion engine is started, fuel injection by the port injector is performed after performing start-up injection control in which fuel injection is performed in the compression stroke by the in-cylinder direct injection injector, and the operating state of the internal combustion engine satisfies a predetermined condition. And control means for performing post-startup injection control for performing fuel injection twice in the compression stroke by the in-cylinder direct injection injector,
With
In the low pressure environment where the atmospheric pressure is lower than a predetermined threshold, the control means
(A) In the starting injection control,
(1) The reference value of the fuel pressure for permitting execution of fuel injection by the in-cylinder direct injection injector is lowered as compared with the case where the fuel injection is not performed in a low pressure environment, and the fuel pressure of the fuel injection by the in-cylinder direct injection injector is reduced. A correction to lower the target value than when not in a low-pressure environment, and
(2) a correction for advancing the fuel injection timing of the fuel injection by the in-cylinder direct injection injector as compared with the case where it is not in a low-pressure environment;
Correct at least one of the
(B) In the post-startup injection control,
(1) The fuel injection amount of the fuel injection by the in-cylinder direct injection injector is reduced as compared with the case where it is not in a low pressure environment, and the ratio of the fuel injection amount by the port injector to the total fuel injection amount is accordingly reduced. Correction higher than if not lower,
(2) a correction for reducing the target value of the fuel pressure of the fuel injection by the in-cylinder direct injection injector as compared with the case where the fuel pressure is not in a low pressure environment, and
(3) a correction for advancing the fuel injection timing of the fuel injection by the in-cylinder direct injection injector as compared with the case where it is not under a low pressure environment;
It is characterized in that at least one of the corrections is performed.

  The “predetermined condition” of the operation state for switching from the start-time injection control to the post-start-time injection control is, for example, when the rotation speed exceeds a predetermined threshold or when the elapsed time since the start-time injection control is started is predetermined. It is satisfied when the threshold value is exceeded.

  In the start-up injection control, fuel injection by the in-cylinder direct injection injector is permitted when the pressure of the fuel supplied to the in-cylinder direct injection injector is increased to a predetermined reference value by a driving force or the like by cranking. .

  After the fuel injection by the in-cylinder direct injection is permitted, the fuel injection by the in-cylinder direct injection is performed while controlling the fuel pressure to be a predetermined target value.

  The fuel injection by the in-cylinder direct injection is performed in the compression stroke, and the fuel spray flies toward the piston rising in the cylinder, and the flight path is changed in the cavity formed in the piston top surface, and then the cylinder top Fly toward the spark plug provided in the. As a result, high-concentration fuel sprays are localized in a space in the vicinity of the spark plug, and combustion is performed with good ignitability (this combustion mode is referred to as “stratified combustion”).

  Under low pressure environment, the fuel spray reach by the in-cylinder direct injection injector increases, making it difficult to localize the fuel spray in the vicinity of the spark plug at an appropriate timing (ignition timing) and good ignitability. It becomes difficult to obtain, and the startability is reduced.

  In the start-up injection control in a low pressure environment, if the reference value for permitting the fuel injection by the in-cylinder direct injection and the target value of the fuel pressure of the fuel injection by the in-cylinder direct injection are lowered, it will be In addition, the execution of fuel injection is permitted when the pressure is increased to a low fuel pressure, and the fuel injection by the in-cylinder direct injection injector is performed at a low fuel pressure.

  Thereby, even in a low pressure environment, it is possible to prevent the fuel spray reach by the in-cylinder direct injection injector from increasing, so that it is possible to suppress a decrease in startability in a low pressure environment.

In the start-up injection control in a low pressure environment, if the fuel injection timing of the fuel injection by the in-cylinder direct injection injector is advanced, the fuel spray injected from the in-cylinder direct injection injector passes through the guide portion on the piston top surface. The flight distance required to reach the vicinity of the spark plug becomes longer. Therefore, even if the reach of the fuel spray by the in-cylinder direct injection injector increases, the fuel spray can be localized near the spark plug at an appropriate timing. As a result, good stratified combustion can be performed even in a low-pressure environment, so that startability can be prevented from being reduced in a low-pressure environment.

  In the post-startup injection control, the fuel amount determined according to conditions such as the intake air amount is divided and injected into fuel injection by the port injection injector and fuel injection by the in-cylinder direct injection injector. The ratio of the injection amount by the port injector and the injection amount by the in-cylinder direct injection injector in the total injected fuel amount is determined according to the operating conditions and the like.

  In the post-startup injection control under a low pressure environment, if the fuel injection amount by the in-cylinder direct injection injector is reduced, the reach of fuel spray by the in-cylinder direct injection injector can be prevented from increasing. Further, by increasing the ratio of the fuel injection amount by the port injection injector to the total fuel injection amount, the fuel injection amount by the in-cylinder direct injection injector can be compensated for by the fuel injection by the port injection injector. It is possible to suppress deterioration in combustion stability and exhaust performance in a low pressure environment.

  In the post-startup injection control under a low pressure environment, if the target value of the fuel pressure of the fuel injection by the in-cylinder direct injection injector is decreased, the reach of the fuel spray by the in-cylinder direct injection injector can be prevented from increasing. It can suppress that combustion stability and exhaust performance fall in a low-pressure environment.

  In the post-startup injection control under a low pressure environment, if the fuel injection timing of the fuel injection by the in-cylinder injector is advanced, the fuel spray injected from the in-cylinder direct injection injector is ignited via the guide portion on the piston top surface. Since the flight distance required to reach the vicinity of the plug becomes longer, the fuel spray can be localized in the vicinity of the spark plug at an appropriate timing even if the reach of the fuel spray by the in-cylinder direct injection injector increases. Become. Therefore, it is possible to suppress a decrease in combustion stability and exhaust performance in a low pressure environment.

  According to the present invention, in an internal combustion engine including an in-cylinder direct injection injector and a port injection injector, it is possible to suppress deterioration in combustion stability and exhaust performance in a low pressure environment.

It is a figure which shows schematic structure of the spark ignition type internal combustion engine which concerns on Examples 1-4. (A) Engine speed, (B) Atmospheric pressure, (C) Ratio of fuel injection amount of in-cylinder direct injection injector and fuel injection amount of port injector when fuel injection control according to Embodiment 1 is performed, It is a time chart showing an example of the time change of. 3 is a flowchart of fuel injection control according to the first embodiment. In fuel injection control which concerns on Example 1, it is a figure which shows an example of a correspondence in the case of setting the ratio of the fuel injection quantity of a cylinder direct injection injector and the fuel injection quantity of a port injection injector according to atmospheric pressure. (A) Engine speed, (B) Fuel pressure of in-cylinder direct injection injector, (C) Target value of fuel pressure of in-cylinder direct injection injector when fuel injection control according to embodiment 2 is performed, (D It is a time chart showing an example of a time change of the fuel injection amount of a cylinder direct injection injector, and (E) the fuel injection amount of a port injection injector. 6 is a flowchart of fuel injection control according to a second embodiment. In the fuel injection control according to the second embodiment, the correspondence in the case of setting the reference value of the fuel pressure that permits the execution of fuel injection by the in-cylinder direct injection injector according to the atmospheric pressure, and the in-cylinder according to the atmospheric pressure It is a figure which shows an example of the correspondence in the case of setting the target value of the fuel pressure of a direct injection injector. (A) Engine speed, (B) Fuel pressure of in-cylinder direct injection injector, (C) Fuel injection timing of in-cylinder direct injection injector, (D) Cylinder when fuel injection control according to Embodiment 3 is performed It is a time chart showing an example of the time change of the fuel injection quantity of an internal direct injection injector, and the fuel injection quantity of (E) port injection injector. 10 is a flowchart of fuel injection control according to a third embodiment. In fuel injection control which concerns on Example 3, it is a figure which shows an example of the response | compatibility in the case of setting the fuel injection timing of a cylinder direct injection injector according to atmospheric pressure. 10 is a flowchart of fuel injection control according to a fourth embodiment.

  Hereinafter, embodiments of the present invention will be described in detail. The dimensions, materials, shapes, relative arrangements, and the like of the components described in the present embodiment are not intended to limit the technical scope of the invention to those unless otherwise specified.

  FIG. 1 is a conceptual diagram schematically showing a schematic configuration of the internal combustion engine and its intake system and exhaust system according to the present embodiment. The engine 1 of FIG. 1 is a spark ignition type internal combustion engine, and a spark plug 12 is provided at the top of the cylinder 2. A piston 3 is slidably inserted into the cylinder 2. A combustion chamber 18 formed by the inner wall of the cylinder 2 and the top surface of the piston 3 communicates with the intake passage 4 through the intake port 9 and also communicates with the exhaust passage 5 through the exhaust port 10. The engine 1 is provided with an intake valve 6 that opens and closes an intake port 9 and an exhaust valve 7 that opens and closes an exhaust port 10.

  The engine 1 is provided with two fuel injection injectors, that is, an in-cylinder direct injection injector 11 that injects fuel into the cylinder 2 and a port injection injector 8 that injects fuel into the intake port 9. The in-cylinder direct injection injector 11 is configured to inject fuel toward a cavity 13 formed on the top surface of the piston 3 when the piston 3 is in a predetermined timing of the compression stroke.

  The engine 1 is provided with an ECU 20 that is a computer that controls the operating state of the engine 1. Measurement data from various sensors (not shown) is input to the ECU 20, and the operating state of the engine 1 and the driver's request are acquired based on the input data, and based on the in-cylinder direct injection injector 11 and the port injection injector 8. Signals for controlling fuel injection, ignition operation by the spark plug 12, and the like are output.

  Here, the fuel injection control of the engine 1 will be described.

  When the engine 1 is started, fuel is injected by the in-cylinder direct injection injector 11. This is referred to as “startup injection control”. After the start-up injection control is started, when the rotational speed of the engine 1 exceeds a predetermined threshold value Ne1, the routine proceeds to “post-startup injection control” in which fuel injection is performed by both the in-cylinder direct injection injector 11 and the port injection injector 8. .

  In the starting injection control, first, the fuel pressure supplied to the in-cylinder direct injection injector 11 is increased by a pump (not shown), and the fuel pressure is increased to a predetermined reference value PR1 by the in-cylinder direct injection injector 11. Fuel injection is permitted.

When fuel injection by the in-cylinder direct injection injector 11 is permitted, the fuel pressure becomes a predetermined target value P.
The fuel injection by the in-cylinder direct injection injector 11 is performed while controlling the fuel pressure so as to be Rreq1.

  The fuel injection by the in-cylinder direct injection injector 11 is performed at a predetermined time Ainjd1 in the latter half of the compression stroke. The fuel injection timing Ainjd1 by the in-cylinder direct injection injector 11 was formed on the top surface of the piston 3 as the fuel spray injected from the in-cylinder direct injection injector 11 flew toward the piston 3 rising in the cylinder 2. The flight path along the lip portion 14 of the cavity 13 is changed to the direction of the spark plug 12 and is adapted to reach the spark plug 12.

  By injecting fuel in the latter half of the compression stroke by the in-cylinder direct injection injector 11, an air-fuel mixture having a high fuel concentration can be localized in the vicinity of the spark plug 12, and combustion by ignition by the spark plug 12 has good ignitability. Can be performed. Such a combustion mode is referred to as “stratified combustion”.

  In the post-startup injection control, the required injection amount calculated in accordance with conditions such as the intake air amount is divided into fuel injection by the port injection injector 8 and fuel injection by the in-cylinder direct injection injector 11 for injection. The ratio of the injection amount by the port injection injector 8 to the injection amount by the in-cylinder direct injection injector 11 in the required injection amount is determined according to the operating conditions of the engine 1 and the like.

  First, fuel is injected into the intake port 9 by the port injector 8, whereby an air-fuel mixture is formed in the intake port 9. This air-fuel mixture is sucked into the combustion chamber 18 as the intake valve 6 is opened.

  Next, fuel injection is performed in the combustion chamber 18 by the in-cylinder direct injection injector 11 at a predetermined time Ainjd1 in the latter half of the compression stroke. As in the case of the start-time injection control, fuel injection by the in-cylinder direct injection injector 11 is performed while controlling the fuel pressure so that the fuel pressure becomes a predetermined target value PRreq1. In the case of post-startup injection control, unlike in the case of start-up injection control, fuel injection by the in-cylinder direct injection injector 11 is performed in the air-fuel mixture atmosphere by the fuel injected by the port injector 8.

  Here, under a condition where the atmospheric pressure is low, such as when traveling at a high altitude, the cylinder pressure decreases, so the reach of fuel spray by the in-cylinder direct injection injector 11 increases. Therefore, even if fuel injection is performed by the in-cylinder direct injection injector 11 at an injection timing adapted under normal atmospheric pressure conditions in a lowland, fuel spray is locally generated in the vicinity of the ignition plug 12 at the timing when ignition by the ignition plug 12 is performed. In some cases, good ignitability could not be obtained. In that case, there is a possibility that the startability of the engine 1 may be deteriorated in the start-up injection control. In the post-startup injection control, the combustion stability of the engine 1 may be reduced or the exhaust performance may be deteriorated.

  In response to this problem, in the system according to the present embodiment, in the post-startup injection control in the low pressure environment where the atmospheric pressure is lower than the predetermined reference value Pa1, the fuel injection amount by the in-cylinder direct injection injector 11 is reduced and requested. Correction was made to increase the ratio of the fuel injection amount by the port injector 8 to the injection amount.

  As the ratio of the fuel injection amount by the in-cylinder direct injection injector 11 relatively decreases, the above-described reduction in combustion stability and exhaust performance due to the increase in the reach of fuel spray by the in-cylinder direct injection injector 11 Can be prevented. Therefore, good combustibility and exhaust performance can be realized even in a low pressure environment.

FIG. 2 shows (A) engine speed and (B) when fuel injection control according to this embodiment is performed.
6 is a time chart showing the change over time in the atmospheric pressure and the ratio of the fuel injection amount of the (C) port injection injector 8 and the fuel injection amount of the in-cylinder direct injection injector 11; In FIG. 2, PFI means fuel injection by the port injector 8, and DI means fuel injection by the in-cylinder direct injection injector 11.

  When the start-time injection control is started at time t0, it is determined that the rotational speed gradually increases due to cranking, and the fuel pressure supplied to the in-cylinder direct injection injector 11 exceeds the reference value PR1 that permits execution of fuel injection. At time t1, fuel injection by the in-cylinder direct injection injector 11 is started. As shown in FIG. 2C, fuel injection by the port injector 8 is not performed here.

  At time t2 when it is determined that the rotational speed of the engine 1 has exceeded the threshold value Ne1, the start-time injection control is switched to the post-start injection control. That is, as shown in FIG. 2C, fuel injection is performed by both the port injector 8 and the in-cylinder direct injector 11.

  At this time, as shown in FIG. 2C, the fuel injection amount by the in-cylinder direct injection injector 11 is lower in a low pressure environment (high ground, represented by a dashed line) than in normal pressure conditions (low ground, represented by a solid line). Is corrected to increase the ratio of the fuel injection amount by the port injector 8. Thereby, it becomes possible to suppress the influence of combustion instability and exhaust deterioration due to an increase in the reach of the fuel spray injected from the in-cylinder direct injection injector 11. Therefore, good combustion and exhaust performance can be realized even in a low pressure environment.

  FIG. 3 is a flowchart of the fuel injection control according to the present embodiment. The processing represented by this flowchart is repeatedly executed by the ECU 20 during operation of the engine 1.

  In step S101, the ECU 20 determines whether or not the rotational speed of the engine 1 is equal to or less than a threshold value Ne1. The rotation speed threshold value Ne1 is a reference value for determining whether or not switching from the start-time injection control to the post-start-up injection control is feasible. When the rotational speed is equal to or less than the threshold value Ne1 (Yes), the ECU 20 executes the processing from step S102 to step S106 (startup injection control). On the other hand, when the rotation speed is greater than the threshold value Ne1 (No), the ECU 20 executes the processing of step S107 to step S111 (post-startup injection control).

  First, start-up injection control will be described.

  In step S102, the ECU 20 determines whether or not the fuel pressure is greater than or equal to the threshold value PR1. The fuel pressure threshold value PR1 is a reference value for determining whether fuel injection by the in-cylinder direct injection injector 11 is feasible. When the fuel pressure is lower than the threshold value PR1 (No), the ECU 20 proceeds to the process of step S103, and boosts the fuel supplied to the in-cylinder direct injection injector 11 by the pump. The pressure increase by the pump is continued until it is determined that the fuel pressure is equal to or higher than the threshold value PR1. If the fuel pressure is greater than or equal to the threshold value PR1 (Yes), the ECU 20 proceeds to the process of step S104.

  In step S104, the ECU 20 calculates a target value PRreq and a fuel injection timing Ainjds (second half of the compression stroke) of the fuel pressure of the fuel injection by the in-cylinder direct injection injector 11, and in the subsequent step S105, the ECU 20 performs the in-cylinder direct injection injector. 11 is calculated.

  In step S105, the ECU 20 executes fuel injection by the in-cylinder direct injection injector 11 using the calculated target fuel pressure PRreq, injection timing Ainjds, and injection amount Qds as fuel injection parameters.

  Next, post-startup injection control will be described.

  In step S107, the ECU 20 determines whether or not the atmospheric pressure is greater than or equal to the threshold value Pa1. The atmospheric pressure threshold Pa1 is a reference value for determining whether or not correction in a low-pressure environment is necessary in the post-startup injection control.

  When the atmospheric pressure is greater than or equal to the threshold value Pa1 (Yes), the ECU 20 proceeds to the process of step S108, and calculates the fuel injection parameter related to the post-startup injection control in the case of the normal pressure condition. Specifically, the ratio between the injection amount by the in-cylinder direct injection injector 11 and the injection amount by the port injection injector 8 is calculated, and based on the ratio and the required injection amount calculated from the operating conditions such as the intake air amount. Then, the injection amount Qdi by the in-cylinder direct injection injector 11 and the injection amount Qpi by the port injection injector 8 are calculated.

  When the atmospheric pressure is lower than the threshold value Pa1 (No), the ECU 20 proceeds to the process of step S109 and calculates a fuel injection parameter related to the post-startup injection control in the low pressure environment. Specifically, the ratio of the injection amount by the in-cylinder direct injection injector 11 and the injection amount by the port injection injector 8 in the post-startup injection control under the normal pressure condition is corrected to a ratio in which the ratio of the port injection injector 8 is increased. Then, the injection amount Qdi from the in-cylinder direct injection injector 11 is corrected to decrease, and the injection amount Qpi from the port injection injector 8 is corrected to increase.

  After executing the process of step S108 or step S109, the ECU 20 proceeds to the process of step S110.

  In step S110, the ECU 20 calculates the target value PRreq of the fuel pressure for fuel injection by the in-cylinder direct injection injector 11 and the fuel injection timing Ainjdi (the second half of the compression stroke).

  In step S111, the ECU 20 executes fuel injection by the port injection injector 8 using the calculated injection amount Qpi as a fuel injection parameter, and performs fuel injection by the in-cylinder direct injection injector 11 using the calculated fuel pressure PRreq and injection. The timing Ainjdi and the injection amount Qdi are executed as fuel injection parameters.

  In this embodiment, the ECU 20 that executes the processing of the flowchart described above corresponds to the “control unit” in the present invention.

  In the post-startup injection control according to the present embodiment, as shown in FIG. 4, correction may be performed so that the ratio of the injection amount by the port injector 8 in the required injection amount becomes higher as the atmospheric pressure becomes lower in a low pressure environment. good. By so doing, it is possible to more reliably suppress the deterioration of combustion stability and exhaust performance in a low pressure environment.

  Next, a second embodiment of the present invention will be described. In the system of the present embodiment, the reference value PR1 and the in-cylinder for permitting execution of fuel injection by the in-cylinder direct injection injector 11 in the start-up injection control in the low pressure environment where the atmospheric pressure is lower than the predetermined reference value Pa1. The correction for reducing the target value PRreq1 of the fuel pressure of the fuel injection by the direct injection injector 11 is performed. Further, in the post-startup injection control under the low pressure environment, correction is performed to reduce the target value PRreq1 of the fuel pressure of the fuel injection by the in-cylinder direct injection injector 11.

By reducing the reference value PR1 for determining whether or not fuel injection can be performed by the in-cylinder direct injection injector 11, the in-cylinder direct injection injector 11 is allowed to perform fuel injection when the pressure is increased to a fuel pressure lower than normal. Will come to be. Further, by reducing the target value PRreq1 of the fuel pressure of the fuel injection by the in-cylinder direct injection injector 11, the fuel injection by the in-cylinder direct injection injector 11 is performed at a low fuel pressure. Thereby, even in a low pressure environment, it is possible to prevent the reach of fuel spray by the in-cylinder direct injection injector 11 from increasing. Therefore, it is possible to suppress the startability from being deteriorated in the start-up injection control in the low pressure environment. In addition, in post-startup injection control under a low pressure environment, it is possible to suppress deterioration in combustion stability and exhaust performance.

  FIG. 5 shows (A) the engine speed, (B) the fuel pressure of the in-cylinder direct injection injector 11, and (C) the fuel pressure of the in-cylinder direct injection injector 11 when the fuel injection control according to this embodiment is performed. 6 is a time chart showing the change over time of (D) the fuel injection amount of the in-cylinder direct injection injector 11 and (E) the fuel injection amount of the port injector 8. In FIG. 5, PFI indicates fuel injection by the port injection injector 8, and DI indicates fuel injection by the in-cylinder direct injection injector 11.

  When start-up injection control is started at time t0, as shown in FIG. 5 (A), the engine speed is gradually increased by cranking, and as shown in FIG. 5 (B), by the driving force of cranking. The fuel supplied to the in-cylinder direct injection injector 11 starts to be pressurized by the action of the driven boost pump. Then, after it is determined that the fuel pressure of the in-cylinder direct injection injector 11 has exceeded the reference value PR1 for permitting execution of fuel injection by the in-cylinder direct injection injector 11, the in-cylinder direct injection injector 11 performs the operation at time t1. Fuel injection is started.

  At this time, as shown in FIG. 5B, in a low pressure environment (indicated by a high altitude, indicated by a one-dot chain line), the reference value PR1 for permitting execution of fuel injection by the in-cylinder direct injection injector 11 is a normal pressure condition ( It is corrected to a lower value than in the case of lowland and solid line). Accordingly, execution of fuel injection by the in-cylinder direct injection injector 11 is permitted at a stage where the pressure is increased only to a fuel pressure lower than that in the normal pressure condition, and fuel injection by the in-cylinder direct injection injector 11 is started.

  Further, as shown in FIG. 5C, under the low pressure environment, the target value PRreq1 of the fuel pressure of the fuel injection by the in-cylinder direct injection injector 11 is corrected to a value lower than that in the normal pressure condition. This correction is applied to both the starting injection control and the post-starting injection control as shown in FIG. As a result, as shown in FIG. 5B, in both the start-time injection control and the post-start-up injection control, the fuel injection by the in-cylinder direct injection injector 11 is performed at a fuel pressure lower than that in the normal pressure condition. become. Therefore, even in a low pressure environment, it is possible to prevent the reach of the fuel spray of the fuel injection by the in-cylinder direct injection injector 11 from increasing.

  FIG. 6 is a flowchart of fuel injection control according to the present embodiment. The processing represented by this flowchart is repeatedly executed by the ECU 20 during operation of the engine 1.

  In step S201, the ECU 20 determines whether or not the rotational speed of the engine 1 is equal to or less than a threshold value Ne1. The rotation speed threshold value Ne1 is a reference value for determining whether or not switching from the start-time injection control to the post-start-up injection control is feasible. When the rotation speed is equal to or less than the threshold value Ne1 (Yes), the ECU 20 executes the processing from step S202 to step S211 (startup injection control). On the other hand, when the rotational speed is greater than the threshold value Ne1 (No), the ECU 20 executes the processing from step S212 to step S216 (post-startup injection control).

  First, start-up injection control will be described.

In step S202, the ECU 20 determines whether or not the atmospheric pressure is greater than or equal to the threshold value Pa1. The atmospheric pressure threshold value Pa1 is a reference value for determining whether or not correction in a low-pressure environment is necessary in the start-up injection control.

  When the atmospheric pressure is greater than or equal to the threshold value Pa1 (Yes), the ECU 20 proceeds to the process of step S203, and calculates a reference value PR1 for determining whether or not fuel injection by the in-cylinder direct injection injector 11 can be performed under normal pressure conditions. .

  When the atmospheric pressure is lower than the threshold value Pa1 (No), the ECU 20 proceeds to the process of step S204, and sets the reference value PR1 for determining whether or not the direct injection injector 11 can execute fuel injection under the normal pressure condition on the low pressure side. The corrected value is set as a reference value for determining whether or not fuel injection by the in-cylinder direct injection injector 11 can be performed in a low pressure environment.

  After executing the process of step S203 or step S204, the ECU 20 proceeds to the process of step S205.

  In step S205, the ECU 20 determines whether or not the fuel pressure is greater than or equal to the reference value PR1 calculated in step S203 or step S204. When the fuel pressure is lower than the threshold value PR1 (No), the ECU 20 proceeds to the process of step S206 and performs pressure increase by the pump of the fuel supplied to the in-cylinder direct injection injector 11. The pressure increase by the pump is continued until it is determined that the fuel pressure is equal to or higher than the threshold value PR1. If the fuel pressure is greater than or equal to the threshold value PR1 (Yes), the ECU 20 proceeds to the process of step S207.

  In step S207, the ECU 20 determines whether the atmospheric pressure is greater than or equal to the threshold value Pa1. The processing content of step S207 is the same as that of step S202.

  When the atmospheric pressure is greater than or equal to the threshold value Pa1 (Yes), the ECU 20 proceeds to the process of step S208, and calculates the target value PRreq1 of the fuel pressure of the fuel injection by the direct injection injector 11 under the normal pressure condition.

  When the atmospheric pressure is lower than the threshold value Pa1 (No), the ECU 20 proceeds to the process of step S209, and corrects the target value PRreq1 of the fuel pressure of the fuel injection by the in-cylinder direct injection injector 11 under the normal pressure condition to a value on the low pressure side. Then, the corrected value is set as the target value of the fuel pressure of the fuel injection by the in-cylinder direct injection injector 11 in a low pressure environment.

  After executing the process of step S208 or step S209, the ECU 20 proceeds to the process of step S210.

  In step S210, the ECU 20 calculates an injection amount Qds of fuel injection by the in-cylinder direct injection injector 11 and a fuel injection timing Ainjds (second half of the compression stroke).

  In step S211, the ECU 20 executes fuel injection by the in-cylinder direct injection injector 11 using the calculated target fuel pressure PRreq1, injection timing Ainjds, and injection amount Qds as fuel injection parameters.

  Next, post-startup injection control will be described.

  In step S212, the ECU 20 determines whether or not the atmospheric pressure is equal to or higher than the threshold value Pa1. The processing content of step S212 is the same as that of step S202.

When the atmospheric pressure is greater than or equal to the threshold value Pa1 (Yes), the ECU 20 proceeds to the process of step S213, and calculates the target value PRreq1 of the fuel pressure of the fuel injection by the direct injection injector 11 under the normal pressure condition.

  When the atmospheric pressure is lower than the threshold value Pa1 (No), the ECU 20 proceeds to the process of step S214, and corrects the target value PRreq1 of the fuel pressure of the fuel injection by the in-cylinder direct injection injector 11 under the normal pressure condition to a value on the low pressure side. Then, the corrected value is set as the target value of the fuel pressure of the fuel injection by the in-cylinder direct injection injector 11 in a low pressure environment.

  After executing the process of step S213 or step S214, the ECU 20 proceeds to the process of step S215.

  In step S215, the ECU 20 calculates the ratio between the injection amount by the in-cylinder direct injection injector 11 and the injection amount by the port injection injector 8, and sets the ratio to the required injection amount calculated from the operating conditions such as the intake air amount. Based on this, the injection amount Qdi by the in-cylinder direct injection injector 11 and the injection amount Qpi by the port injection injector 8 are calculated. Further, the fuel injection timing Ainjdi (second half of the compression stroke) of the fuel injection by the in-cylinder direct injection injector 11 is calculated.

  In step S216, the ECU 20 executes fuel injection by the port injection injector 8 using the calculated injection amount Qpi as a fuel injection parameter, and performs fuel injection by the in-cylinder direct injection injector 11 with the calculated fuel pressure PRreq1, injection. The timing Ainjdi and the injection amount Qdi are executed as fuel injection parameters.

  In this embodiment, the ECU 20 that executes the processing of the flowchart described above corresponds to the “control unit” in the present invention.

  In the start-up injection control and the post-start-up injection control of the present embodiment, as shown in FIG. 7, the fuel for permitting the fuel injection by the in-cylinder direct injection injector 11 as the atmospheric pressure becomes lower in a low pressure environment. You may correct | amend so that the reference value PR1 of pressure may become low. Further, the correction may be made so that the target value PRreq1 of the fuel pressure of the fuel injection by the in-cylinder direct injection injector 11 becomes lower as the atmospheric pressure becomes lower in the low pressure environment. By so doing, it is possible to more reliably suppress the deterioration of the startability, combustion stability and exhaust performance of the engine 1 in a low pressure environment.

  Next, a third embodiment of the present invention will be described. Under a low pressure environment, the reach of the fuel spray injected from the in-cylinder direct injection injector 11 increases. Therefore, from the in-cylinder direct injection injector 11 at the injection timing that is adapted so that the timing at which the fuel spray injected from the in-cylinder direct injection injector 11 reaches the vicinity of the spark plug 12 under the normal pressure condition coincides with the ignition timing. Even if fuel injection is performed, the fuel spray may reach the vicinity of the spark plug 12 at a timing earlier than the ignition timing in a low pressure environment.

Therefore, in the system of the present embodiment, the injection timing Ainjd1 of the fuel injection by the in-cylinder direct injection injector 11 is advanced in the start-up injection control and the post-startup injection control in a low pressure environment where the atmospheric pressure is lower than the predetermined reference value Pa1. It was decided to correct the angle. By advancing the injection timing Ainjd1 of the fuel injection by the in-cylinder direct injection injector 11, the fuel spray injected from the in-cylinder direct injection injector 11 follows the cavity 13 and the lip portion 14 formed on the top surface of the piston 3. The flight distance required to fly and reach the vicinity of the spark plug 12 increases. Therefore, even if the reach of the fuel spray by the in-cylinder direct injection injector 11 increases in a low pressure environment, the fuel spray can be localized near the spark plug 12 at an appropriate timing. Accordingly, it is possible to suppress a decrease in startability of the engine 1 in the start-up injection control in a low pressure environment, and a decrease in combustion stability and exhaust performance in the post-startup injection control.

  FIG. 8 shows (A) the engine speed, (B) the fuel pressure of the in-cylinder direct injection injector 11, and (C) the fuel injection of the in-cylinder direct injection injector 11 when the fuel injection control according to this embodiment is performed. It is a time chart showing a time change of time, (D) fuel injection amount of in-cylinder direct injection injector 11, and (E) fuel injection amount of port injection injector 8. In FIG. 8, PFI means fuel injection by the port injection injector 8, and DI means fuel injection by the in-cylinder direct injection injector 11.

  When starting injection control is started at time t0, as shown in FIG. 8 (A), the engine speed is gradually increased by cranking, and as shown in FIG. 8 (B), by the driving force of cranking. The fuel supplied to the in-cylinder direct injection injector 11 starts to be pressurized by the action of the driven boost pump. Then, after it is determined that the fuel pressure of the in-cylinder direct injection injector 11 has exceeded the reference value PR1 for permitting execution of fuel injection by the in-cylinder direct injection injector 11, the in-cylinder direct injection injector 11 performs the operation at time t1. Fuel injection is started (startup injection control).

  As shown in FIG. 8C, in a low pressure environment (high ground, indicated by a one-dot chain line), the fuel injection timing Ainjd1s by the in-cylinder direct injection injector 11 in the start-up injection control is a normal pressure condition (indicated by a low ground, solid line). The timing is corrected to a time on the more advanced side than in the case of. In addition, the fuel injection timing Ainjd1i by the in-cylinder direct injection injector 11 in the post-startup injection control is corrected to a timing that is ahead of the normal pressure condition (indicated by a low ground and a solid line). Thereby, the fuel injection by the in-cylinder direct injection injector 11 is performed earlier than in the case of the normal pressure condition in the compression stroke. Therefore, in a low pressure environment, even if the reach of fuel spray by the in-cylinder direct injection injector 11 increases, the fuel spray from the in-cylinder direct injection injector 11 can be localized in the vicinity of the spark plug 12 at an appropriate timing. become able to.

  FIG. 9 is a flowchart of the fuel injection control according to the present embodiment. The processing represented by this flowchart is repeatedly executed by the ECU 20 during operation of the engine 1.

  In step S301, the ECU 20 determines whether or not the rotational speed of the engine 1 is equal to or less than a threshold value Ne1. The rotation speed threshold value Ne1 is a reference value for determining whether or not switching from the start-time injection control to the post-start-up injection control is feasible. When the rotation speed is equal to or less than the threshold value Ne1 (Yes), the ECU 20 executes the processing from step S302 to step S308 (startup injection control). On the other hand, when the rotational speed is larger than the threshold value Ne1 (No), the ECU 20 executes the processing of step S309 to step S313 (post-startup injection control).

  First, start-up injection control will be described.

  In step S302, the ECU 20 determines whether or not the fuel pressure is greater than or equal to a threshold value PR1. The fuel pressure threshold value PR1 is a reference value for determining whether fuel injection by the in-cylinder direct injection injector 11 is feasible. If the fuel pressure is lower than the threshold value PR1 (No), the ECU 20 proceeds to the process of step S303, and boosts the fuel supplied to the in-cylinder direct injection injector 11 by the pump. The pressure increase by the pump is continued until it is determined that the fuel pressure is equal to or higher than the threshold value PR1. If the fuel pressure is greater than or equal to the threshold value PR1 (Yes), the ECU 20 proceeds to the process of step S304.

  In step S304, the ECU 20 determines whether or not the atmospheric pressure is greater than or equal to the threshold value Pa1. The atmospheric pressure threshold value Pa1 is a reference value for determining whether or not correction in a low-pressure environment is necessary in the start-up injection control.

  When the atmospheric pressure is greater than or equal to the threshold value Pa1 (Yes), the ECU 20 proceeds to the process of step S305 and calculates the fuel injection timing Ainjd1s by the in-cylinder direct injection injector 11 under normal pressure conditions.

  When the atmospheric pressure is lower than the threshold value Pa1 (No), the ECU 20 proceeds to the process of step S306, corrects the fuel injection timing Ainjd1s by the in-cylinder direct injection injector 11 under the normal pressure condition to a value on the advance side, and after correction Is set as the fuel injection timing by the in-cylinder direct injection injector 11 in a low pressure environment.

  After executing the process of step S305 or step S306, the ECU 20 proceeds to the process of step S307.

  In step S307, the ECU 20 calculates an injection amount Qds of fuel injection by the direct injection injector 11 and a target value PRreq1 of the fuel pressure.

  In step S308, the ECU 20 executes fuel injection by the in-cylinder direct injection injector 11 using the calculated target fuel pressure PRreq1, injection timing Ainjd1s, and injection amount Qds as fuel injection parameters.

  Next, post-startup injection control will be described.

  In step S309, the ECU 20 determines whether or not the atmospheric pressure is greater than or equal to the threshold value Pa1. The processing content of step S309 is the same as that of step S304.

  If the atmospheric pressure is greater than or equal to the threshold value Pa1 (Yes), the ECU 20 proceeds to the process of step S310, and calculates the fuel injection timing Ainjd1i by the in-cylinder direct injection injector 11 under normal pressure conditions.

  When the atmospheric pressure is lower than the threshold value Pa1 (No), the ECU 20 proceeds to the process of step S311 and corrects the fuel injection timing Ainjd1i by the in-cylinder direct injection injector 11 under the normal pressure condition to a value on the advance side. Is set as the fuel injection timing by the in-cylinder direct injection injector 11 in a low pressure environment.

  After executing the process of step S310 or step S311, the ECU 20 proceeds to the process of step S312.

  In step S312, the ECU 20 calculates the ratio between the injection amount by the in-cylinder direct injection injector 11 and the injection amount by the port injection injector 8, and sets the ratio to the required injection amount calculated from the operating conditions such as the intake air amount. Based on this, the injection amount Qdi by the in-cylinder direct injection injector 11 and the injection amount Qpi by the port injection injector 8 are calculated. Further, a target value PRreq1 of the fuel pressure for fuel injection by the in-cylinder direct injection injector 11 is calculated.

  In step S313, the ECU 20 executes fuel injection by the port injection injector 8 using the calculated injection amount Qpi as a fuel injection parameter, and performs fuel injection by the in-cylinder direct injection injector 11 with the calculated fuel pressure PRreq1, injection. The timing Ainjdi and the injection amount Qdi are executed as fuel injection parameters.

  In this embodiment, the ECU 20 that executes the processing of the flowchart described above corresponds to the “control unit” in the present invention.

  In the start-up injection control and the post-start-up injection control of this embodiment, as shown in FIG. 10, the fuel injection timing by the in-cylinder direct injection injector 11 is more advanced as the atmospheric pressure becomes lower in a low pressure environment. You may correct | amend so that it may become. By so doing, it is possible to more reliably suppress the deterioration of the startability, combustion stability and exhaust performance of the engine 1 in a low pressure environment. However, in this case, the fuel spray from the in-cylinder direct injection injector 11 flies toward the cavity 13 in the combustion chamber 18, and its flight path is changed to the direction of the spark plug 12 along the lip portion 14. It is necessary to advance the angle within a range where the movement of flying toward the spark plug 12 is possible. Therefore, there is an upper limit value that can be advanced.

  The correction of the injection control at start-up and the post-start-up injection control in the low pressure environment according to each embodiment described above may be combined within a possible range.

In the present embodiment, in a low pressure environment where the atmospheric pressure is lower than the predetermined reference value Pa1,
(A) a correction for setting the reference value PR1 of the fuel pressure for determining whether or not the fuel injection by the in-cylinder direct injection injector 11 in the start-up injection control to be performed is a low-pressure side value;
(B) correction for setting the fuel pressure target value PRreq1 of fuel injection by the in-cylinder direct injection injector 11 in the starting injection control to a value on the low pressure side;
(C) a correction for setting the fuel injection timing Ainjd1s of the fuel injection by the in-cylinder direct injection injector 11 in the start-up injection control to a value on the advance side;
(D) a correction for reducing the fuel injection amount Qdi by the in-cylinder direct injection injector 11 in the post-startup injection control and increasing the ratio of the fuel injection amount by the port injector 8 to the required injection amount;
(E) correction for setting the target value PRreq1 of the fuel pressure of the fuel injection by the in-cylinder direct injection injector 11 in the post-startup injection control to a value on the low pressure side;
(F) correction for setting the fuel injection timing Ainjd1i of fuel injection by the in-cylinder direct injection injector 11 in the post-startup injection control to a value on the advance side;
An example of performing is described.

  FIG. 11 is a flowchart of fuel injection control according to the present embodiment. The processing represented by this flowchart is repeatedly executed by the ECU 20 during operation of the engine 1.

  In step S401, the ECU 20 determines whether the rotational speed of the engine 1 is equal to or less than a threshold value Ne1. The rotation speed threshold value Ne1 is a reference value for determining whether or not switching from the start-time injection control to the post-start-up injection control is feasible. When the rotation speed is equal to or less than the threshold value Ne1 (Yes), the ECU 20 executes the processing from step S402 to step S413 (startup injection control). On the other hand, when the rotation speed is greater than the threshold value Ne1 (No), the ECU 20 executes the processing from step S414 to step S421 (post-startup injection control).

  First, start-up injection control will be described.

  In step S402, the ECU 20 determines whether or not the atmospheric pressure is greater than or equal to a threshold value Pa1. The atmospheric pressure threshold value Pa1 is a reference value for determining whether or not correction in a low-pressure environment is necessary in the start-up injection control.

  When the atmospheric pressure is equal to or higher than the threshold value Pa1 (Yes), the ECU 20 proceeds to the process of step S403, and calculates a reference value PR1 for determining whether or not fuel injection by the in-cylinder direct injection injector 11 can be performed under normal pressure conditions. .

  When the atmospheric pressure is lower than the threshold value Pa1 (No), the ECU 20 proceeds to the process of step S404, and sets the reference value PR1 for determining whether or not the direct injection injector 11 can execute fuel injection under the normal pressure condition on the low pressure side. The corrected value is set as a reference value for determining whether or not fuel injection by the in-cylinder direct injection injector 11 can be performed in a low pressure environment.

  After executing the process of step S403 or step S404, the ECU 20 proceeds to the process of step S405.

  In step S405, the ECU 20 determines whether or not the fuel pressure is greater than or equal to the reference value PR1 calculated in step S403 or step S404. When the fuel pressure is lower than the threshold value PR1 (No), the ECU 20 proceeds to the process of step S406, and boosts the fuel supplied to the in-cylinder direct injection injector 11 by the pump. The pressure increase by the pump is continued until it is determined that the fuel pressure is equal to or higher than the threshold value PR1. If the fuel pressure is greater than or equal to the threshold value PR1 (Yes), the ECU 20 proceeds to the process of step S407.

  In step S407, the ECU 20 determines whether the atmospheric pressure is equal to or higher than the threshold value Pa1. The processing content of step S407 is the same as that of step S402.

  When the atmospheric pressure is equal to or higher than the threshold value Pa1 (Yes), the ECU 20 proceeds to the process of step S408, and calculates the target value PRreq1 of the fuel pressure of the fuel injection by the direct injection injector 11 under the normal pressure condition. Subsequently, the ECU 20 proceeds to the process of step S409, and calculates the fuel injection timing Ainjd1s by the in-cylinder direct injection injector 11 under the normal pressure condition.

  When the atmospheric pressure is lower than the threshold value Pa1 (No), the ECU 20 proceeds to the process of step S410 and corrects the target value PRreq1 of the fuel pressure of the fuel injection by the in-cylinder direct injection injector 11 under the normal pressure condition to a value on the low pressure side. Then, the corrected value is set as the target value of the fuel pressure of the fuel injection by the in-cylinder direct injection injector 11 in a low pressure environment. Subsequently, the ECU 20 proceeds to the processing of step S411, corrects the fuel injection timing Ainjd1s by the in-cylinder direct injection injector 11 under the normal pressure condition to the advance side value, and sets the corrected value in the in-cylinder under the low pressure environment. The fuel injection timing by the direct injection injector 11 is set.

  After executing the processing of step S408 to step S409 or the processing of step S410 to step S411, the ECU 20 proceeds to the processing of step S412.

  In step S412, the ECU 20 calculates an injection amount Qds of fuel injection by the in-cylinder direct injection injector 11.

  In step S413, the ECU 20 executes fuel injection by the in-cylinder direct injection injector 11 using the calculated target fuel pressure PRreq1, injection timing Ainjd1s, and injection amount Qds as fuel injection parameters.

  Next, post-startup injection control will be described.

  In step S414, the ECU 20 determines whether or not the atmospheric pressure is greater than or equal to the threshold value Pa1. The processing content of step S414 is the same as that of said step S402.

If the atmospheric pressure is greater than or equal to the threshold value Pa1 (Yes), the ECU 20 proceeds to the process of step S415, and calculates the ratio between the injection amount by the in-cylinder direct injection injector 11 and the injection amount by the port injection injector 8 in the normal pressure condition. Then, the injection amount Qdi by the in-cylinder direct injection injector 11 and the injection amount Qpi by the port injection injector 8 are calculated based on the ratio and the required injection amount calculated from the operating conditions such as the intake air amount. Subsequently, the ECU 20 proceeds to the process of step S416, and calculates the target value PRreq1 of the fuel pressure of the fuel injection by the direct injection injector 11 under the normal pressure condition. Subsequently, the ECU 20 proceeds to the process of step S417, and calculates the fuel injection timing Ainjd1i by the in-cylinder direct injection injector 11 under the normal pressure condition.

  When the atmospheric pressure is lower than the threshold value Pa1 (No), the ECU 20 proceeds to the process of step S418, and the injection amount by the in-cylinder direct injection injector 11 and the injection amount by the port injection injector 8 in the post-startup injection control in the case of the normal pressure condition. Is corrected to a ratio obtained by increasing the ratio of the port injection injector 8, the injection amount Qdi by the in-cylinder direct injection injector 11 is corrected to decrease, and the injection amount Qpi by the port injection injector 8 is corrected to increase. Subsequently, the ECU 20 proceeds to the process of step S419, corrects the target value PRreq1 of the fuel pressure of the fuel injection by the direct injection injector 11 under the normal pressure condition to a value on the low pressure side, and sets the corrected value under the low pressure environment. Is set as the target value of the fuel pressure of the fuel injection by the in-cylinder direct injection injector 11. Subsequently, the ECU 20 proceeds to the processing of step S420, corrects the fuel injection timing Ainjd1i by the in-cylinder direct injection injector 11 under the normal pressure condition to the advance side value, and sets the corrected value in the in-cylinder under the low pressure environment. The fuel injection timing by the direct injection injector 11 is set.

  After executing the process of step S415 to step S417 or the process of step S418 to step S420, the ECU 20 proceeds to the process of step S421.

  In step S421, the ECU 20 executes fuel injection by the port injection injector 8 using the calculated injection amount Qpi as a fuel injection parameter, and performs fuel injection by the in-cylinder direct injection injector 11 using the calculated fuel pressure PRreq1, injection. The timing Ainjdi and the injection amount Qdi are executed as fuel injection parameters.

  In this embodiment, the ECU 20 that executes the processing of the flowchart described above corresponds to the “control unit” in the present invention.

  In addition, although the present Example demonstrated the example which performs all the correction | amendment in the injection control at the time of start in the low pressure environment which concerns on Examples 1-3, and the injection control after a start, various things other than a present Example are included within the scope of the present invention. Combinations of these are possible.

DESCRIPTION OF SYMBOLS 1 Engine 2 Cylinder 3 Piston 4 Intake passage 5 Exhaust passage 6 Intake valve 7 Exhaust valve 8 Port injection injector 9 Intake port 10 Exhaust port 11 In-cylinder direct injection injector 12 Spark plug 13 Cavity 14 Lip part 18 Combustion chamber 20 ECU

Claims (1)

A port injection injector for injecting fuel into the intake passage of the internal combustion engine;
An in-cylinder direct injection injector for injecting fuel into a cylinder of the internal combustion engine;
When the internal combustion engine is started, fuel injection by the port injector is performed after performing start-up injection control in which fuel injection is performed in the compression stroke by the in-cylinder direct injection injector, and the operating state of the internal combustion engine satisfies a predetermined condition. And control means for performing post-startup injection control for performing fuel injection twice in the compression stroke by the in-cylinder direct injection injector,
With
In the low pressure environment where the atmospheric pressure is lower than a predetermined threshold, the control means
(A) In the starting injection control,
(1) The reference value of the fuel pressure for permitting execution of fuel injection by the in-cylinder direct injection injector is lowered as compared with the case where the fuel injection is not performed in a low pressure environment, and the fuel pressure of the fuel injection by the in-cylinder direct injection injector is reduced. A correction to lower the target value than when not in a low-pressure environment, and
(2) a correction for advancing the fuel injection timing of the fuel injection by the in-cylinder direct injection injector as compared with the case where it is not in a low-pressure environment;
Correct at least one of the
(B) In the post-startup injection control,
(1) The fuel injection amount of the fuel injection by the in-cylinder direct injection injector is reduced as compared with the case where it is not in a low pressure environment, and the ratio of the fuel injection amount by the port injector to the total fuel injection amount is accordingly reduced. Correction higher than if not lower,
(2) a correction for reducing the target value of the fuel pressure of the fuel injection by the in-cylinder direct injection injector as compared with the case where the fuel pressure is not in a low pressure environment, and
(3) a correction for advancing the fuel injection timing of the fuel injection by the in-cylinder direct injection injector as compared with the case where it is not under a low pressure environment;
A fuel injection control device for a spark ignition type internal combustion engine, wherein at least one of the corrections is performed.

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