Fuel injection control apparatus

A fuel injection control apparatus for an internal combustion engine, the internal combustion engine including a piston reciprocating in a cylinder and a fuel injector arranged to inject a fuel into a combustion chamber facing the piston in the cylinder,

• the apparatus comprising:
• an air amount detector configured to detect an amount of an air flowing into the cylinder or a physical quantity having a correlation with the amount of the air;
• and
• an electronic control unit having a microprocessor and a memory, wherein
• the microprocessor is configured to function as:
• an injection time calculation unit calculating a target injection time of the fuel including a first target injection time and a second target injection time, based on the amount of the air or the physical quantity detected by the air amount detector;
• a crank angle determination unit determining a first crank angle at which a fuel injection by the fuel injector is to be started and a second crank angle at which the fuel injection is to be ended;
• and
• an injector control unit controlling the fuel injector so as to inject the fuel in a first injection mode in which the fuel is injected for the first target injection time from a first time point corresponding to the first crank angle or a second injection mode in which the fuel is injected for the second target injection time from a second time point corresponding to a target crank angle, the target crank angle being obtained by decreasing a crank angle range corresponding to the second target injection time from the second crank angle, and
• the injector control unit is configured to control the fuel injector so as to inject the fuel in the first injection mode at a first time and inject the fuel in the second injection mode at a last time, when the fuel is injected a plurality of times within an area from a start of an intake stroke of the internal combustion engine to an end of a compression stroke of the internal combustion engine.

A fuel injection control method for an internal combustion engine, the internal combustion engine including a piston reciprocating in a cylinder and a fuel injector arranged to inject a fuel into a combustion chamber facing the piston in the cylinder,

• the method comprising:
• detecting an amount of an air flowing into the cylinder or a physical quantity having a correlation with the amount of the air;
• calculating a target injection time of the fuel including a first target injection time and a second target injection time, based on the amount of the air or the physical quantity;
• determining a first crank angle at which a fuel injection by the fuel injector is to be started and a second crank angle at which the fuel injection is to be ended;
• and
• controlling the fuel injector so as to inject the fuel in a first injection mode in which the fuel is injected for the first target injection time from a first time point corresponding to the first crank angle or a second injection mode in which the fuel is injected for the second target injection time from a second time point corresponding to a target crank angle, the target crank angle being obtained by decreasing a crank angle range corresponding to the second target injection time from the second crank angle, wherein
• the controlling includes controlling the fuel injector so as to inject the fuel in the first injection mode at a first time and inject the fuel in the second injection mode at a last time, when the fuel is injected a plurality of times within an area from a start of an intake stroke of the internal combustion engine to an end of a compression stroke of the internal combustion engine.