Abstract: The fuel injection control device and fuel injection control method according to the present invention allow a fuel injection device to perform fuel injection in the case where an open period of the intake valve and an open period of the exhaust valve overlap with each other, and sets the timing to start injection to the closing timing of the exhaust valve, and that sets the timing to end injection to the timing at which a deceleration rate of intake air speed becomes the local maximum. As such, the homogeneity of in-cylinder air-fuel mixture can be improved while preventing the adhesion of fuel to the inner wall of the intake port and the blow-through of fuel to the exhaust passage from occurring.

Abstract: A fuel injection control device and a fuel injection control method according to the present invention are applied to an internal combustion engine including a blow-by gas recirculation device configured to return blow-by gas into an intake passage. According to the present invention, a dilution ratio which indicates how much lubricating oil of the internal combustion engine is diluted with unburned fuel mixed in the lubricating oil is determined. Then, fuel reduction control for reducing fuel supply to the internal combustion engine by a subtractive fuel amount depending on the dilution ratio is performed in a period from an onset of start-up of the internal combustion engine to when a number of combustion cycles accumulated from the onset of the engine start-up reaches a threshold value.

Abstract: The fuel injection control device and fuel injection control method according to the present invention allow a fuel injection device to perform fuel injection in the case where an open period of the intake valve and an open period of the exhaust valve overlap with each other, and sets the timing to start injection to the closing timing of the exhaust valve, and that sets the timing to end injection to the timing at which a deceleration rate of intake air speed becomes the local maximum. As such, the homogeneity of in-cylinder air-fuel mixture can be improved while preventing the adhesion of fuel to the inner wall of the intake port and the blow-through of fuel to the exhaust passage from occurring.

Abstract: A fuel injection control apparatus for fuel injection at optimum timing in correspondence with level of gas flow velocity in an intake port upon intake stroke injection. A fuel injection valve is controlled so as to set a large majority (more than half) of an injection period to inject fuel during an intake stroke in respective cylinders within a period where intake port gas pressure is increased. Upon intake stroke injection, the fuel is injected at optimum timing in correspondence with the direction and the level of gas flow velocity in the intake port. Accordingly, the status of air-fuel mixture in a combustion chamber is excellent. It is possible to improve fuel consumption and to reduce exhaust emission.

Abstract: A fuel injection control apparatus for fuel injection at optimum timing in correspondence with level of gas flow velocity in an intake port upon intake stroke injection. A fuel injection valve is controlled so as to set a large majority (more than half) of an injection period to inject fuel during an intake stroke in respective cylinders within a period where intake port gas pressure is increased. Upon intake stroke injection, the fuel is injected at optimum timing in correspondence with the direction and the level of gas flow velocity in the intake port. Accordingly, the status of air-fuel mixture in a combustion chamber is excellent. It is possible to improve fuel consumption and to reduce exhaust emission.