FUEL INJECTION DEVICE AND CONTROL METHOD THEREFOR

摘要

This device is applied to an internal combustion engine that has a fuel injection valve for injecting fuel directly into the combustion chamber, a supercharger and an exhaust purification device. As a fuel injection from the fuel injection valve, a post-injection is executed separately from the fuel injection for torque generation. The device includes an air amount sensor provided on the intake passageway upstream of the supercharger, and a pressure sensor provided on the intake passageway downstream of the supercharger. A correction term Kg is calculated based on the rate of change ?P of the air pressure P detected by the pressure sensor (S 103). An upper-limit injection amount Qgd is set based on the engine rotation speed NE, the passageway air amount GAp detected by the air amount sensor, the correction term Kg and a main injection amount Qm (S104, S105). Using the upper-limit injection amount Qgd, a target post-injection amount is restricted (S106, S107).