Patent attributes
An internal combustion engine is provided in which fuel pressure is changed and fuel injection is controlled in accordance with engine operating conditions. The internal combustion engine comprises a cylinder, a direct injection injector, a detection unit, and a control unit. The control unit includes two maps describing two factors of a fuel injection characteristic coefficient and an invalid injection period with respect to the fuel pressure of the direct injection injector. A first calculating section calculates a required fuel injection quantity. A second calculating section calculates a required fuel injection period in accordance with the required fuel injection quantity and the two factors of the fuel injection characteristic coefficient and the invalid injection period with respect to the fuel pressure. A controlling section controls the fuel injection such that the fuel is injected for the required fuel injection period.