Fuel injection control device for internal combustion engine

A fuel injection control device for an internal combustion engine having a plurality of cylinders and a plurality of fuel injectors, the fuel injectors performing a divided injection to the cylinders, respectively, the fuel injection control device comprising:

• an accumulator that supplies accumulated fuel to each of the plurality of fuel injectors;
• and
• a fuel pressure sensor that detects fuel pressure inside of the accumulator,
• wherein:
• the fuel injection control device detects the fuel pressure at a predetermined frequency and calculates a drop amount of the fuel pressure in accordance with fuel injection based on the detected fuel pressure;
• the fuel injection control device acquires a fluctuation amount of a fuel injection amount of each of the fuel injectors from the drop amount of the fuel pressure and learns an injection characteristic of each of the fuel injectors, the injection characteristic indicating a correlation between the fuel injection amount and the fluctuation amount;
• the fuel injection control device calculates a correction parameter for correcting the fuel injection amount of each of the fuel injectors based on the injection characteristic of each of the fuel injectors;
• and
• the fuel injection control device disallows the learning of the injection characteristic using the fuel pressure detected within the fuel injection period when a detection timing of the fuel pressure is within a fuel injection period of a predetermined fuel injector among the plurality of fuel injectors.