Fuel injection control apparatus of internal combustion engine

A fuel injection control apparatus of a compression self-igniting internal combustion engine that, with a fuel injection valve, is capable of performing injection by dividing an amount of fuel injected in order to contribute to torque production of the internal combustion engine between a main injection and a sub injection that is performed prior to the main injection, the fuel injection control apparatus comprising:

• a total fuel injection amount calculation portion that calculates a total fuel injection amount that contributes to torque production based on the torque required by the internal combustion engine;
• a divided injection amount calculation portion that obtains, as a divided injection amount that is divided from the total fuel injection amount, an injection amount when executing the sub injection that prevents a heat production amount in initial injection of the main injection from decreasing to a threshold value or less, and suppresses a peak value of a heat production ratio that accompanies combustion of fuel injected in the main injection to less than a predetermined value;
• an upper/lower limit limiting portion that gives a limit at predetermined upper and lower limit values to the divided injection amount obtained with the divided injection amount calculation portion;
• and
• a sub injection timing setting portion that sets an injection timing in execution of the sub injection of the divided injection amount obtained by giving a limit with the upper/lower limit limiting portion.