Fuel injection control apparatus of cylinder injection type internal combustion engine

A fuel injection control apparatus for an internal combustion engine, wherein the internal combustion engine includes a cylinder, an intake passage, which is connected to the cylinder, a main fuel injection valve, and an auxiliary fuel injection valve, wherein the main fuel injection valve directly injects pressurized fuel, which is supplied from a high pressure pump, to the cylinder, and wherein the auxiliary fuel injection valve injects fuel to the intake passage, the apparatus comprising:

• means for causing the auxiliary fuel injection valve to inject fuel during cranking of the internal combustion engine;
• means for determining whether the pressure of the pressurized fuel is greater than or equal to a predetermined value during cranking of the internal combustion engine;
• means for predicting whether the pressure of the pressurized fuel decreases below a permissible value, which is less than the predetermined value, due to injection of pressurized fuel by the main fuel injection valve during a period from a point of time after the pressure of the pressurized fuel becomes greater than or equal to the predetermined value till when fuel injected from the auxiliary fuel injection valve reaches the interior of the cylinder through the intake passage;
• and
• means for causing the main fuel injection valve to start injecting the pressurized fuel when the pressure of the pressurized fuel is greater than or equal to the predetermined value and it is predicted that the pressure of the pressurized fuel will not decrease below the permissible value during the period.

A controlling method of a fuel injection control apparatus of an internal combustion engine, wherein the internal combustion engine includes a cylinder, an intake passage, which is connected to the cylinder, a main fuel injection valve, and an auxiliary fuel injection valve, wherein the main fuel injection valve directly injects pressurized fuel, which is supplied from a high pressure pump, to the cylinder, and wherein the auxiliary fuel injection valve injects fuel to the intake passage, the method comprising:

• causing the auxiliary fuel injection valve to inject fuel during cranking of the internal combustion engine;
• determining whether the pressure of the pressurized fuel is greater than or equal to a predetermined value;
• predicting whether the pressure of the pressurized fuel decreases below a permissible value, which is less than the predetermined value, due to injection of pressurized fuel by the main fuel injection valve during a period from a point of time after the pressure of the pressurized fuel becomes greater than or equal to the predetermined value till when fuel injected from the auxiliary fuel injection valve reaches the interior of the cylinder through the intake passage;
• and
• causing the main fuel injection valve to start injecting the pressurized fuel when the pressure of the pressurized fuel is greater than or equal to the predetermined value, and it is predicted that the pressure of the pressurized fuel will not decrease below the permissible value during the period.