Control Device for Internal Combustion Engine

A control device for an internal combustion engine adapted to supply a fuel discharged from a high-pressure fuel pump to an injector through a common rail, the high-pressure fuel pump including a pressurizing chamber, an electromagnetic valve adapted to open a fuel supply path to the pressurizing chamber when being energized, and a plunger adapted to perform reciprocating motion for introducing the fuel into the pressurizing chamber through the electromagnetic valve and pressurizing the fuel, the control device comprising:

• an amount-of-injection control unit adapted to control an amount of the fuel injected through the injector to a target amount of injection;
• and
• a pressure control unit adapted to control a discharge flow rate of the fuel discharged from the high-pressure fuel pump for controlling a fuel pressure in the common rail to a target pressure,
• wherein the pressure control unit includes
• a feedback control unit adapted to calculate a target discharge flow rate of the fuel discharged from the high-pressure fuel pump to the common rail, based on a pressure deviation between the fuel pressure and the target pressure,
• a discharge flow rate calculation unit adapted to calculate a balanced discharge flow rate by increasing or decreasing the target discharge flow rate such that the target discharge flow rate of the fuel to the common rail is balanced with the flow rate of the fuel flowed out from the common rail by being injected through the injector,
• a discharge flow rate restricting unit adapted to output a restricted discharge flow rate having an upper limit corresponding to the balanced discharge flow rate, based on the pressure deviation, and
• an energization start angle calculation unit adapted to calculate a phase angle of the reciprocating motion of the plunger at start of energization of the electromagnetic valve in the high-pressure fuel pump, based on the restricted discharge flow rate.