Patent ID: 8027781

Claim:
A control device of a compression ignition internal combustion engine comprising: a small quantity injection control means for performing small quantity injection of fuel at predetermined timing on a delayed side of a compression top dead center of the internal combustion engine to increase output torque of the internal combustion engine; a torque increase amount obtaining means for obtaining an increase amount of the output torque caused with the small quantity injection or physical quantity correlated with the increase amount as a torque increase amount sensing value; a fuel property determination means for determining a fuel property based on the torque increase amount sensing value; an adaptation value setting means for variably setting an adaptation value used for control of the internal combustion engine in accordance with the fuel property determination result provided by the fuel property determination means; a confirmation injection control means for performing the small quantity injection again while an operation state of the internal combustion engine is controlled based on the adaptation value set by the adaptation value setting means; and an accuracy determination means for determining accuracy of the fuel property determination result or the adaptation value based on whether a confirmation sensing value, which is the torque increase amount sensing value obtained when the confirmation injection control means performs the small quantity injection, is outside a predetermined range.