Control apparatus and method for direct-injection spark-ignition internal combustion engine

摘要

In control apparatus and method for a direct-injection spark-ignition internal combustion engine, a stratified combustion is performed to raise an exhaust temperature under a condition prior to a completion of an engine warm-up, the stratified combustion being provided with a lean air-fuel mixture formed over a whole combustion chamber through a fuel injection at a suction stroke and a rich air-fuel mixture formed in an inner space surrounding a spark plug at the combustion chamber through a fuel injection at a compression stroke and a fuel injection quantity of the fuel injection at the suction stroke and a fuel injection quantity of the fuel injection at the compression stroke is corrected by means of a feedback correction coefficient so that an average air-fuel ratio over the whole combustion chamber is controlled to be a predetermined target air-fuel ratio, wherein one of the fuel injection whose fuel injection quantity being larger than the other fuel injection being corrected in both increase and decrease directions by means of the feedback correction coefficient, and wherein the other fuel injection being corrected only in an increase direction by means of the feedback correction coefficient. Such a fuel injection quantity control as described above has six examples.