Patent ID: 6901906

Claim:
An apparatus for controlling an air-fuel ratio in a direct-injection internal combustion engine, comprising: an air-fuel ratio sensor provided in an exhaust passage of the engine; and a controller which i) selects between a first injection mode injecting fuel once in one cycle and a second injection mode injecting the fuel a plurality of times in one cycle, and controls the execution of the selected fuel injection mode, ii) performs feedback control based on a value output from the air-fuel ratio sensor such that an engine air-fuel ratio becomes a stoichiometric air-fuel ratio when either the first injection mode or the second injection mode is executed, and iii) changes a control center of the feedback control in the second injection mode by adjusting a correction coefficient toward a rich side relative to a control center of the feedback control in the first injection mode, so as to make the air-fuel ratio become equal to the stoichiometric air fuel ratio.