Direct injection internal combustion engine and controlling method therefor

摘要

A direct injection internal combustion engine includes catalysts for purifying exhaust gases, the catalysts being disposed in an exhaust passage of the engine. A control device controls the engine so as to warm up or activate the catalysts. The control device includes a first control part for controlling the engine with an air-fuel ratio of the engine being set at a value in proximity to a stoichiometric air-fuel ratio, an ignition timing being set at a point after a top dead center and a fuel injection timing being set within a compression stroke, and a second control part for controlling the engine with an air-fuel ratio of the engine being set at a value in proximity to a stoichiometric air-fuel ratio, with an ignition timing being set before a top dead center and a fuel injection timing being set within a compression stroke after the first control part controls the engine. The controlling operation performed by the first control part enables stable after-burning and raises the exhaust temperature. The following controlling operation of the second control part enables CO and O2 to coexist in the exhaust gases and react on the catalysts