Patent ID: 7654245

Claim:
A method for operating a spark-ignition, direct-injection internal combustion engine having a cylinder ( 4 ) with a piston ( 17 ) and a cylinder head ( 19 ) with a fuel injector ( 3 ) and a spark plug ( 5 ), wherein fuel ( 2 ) is injected by means of an injector ( 3 ) into the cylinder ( 4 ) of the internal combustion engine and is ignited by means of the spark plug ( 5 ), said method comprising the steps of: determining as a function of at least the load of the internal combustion engine, a crank angle (α 1 ) at which a first injection ( 9 ) of fuel ( 2 ) takes place, and performing the first injection whereby a lean mixture ( 13 ), whose local air ratio (λ 1 ) is greater than 1.0, is generated in the cylinder ( 4 ); subsequently, determining as a function of at least the load of the internal combustion engine, a crank angle (α 2 ) at which a second injection ( 10 ) of fuel ( 2 ) takes place, and initiating a second injection whereby a mixture cloud ( 14 ) is formed, which is richer than the lean mixture ( 13 ) of the first injection and which is embedded in the lean mixture ( 13 ) and whose local air ratio (λ 2 ) is less than or equal to 1.0, is generated in the cylinder ( 4 ); subsequently, initiating a third injection ( 11 ) of fuel ( 2 ) in the form of a stratified injection for generating a locally enriched and ignitable fuel/air mixture in the region of the spark plug ( 5 ) at least close in terms of time to an ignition time ( 12 ) and igniting the locally enriched fuel/air mixture.