Patent ID: 7073479

Claim:
A method of operating a spark-ignition internal combustion engine with direct fuel injection including a combustion chamber with a fuel injector, and an ignition source, said method comprising the steps of: feeding combustion air to a combustion chamber of the engine, injecting a first fuel quantity as a pre-injection quantity (M VE ) in an intake stroke of the internal combustion engine, such that a homogeneous fuel/air mix with a fuel/air ratio (Î») of greater than 1 is formed in the combustion chamber, then injecting in an expansion stroke of the internal combustion engine a second fuel quantity into the combustion chamber as a main injection quantity (M HE ), so as to form a stratified fuel/air mix cloud with a fuel/air ratio (Î») of less than 1 in the vicinity of the ignition source, and then, after the end of injection of the main injection quantity (M HE ), igniting the stratified fuel/air mix cloud.