US Patent 7305964 Method for operating an internal combustion engine

In a method for operating a self ignition internal combustion engine in which fuel is injected directly into a combustion chamber by means of an injection nozzle, such that a portion of the fuel is injected into the combustion chamber as a pre-injection amount forming a homogenous pre-mixture providing for a combustion phase comprising a low temperature phase and a high temperature phase and the main fuel amount is injected into the combustion chamber during the high temperature phase of the pre-injection fuel combustion such that the ignition of the main injection amount takes place after the start and before the end of the high temperature phase.