Internal combustion engine and method for controlling an internal combustion engine

摘要

An internal combustion engine, comprising: a combustion condition switching section for switching a combustion condition of the engine into a stratified lean air-fuel m ixture ratio charge combustion, a homogeneous lean air-fuel mixture charge combustion, or a homogeneous stoichiometric air-fuel mixture ratio charge combustion in which an air-fuel mixture ratio is feedback controlled so as to render the air-fuel mixture ratio approach to the stoichiometric air-fuel mixture ratio; a purge section for purging a vaporized fuel into an intake air system of the engine under a predetermined engine driving condition; a presence-or-absence-of-purge dependent learning section for learning an air-fuel mixture ratio feedback coefficient separately from the same according to an execution or no execution of the purge of the vaporized fuel through the purge section when the combustion condition is switched into the homogeneous stoichiometric air-fuel mixture ratio charge combustion and for deriving each learning value on a fuel supply quantity to the engine such that the air-fuel mixture ratio feedback correction coefficient is maintained in a vicinity to a reference value thereof during the corresponding one of the