Method for operating an internal combustion engine especially for motor vehicles

Abstract

The invention relates to a method for operating an internal combustion engine, especially for motor vehicles, the engine having a catalytic converter; in the method, for heating up the catalytic converter, there is a switchover between a homogeneous operating mode with a one-time injection of fuel into a combustion chamber of the engine and an operating mode with subdivided injection of fuel at at least two injection time points into the combustion chamber of the engine; wherein, for subdivided injections, both injection time points lie ahead of an ignition of an air/fuel mixture, the first injection time point essentially corresponds to the injection time point of the homogeneous operating mode during the switchover operation from the homogeneous operating mode to the operating mode with subdivided injection, and the second injection time point of the subdivided injection takes place at first so early that the mixture arising during operation with subdivided injection corresponds approximately to a homogeneous mixture and, after the completed switchover, the second injection time point is shifted toward late until a pregiven mixture preparation is present and, for a switchover from the operating mode with the subdivided injection to the homogeneous operating mode, the shift of the second injection time point takes place in the opposite direction. Furthermore, the invention relates to a computer program which is suitable to carry out the method when the method is carried out on a computer.