Patent ID: 7500354
Filing Date: 2009-03-10
Classification: F01N,F02D,Y02T

Abstract:
1. A method for operating an internal combustion engine equipped with a three-way catalytic converter, comprising: setting a lambda value of the air/fuel mixture, with which the internal combustion engine is supplied, below and above a stoichiometric set value in a cyclically alternating manner during a forced activation, the lambda value in rich phases being less than the stoichiometric set value and in lean phases being greater than the stoichiometric set values; and matching during the forced activation, the rich phases and the lean phases to one another according to a specified criterion, wherein based on an air mass flow that is supplied to the internal combustion engine in the rich and lean phase, a volume is determined for an oxygen mass relevant to a filling or emptying process of a three-way catalytic converter and used as a criterion to determine the switching points between the rich and the lean phases, and wherein the amount by which the lambda value in rich phases is set below the set value is selected so that it is equal to the amount by which the lambda value in lean phases is set above the set value.