Procedure and control unit for an accelerated heating of a catalyst in an exhaust gas system of a supercharged combustion engine with a variable valve control

摘要

Suggested is a procedure for heating a catalyst in the exhaust gas system of a supercharged combustion engine with direct fuel injection and variable gas exchange valve control by producing a reactive exhaust gas fuel/air mixture in the exhaust gas system, whereby an air percentage of the reactive fuel/air mixture is thereby produced that air is rinsed from a suction system of the combustion engine over its combustion chambers into the exhaust gas system. The invention distinguishes itself thereby that the combustion engine is operated in idle mode after a cold start with a greater valve overlap and/or a greater valve overlap profile than in a normal operation where the catalyst is already heated as well as with an apportionment of a fuel amount that has to be injected before a combustion into at least two partial injections per ignition and combustion chamber and with a suboptimal ignition angle efficiency.