METHOD FOR OPERATING A SPARK-IGNITION ENGINE WITH DIRECT INJECTION

摘要

The invention relates to a method for operating a spark-ignition engine with direct injection, according to which the engine is operated either by charge stratification or homogeneously. According to the invention the intake and discharge valves are controlled to move into their open and/or closed positions with control times which vary with the engine operating state. To determine the control times base control times are used which are reversibly predetermined by one family of base control time characteristic curves each for operation by charge stratification and homogeneous operation. The base control times can be modified by correction control times to raise the exhaust-gas temperature and/or bring about an internal exhaust-gas recirculation and/or generate a charge displacement. Said method is used, for example, for operating spark-ignition engines in motor vehicles.