METHOD FOR ADJUSTING THE COMPRESSION RATIO IN A COMBUSTION ENGINE DURING THE TRANSITION BETWEEN THE HCCI COMBUSTION MODE AND THE SPARK-IGNITED COMBUSTION MODE

摘要

An operating mode of an internal combustion engine, in particular a directly injected internal combustion engine featuring a plurality of combustion chambers, in particular for a direct-injection gasoline engine for a motor vehicle, an operating mode having at least in part low-NOx combustion (NAV) and having a plurality of partial operating modes wherein it is switched between another partial operating mode and a NAV partial operating mode, wherein in the case of said NAV partial operating mode, at an ignition point (ZZP) a largely homogeneous, lean fuel/exhaust gas/air mixture having a combustion air ratio of lambda=1 is spark ignited in the respective combustion chamber by means of an ignition device, and where a flame front combustion (FFV) initiated by the spark-ignition transitions to a controlled auto-ignition (RZV). The operational stability of the respective partial operating mode can be improved by variation of the compression ratio epsilon.