Patent ID: 8616182
Filing Date: 2013-12-31
Classification: F01N,F02D,Y02T

Abstract:
1. Method for transitioning a direct-injection internal combustion engine fluidly coupled to a passive SCR system including a three-way catalytic converter upstream to an ammonia-selective catalytic reduction catalyst from an HCCI combustion mode and a SI combustion mode, the method comprising: determining a preferred air/fuel ratio to achieve a minimum fuel consumption and maintain combustion stability at an acceptable level for a predetermined engine operating point during the SI combustion mode; substantially immediately controlling a fuel injection timing, an engine spark timing and an engine valve lift from respective HCCI combustion mode settings to respective SI combustion mode settings; only after the fuel injection timing, the engine spark timing, and the engine valve lift settings are operative at the respective SI combustion mode settings, coordinating a transition to the preferred air/fuel ratio coincident with a transition from a HCCI combustion mode engine valve phase setting to a SI combustion mode engine valve phase setting; and once the transition to the SI combustion mode engine valve phase setting is complete, operating the engine at the preferred air/fuel ratio.