VARIABLE VALVE TIMING CONTROL DEVICE FOR INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To restrain discharge of HC immediately after starting an internal combustion engine. SOLUTION: Discharge of unburnt gas HC is reduced while stable operability is secured by controlling a valve overlap center to the advance angle side rather than an exhaust top dead center while maintaining valve overlap quantity roughly the same against standard valve timing to be set in accordance with a load of an engine and rotating speed at the start of the engine and for a specified period of time after starting it. In the meantime, discharge of the unburnt gas HC is reduced by controlling it to the delay angle side while the overlap quantity is maintained roughly the same against the standard valve timing after a specified period of time passes after temperature of the engine rises.