Improvements to engine shutdown and restart

摘要

The invention relates to methods of stop/start of an internal combustion engine preferably provided with a continuous variable valve lift (CVVL) system. A method is disclosed to cease rotation of an engine, which comprises stopping the fuel supply and controlling the cylinder charge from the inlet 3 such that a cylinder 1 predicted to stop on a power stroke has a reduced air charge on its inlet stroke, and a cylinder predicted to stop on a compression stroke has a full air charge on its inlet stroke. Other methods refer to controlling an active tappet 6 and thereby a poppet valve 5 to provide a high or full air charge to a combustion chamber. Wherein the air charge in the combustion chamber causes a rapid slowdown of the engine, minimises irregular rotation of the engine as it stops, or provides at least one combustion chamber with the maximum possible air charge as it stops or upon a restart demand.