| 摘要 |
A method for early intake valve closing in an internal combustion engine having a crankshaft and at least one exhaust valve, the crankshaft having a top dead center position and a bottom dead center position, includes the step of determining engine operating load conditions and parameters. One of a plurality of predetermined valve lift profiles, each of which correspond to a respective range of engine operating load conditions and parameters, is selected dependent at least in part upon the engine operating load conditions and parameters. The engine is commanded to operate the engine intake valves according to the selected one of the plurality of predetermined valve lift profiles to thereby optimize fuel economy and reduce emissions at light to moderate engine loads, to improve torque and power at relatively full engine loads, and improve cold start engine operation under cold start engine conditions.
|
