A System and method for adaptive control of variable vale lift tappet switching

摘要

A method of controlling cylinder valve switching between a first valve condition and a second valve condition eg for transitioning between combustion modes of an engine 10 comprises adjusting timing of a signal to switch between said valve conditions in response to information from a combustion sensor 142, eg knock sensor, cylinder pressure sensor, ion current sensor or gasket type sensor. The combustion modes may include spark ignition and homogeneous compression ignition. The cam profiles may be changed by switching tappets controlled by an oil circuit. The engine cylinder may have two intake valves actuated with different lift profiles by a common camshaft, an actuating tappet of one of the intake valves having a deactivation device and controlled in response to signals from the combustion sensor.