Patent attributes
Arrangements for stabilizing valve timing adjustment mechanisms such as cam phasers during operation of an engine are described. The described approaches are particularly well suited for use during skip fire control, although they may be used advantageously in other applications as well. In general, the phase of an adjustable phase camshaft is controlled relative to a crankshaft of an engine. In one aspect, at least one of (i) firing events in a skip fire firing sequence, and (ii) dynamically determined valve actuation events are used in the control of the camshaft phase during operation of the engine. In some embodiments, hydraulic pressure within a cam phaser is varied in a manner that maintains the phase of the camshaft substantially more stable through transitory variations in torque applied to the camshaft by the actuation of the valves than would occur without the variations in hydraulic pressure.
