Patent ID: 6656089
Filing Date: 2003-12-02
Classification: F01L,F02D,Y02T,Y10T

Abstract:
A valve timing control system for an internal combustion engine, for controlling valve timing for opening and closing at least one of an intake valve and an exhaust valve by changing a cam phase which is a phase of at least one of an intake cam and an exhaust cam, relative to the crankshaft, the engine having a camshaft on which at least one of the intake cam and the exhaust cam is arranged,the valve timing control system comprising: a cam phase-varying device for varying the cam phase by rotating the camshaft relative to the crankshaft; deceleration fuel cut-off operation-determining means for determining whether or not the engine is performing a fuel cut-off operation in which supply of fuel to the engine is stopped during deceleration; and cleaning control means for forcibly driving said cam phase-varying device within a predetermined cam phase range when a predetermined delay time has elapsed after the deceleration fuel cut-off operation is started, to thereby prevent undesired locking of said cam phase-varying device.