Patent ID: 6330870
Filing Date: 2001-12-18
Classification: F01L,F02D,F15B,Y02T

Abstract:
A variable valve timing control system for an internal combustion engine, comprising: a variable valve timing adjuster for making the valve timing variable by changing the rotational phase (as will be called the ""camshaft phase"") of a camshaft with respect to the crankshaft of the internal combustion engine, said variable valve timing adjuster including a lock mechanism for locking said camshaft phase at a substantially intermediate lock position of its adjustable range when the variable valve timing control is not made, wherein the oil pressure for driving said lock mechanism and said variable valve timing adjuster is controlled by a hydraulic control valve,wherein the improvement comprises:lock position learning means for learning said lock position on the basis of said camshaft phase which is detected during a lock control for locking said camshaft phase at said lock position.