Patent ID: 6196173
Filing Date: 2001-03-06
Classification: F02D,Y02T

Abstract:
A valve timing control system for an internal combustion engine which has a crank shaft and a cam shaft operatively connected with said crank shaft so as to rotate in synchronism therewith whereby intake and exhaust valves are driven to open and close by virtue of a valve operating mechanism mounted on said cam shaft in synchronism with the rotation of said crank shaft, said valve timing control system comprising:crank angle detecting means for detecting a crank angle of said crank shaft in said internal combustion engine;cam angle detecting means for detecting a cam angle of said cam shaft in said internal combustion engine;advance amount calculating means for calculating an advance amount which is a phase difference between said crank angle and said cam angle;variable valve timing means for advancing and retarding said cam angle with respect to said crank angle through the use of a lubricating oil pressure in said internal combustion engine;learning means for learning a phase difference between said crank angle and said cam angle at a mechanically stopped position of said variable valve timing means; andvalve timing control variable calculating means for calculating a valve timing control variable, for driving said variable valve timing means, on the basis of a deviation between said phase difference value learned by said learning means and said phase difference calculated by said advance amount calculating means,wherein said learning means learns said phase difference between said crank angle and said cam angle at said mechanically stopped position when said internal combustion engine is not idling.