Patent ID: 6341586
Filing Date: 2002-01-29
Classification: F01L,F02D,Y02T

Abstract:
A valve timing control system for an internal combustion engine having a crankshaft, an intake valve, an exhaust valve, an intake cam for opening and closing said intake valve, and an exhaust cam for opening and closing said exhaust valve, the valve timing control system controlling valve timing of at least one of said intake valve and said exhaust valve by changing a cam phase which is a phase of at least one of said intake cam and said exhaust cam, relative to said crankshaft,the valve timing control system comprising: actual cam phase-detecting means for detecting said cam phase as an actual cam phase: a cam phase change mechanism for changing said cam phase: operating condition-detecting means for detecting operating conditions of said engine; fuel cut-off determination means for determining whether or not fuel cut-off is being carried out for cutting off supply of fuel to said engine; desired cam phase-setting means for setting a desired cam phase according to said detected operating conditions of said engine, and fixing said desired cam phase at a constant value during said fuel cut-off; cam phase control means for controlling said cam phase change mechanism such that said cam phase change mechanism causes said cam phase to become equal to said desired cam phase, and holds said cam phase at and after a predetermined timing during said fuel cut-off; and actual cam phase deviation calculation means for calculating an amount of deviation of said actual cam phase based on a plurality of values of said actual cam phase detected at and after said predetermined timing during said fuel cut-off, and said constant value of said desired cam phase.