Patent ID: 6266606
Filing Date: 2001-07-24
Classification: F01L,F02D,Y02T

Abstract:
A control system for an internal combustion engine comprising:operation state detection means for detecting the operation state of an internal combustion engine;a valve timing changing unit for changing the valve timing of at least one of an intake valve and an exhaust valve to change the valve overlap amounts of the intake valve and the exhaust valve,actual valve timing detection means for detecting the position of actual valve timing to provide a detection value;target advance angle setting means for setting target valve timing based on the detection result of the operation state detection means;first storage means for storing the detection value of the actual valve timing detection means when the target advance angle set by the target advance angle setting means is a predetermined value, whose storage value is updated;actual advance angle calculating means for calculating the advance angle of a valve based on the storage value of the first storage means and the detection value of the actual valve timing detection means; andcontrol means for controlling the valve timing changing unit to change the actual advance angle calculated by the actual advance angle calculating means to the target advance angle set by the target advance angle setting means, whereinthe system further comprises:second storage means for storing the detection value of the actual valve timing detection means when the target advance angle set by the target advance angle setting means is a predetermined value, whose storage value is updated only once during one operation cycle from start to stop; andfail judging means for judging a fail of the valve timing changing unit based on the target advance angle set by the target advance angle setting means, the detection value of the actual valve timing detection means and the storage value of the second storage means.