ABNORMALITY DETECTION DEVICE FOR INTERNAL COMBUSTION ENGINE HAVING VARIABLE VALVE TIMING MECHANISM

摘要

PURPOSE: To suppress erroneous detection in an internal combustion engine having a variable valve timing mechanism in detecting abnormality of displacement angle of a cam shaft in respect to a crank shaft. CONSTITUTION: An abnormality detection device VC for an internal combustion engine having a variable valve timing mechanism detects abnormality occurrence in a displacement angle of an intake side cam shaft 23 in respect to a crank shaft 14 due to erroneous streaching of a timing belt 35 on an intake side timing pulley 27. For detecting abnormality, a determination displacement angle A is calculated by subtracting a displacement angle between the slowest displacement angle of the intake side cam shaft 23 and a structure actual displacement angle VT, from the structure actual displacement angle VT. When deviation between the determination displacement angle A and a displacement angle 30 CA in structure of a VVT 50 is a first specified value (e) or more, valve timing fail of a displacement angle of the intake side cam shaft 23 is detected in respect to the crank shaft 14.