AIR-FUEL RATIO CONTROL DEVICE FOR INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To provide am air-fuel ratio control device for an internal combustion engine, capable of quickly advancing learning of an air-fuel ratio learning value when an abnormality is generated in a fuel system, while securing stability of air-fuel ratio control as such as possible. SOLUTION: An electronic control device 20 performs feedback control for fuel injection quantity, based on an air-fuel ratio feedback correction value. The electronic control device 20 performs a skip control with prescribed skip amount to skip timing in which an engine air-fuel ratio reverses between rich and lean states by making a theoretical air-fuel ratio as a reference and updates the air-fuel ratio feedback correction value by subsequently performing an integral control using a prescribed integral amount. The electronic control device 20 learns an air-fuel ratio learning value for compensating steady deviation between the engine air-fuel ratio and the theoretical air-fuel and increase skip amount and integral amount, on the condition that deviation between the learning value and the reference value is larger than prescribed amount.