Patent ID: 6848439
Filing Date: 2005-02-01
Classification: F02D,G01N,Y02T

Abstract:
1. An air-fuel ratio control apparatus of an engine, for feedback controlling an air-fuel ratio of combustion mixture of said engine, said apparatus comprising: an oxygen concentration detector in which a detection signal thereof is changed according to oxygen concentration in engine exhaust air, and said detection signal has a linearity to an air-fuel ratio within a predetermined air-fuel ratio range inclusive of a stoichiometric air-fuel ratio; and a control unit receiving the detection signal from said oxygen concentration detector, to output an air-fuel ratio feedback control signal based on said detection signal, wherein said control unit limits a change in said air-fuel ratio feedback control signal calculated on the basis of said detection signal which is outside a region indicating said linearity so as to be smaller than that in said air-fuel ratio feedback control signal calculated on the basis of said detection signal which is within said region indicating said linearity.