Patent ID: 6453887
Filing Date: 2002-09-24
Classification: F02D,F02M,Y02T

Abstract:
A fuel vapor emission control device of an engine which is air-fuel ratio feedback controlled, comprising:a canister which adsorbs fuel vapor generated in a fuel tank of the engine, a purge passage which connects the canister and an intake passage of the engine, a purge valve which opens and closes the purge passage, and a controller functioning to: compute a target air-fuel ratio feedback deviation, which is the deviation between a target value of the air-fuel ratio feedback correction coefficient and a basic value of the air-fuel ratio feedback correction coefficient, compute an actual air-fuel ratio feedback deviation which is the deviation between an actual air-fuel ratio feedback correction coefficient and the basic value of the air-fuel ratio feedback correction coefficient, set a target purge rate according to the difference between the target air-fuel ratio feedback deviation and the actual air-fuel ratio feedback deviation, and drive the purge valve so that the purge rate becomes the target purge rate.