Patent ID: 6450159
Filing Date: 2002-09-17
Classification: F02D

Abstract:
A fuel vapor treatment apparatus in an internal combustion engine comprising:a fuel tank; a canister for adsorbing and collecting fuel vapor generated in said tank; a purge pipe for supplying to an intake system of said engine the fuel vapor that has been purged from said canister by using an intake negative pressure of said engine; a purge control valve disposed in said purge pipe, for controlling a purge air quantity supplied to said intake system of said engine; a control signal output unit for outputting a control signal to said purge control valve; a purge air quantity estimation unit for estimating said purge air quantity; an intake air amount detection unit for detecting an intake air amount into said engine; a fuel injection quantity calculation unit for calculating a fuel injection quantity to said engine; an air-fuel ratio detection unit for detecting an air-fuel ratio of the combustion mixture of said engine; and a concentration estimation unit for estimating a fuel vapor concentration in said purge air based upon said purge air quantity, said intake air amount, said fuel injection quantity and said air-fuel ratio, to output a signal indicative of said estimated concentration.