Patent ID: 6438948
Filing Date: 2002-08-27
Classification: F02B,F02D,F02M,Y02T

Abstract:
A device for purifying the exhaust gas of an internal combustion engine comprising:a particulate trap disposed in the engine exhaust system; an exhaust gas recirculation passage communicating the upstream of said particulate trap in said engine exhaust system with the engine intake system; a control valve for controlling the amount of exhaust gas recirculated through said exhaust gas recirculation passage to be an optimum amount in accordance with an engine operating condition; a fresh air detection means for detecting an amount of fresh air introduced into said engine intake system during a fuel-cut; and an estimation means for estimating an amount of particulate trapped by said particulate trap on the basis of said amount of fresh air detected by said fresh air detection means after said control valve is opened to a predetermined opening degree.