Patent ID: 6928809
Filing Date: 2005-08-16
Classification: F01N,F02B,F02D,F02M,Y02T,Y10S

Abstract:
1. An exhaust gas purification method for an internal combustion engine having a particulate filter disposed in an exhaust passage of the engine and trapping particulate in an exhaust gas, the method comprising: executing a control for burning particulate accumulated on the particulate filter and thereby regenerating the particulate filter; determining whether regeneration of the particulate filter is completed; detecting a filter differential pressure between an inlet and an outlet of the particulate filter immediately after it is determined that regeneration of the particulate filter is completed; and estimating an ash accumulation amount that is an amount of ash accumulated on the particulate filter based on the detected filter differential pressure; wherein the estimating of the ash accumulation amount comprises calculating, based on a plurality of filter differential pressures which are caused at different times when the particulate filter is regenerated, but each of which is detected immediately after it is determined that regeneration of the particulate filter is completed, an approximation line representative of a relation between the ash accumulation amount and a mileage of a vehicle associated with the internal combustion engine, and estimating a present ash accumulation amount from the calculated approximation line and a present mileage of the vehicle.