Abgasemissionssteuerungssystem für einen Verbrennungsmotor und Steuerungsverfahren dafür

摘要

An exhaust emission control system for an internal combustion engine, which is capable of confirmedly and accurately estimating the amount of deposition of particulates on a filter, and properly inhibiting regeneration of the filter based on the estimated amount of the particulate deposition. A filter collects particulates from exhaust gases. The filter is regenerated when the amount of deposition of particulates which is estimated based on operating conditions of the engine has reached a first predetermined threshold value. The regeneration of the filter is inhibited when the amount of deposition of particulates which is estimated according to the differential pressure detected between upstream and downstream sides of the filter by a differential pressure sensor when the engine speed is increased to a predetermined rotational speed is not smaller than a second predetermined threshold value larger than the first predetermined threshold value.