Patent ID: 7841171

Claim:
An exhaust emission control device for an internal combustion engine which includes a collector that collects particulates (PM) in exhaust gas from the engine, and which burns the particulates deposited on the collector to recondition the collector when the amount of collected PM in the collector is approximately equal to a predetermined amount, the device comprising: an inflow estimating device for estimating the amount of inflow of PM into the collector; a decrease estimating device for estimating a basic amount of decreased PM that flows into the collector and is burned and decreased; an ash estimating device for estimating the amount of ash deposited on the collector; a correction device for correcting the basic amount of decreased PM based on the amount of ash estimated by the ash estimating device such that the amount of decreased PM decreases as the amount of ash estimated by the ash estimating device increases; and a PM deposit estimating device for estimating an amount of deposited PM by a history expression based on the amount of inflow of PM estimated by the inflow estimating device and the amount of decreased PM corrected by the correction device.