Patent ID: 8286420

Claim:
A DPF accumulation amount estimating apparatus which estimates an accumulation amount in a DPF (diesel particulate filter) provided therewith for removing PM (particulates (particulate matters)) in an exhaust gas, the DPF being installed in an exhaust passage connected to an exhaust port, the DPF accumulation amount estimating apparatus comprising: a PM emission amount model in which a PM emission amount is set on the basis of an operating condition of an engine; a PM regeneration amount model in which a PM regeneration amount is set on the basis of the temperature difference between an outlet temperature and an inlet temperature of the DPF; and a DPF differential pressure model in which a PM accumulation amount is set on the basis of a differential pressure between an exhaust gas flow rate and the DPF, wherein the emission amount from the PM emission amount model, the regeneration amount from the PM regeneration amount model, and a corrected PM accumulation amount, which has been obtained by correcting the estimated value of the PM accumulation amount from the DPF differential pressure model by using a coefficient K determined on the basis of an engine speed and an engine fuel injection amount, are used to calculate an estimated PM accumulation amount of the DPF.