Patent ID: 8051641

Claim:
An exhaust gas purifying apparatus for an internal combustion engine, comprising: a catalyst that is placed in an exhaust passage of the internal combustion engine; inlet gas temperature obtaining means for obtaining an inlet gas temperature of an exhaust gas at a catalyst inlet; catalyst temperature estimating means for estimating a catalyst temperature of the catalyst; outlet gas temperature estimating means for estimating an outlet gas temperature of the exhaust gas at a catalyst outlet considering a degree of influence of the inlet gas temperature and a catalyst temperature at a region closer to the catalyst outlet; and temperature correcting means for correcting an estimated value of the catalyst temperature estimated by the catalyst temperature estimating means on the basis of an estimated value of the outlet gas temperature estimated by the outlet gas temperature estimating means, wherein the temperature correcting means determines an estimated value correction amount of the estimated value of the catalyst temperature at each region of the catalyst divided into a plurality of parts on the basis of the degree of influence.