Patent ID: 8534051

Claim:
An exhaust purification device of an internal combustion engine, comprising: an engine exhaust passage for directing an exhaust gas; an exhaust purification catalyst having an oxidation function arranged in the engine exhaust passage; a small-sized oxidation catalyst arranged in the engine exhaust passage upstream of the exhaust purification catalyst; and a fuel feed valve for feeding fuel into the small-sized oxidation catalyst arranged in the engine exhaust passage upstream of the exhaust purification catalyst; wherein the small-sized oxidation catalyst has a volume smaller than the exhaust purification catalyst, and the small-sized oxidation catalyst receives and passes through a part of the exhaust gas flowing into the exhaust purification catalyst, wherein a first amount of fuel required for the small-sized oxidation catalyst to emit heat is fed from the fuel feed valve when using a heat of oxidation reaction generated at the small-sized oxidation catalyst due to a fuel fed from the fuel feed valve to raise the exhaust purification catalyst in temperature, wherein an amount of fuel greater than the first amount is fed from the fuel feed valve when reforming fuel fed from the fuel feed valve by the small-sized oxidation catalyst and using a reformed fuel flowing out from the small-sized oxidation catalyst to raise the exhaust purification catalyst in temperature or performing exhaust purification processing in the exhaust purification catalyst, wherein when using the reformed fuel flowing out from the small-sized oxidation catalyst so as to make the temperature of the exhaust purification catalyst rise or when performing an exhaust purification processing at the exhaust purification catalyst, a temperature of the exhaust gas flowing out from a combustion chamber is made to rise or an amount of unburned HC discharged from the combustion chamber is made to increase, and wherein when the temperature of the exhaust gas flowing out from the combustion chamber is made to rise, if the temperature of the small-sized oxidation catalyst reaches a predetermined allowable temperature, the amount of fuel fed from the fuel feed valve is made to decrease and the temperature of the exhaust gas discharged from the combustion chamber is made to further rise.