Catalyst warming apparatus of internal combustion engine

It is an object of the present invention to provide a technology capable of producing an appropriate combustible mixture in an apparatus for heating an exhaust-purifying catalyst (16) disposed in an exhaust passage (14) of an internal combustion engine, without providing a special pre-mixing chamber for mixing fuel and air, by burning the combustible mixture in the exhaust passage (14) upstream of the exhaust-purifying catalyst (16) when the exhaust-purifying catalyst is inactive. [0002] To achieve this object, in a catalyst warming apparatus of the internal combustion engine according to the present invention, a sub exhaust-purifying catalyst (15) is disposed in the exhaust passage (14) upstream of a main exhaust-purifying catalyst (16), and the fuel components and air are discharged from the internal combustion engine (1) when the main exhaust-purifying catalyst (16) needs to be warmed up. Thus, the fuel components and air discharged from the internal combustion engine (1) are mixed into a combustible mixture in the sub exhaust-purifying catalyst (15), and the resultant combustible mixture is burned upstream of the main exhaust-purifying catalyst (16).