Exhaust gas purifying apparatus for internal combustion engine

摘要

An exhaust gas purification apparatus for an internal combustion engine is provided. An exhaust purifying catalyst is provided in an exhaust passage (12) for the engine and a fuel adding valve (15) is provided in the exhaust passage (12) at a position upstream of the exhaust purifying catalyst. The exhaust gas purification apparatus includes anti-clog means for causing the fuel adding valve (15) to perform anti-clog fuel addition for injecting fuel to prevent clogging of the fuel adding valve (15), the exhaust gas purification apparatus is characterized in that the exhaust gas purification apparatus comprises:
catalyst activation estimation means for estimating if the exhaust purifying catalyst is in an activated state or not;
wherein, in a situation where the anti-clog fuel addition should be conducted, if the catalyst activation estimation means estimates that the exhaust purifying catalyst has not been activated, the anti-clog means performs reduction control in which a fuel addition amount per unit time is restricted or the anti-clog fuel addition is prohibited until the exhaust purifying catalyst is activated.