EXHAUST EMISSION CONTROL DEVICE FOR INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To provide a technique that can prevent clogging of a filter and suppressing degradation of a filter function, in an exhaust emission control device with filter for an internal combustion engine. SOLUTION: The exhaust emission control device comprises: the filter 20; an exhaust fine particle amount estimating means 35 for estimating a fine particle amount exhausted from the internal combustion engine 1 per unit of time; a reducing agent supplying means 28 for supplying reducing agent to the fine particles trapped by the filter 20 and oxidizing and removing the fine particles without generating luminous flame; a reducing agent supply interval determining means 35 for shortening time intervals of supplying the reducing agent by the reducing agent supplying means 28, when the fine particle amount estimated by the exhausted fine particle amount estimating means 35 is larger than the fine particle amount oxidized and removed by supplying the reducing agent from the reducing agent supplying means 28.