Exhaust purifying apparatus for internal combusion engine

摘要

An exhaust purifying apparatus for an internal combustion engine having a DPNR converter ( 26 ), a fuel adding device ( 46 ), and an electronic control device ( 50 ) is provided. The DPNR converter ( 26 ) is located in an exhaust passage ( 14 ) of the internal combustion engine ( 10 ). The DPNR converter ( 26 ) traps particulate matter in exhaust gas. The fuel adding device ( 46 ) adds fuel to exhaust as that passes through the DPNR converter ( 26 ). The electronic control device ( 50 ) estimates a combustion rate of particulate matter in the DPNR converter ( 26 ) in a state where the fuel adding device ( 46 ) adds fuel to the exhaust gas. Based on the estimated combustion rate, the electronic control device ( 50 ) sets a manner of adding fuel by the fuel adding device ( 46 ). As a result, the exhaust purifying apparatus suppresses excessive temperature increase of a DPNR converter ( 26 ) to which fuel is added.