Exhaust purifying apparatus and exhaust purifying method for internal combustion engine

摘要

In an exhaust purifying apparatus, a fuel adding valve ( 31 ) supplies unburned fuel to an exhaust passage ( 14 ) of a diesel engine ( 10 ) so that particulate matter collected in a catalytic converter ( 33 ) is burned and removed. The supply of unburned fuel from the fuel adding valve ( 31 ) is executed even after an electronic control unit ( 41 ) determines that particulate matter in the catalytic converter ( 33 ) has been burned and removed. This reduces the amount of particulate matter remaining unburned in the catalytic converter ( 33 ).