EXHAUST EMISSION CONTROL DEVICE

摘要

PROBLEM TO BE SOLVED: To provide technique for regenerating emission control functions of an exhaust emission control device without depending on operating conditions of an internal combustion engine. SOLUTION: A emission control unit 200 is provided with a trunk passage 30a, a circular passage 30b connected to the trunk passage, and a passage changing part 250 including a change-over valve 251 provided at a connection part between the trunk passage and the circular passage to change passages for exhaust gas. The circular passage includes a first emission control part 210 to eliminate carbon-containing particles and NOx contained in exhaust gas. A partial trunk passage 30a2 on the downstream side contains a second emission control part 220 to eliminate NOx contained in exhaust gas. The emission control unit is provided with a reducer injecting nozzle 261 to supply reducer to regenerate the emission control functions of the two emission control parts into a first partial circular passage 30b1.