| 摘要 |
PROBLEM TO BE SOLVED: To provide an exhaust emission control device allowing a catalyst to stably exert an emission control function by preventing poisoning of the catalyst caused by reducing components.SOLUTION: An exhaust emission control device 100 includes a catalyst part 60 arranged on an exhaust pipe 29 in which exhaust gas flows. The catalyst part 60 has a carrier including an OSC material having oxygen storage capacity, and a precious metal catalyst carried by the carrier, and includes an air injection (AI) 72 arranged on an upstream side of the catalyst part 60 in the exhaust pipe 29, and a gas sensor 70 arranged on a downstream side of the catalyst part 60 in the exhaust pipe 29. The catalyst part is constructed to jet oxygen-containing gas from the AI 72 when exhaust gas in the catalyst part 60 is determined to be reducing atmosphere on the basis of an air-fuel ratio or an oxygen concentration of the exhaust gas measured by the gas sensor 70 and duration of the reducing atmosphere exceeds a predetermined reference value. |
