| 摘要 |
PROBLEM TO BE SOLVED: To provide an exhaust emission control device capable of detecting leakage of fuel added as a reducing agent. SOLUTION: This exhaust emission control device comprises a catalyst 20 for exhaust emission control provided in an exhaust system, a fuel adding apparatus 28 for adding fuel as a reducing agent to the catalyst 20 for exhaust emission control, a fuel supply source 6 for supplying fuel to the fuel adding apparatus 28, an emergency shutdown valve 31 formed by fitting the fuel supply source 6 on a fuel supply path 29 connected to the fuel adding apparatus 28, and a shutdown valve position detecting means for detecting that the emergency shutdown valve 31 is at a closed position. If fuel pressure on the upstream side acting on the emergency shutdown valve 31 is larger than that in the downstream, there is a possibility of fuel leakage, therefore the emergency shutdown valve 31 is controlled so as not to open even when an opening command is outputted. When an exhaust air-fuel ratio is not changed to the rich side even if a fuel adding command is outputted, added fuel leakage can be detected in the downstream of the emergency cutoff valve 31. |
