| 摘要 |
<p>Provided is an exhaust emission control device for an internal combustion engine capable of preventing NOx purification performance from degrading according to the operating condition. The exhaust emission control device comprises an NOx purification catalyst for adsorbing or occluding NOx in exhaust emissions and reducing the NOx, which is provided in an exhaust pipe (4), a catalyst converter (31) for continuously reducing the NOx in the exhaust emissions by using a reducing gas, which is provided in the exhaust pipe (4), a fuel reformer (50) for reforming fuel to manufacture a reformed gas containing hydrogen and carbon monoxide and supplying the reformed gas as the reducing gas from an introduction port (14) provided on the upstream side of the NOx purification catalyst (33) and the catalyst converter (31) of the exhaust pipe (4), which is provided separately from the exhaust pipe (4), an operating condition detecting means for detecting the operating condition of an engine, and an enriching means (40) for enriching the exhaust air-fuel ratio. The enriching means enriches the exhaust air-fuel ratio by supplying the reducing gas into the exhaust pipe (4) by using the fuel reformer (50) when the operating condition detected by the operating condition detecting means is a high-load operating condition.</p> |
