| 摘要 |
An exhaust purification device for an internal combustion engine, in which reduction of NOx by a NOx purification catalyst can be promoted immediately after the start of the engine. The exhaust purification device has a fuel reformer (50) provided separately from an exhaust pipe (4), reforming fuel to produce a reducing gas containing carbon monoxide, hydrogen, and hydrocarbon, and supplying the reducing gas to that portion of the exhaust pipe (4) which is located upstream of the NOx purification catalyst (33); an exhaust gas temperature sensor (34) for detecting the temperature T EX of exhaust gas flowing in the exhaust pipe (4); and a reformer control section (41) which, when the temperature T EX detected by the exhaust gas temperature sensor (34) is not higher than a first determination temperature T 1 , starts controlling the fuel reformer (50) to start supply of the reducing gas to the exhaust pipe (4) and, when the temperature detected by the exhaust gas temperature sensor (34) becomes not lower than a second determination temperature T 2 higher than the first determination temperature T 1 , stops controlling the fuel reformer (50) to stop supply of the reducing gas to the exhaust pipe (4). |
