| 摘要 |
An oxidation promoting catalyst (42) which converts nitrogen monoxide in exhaust gas to nitrogen dioxide, and a diesel particulate filter (41) which traps soot in the exhaust gas, are installed in an exhaust gas passage of a diesel engine (1). A control unit (21) determines whether or not it is necessary to regenerate the filter based on the exhaust gas pressure detected by an exhaust gas pressure sensor (24), and when it is necessary to regenerate the filter, it increases the nitrogen monoxide in the exhaust gas by performing an advance correction of the fuel injection timing of a fuel injector (14) so as to promote generation of nitrogen dioxide by the oxidation promoting catalyst. The nitrogen dioxide decreases the combustion temperature of the soot trapped by the diesel particulate filter (41), and efficiently regenerates the filter. <IMAGE> |
