| 摘要 |
<p>PROBLEM TO BE SOLVED: To solve a clogging condition of a catalyst, in the case where a diesel engine is frequently driven with a low speed and low load to deteriorate a catalyst purifying ratio and an exhaust efficiency by sticking the soot in exhaust gas on a catalyst surface. SOLUTION: A pressure sensor (a back pressure sensor) 45 is arranged in an exhaust passage 46 for connecting a turbocharger 35 and a catalyst converter 100 to each other. In the case where an output of a sensor 45 in a prescribed operating condition of an engine is a prescribed value or more, it is judged by an ECU 92 that clogging is generated in a catalyst. An opening of a nozzle vane 74 of the turbocharger 35 is regulated by the ECU 92 so as to increase supercharging pressure on the basis of its judgment. An attached material on a catalyst surface is eliminated by exhaust gas of a high temperature and high pressure in association with an increase in supercharging pressure.</p> |
