| 摘要 |
PURPOSE: To provide a diesel engine capable of making compatible the reduction of smoke with the reduction of NOx by raising the upper limit value of an EGR rate allowing the exhaustion of smoke to be suppressed. CONSTITUTION: A low NOx combustion mode in which a fuel injection timing IT is set to 36°BTDC remarkably spark-advanced as compared with approx. general 10°BTDC is executed. At the fuel injection timing IT, even if the EGR rate Regr is increased to approx. 56%, the amount of exhaustion of smoke can be suppressed to an extremely low value. Further, at the timing, both smoke and NOx can be reduced since the amount of exhaustion of NOx is also suppressed by a large amount of EGR. |
