| 摘要 |
PROBLEM TO BE SOLVED: To accurately detect actual ignition timing of a diesel engine without an influence on a change of noise for each combustion cycle. SOLUTION: An absolute value is integrated for each crank angleθduring a prescribed sampling period (θs-θf) after mounting a knock sensor taken as an acceleration sensor in a cylinder block and extracting vibration acceleration in a range of 5 kHz-10 kHz by filtering process. An integrated value Sθfor each crank angleθis temporarily stored as integrated value data. An ignition timing determination level S_SL is determined by multiplying an integrated value Sf in the finishing timingθf of a sampling period by a threshold ratio corresponding to operating conditions, and compared with the integrated value data. A crank angleθwhen the integrated value Sθexceeds the ignition timing determination level S_SL is regarded as an actual ignition timing. The fuel injection timing IT is corrected so as to bring the actual ignition timing closer to the target ignition timing. COPYRIGHT: (C)2010,JPO&INPIT
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