| 摘要 |
PROBLEM TO BE SOLVED: To provide an engine controller capable of improving fuel economy by setting an air-fuel ratio of an internal combustion engine and a continuation time when NOx purging. SOLUTION: This engine controller is provided with a NOx catalyst 18 for storing NOx when an air-fuel ratio is in a lean condition and reducing and eliminating the stored NOx when an air-fuel ratio is the theoretical air-fuel ratio or in a rich condition, a NOx sensor 19 for detecting amount of emitted NOx on the downstream side of the NOx catalyst 18, an operation condition detection means for detecting an operation condition, a NOx purge control practice determining means 22 for switching the air-fuel ratio to the theoretical air-fuel ratio or the rich condition when determining that the NOx purge for emitting the stored NOx is performed, a NOx purge air-fuel ratio setting means 23 for setting the air-fuel ratio when performing the NOx purge as the air-fuel ratio at purging time to correct the air-fuel ratio at purging time from the amount of emitted NOx, and a NOx purge continuation time setting means 24 for setting continuation time when performing the NOx purge to correct the continuation time from the amount of emitted NOx. COPYRIGHT: (C)2008,JPO&INPIT
|
