| 摘要 |
PROBLEM TO BE SOLVED: To give a catalyst allowance in a NOx occlusion capacity after start by reducing a NOx storage quantity of the catalyst after start. SOLUTION: There is a possibility that the NOx occlusion quantity of the lean NOx catalyst 39 is saturated before a temperature of the lean NOx catalyst 39 rises to an activation temperature after start and a NOx conversion capacity drops when the NOx occlusion quantity of the lean NOx catalyst 39 at the stop of the engine is high. An ECU 16 determines that there is a possibility of stopping the operation of an engine 11 after the completion of deceleration during the deceleration, and changes operation to rich operation to reduce and remove NOx stored in the lean NOx catalyst 39. Consequently, the NOx occlusion quantity of the lean NOx catalyst 39 can be reduced before the stop of the operation of the engine 11, and the NOx occlusion quantity of the lean NOx catalyst 39 can be prevented from being saturated before the temperature of the NOx catalyst 39 rises to the activation temperature after start. COPYRIGHT: (C)2009,JPO&INPIT
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