| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain the exhaust emission control device for an internal combustion engine which does not invite the deterioration of an emission by the saturation of NOx storage reduction type catalyst after the returning of fuel cut. SOLUTION: NOx storage amount increases limit amount dRnox is set at the returning time from a fuel cut ('YES' at S910∼S930) (S950) and when the increase amount of NOx storage amount s NOx after fuel cut return becomes larger than NOx storage amount increase limit amount dRnox ('YES' at S960), a rich spike control treatment is carried out (S970). Therefore, as the execution timing of the rich spike control treatment carried out after returning from the fuel cut is judged by using NOx storage amount increase limit amount dRnox instead of the storage allowable value which is a temporary inaccurate value by the fuel cut, the rich spike control is carried out by a not too late proper timing after returning from the fuel cut.</p> |
