| 摘要 |
An air-fuel ratio control apparatus of the present invention comprises an inverse direction spike introducing section and an inverse direction spike interval setting section. The inverse direction spike introducing section introduces, while an air-fuel ratio correction required by an output of a downstream air-fuel ratio sensor is being carried out, an inverse direction spike which is an air-fuel ratio spike to temporarily change an air-fuel ratio of an exhaust gas toward a direction opposite to a direction of the air-fuel ratio correction with respect to a target control air-fuel ratio. The inverse direction spike interval setting section sets, based on an operating state of an internal combustion engine system, an inverse direction spike interval which is an interval between two of the inverse direction spikes next to each other in time. |
