| 摘要 |
An embodiment (control apparatus) of an internal combustion engine control apparatus according to the present invention determines whether a rich demand or a lean demand of an air-fuel ratio demand is being produced on the basis of an output value (Voxs) of a downstream air-fuel ratio sensor (67) disposed downstream of a three-way catalyst (43). The control apparatus, when the rich demand is being produced, sets an upstream target air-fuel ratio (abyfr) to a target rich air-fuel ratio (afRich). When the lean demand is being produced, the control apparatus sets the upstream target air-fuel ratio (abyfr) to a target lean air-fuel ratio (afLean). The target rich air-fuel ratio (afRich) and the target lean air-fuel ratio (afLean) are varied in accordance with an intake air amount (Ga). Further, the control apparatus increases the amount of purging of evaporated fuel as the magnitude of the difference between the target rich air-fuel ratio (afRich) and the target lean air-fuel ratio (afLean)(air-fuel ratio amplitude (?AF); |afLean - afRich|) increases. |
