| 摘要 |
An apparatus for controlling an air-fuel ratio for an internal combustion engine in which the air-fuel ratio is controlled to the leaner side of a stoichiometric air-fuel ratio in a normal operating condition. As the speed reduction ratio decreases, the air-fuel ratio is controlled so as to become increasingly leaner than the stoichiometric air-fuel ratio. Thus, when the speed reduction ratio is relatively large, the air-fuel ratio is controlled so as to be richer than a critical air-fuel ratio concerning misfire, thereby preventing occurrence of a surge in the engine output which would otherwise be caused by a change in combustion state. When the speed reduction ratio is relatively small, the air-fuel ratio is made to approach said critical air-fuel ratio in order to decrease the rate of fuel consumption. |
