| 摘要 |
<p>An internal-combustion engine (10) of the invention includes a catalyst (52) which has an oxidizing ability and is provided in an exhaust passage, wherein an air/fuel ratio of an air/fuel mixture is controlled so that the air/fuel ratio leaner than a theoretical air/fuel ratio and the air/fuel ratio richer than the theoretical air/fuel ratio are alternated with a predetermined amplitude with respect to a target air/fuel ratio. On the assumption that the temperature of the catalyst is referred to as a catalyst temperature, an amplitude set according to the catalyst temperature is adopted as the predetermined amplitude, and the amplitude set when the catalyst temperature is higher than a predetermined temperature is smaller than the amplitude set when the catalyst temperature is lower than the predetermined temperature.</p> |
