| 摘要 |
PROBLEM TO BE SOLVED: To ensure excellent emission by air-fuel ratio control in which a condition of a catalyst is considered upon re-starting after the automatic stop of an internal combustion engine. SOLUTION: In the air-fuel ratio control immediately before the automatic stop of the internal combustion engine, an oxygen storage (adsorption and occulusion) amount of a three-way catalyst 13 is consumed, that is, fuel injection is carried out so as to be an air-fuel ratio rich side from a neutral state to purposely carry out transition, and in the air-fuel ratio control at the re-starting after the automatic stop, the fuel injection is carried out such that an equivalent ratio which is the inverse number of an air-fuel ratio is in a lean side in order to make the three-way catalyst 13 supply oxygen which is insufficient. Accordingly, the oxygen storage amount of the three-way catalyst 13 in the re-starting after the automatic stop of the internal combustion engine 1 is quickly returned to the neutral state, thereby ensuring the excellent emission. |
