| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To effectively avoid problems such as abnormal combustion, combustion noise and the like in a high-load area while improving thermal efficiency by making an air-fuel ratio lean. <P>SOLUTION: In this method for controlling a spark ignition engine, the air-fuel ratio of an air-fuel mixture is made lean in comparison with a theoretical air-fuel ratio in the whole area of the engine load. When the engine load is increased to a predetermined first load X1 or more, a compression ratioεis reduced according to an increase in the load. When the engine load is increased to a second load X2 higher than the first load X1 or more, for example, ignition timingθig by an ignition plug 11 is retarded, thereby relatively delaying combustion start timing of the air-fuel mixture. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
