| 摘要 |
PURPOSE:To surely suppress knocking, by first reducing compression ratio upon detection of knocking, and delaying ignition timing when knocking cannot be suppressed irrespective of reduction in compression ratio by a predetermined amount. CONSTITUTION:When a control circuit 24 receives an output from a knocking sensor 7 during engine operation and decides creation of knocking, it compares a real compression ratio E given by a compression ratio sensor 28 with a minimum compression ratio E0 dependent upon engine rotational speed. When E> E0 is given, the real compression ratio is reduced by a predetermined amount DELTAE to determine a maximum compression ratio E, and a variable compression ratio control valve 22 is controlled to control a position of a compression ratio varying piston 10. Further, when it is decided that subsequent knocking is created, and E<=E0 is given, a real ignition timing is reduced by a predetermined amount to determine a final timing advance and delay ignition timing of an ignition plug 8. |
