| 摘要 |
PROBLEM TO BE SOLVED: To eliminate knocking while checking reduction in heat efficiency as the valve timing is delayed when the air-fuel ratio is lean. SOLUTION: A variable valve timing device 1, an igniter 2 and a knock sensor 3 are arranged, and when the air-fuel ratio is stoichimetric when detecting the knocking, the valve timing is delayed, and when the air-fuel ratio is lean when detecting the knocking, a delay in the valve timing is prohibited, and the ignition timing is delayed. |
