| 摘要 |
PURPOSE:To prevent the generation of hunting by comparing the engine load and the predetermined load threshold value which varies in a prescribed relation for the engine revolution speed and lowering the supercharge pressure when the engine load is larger than the above- described threshold value and the delay angle correction value is over a standard value. CONSTITUTION:In Step 101-107, a delay angle correction value thetaK is obtained on the basis of the knocking generation state. In Step 107, the fundamental advance angle value thetaB is obtained from the engine load (intake air quantity Q/engine revolution speed N) and the engine revolution speed Ne. The actual advance angle value thetaEK (thetaEX thetaB-thetaK) is obtained. Then, in Step 110, the load threshold value which varies according to the number of revolution and the load Q/N at present are compared, and when the engine load is smaller than the threshold value, the delay angle correction value thetaK is excluded from the object of the judgement for increasing/decreasing supercharge pressure. When the load is larger than the load threshold value, it is considered that the fuel having a low octane number is used when the delay angle correction value thetaK is over a standard value, and the supercharger pressure is lowered, and therefore, the supercharge pressure is not increased during the use of the fuel having a low octane number, and the hunting of the supercharge pressure control valve is prevented. |
