| 摘要 |
PURPOSE:To promptly set a supercharge pressure to the optimum engine setting for an octane number of fuel in use, by decreasing the supercharge pressure, when an ignition delay timing amount in the time of detecting knocking is in a preset value or more, in such a manner that the larger is a decreased amount of the supercharge pressure the smaller the above described preset value is decreased. CONSTITUTION:A signal from a knocking sensor 27 is input to a control unit 30, and an ignition timing control signal, fed to an ignitor 15, delays the timing in accordance with the signal of knocking. When a delay timing amount reaches a preset value, a preset value of supercharge pressure is decreased by adjusting a waste gate valve 9 in a supercharger 7. The larger is the decrease amount of this supercharge pressure, to the smaller value the above described preset value of delay timing is changed. In this way, an engine enables the preset value to be set larger increasing a noise margin while the supercharge pressure to be set most suitable for an octane number of gasoline in use. |
