| 摘要 |
<p>PURPOSE:To prevent occurrence of shock at the time of changing the mode of engine operation from operation under high supercharging pressure to the operation under low supercharging pressure, by advancing the ignition timing by the rate corresponding to the drop of supercharging pressure caused by changing the mode of engine operation. CONSTITUTION:A by-pass passage 2a is connected to an exhaust passage 2 in the manner of by-passing a turbine 4 of a turbocharger 3, and a waste gate valve 6 for opening and closing the by-pass passage 2a is driven by a pressure- responsive type actuator 7. The actuator 7 is driven under the control of a solenoid valve 18 which is controlled by a controller 20. With such an arrangement, when knocking is detected by a knock sensor 21, the ignition timing is delayed to prevent knocking of an engine. Further, the ignition timing is controlled to advance by the rate corresponding to the drop of supercharging pressure caused at the time of changing the mode of engine operation from operation under high supercharging pressure to operation under low supercharging pressure.</p> |
