| 摘要 |
<p>PURPOSE:To make the maximal supercharging pressure widely variable by providing a first actuator operating in the direction of closing a bypass passage of a turbine concurrently with a second actuator operating in the direction of opening this bypass passage. CONSTITUTION:When a supercharging pressure is increased through operation of a turbo-charger 14 to reach a maximal supercharging pressure, a waste gate valve 15 is clockwise rocked through operation of a second actuator 18 and thus is gradually opened. Consequently, the supercharging pressure through operation of the turbo-charger 14 is prevented from exceeding the maximal supercharging pressure level, whereby it is kept at this maximal level. On the other hand, when the alcohol concentration M in the fuel is approximately 0% and the maximal supercharging pressure is controlled nearly to 0kg/cm<2>.G, a force which acts on the waste gate valve 15 through operation of a first actuator 17 is lost. In this way, the maximal supercharging pressure can be made widely variable from a level approximate to 0kg/cm<2>.G or so in corresponding relation to the operation conditions of the engine.</p> |
