PURPOSE: To improve a rise up of output torque by providing primary and secondary throttle valves in an intake passage on the upstream side from a mechanical supercharger and increase-correcting an opening of the secondary throttle valve when a selector means, which disconnectably connects all engine output shaft to the supercharger, is switched to a connected condition.
CONSTITUTION: A mechanical supercharger 6, driven by rotating an engine output shaft through an electromagnetic clutch 15 as a selector means, is provided in an intake passage 1, and a bypass passage 21 is provided in the intake passage 1 so as to detour around this supercharger 6. A primary side throttle valve 4 is provided in the intake passage 1 in the intake upstream side from a supercharger suction side connection part of this bypass passage 21, while a secondary throttle valve 5 is provided in the intake passage 1 between the supercharger suction side connection part of the bypass passage 21 and the supercharger 6. When the electromagnetic clutch 15 is switched from a disconnected condition to a connected condition by a control unit 32 in accordance with an engine speed and an accelerator opening, an opening of the secondary side throttle valve 5 is controlled so as to be increase-corrected.
HATAMURA KOICHI
GOTO TAKESHI
WATANABE YOJI
