| 摘要 |
PURPOSE:To heighten the charging efficiency of intake in the heavy-load operation of an engine and promote its fuel efficiency in the light-load operation, by providing a shutoff valve in a main passage for the high-speed operation, providing a swirl producer in an auxiliary passage for the low-speed operation, and expanding a swirl in he light-load operation. CONSTITUTION:In the low-speed operation of an engine, a main passage 21 is closed by a shutoff valve 24. Since the form of an intake port 16 is made appropriate for the supply of the intake in the low-speed operation, inertial supercharging is efficiently performed. Because the intake is constricted by an intake Venturi section 40 and flows into a cylinder 12 along its inside 12A, the speed of the inflow of the intake is greatly increased to promote the atomization of injected fuel from an injector 23. In the high-speed operation of the engine, the main passage 21 is opened so that sucked air from a manifold 15 is supplied into the cylinder 12 through both the main passage and an auxiliary passage 22 and the intake port 16. |
