| 摘要 |
PURPOSE:To improve suction efficiency by communicating a primary suction passage with the wall of a passage side between a throttle valve which opens at the high rotary speed of an engine, in a secondary suction passage and a fuel injection valve, and by providing a communicating section on the wall opposite to a suction valve which opens at the low rotary speed of the engine too, out of two suction valves provided on each cylinder. CONSTITUTION:No.1 suction valve 7a which opens and closes over the entire operating range of an engine and No.2 suction valve 7b which opens and closes only at the high rotary speed of the engine, are provided for performing suction from both a secondary suction passage 16 as a common suction passage to each suction valve and a primary suction passage 25. Suction from the primary suction passage 25 is performed throughout the entire range of engine operations and suction from the secondary suction passage 16 is performed only when a throttle valve 18 is fully opened at the high rotary speed of the engine. The primary suction passage 25 is opened to the wall opposite to No.1 suction valve 7a in a space between the throttle valve 18 in the secondary suction passage 16 and a fuel injection valve 19, and suction air from the primary suction passage 25 is sucked in at the low rotary speed of the engine through a suction port of No.1 suction valve 7a because of its inertia.
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