| 摘要 |
PURPOSE:To improve the output power of an engine in its regions of high and medium speed rotation, by providing auxiliary enlarging chambers which communicate with intake passages downstream to a main enlarging chamber and by prescribing the length of each of passages from the auxiliary enlarging chambers to intake ports. CONSTITUTION:A main enlarging chamber 17 is provided in a main intake passage 12 downstream to a throttle valve 15. Auxiliary enlarging chambers 18, which communicate with intake passages 12a, 12b downstream to the main enlarging chamber 17, are provided. The length l2 of each of passages between the auxiliary enlarging chambers 18 and intake ports 3 is set larger than that l1 of passages between the main enlarging chamber 17 and the intake ports. As a result, a main intake-inherent pulsation effect and an auxiliary intake-inherent pulsation effect are produced by the main enlarging chamber 17 and the auxiliary enlarging chambers 18, respectively, to heighten the charging efficiency of the engine in its regions of high and medium speed rotation to improve the output power of the engine. |
