| 摘要 |
PROBLEM TO BE SOLVED: To provide a new technique that can adjust the amount of intake air without using any expensive valve, for example, and solve the problems in valve durability abnormal noise during valve opening/closing.SOLUTION: An engine includes a main passage 34 in which a main valve 54 is provided, and first and second bypass passages 36A, 36B that bypass the main valve 54. The engine further includes a valve device 56 capable of opening and closing the first and second bypass passages 36A, 36B. Both of the first and second bypass passages 36A, 36B are closed or at least intermittently opened before startup of the engine. Each of the first and second bypass passages 36A, 36B is at least intermittently opened during cold idling. One of the first and second bypass passages 36A, 36B is closed and the other is opened during warm-up idling. |
