| 摘要 |
PURPOSE:To reduce noise by connecting a branch pipe on the way of a first intake pipe at a specified distance from the upstream opening end of the first intake pipe. CONSTITUTION:An intake system 2 for supplying air to an engine body 1 consists of a first intake pipe 3, air cleaner 4 and intake manifold as second intake pipe 5 connected in the order mentioned from the upstream side. To the intermediate portion of the first intake pipe 3 in the upstream side of the air cleaner 4 is connected a branch pipe 6 having the end closed. In a position where l2=lambda/4 (l2: length from intake pipe 7 to branch pipe 6, lambda: wave length), the branch pipe 6 is connected to the first intake pipe 3 to display the noise reducing effect to the maximum limit in that position. |
