| 摘要 |
<p>PURPOSE:To improve air intake inertia effect over full rotating area by communicating independent air intake passages connecting an air intake expansion chamber and respective cylinders mutual in a communicating unit provided in parallel with the expansion chamber and by controlling the communication according to engine running condition. CONSTITUTION:Respective air intake ports of cylinders 4a-4d are communicated by lower stream ends of independent air intake passages 12-15, and upper stream ends of the passages are connected to an air intake expansion chamber 16 extending in parallel with the engine longitudinal direction. And on the way of respective passages 12-15, a communicating unit 12 extending in parallel with the chamber 16 and communicating to respective passages 12-15 mutually through branch holes 21 branched from respective passages 12-15 is connected. Each branch hole 21 is provided with an opening and closing valve 23 respectively and each valve 23 is controlled to open and close by a control means 25 through a valve shaft 24. This time, each opening and closing valve 23 is controlled to close in a low rotating area in which engine rotating number is less than a set value and to open in a high rotating area.</p> |
