| 摘要 |
PURPOSE:To prevent increase of pumping loss due to resonant effect by classifying into two cylinder groups having no adjoining intake sequence then communicating respectively with a collecting pipe while providing main and sub intake path systems between the intake tube and the collecting pipe and setting specific relation between the length and the diameter of respective intake system. CONSTITUTION:Resonant tubes 81, 82 are branched as main intake systems from an intake tube 9 then take in the air into the cylinders 21-23 and 24-26 having no adjoining intake sequence through collecting pipes 71, 72. Auxiliary intake paths 101, 102 are branched from main intake system from the intake tube 9 and communicated with respective collecting pipe 71, 72 then primary throttle valve 11 is provided at the open end. Assuming the lengths and the diameters of respective intake tube 81, 82 and 101, 102 to be L, D and (l), (d), they are set to satisfy the relation d/l<1/2D/L<1/2>. Consequently, low resonant effect of only the auxiliary intake tubes 101, 102 will occur when the secondary throttle valve 12 is closed under low speed, resulting in reduction of pumping loss due to excessive resonant effect. |
