| 摘要 |
PURPOSE:To reduce the suction resistance of low speed suction passages by setting the opening area of the opening sections to the high speed suction passages of the low speed suction passages larger than the cross area of the low speed suction passages. CONSTITUTION:The down-stream end sections of low speed suction passages 25 and 26 are connected from the upper side to high speed passages 21 and 22 at opening sections 27 and 28, which are set to the same dimension d1 as the internal diameter in the car longitudinal direction of the low speed suction passages 25 and 26 in the longitudinal direction, but are set to specified value d2 larger than the internal diameter in the vertical direction of the low speed passages 25 and 26 in the car cross direction. The opening cross area of the opening sections 27 and 28 are, therefore, larger than the cross area of the low speed suction passages 25 and 26. This allows the suction air in the low speed suction passages to flow into the high speed suction passages 21 and 22 smoothly resulting in the practical elimination of the generation of the suction resistance near the opening sections 27 and 28. |
