| 摘要 |
PURPOSE:To keep the interior of a cabin silent by establishing a region where sound pressures is lowered, within a drafter box with the provision of an opening to the cabin in this region. CONSTITUTION:The plural number of louvers 4 is provided for an opening, which opens outside a car, of a drafter box 1. And the width of the louver 4 is widened as it goes downward so as to establish a region where the sound pressure of sounds which come into the drafter box 1 through each of the louvers 4, is lowered. And another opening 3 is provided inside the cabin in this region. Accordingly, even if the cabin is communicated to atmosphere with a one-way valve 5 opened, this configuration is capable of preventing outside noise from coming into the cabin, and of also keeping the interior of the cabin silent without impairing the effect of ventilation. |
