| 摘要 |
<p>PURPOSE:To reduce the noise and pressure loss generated at the time of passing air in a flexible pipe. CONSTITUTION:A shoulder-pack band is put on one's shoulder to shoulder the whole body of a blower, while an engine 64 is driven, the rotation is transmitted to a fan in a fan case 69 to rotate the fan, and the wind generated there is sent to a target place through a discharge pipe 72 a flexible pipe 74 a wind discharge pipe 76. The flexible pipe is formed of a flexible outer pipe 80 having an irregular side section, a flexible inner pipe 82 having pores 83, and a sound absorbing material 81 interposed between the flexible inner and outer pipes 80, 82. The flat inner surface of the flexible pipe never case a vortex in the wind passing there, and even if generated, it is only small. Further, the noise based on this is absorbed by the sound absorbing material 81, and the noise is remarkably reduced. Since the inner surface of the flexible pipe is flat, a pressure loss in this part is also reduced.</p> |
