| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a duct capable of reducing disturbance in flow generated in the upstream, and the downstream of a bellows part compared to conventional devices. SOLUTION: In this duct 10 comprising a bellows part 20 and normal parts 30 without having bellows, in which an inner diameter of a trough 22 in the bellows part 20 is smaller than an inner diameter of the part 30, inner surfaces 22b and 22d of the trough 22 in the bellows part 20 are connected to inner surfaces 31a and 32a of the normal part 30 by inclination surfaces 41a and 42a of a more gentle inclination than the inclination of a side wall 23 connecting a peak 21 to the trough 22 in the bellows part 20.</p> |
