| 摘要 |
PROBLEM TO BE SOLVED: To reduce the ventilation resistance of air flowing through the inside of a ventilation duct in which a through hole is formed in the duct wall. SOLUTION: This ventilation duct 1 for sucking air comprises a recessed part 4 recessed from the basic shape inner peripheral surface of the duct wall to the outside of the duct. A through hole 3 extending through the duct wall is formed at the upstream side portion 41 of the recessed part. The length of the recessed part 4 along the flow in the duct is larger than the size of the through hole 3. Preferably, the downstream side portion 42 of the recessed part is made generally parallel to the through hole 3 or made to project toward the inside of the duct, and the through hole is formed in the direction of 0-60°to the center axis of the duct. COPYRIGHT: (C)2011,JPO&INPIT |
