| 摘要 |
PROBLEM TO BE SOLVED: To perform scraping with a filter part and a ventilation fan cover frame body forming an integral object, by a method wherein a filter mounted on a ventilation fan cover frame body is formed of metallic fibers, in such a manner that a gap between the metallic fibers has a high thickness part and a gap between the metallic fibers has a high thickness part. SOLUTION: A ventilation fan cover A consists of a frame body B and a filter C. The frame body B thereof is formed such that a single aluminum or aluminum alloy foil is folded for molding and formed approximately in a disc-from in cross section having a protrusion part 1 in a trapezoidal shape in cross section and a flange part 2 approximately in a plane-form state. A notch opening part 3 is formed in the upper surface of the protrusion part 1, and the filter C formed of metallic fibers and by using a binder is mounted on the notch opening part 3. A full curl part 4 is formed at the peripheral edge part of a flange part 2. Further, a filter C has a given part being crashed to form a thin part and is formed in a pattern having an expansion part (a thick section part) 11 protruded from one side surface, namely, a pattern having the expansion part 11 surrounded with a thin section part 12. |
