| 摘要 |
PURPOSE:To prevent penetration of water and forming rusts, by remaining the upper part of a flange thickness with cutting off its central part deeply and its lower part shallowly to form the upper and lower parts into a pair of long and short projected edges, bending the lower short projected edge upward and the upper long projected edge downward to press integrally into one body. CONSTITUTION:A peripheral wall of a pan body 2 formed of a clad steel plate 1, etc., by dies is bent outward to form a holizontal flange 3. Then, the thick part of the flange 3 is bitten to cut off a part A and to form the long projected edge 4 on the upper part of the flange 3 and short projected edge 5 on the lower part. Furthermore, the short projected edge 5 in the pair of long and short projected edges 4, 5 is bent along with the central deep cut pane by a roll roller, then the long projected edge 4 is bent so as to cover the surface of projected edge 5, and buffed to integrate into the one body. As a result, the curled part tightly filled of its inner part is formed to prevent the penetration of water from the flange part of the pan.
|
