| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method of a fin for heat exchangers by which the manufacture of the fin for heat exchangers on which a collared through hole having an oval cross section is formed is performed at low cost and a die with which the method is performed. SOLUTION: When manufacturing the fin 20 for heat exchangers by forming a collared oval through-hole 22 on which a collar having a prescribed height is formed so as to enclose the periphery of the oval through hole into which a tube for heat exchangers having an oval cross section is inserted, a container part 30 having a circular cross section is formed on a planar metallic sheet 21, formed into an container part 36 having the prescribed diameter, the prescribed height and the oval cross section by applying a plurality of times of drawing to the circular container part 30 and the collared oval through-hole 22 is formed by piercing the through hole to the oval container part 36. COPYRIGHT: (C)2004,JPO&NCIPI |
