| 摘要 |
PURPOSE: To provide a method and a die for manufacturing a fin for a heat exchanger in which wrinkles or ring marks are suppressed in the vicinity of a collar when manufacturing the fin for the heat exchanger. CONSTITUTION: This manufacturing method comprises a bulging step a for forming a dome-like part 10 having the diameter of a bottom surface larger than the diameter of a through hole 7 having the collar in a thin metal plate 9, and for forming a recessed part 68 having the diameter larger than the diameter of the bottom surface of the dome-like part 10 and recessed in the direction opposite to the projecting direction of the dome-like part 10 is formed in a ring shape so as to surround the dome-like part 10, a step b of a plurality of stages for forming the dome-like part 10 and the recessed part 68 to a truncated conical part of a predetermined height by the forming of a plurality of stages of the dome-like part 10, a piercing step c for cutting a through hole in the truncated conical part of the predetermined height, a burring step d for raising an edge part of the through hole to form the collar, and a flaring step e for forming a flange 6 on a tip of the collar. |
