As the metallic plate for flattened tube production, production manner null of the flattened tube

摘要

PROBLEM TO BE SOLVED: To prevent deviation in a position between reinforcing wall forming parts and between side wall forming parts in the case where a metallic plate is pressed for brazing after it is folded in a hairpin bend. ;SOLUTION: The flat tube is composed of two flat wall forming parts continued through a connecting part, a plurality of reinforcing wall forming parts 83, 84 integrally formed bulgingly on each flat wall forming part, and side wall forming parts integrally formed bulgingly on both side edges. A projection 85 is formed on the tip end face of the reinforcing wall forming part in one flat wall forming part, while a recess 86 for the projection 85 to be fitted to is formed on the tip end face of the reinforcing wall forming part 84 of the other flat forming part which is to be abutted on the counterpart 83. Assuming A is the cross section, B the height, C the maximum width, and D the tip end width respectively of the projection 85, and assuming (a) is the cross section, b the depth, c the maximum width, an d the opening width respectively of the recess 86, the following relations are fulfilled; Aa, A/a≤1.5, B/b≤1.5, C/c≤1.5, and D/d≤1.5.;COPYRIGHT: (C)2003,JPO