To prevent fellow reinforcing wall forming parts and fellow side wall forming parts from displacement when pressurizing a metal plate for brazing after bending the metallic plate in a hairpin-shape.
The metal plate 80 is provided with two flat wall forming parts 89, 90 connected together by a joint part 88, and the reinforcing wall forming parts 83, 84 and the side wall forming parts 81, 82 formed in the flat wall forming parts 89, 90. Protrusions 100 are formed on a tip face of the reinforcing wall forming part 83 of the left flat wall forming part 89, and recesses 101 engaged with the protrusions 100 are formed in a tip face of the reinforcing wall forming part 84 of the right flat wall forming part 90. Sub-protrusions 102 are formed to press side faces of the protrusions 100 when engaging the protrusions 100 with the protrusions 101, in both side portions of the protrusions in the tip face of the wall forming part 84. A relation of 0.01≤E/(A+a)≤0.5 is satisfied, where A is a cross-sectional area of the projection 100 cut by a flat face right-angled to longitudinal directions of the reinforcing wall forming parts 83, 84, a is a cross-sectional area of the recess 101, and E is total cross-sectional area of the sub-protrusion 102.
KAWAMATA YASUJI
TAMURA TAKASHI
HOSHINO RYOICHI
OGASAWARA NOBORU
Einosuke Kishimoto
Akira Watanabe
Kiyosue Yasuko