Method of making a tube for a heat exchanger

摘要

Method for manufacturing dimpled, flattened tubes for heat exchangers including the steps of: a) providing an elongated strip of aluminum based material (22) having opposed edges (24,26) and a braze alloy on only one side thereof; b) forming dimples (30) in the strip (22) such that the dimples (30) project to the side of the strip (22) opposite the strip one side and the dimples (30) on one side of a predetermined fold line (28) located between opposed edges will align with the dimples (30) on the other side of the fold line (28); c) placing slits (34) extending through the strip (22) at the apexes (44) of the dimples (30) on at least one side of the fold line (28); d) folding the strip (22) along the fold line (28) and bringing the edges (24,26) into contact with one another while causing the apexes (44,46) of aligned ones of the dimples (30) to abut one another; e) welding the edges (24,26) to each other to form a tube; and f) causing the braze alloy to flow from the strip one side through the slits to the interior of the tube and braze the apexes (44,46) of the aligned dimples (30) together.