| 摘要 |
PURPOSE:To obtain a lightweight heat exchanger having corrosion resistance by plating the surface of an Al-made tube with an Al brazing material of a base electrode potential, containing Mg, inserting an Al-made corrugated fin between bent tubes, and heating them in a vacuum furnace. CONSTITUTION:An Al brazing material 3 which contains Mg and has a composition of a baser electrode potential than an Al-made extruding tube 1 is melted and plated to the surface of the 1 having a partition wall 1a and a hole 1b. The tube 1 is bent in the shape of a snake motion, an Al-made corrugated fin 2 is inserted between each adjacent tube 1, and thereafter, they are heated to a melting temperature of the brazing material 3 in a vacuum furnace and the tube 1 and the fin 2 are joined through a molten plating layer of the brazing material 3. The Mg content of the brazing material 3, and the thickness of the molten plating layer are set to 0.05-3.0% and 30-50mum, respectively. In this way, a fin buckling phenomenon of the time of brazing can be prevented, the fin can be made lightweight, and corrosion resistance of a bent part of the tube is improved. |
