Patent GB-689776-A (GB)
Title: Improvements in methods of, and apparatus for, manufacturing radiators, particularlyfor automobile vehicles
IPC: F28F9/02
Filed: 1948-12-21
Abstract: 689,776. Making radiators and oil coolers; welding by pressure. SOC. ANON. DES USINES CHAUSSON. Dec. 21, 1948 [Dec. 23, 1947], No. 32993/48. Classes 83 (ii) and 83 (iv). [Also in Group XIII] Radiators and oil coolers are made by forming tubes with forge-welded seams from sheets or strips or aluminium or other light metal and connecting the tubes in cluster-fashion to a header 37 and a casing 44, Fig. 12. After forming the strip into a tube 1, Fig. 1, it is passed on to a mandrel 2 on which the overlapping edges are heated and welded together by pressure between the mandrel and an uppertool 4. Channels 5, 6, 7 and 8 are provided in the tool 4, the mandrel 2 and a lower supporttool 3 for the passage of cooling or heating fluid. Alternatively, electrical heating means may be provided to control the temperatures of the tools and also bring the edges 1<SP>1</SP>, 1<SP>2</SP> of the strip to the welding temperature. The tubes may be formed in a continuous process, Fig. 2, wherein strip metal is wound from a drum 9, through a pickling bath 10 and through roll passes 11, 12 and 13 where it is rolled into channel-shape. A fixed mandrel 14 carried by a support 15 is provided around which the strip is closed into tube-form by a further roll pass 16. A heating means, for example a blow-pipe 17, is provided to heat the seam which is then welded by pressure between a pair of rolls 18, 19. Alternatively, the edges of the tube may be brazed or welded together before the forge-welding operation. The seam may then be cooled by air from a blower 20 and the tube cut into lengths by a shearing or cutting means 21, additional shaping of the tube being effected, if desired, before the latter operation, or in another machine (not shown), in which a shaped mandrel is adapted to move with the tube. Instead of applying pressure to the seam through a mandrel, the tube 22, Fig. 3, may be welded without internal support. A honeycomb-section, Fig. 6, may be formed for an oil cooler and provided with a web 32 which is secured to the centre portion 31 and edges 29, 30 of the strip during the seaming operation. Front surfaces 36 of adjacent honeycomb-sections may be connected by welding, glueing or other method to form the cooling element. The tubes 38 of a radiator, Fig. 10, are attached to the header 37 after having fins 39 positioned thereon by locating a plate 40 of aluminium solder over the ends of the tubes and immersing the header in a bath 42 of flux which is heated at 43 to fuse the solder and form the joints by capillary action. The tubes may be protected internally and externally by a chromate treatment or a chemical method. Alternatively, the header 37 of aluminium may be plated on one face with an aluminium-silicon solder instead of using a plate 40. The fins 39 are then secured to the tubes by welding, hard or soft soldering, or glueing; except in the latter case, subsequent treatment in an oven or bath of flux is necessary. In the latter case, the radiator is sealed with plugs and provided with a pressure valve before being immersed in glue containing a diluting agent and preferably aluminium powder which increases the conductivity of the glue and provides an anti-corrosive coating for the outer surface of the radiator. The diluting agent is then drained and evaporated before baking the radiator in a stove for thirty minutes at a temperature between 180‹ and 200‹ C. to effect polymerization of the glue, the pressure valve permitting air to escape within the radiator. The casing 44, Fig. 12, may be attached to the header 37 by forge-welding in a single stroke of the tool 47, or by autogenous welding, brazing, glueing or the like. Adaptors and like parts may also be secured to the casing 44 by one of the above methods.