GB929664A - Improvements in or relating to methods and apparatus for soldering plates to tubes of cooling radiators for internal combustion engines - Google Patents

Abstract

929,664. Making heat exchangers; soldering. SOC. ANON. DES USINES CHAUSSON. Nov. 20, 1959 [Dec. 26, 1958], No. 39521/59. Classes 83 (2) and 83 (4). Header plates are secured to the tubes of a radiator for an internal-combustion engine by dip soldering. After the tubes have been assembled with the cooling gills, the ends are expanded in the header plates and the assembly is preheated to at least 122 ‹F. One end of the assembly is dipped in a bath of circulating flux at a temperature of at least 122‹ F., drained, dried by passing through a stove and dipped in a bath of molten solder, and an air jet is directed through the tubes from the opposite end to remove excess solder. Subsequently the process is repeated on the other end. The soldering of both ends is carried out by a machine having a rotary work-table 9 mounted on a fixed base 1 and reciprocable vertically by a double-acting ram 8. In its lower position the table 9 is located by engagement of a fixed pin 19 with one of a number of sockets 20 on the table 9. Work-holders are carried on shafts 40 radially journalled in the table 9. A disc 41 secured to each shaft 40 carries a projection 49 held by a torsion spring 43 in engagement with a stop 50 on member 44 rotatably carried on the shaft 40 but normally prevented from rotation by a spring-loaded detent 47 on the table 9. After preheating to at least 122‹ F. the assembly is secured with its tubes vertical between clamps 35, 35a, Fig. 10, carried by two hinged frame members 21, 23 which are secured together by a latch 24, the frame member 21 being rigidly attached to a shaft 40 at the first work-station a. The assembly is moved by step-by-step rotation of the table 9. At b one end of the assembly is dipped into a flux bath 51 at 176‹ F. by lowering of the table 9. The assembly is tilted by actuation of a lever to engage a roller 42 on the disc 41 and is raised clear of the flux bath 51 and returned to vertical as the flux drains off. At work stations c, d, e, f the flux is dried in a hot air stove 59 and at station g the assembly is dipped into a solder bath 60 by lowering of the table 9. The bath contains a screen which prevents solder entering grooves on the header plate which are provided to receive the edges of the water box. As the table 9 is raised fingers 61 engage an arm 62 centrally pivoted coaxially of the table 9 so that as the assembly moves from g to h the arm 62 and the table 9 rotate together. At the same time a nozzle 71 carried by a ram 69 on the arm 62 is traversed across the upper ends of the tubes to blow air through the tubes. The arm 62 is released when the table 9 descends at station h. A member 74 raises the detent 47 and a slotted sector 77 engages the rollers 42 on the disc 41 which together with the assembly is rotated through 180 degrees. The whole sequence of operations is repeated to solder the other header plate to the tubes as the assembly passes through work stations i . . . a.