Abstract: The invention provides a convection type brazing apparatus for metal workpieces such as aluminum, copper, iron and so forth that enables uniform heating of the metal workpieces to prevent deformation of the workpieces and can shorten a heating time to achieve a higher operation efficiency. A heating medium gas heated by a tube heater 36 in a thermal medium gas heating chamber 45 is forwarded by a fan 37 to manifolds 41A and 41B located on both left and right sides, to be blown through a multitude of nozzles 43 toward workpieces W to which a brazing material and flux have been applied in advance. Once the workpieces temperature has reached a predetermined temperature for brazing, a switching valve located in an upper duct 48 is activated so that the heating medium gas is intermittently blown to the workpieces. As a result, a temperature slope of the workpieces is minimized and uniform brazing can be performed.

Abstract: The invention provides a convection type brazing apparatus for metal workpieces such as aluminum, copper, iron and so forth that enables uniform heating of the metal workpieces to prevent deformation of the workpieces and can shorten a heating time to achieve a higher operation efficiency.

Abstract: A metal workpiece to which a brazing material and a flux are previously adhered is set into an index type convection furnace, and a heating medium gas is blown to this metal workpiece, so that the temperatures of the workpiece are increased up to the brazing temperature. After that, the temperatures of the heating medium gas are varied between the temperature slightly higher than the brazing temperature and the temperature at least 5% lower than that, in a predetermined period, while brazing. According to this method, a temperature slope of the workpiece is eliminated and uniform brazing is possible.