Abstract: Articles to be brazed are preheated to an increased temperature in a preheating process and the temperature of the articles to be brazed is measured. Conversion data obtained and stored for different combinations of articles to be brazed is referred to on the basis of the measured temperature and a time for which brazing filler metal supply nozzles are kept in a wait state is set on the basis of the conversion data to define the timing for supplying the brazing filler metal wires (S40). A heating burner moves forward and then a timer starts counting the time for which the nozzles are kept in the wait state (S42). When the nozzle wait timer has counted the set time and expired, the brazing filler metal supply nozzles move forward and supply the wires to braze the articles (S43 to 45). In this way, the articles to be brazed, heated by the heating burner, are at an increased temperature suitable for brazing at the time when the brazing filler metal wires are supplied.

Abstract: A flux supply device comprises a liquid replenishing portion containing a liquid flux for replenishment, a liquid holding portion connected to the lower end of the liquid replenishing portion with a first electromagnetic valve provided therebetween, and a liquid supply portion connected to the lower end of the liquid holding portion with a second electromagnetic valve provided therebetween. The lower end of the liquid supply portion is located in a flux storage tank in which a mixed gas is generated. A gas blow-in pipe for supplying a combustible gas is also located in the flux storage tank. The first electromagnetic valve and the second electromagnetic valve are controlled in given timing so that one opens and closes and then the other opens and closes, alternately and repeatedly. This prevents the pressure variation in the flux storage tank from affecting the liquid replenishing portion and the surface level of the liquid flux in the flux storage tank is kept unchanged.

Abstract: A gas flow rate control device disposed between a gas burner and a combustible gas source and a burning-supporting gas source connected to the gas burner has gas flow rate setting means for setting a flow rate of the combustible gas to be supplied to the gas burner, gas ratio setting means for setting a gas ratio between the flow rate of the combustible gas and a flow rate of the burning-supporting gas to be supplied to the gas burner, a first control valve for controlling the amount of combustible gas supplied to the gas burner, a second control valve for controlling the amount of burning-supporting gas supplied to the gas burner, and control means for controlling the first and second control valves on the basis of the set flow rate of the combustible gas and the set gas ratio so that the amounts of the combustible gas and the burning-supporting gas supplied to the gas burner correspond to the flow rates set.

Abstract: A gas flow rate controller arranged between a gas burner and a flammable gas source and a combustion-assisting gas source includes a gas flow rate setting means for producing a flow rate setting signal corresponding to a preset flow rate of gas flowing toward the gas burner. A ratio setting means produces a flammable gas setting reference signal and a combustion-assisting gas flow rate setting signal at a predetermined ratio, based on the flow rate setting signal produced by the gas flow rate setting means. The flow rate of the flammable gas detected is compared with the flammable gas setting reference signal produced and the flow rate of the combustion-assisting gas detected is compared with the combustion-assisting gas flow rate setting reference signal produced. Control valves are feedback controlled so that any differences therebetween will become zero. Thus the mixing ratio between the gases is kept constant even if the gas pressures change.