Method for controlling temperature of copper brazing furnace

Abstract

The invention discloses a device for controlling the temperature of a copper brazing furnace. A direct-current power source supplies heating resistors distributed in the copper brazing furnace. 380 V alternating currents are converted into direct currents by means of three-phase bridge rectifier filters. The direct currents serve as the power source of the heating resistors, then the direct currents are inverted into the alternating currents which are the same as the direct currents in frequency but different in amplitude through a power inverter, the alternating currents serve as a first power source, a second power source, a third power source, a fourth power source and a fifth power source, and the six power sources are superimposed to form a total power source of the heating resistors. The temperature inside the copper brazing furnace is detected through a programmable logic controller (PLC), and then the power source of the heating resistors is analyzed, judged, controlled and switched in. According to the method, the influences of environmental changes on the temperature of the copper brazing furnace are avoided by means of the effective control over the power source, and it is guaranteed that the temperature in the copper brazing furnace is constant.

Description

technical field [0001] The invention belongs to the field of temperature control of copper brazing furnaces, in particular to a method for controlling the temperature of copper brazing furnaces. Background technique [0002] Copper brazing technology uses special brazing alloys of copper, tin and phosphorus to braze brass and red copper into tubes and heat dissipation strips into a high-strength metal whole. It uses extremely thin copper alloy solder to place near or inside the welding surface of the part that needs to be connected. After installation and drying, the parts are heated under the protection of a certain inert atmosphere to spread between the molten metal of the brazing alloy and the non-melting metal. After cooling, the brazing filler metal forms a metallic bond with the contact surface of the component. [0003] Copper brazing technology uses extremely thin copper alloy material, which has good thermal conductivity, high strength and high softening point. Mo...

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Problems solved by technology

[0005] Since there is a first-order time-delay temperature object with a large time lag in the temperature control process of the copper brazing furnace, it is generally impossible to achieve good results by using genetic algorithms to optimize the PID parameters, and serious overshooting occurs.

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