Design And Study On The Controlling System Of High-speed Welding And Corrugating Of Thin Copper Tube

The corrugated copper tube outer conductor of the coaxial cable is made by the 0.2~0.4mm thin sheet via tube-shaping, welding, corrugating and other several procedures. On basis of the analysis on the process of welding and corrugating thin copper tube, this paper presents a developing work of the controlling system of high-speed welding and corrugating of thin copper tube.The developed system makes use of PLC combined with human-machine-interface as the logical control devices, controls the entire production process working sequentially and automatically according to the designed logic control circuit and ladder diagram program of the PLC. In addition, the single-action or linkage of the motile parts can be achieved for the debugging works. The displaying interface of human-machine-interface and the parameter transformation system centered with C8051F020 single-chip computer are be designed to display in real-time the running status of the devices and the process parameters. The system takes the Siemens 6RA70 DC regulators with its control circuit as the speed modulation device. The regulators may work at the better condition by setting the interior parameters and running the automatic optimization to ensure the DC electromotor running steadily. The speed signal of the hauling regulator is output to the main speed-set-point of the corrugating regulator, so the speed of the corrugating electromotor will be adjusted and follow that of the hauling electromotor to ensure the stability of the corrugation pitch. The welding current is manipulated by tracing the processed voltage signal of the hauling electromotor to guarantee the stability of the heat input to the welded joint in the entire production process.In the actual production line, the system presents welding speed of 11m/min or above, the fine weld joint and stable dimension of corrugation, so the product quality achieves the best grade. There is the simple structure of hardware in this system with the convenient operation, the reliable control and high production efficiency.