Whole Design For The Welder Of The Double-helical Friction Stir Welding Based On Open Cnc System

Friction stir welding (FSW) was invented by TWI (The Welding Institute) in Cambridge UK in 1991, it is well known that this economical joining method has excellent welding property and also has advantage in protecting environment. FSW is finding vast applications in. the space flight apparatus, aviation production, shipbuilding, high speed train, natural gas packet, automotive industry. It will be an important revolution in joining high strength aluminum and its alloy. Although FSW has short history, welding workers has made great progress in FSW, including its principle, materials welded, welding machine and its application.Based on seam welding and spot welding of FSW, the thesis put forward double-helical friction stir welding method. Compared with seam welding of FSW, double-helical friction atir welding could be applied in arc seam and had various demands in the welding space; Compared with spot welding, it adopted lifting stir-pin to avoid the fluence of key hole, and this method could reduce the possibility of internal flaw effectively. Based on itself characteristic, double-helical friction stir welding method was applied in the situation of aluminium-all riveting and circular-seam welding.Based on the theory research and simulation experiment, the thesis designed the mechanical structure of double-helical friction stir welder. The slope could not be changed and the influence of key hole could be eliminated by the lifting stir-pin in the process of the welding. The welder controlled two stepper motors, three AC motors and one DC motor. So based on open CNC system, the welder adopted the frame containing the industrial computer and controlling cards. The stepper motor motion controlling card provided the stepper motors with the parameters of speed, direction and distance; the anolog output card provided the AC motors and DC motor with controlling voltages which was used to control their speed to meet the demand of technology parameters. Based on the electric hardware of the open CNC system, the human-computor controlling software was developed for the double-helical friction stir welder. Though the modification of the operating parameters, the technology parameters could be optimized and the double-helical friction stir welder could be applied in the diverse situations. The double-helical friction stir welding method could be the complementarity of other FSW methods, as a characteristic FSW method. The development of the double-helical friction stir welder could achieve the experiment of the double-helical friction stir welding, optimize the parameters of the double-helical friction stir welding and make further research on the spot array of the double-helical friction stir welding locationg.