Design For Fixture Of Laser Welding Of Body-in-white And Research On The Effects Of Incident Angle On The Welding Performance

Laser processing technology, as one of the advanced manufacturing technologies, has been applied more and more widely on the auto industry of industrial developed countries, laser cutting and welding gradually become the standard process. Three-dimensional laser cutting technology which can replace punch die and trimming die in the stamping process, can not only reduce the cost of die design and manufacture, but also greatly shorten the design cycle of a new car; laser welding technology which can be applied in body-in-white (BIW) assembly welding,can not only improve the strength, stiffness and security of the body, but also reduce the consumption of body material and weight, the BIW laser cutting and welding production line and flexibility fixture have been initial designed in this paper. The effect of laser beam incident angle on galvanized sheet welding performance is a difficult problem, which has been mainly researched.Firstly, the BIW laser cutting and welding production line and flexibility fixture have been researched. The structure and process of the door have been analyzed. Based on the consideration of flexible and safety, the overall layout of BIW is designed. According to principle of modern techniques, economy, and production practice, selecting and designing the main equipments. Base on the desige idea of standardization and modularization, the BIW flexible laser welding fixture of BIW was designed and trial-produced.Secondly, the principle of laser welding and its application in auto manufacture are discussed. Several welding methods of galvanized steel sheet are compared, that include laser welding, arc welding, resistance spot welding. The difficult point of galvanized sheet laser welding and main influencing factors of welding performance are analyzed. The methods of improving welding performance are proposed, including change procedure measure, optimize parameter and welding process, on-line detection controls.Finally, the effects of laser beam incident angle on galvanized sheet welding performance have been intensive study. The relatively ideal process parameters is obtained by orthogonal test. Then galvanized sheet welding experiment under different incident angles were carried out based on the relatively ideal parameters of vertical incidence. The transverse weld topography, the connect width between plates and tension and shear load, hardness, metallographic structure were analyzed when the incident angle changed. According to experiment data, the effects of laser beam incident angle variation on galvanized sheet welding performance and threshold incident angle have been obtained. This study will lay the foundation for laser welding applied to BIW.