Research On The Laser Filler Wire Welding Technology Of The Car Roof And Side Panel

The growing competition of Global car manufacturing enterprises becomes moreand more intense. In their car (body) manufacturing, each auto manufacturersactively introduces and adopts the advanced processing technology to adapt to thedemand of the market. A developed new connection processing technology namedLaser wire filling brazing aimed at coating metal, especially the connection ofgalvanized steel sheet,was developed by the German car makers originally. LaserWire filling welding processing manufacturing technology as a new technology whichcan effectively improve the processing quality and efficiency, get a quick application.Since the product of Chinese car joint venture is now almost at synchronousmanufacturing stage with foreign, laser wire filling welding processing technologyhas been applied. But presently,in the domestic car (body) processingmanufacturing,the application of laser wire filling welding technology is still less, andthere is just simple application of laser wire filling welding technology. With thescope of the application of this technology widely extended and the problemsappearing during the actual production, there is still a lot of work to do about theresearch of laser wire filling brazing technology. As in production practice, laser wirefilling brazing techniques referred to many influencing factors, the production processusually appears welding quality problems. After the problems, because of the onlysimple application of the laser wire filling welding system without a systemunderstanding for the laser wire filling welding system, only purely according to theusual experience to repeatedly adjust that it greatly reduces the production efficiencyand also has a great effect on the production plan.So enterprise hope to be able tomaster the laser wire filling welding technology, known well the characteristics of thelaser wire filling welding so that they can make better use of the advantages of thelaser wire filling welding and can improve the quality of the Chinese automobileproduction, also they can reduce the dependence on the foreign countries. So developing the research on laser wire filling welding technology has a greattheoretical and practical significance.Firstly,this paper studied the laser wire filling brazing mechanism andtechnology of the car roof and side panel.In this paper,it use low power pulse Nd:YAG laser to laser wire filling weld the car roof and side panel of a car, discussing thelaser wire filling welding equipment and the function of its key equipment, analyzingthe quality factors which affects the laser wire filling welding, such as: welding type,laser power, welding speed, wire speed and defocused quantity, discussing theimpacting of the change of the influence factors on the quality of welding, and itobtained the variation scope of some parameters above and the change relationshipbetween them.Then,in this paper,it builds a three-dimensional model of the car roof and sidepanel, through the software Ansys Workbench,it simulating and analyzing the stressdistribution of two ways of welding,that is the laser wire filling welding and spotwelding,and through comparing it further discuss the relative superiority of the laserwire filling welding to the traditional welding spot welding processes. In this paper, itmaking the thermal analysis and the simulation analysis of thermal stress of the laserwire filling welding, and geting the temperature field and stress and strain distributionof the laser wire filling welding, laid the foundation for the following of the thermalanalysis of the laser wire filling welding.Finally, it introduced the monitoring method which is during the laser wirefilling welding experiments of the car roof and side panel, discussing the quality thatis after laser wire filling welding, listing the general common welding defects,analyzing the common cause of these welding defects, and described the repairmeasures for the larger welding quality defects in the laser wire filling weldingcombined with the actual processing production process.