| The modern car body is generally made from hundreds of complex shape stampingparts, assembled by welding and assembling, due to the deviation of stamping parts,welding and assembling deformation and fixture deviation factors, after welding andassembling, assembly often cannot meet the precision requirements. The body is a majorcarrier of automobile assemblies and parts, its quality is directly related to the quality ofvehicle. Body-size deviation is too large will directly cause the difficulties in assembly,affect the appearance, wind noise, sealing, driving stability and comfortableness of thevehicle. In order to ensure the vehicle’s appearance and internal quality，it is necessary tocarry out the study of the control method of welding and assembling precision of carbody stamping parts. This article is based on the actual background of the industrialproduction, and completed with the help of the project of CQUT and A domestic carbrands enterprises．First, analyzed the impact factors of welding and assembling precision of the carbody stamping parts, based on quality control theory of "man, machine, material, method,environment", and then systematically expounds how to control welding and assemblingprecision of car body from the above five aspects. In the aspect of welding andassembling deformation prediction, this article based on research outcome of previousscholars, using HYPERMESH and ANSYS, these two finite element analysis software,Ignoring the case of spot welding heat and plastic deformation, considering two mainfactors of welding and assembling deviation those stamping parts precision and fixturepositioning error, predicting welding and assembling deformation of Front Skirt UpperBeam Assembly. Through welding and assembling experiments show that the method hasthe ability to predict the deformational trend. In the welding and assembling experiments,using different spot welding sequence, after measuring, the results show that the differentspot welding sequence impact the welding deformation, The results of this study provethat from the experimental data, in order to reduce the accumulation of welding errors,for assemblies, like the Front skirt Upper Beam Assembly, Rear Skirt Board Assemblyand Rear Shelf Board Assembly, the main welding spots are symmetrical, arrayed like aline, and a large of number, should put to use the welding sequence from the middle toboth sides. In the end, author used an example to show the control method of welding and assembling precision of car body stamping parts, through a period of SOP productionproved that the effect of those approaches are significant. This article according to theprecision problems of Front skirt Upper Beam Assembly in this type of car during thetest manufacture stage of welding and assembling, searching for a feasible solution,doing experiment, in order to obtain the process law that not only solve the problem ofthis cars, but also provide reference for the development of subsequent cars. |
