Body In White Assembly And Welding Fixture Design And Spot Welding Robot Welding Simulation

Body-in-White welding technology is the crucial technology in the process of improving the whole quality and efficiency, the welding quality is good or not acts crucial role to the car quality. Car-body has significant effects on Car-Esthetics, Human Factors Engineering, Fuel Economy and Security. Welding fixtures for Body-in-White are the key factors to guarantee the high welding quality.This thesis researches on the welding fixtures design for Subassembly of Side Member and Wheelhouse Front Left-hand, which is an important part of the welding fixtures designs. First of all, this thesis presents the characteristic of Body-in-White, and gives the detail introductions to the characteristic and requirements of welding fixtures, which are the foundations for welding fixture design. The purpose of using welding fixtures is to finish the welding task, so this thesis gives a detail introduction to the spot welding technology, which is commonly used in Body-in-White welding process, and then gives some introductions to other welding technologies.One of the main tasks in the thesis is to do the 3D welding fixtures design for Subassembly of Side Member and Wheelhouse Front Left-hand. The thesis analyzes assessment basis for the fixtures design, and summarizes the logic structure on the basis of design experience. Two different sets of welding fixtures are designed after the structure analysis to the Side Member and Wheelhouse Front Left-hand. After the contrast and the analysis to the two sets of welding fixtures, the structure analysis to the one in use is deeply investigated. Then, the principle and the methods of setting welding guns are discussed. Flexible design philosophy is used during the whole 3D fixture design process.Another task of the thesis is to do the 2D design of the 3D fixtures, which includes the reference map and the dimensioning to the parts. Reference map is of great importance as it could show the locating points clearly. Not only were the principle and the methods of the dimensioning discussed by detail, but the concrete and typical examples were also illustrated here. And the technique requirements are given in the end. The welding fixtures design approach discussed in this thesis has some universality, which means the approach could also be used to design fixtures for other parts of the car.The third task of the thesis is to do welding simulation of spot welding robots. The thesis analyses the methods of Traveling Salesman Problem Arithmetic, which is nowadays a typical arithmetic in the welding route planning fields. Traveling Salesman Problem Arithmetic, together with a kind of commercial software, Robcad, could do a good job in solving the problems on the welding route planning of spot welding robots, which is proved by a simulation example designed and executed in Robcad.