The Assembly Deviation Analysis Of Flexible Thin Pieces

Flexible sheet metal is an important part of the car body. The assembly quality of the flexible pieces is directly related to the appearance of the vehicle body, Sealing and driving performance, which occupy a very important position in the automobile manufacturing process. Controlling manufacturing deviations of the flexible stamped parts and deviations during welding process, analyzing robustness of welding fixture and optimizing the anchor points can improve positioning accuracy and assembly quality. Supported by the National Natural Science Project (No.51175466) and (No.51175466), carried out a study on assembly deviation analysis of flexible sheet metal parts, the main work and research contents are as follows:In chapter one:describes the research status of assembly variation analysis of flexible thin parts. Then describes studies of the robustness analysis of the assembly fixture and for optimization of fixture at home and abroad. Besides, this section presents the research background, the main content and the overall framework.In chapter two:Describes the factors affecting the flexible member assembly variation, then analyzes the characteristics of flexible stamping parts and quality of stamping. This section also describes welding distortion, welding jig and welded structures.In chapter three:Integrates advantages of the simulated annealing algorithm and particle swarm optimization and the simulated annealing algorithm is introduced into the particle swarm algorithm. For optimization of the flexible member positioned fixture, this paper presents a fixture point optimization method based on the simulated annealing particle swarm algorithm, in which the number and location of anchor points were optimized.In chapter four:Propose robustness optimization analysis of fixture based on the Positioning methods of the flexible member, describes the methods and procedures of the robustness analysis, modeling the Robustness analysis for flexible fixture and solving the mathematical model of the objective function.In chapter five:Analyzes assembly bias of the flexible sheet metal parts and Studies assembly process of the flexible member. The sensitivity matrix of each feature points is obtained through the influence coefficient method. Besides, we establish relationships between various input bias and assembly variation combined with limited element method. Finally, we do the assembly variation analysis using a Simple and flexible panels as an example.In chapter six:Reviews and summarizes the main research contents of the text and future research and development are discussed.