Research On Assembly Quality Of The JR95 Automobile Headlamp System Based On Dimensional Engineering

In the process of rapid economic globalization,with the rapid development of the national economy of developing countries,the automotive industry has also grown at a sustained and rapid rate,which has led to intense competition among automotive companies.As one of the important factors to measure the manufacturing level of an enterprise,the automobile assembly quality has always been valued by the OEMs.The assembly quality of the headlamps and peripheral components directly determines the visual sensory quality of the car front face.And this area involves the special headlamp structure,the influence of deviations on the uncontrollable peripheral component quality and complicated assembly processes,etc.So controlling the accuracy of assembly deviations in this area has become a difficult issue for each OEM.Dimensional engineering is one of the core technologies for improving the quality of automobiles.It can analyze the deviations that may occur in the assembly process through simulation in the dimension design stage,effectively identifying the key source of dimensional deviations of the entire vehicle,white body,and parts in the production stage.It can improve the efficiency of solving dimensional defects.Therefore,this paper analyzes and optimizes the assembly quality of the headlamp area using the dimensional engineering technology focus on the dimensional deviation problem.The main research content of this article is as follows:(1)The headlamp assembly method and headlamp system assembly structure are summarized,and the current research status of dimensional engineering in the headlamp system is introduced.(2)The assembly structure of headlamps,bonnet of engine,fenders,engine compartments,and hinges is determined by the assembly process of the headlamp system of the JR95 model.The dimensional engineering design of this article's research object includes the introduction of original tolerance,positioning information and assembly relationship.The 3DCS three-dimensional assembly simulation software is used to analyze the deviation of the assembly structure and the optimized solution is put forward through the simulation results.(3)Adjust the anchor points of the headlamps and fenders and the controlling orientation of the anchor points so that the measurement gaps,flush,parallelism between the headlamp and bonnet of an engine,and the parallelism between the fender and the bonnet of an engine can reach a reasonable range.However,the overshoot rate of parallelism between headlamp and fender still does not meet DTS requirements.(4)In-depth research on the locating layout plan of the entire headlamp system,combined with 3DCS numerical simulation,the four key anchor points affecting the assembly deviation are determined through the single-factor multi-objective analysis method.The coordinate values of these four key positioning points(A,B,C,D)are independent variables,and the overshoot rate of gap parallelism between headlamp and fender is an optimization goal.The radial basis(RBF)neural network algorithm is used to establish the function relationship between variables and obtain the interactive influence of independent variables on the optimization goals.The multi-island genetic algorithm(Multi-island GA)is used to find the independent variable parameter combination that minimizes the optimization target value,that is,A=-200.02 mm,B=-219.96 mm,C=80.00 mm,D=620.00 mm.