Research On Quality Control Of Body-in-white Manufacturing Dimension

The quality of body-in-white has a direct influence upon the appearance and assembly performance of the vehicle, and it is an important part of the quality control of automotive. Now academia and automotive enterprises focus on the control method of body-in-white.This paper analyzes the factors influencing the dimension of body-in-white and the detecting system. And do some research on the characteristics of measured data of body-in-white, so we can speculate the variation trend to the judge the quality reasons. This paper also made a research in the evaluation methods of manufacturing dimension and analysis the strengths and weaknesses of each method. This part introduces continuous improvement indicators to evaluate the stability of manufacturing dimension; pass rate index is the percent of pass from the perspective of theoretical design; Audit evaluation is used to describe the body-in-white manual. Then, the paper introduces the method of quality control chart, and put forward the combined utilization of Shewhart control chart and CUSUM control chart to detect the change of body size, and use the EWMA quality control chart which is sensitive to variation to judge the aberrance. Coordinate Measuring Machine (CMM) is used to measure the functional dimension. This paper analyzes the deviation of sample and total with Monte Carlo method, so we can judge the general by using the sample data. Then, use Principal Component Analysis to analysis the deviation of body-in-white. We can construct decision tree model of body size to analysis the deviation to put forward effective improvement.Finally, this paper did a research in the case of bulkhead part of A automobile enterprises. This part studied the quality control of bulkhead dimension from the perspective of theory and practical engineering application. The research method of this paper, in order to improve the manufacture of body size provides strategies and concrete control methods. The purpose of this case is to improve the quality of the bulkhead part. This case is a good guide to other parts dimension control.