Study Of Manufacturing Process Quality Control About Passenger Car Door Hinge

Door hinge is one of the critical components in the car. After review the manufacturing condition of door hinge in one machinery factory, big amount of scrap parts seems that process has problem. The reject rate of some critical process is about 50%. In order to solve this problem, analysis the manufacturing process of the single part and assembly, find out the bottle neck process of quality. Calculate the PPK to these critical process dimensions, and take actions such as increase inspection frequency or set high precision machines to improve the process capacity. Reorganize the process quality control system. The new system take effect and improve the accept rate from 50% to 90% above. As the tighten torque of door hinge bolt has a big range of motion, try to set up mathematical model to predict torque. After review the predict results by using time series method, grey system modeling method, neural network model, the method of neural network has the best precision of predict.