Quality Control And Study Of Bushing Manufacturing Process

Fast growing Chinese auto market tops U.S.auto market and became the first in the world years ago,and it's bringing good opportunities for local automotive component companies.However,local small and medium automotive component companies are facing pressures both from higher requirement of OEMs and losing share of the market due to competitiveness from foreign-backgrounded component companies.Local companies account for around 80% of total number,only have 30% of the whole market share due to weaknesses of product quality and production management.How to implement quality tools according to industrial criteria to improve product quality has become an urgent task for local small and medium automotive component companies' long term development.In this paper,a rubber bush in chassis,which is important for safe and comfortable driving,and manufactured by a typical local small and medium component company,is taken as an object of study by analyzing the process from raw material to final product.Key points of process are identified,and parameters of tube-cutting and e-coating are optimized by using Design of Experiment(DOE).Flow Chart and Failure Mode Effects and Analysis(FMEA)are introduced to predict kinds of failures in the process and risk-proofing actions are figured out accordingly and making the whole process getting more robust.Two critical processes,tube-cutting and swaging are studied and improved by using FMEA.Measuring System Analysis(MSA)and Statistics Process Control(SPC)are introduced to study the measuring system and manufacturing process capability,which are improved from 0.5 to 1.43 after taking actions,and long-term stability is realized.By using Control Plan(CP)to integrate all quality tools above,a robust quality control system is formed up.All of these analysis and studies,are helping this company decreasing NG parts as well as customer complaints from 2.5 incidents per month to 0.4.Manufacturing process stability and overall competitiveness with better quality performance are finally realized in this company.