Research On Welding Quality Improvement Of Flow-through Sinks For Model T Of Company Y Based On DMAIC Process

Company Y is a leading enterprise in the domestic bus industry.The model T developed and produced by the company is a high-grade commercial vehicle,which is the star product of company Y.However,this model has the problem of poor appearance.The solder joint defect of the flow-through sinks is an important factor causing the low appearance of the model T.Aiming at the quality of solder joint of the model T,this thesis studies and applies the Six Sigma method and tools to improve the quality of this problem.In this thesis,we firstly collect data to clarify the current situation of the weld joint quality problem in the flow-through sinks,and then introduce the process of Six Sigma DMAIC to improve it.In stage D,a project team is established to formulate improvement goals;in stage M,the reliability of the measurement and analysis system are checked,which use a combination of theoretical test and the Kappa method;in stage A,the brainstorming method,fishbone diagram method,and FMEA are used to analyze the results of the key influencing factors that lead to welding defects in resistance spot welding;in stage I,for the key influencing factors,the project team formulates corresponding improvement measures,and for the most important influencing factor "welding parameters",Y company G division organizes a team to conduct experimental of design,and then combines with Minitab software for data analysis,and obtain the optimal welding parameter configuration model that improve the welding quality effectively.In stage C,the quality management process system is optimized in the management dimension and control measures are established to maintain the improvement results achieved in the business dimension.Subsequently,the project team verifies the improvement content,and compares the obtained improvement data with the data before improvement to confirm the improvement effect of the Six Sigma project.The results show the quality of the solder joints of the flow-through sinks is improved significantly,which prove the effectiveness of the improvement measures.In order to ensure the long-term implementation of the measures,the project team has solidified the standards of each measure and written it into the process system.After the optimization of the process of Six Sigma DMAIC,the G division of the company Y has clarified the direction of quality improvement,and optimized the system and method of quality management.Finally,this thesis summarizes the gains brought to the enterprise for this Six Sigma improvement project,analyzes the shortcomings of this improvement,and look forward to the broader application scenarios of the Six Sigma method.Optimized by the process of Six Sigma DMAIC,not only the welding quality of flow-through sinks of the model T of the company Y has been improved,but also series of process systems have been improved,so that the quality management mode of the G division of the company Y has realized the transformation from product inspection to total quality management.So the purpose of this study has basically been achieved.