Analysis And Improvement Of Machining Quality Issues Of Hydraulic Turbine Head Cover

Hydropower station is vital for the people and country,solid quality is the eternal pursuit of hydro turbine.In this paper,the quality of the turbine in the customer site feedback and data survey,found that the machining quality of turbine Head Cover is the most prominent.The analysis and improvement of the machining of Head Cover is of great significance to the hydraulic turbine and machining field.This article has the following main points.Firstly,Base on the quality problem and customer requirement of head cover,the position and function of Head Cover in the hydraulic turbine and the internal structure,components are introduced.The machining process,the failure mode,the quality risk and the key dimensions of Head Cover are analyzed.And aiming at the problem of project quality cost calculation,the quality cost model(internal failure cost,external failure cost,cost of prevention and identification)was used to provide the basis for quantitative analysis of the effect of the top cover project improvement and quality cost.Second,In view of the traditional problem of Single piece and small batch,Six Sigma,total quality management and zero defect theory were adopted synthetically.The overall quality management and zero defect prevention was used as a guiding ideology,six sigma project management was used as a improvement method,and all kinds of quality tools was used as a specific tools to analysis and improve quality.Finally,The system diagram and 5Why method were used to study the 30 root causes of machining quality problem.And the value engineering is applied to the priority of 30 improvement measures.Base on implementation follow-up and effect verification of measures,perform the standardization of procedures to consolidate the improvement.The practical project of this paper had accomplished the project target(cost rate and defect rate decreased by 50%).In order to continual improve,the QC team was set up,8D and FMEA were used to solve and prevention of quality problems,in order to achieve total quality management in the whole hydraulic turbine machining process.