The Manufacturing Quality Improvement Of Medium And Low Pressure Hydraulic Cylinder In H Company Based On Six Sigma Management

Hydraulic technology is not only widely used in various types of mechanical fixed equipment,such as metal cutting machine tools,manipulators,water conservancy projects,shipbuilding machinery and equipment,etc.,but also widely used in various types of mobile machinery and equipment,such as construction machinery and equipment,various civil and military vehicles,etc.,but also widely used in aerospace,ocean and deep-sea operations.This paper takes the medium and low-pressure hydraulic cylinder produced by H company as the research object,and analyzes the whole process of product design,raw materials,machining,assembly,testing,etc.,and according to the manufacturing process of the problem,the Six Sigma Management Quality Improvement Model(DMAIC)is adopted.The quality of the hydraulic cylinder is comprehensively analyzed,and improvement measures are proposed to improve the quality of the hydraulic cylinder.In the definition stage of this paper,through the voice of the customers,combined with the quality feedback sheets of H company and the internal qualification rate record data,the key output variable Y is finally determined,which is subdivided into Y1(hydraulic cylinder oil leakage)and Y2(hydraulic cylinder oil leakage)tank paint peeling.Then define the scope of improvement,establish a quality improvement team,and make an improvement plan.In the measurement stage,the measurement system of the hydraulic cylinder oil leakage measurement system,the inspector’s detection measurement system,and the hydraulic cylinder paint adhesion measurement system are analyzed to ensure sufficient discrimination and accuracy.In the data analysis of the production process ability related to the oil leakage of the hydraulic cylinder and the paint adhesion,it is found that the production process force is lacking,hence it must be improved.In the analysis stage,through the cause and effect diagram,5WHY analysis,PFMEA tool to find the most critical input variable X of hydraulic cylinder oil leakage,through the cause and effect diagram,5WHY analysis,PFMEA tool to confirm the most critical input factor X of the paint adhesion problem,and determine significant factor.In the improvement stage,the significant factors that need to be improved are found through the analysis stage,these input factors are specifically solved,and the process capability before and after improvement is compared through CPK.In the control stage,use the quality control chart to observe the maintenance situation after improvement,document the improvement results,and finally count the economic benefits produced by this quality improvement,and then end the plan.Starting from the actual situation of the factory,Company H proposed the management method of Six Sigma to improve the quality of hydraulic cylinders,and achieved practical economic benefits.This case study can be applied as a reference for counterpart companies and practitioners.