| Owing to the situation of high growth of products,the dominant problem was the quality bottleneck and capacity bottleneck in the process of production.In present paper,in light of the production status of D Company,based on the Six Sigma and lean production concept,DMAIC process improvement,processing unit layout and logistics improvement and pull production system establishment were repectively carried out,which improved the casting quality and production efficiency of roller roller Bearing Seat.(1)Depending on the DMAIC analysis method and tools,the casting pass rate of Bearing Seat was following improved.The key influencing factors was indentified by SIPOC flow chart.Subsequently,CE matrix,FMEA analysis,chi square analysis and other tools were used to determine the main influencing factors of casting defects.Meanwhile,the operation specifications of sand core production,modeling,melting and other casting processes were revised,which made the casting pass rate of Bearing Seat increase from 89.18% to 96.22%;(2)Improving machining unit layout and process flow,to improve production and logistics transfer efficiency.ECRS analysis method was adopted to design optimization and high speed cutting improvement,and put forward three kinds of unit layout plan.Based on quantitative comprehensive evaluation method,optimal layout scheme and logistics flow.As a result,the number of equipment was reduced from 6to 4,and the number of staff was decreased from 10 to 4 in comparsion with the original production pattern of fleet,which lead to the production balance rate increase from 60.5% to 91.67%;(3)Pull production system was to established to attain the integration of improvement and information system.Through the establishment of single-piece flow-pull production mode,the construction of DNC distributed numerical control system,the construction of MES manufacturing execution system,and the integration of DNC and MES,the production process information control and intelligent production scheduling were excuted;(4)The Witness simulation software system is simulated to evaluate the improved layout and logistics operation effect.The software Witness was used for simulation.The simulation of equipment load and logistics on production line was completed through the steps of model establishment,Machine and Buffer design,Path design,Track and Vehicle setting,and operation simulation,etc.,and the operation effect of production line after production and logistics improvement was verified.Following the present paper,the casting quality and production efficiency of roller roller Bearing Seat were subsequently improved,which saved more than 1.4million yuan for D Company.What is more,it has certain practical significance and reference value for the research on the quality and production efficiency improvement of other product.This thesis includes 63 figures,31 tables and 71 references. |
