Casting Process Design And Simulation Analysis For Railway Electric Connector Shells

The end cover and side cover of electric connector shells of rail train are easy to produce shrinkage defects during manufacturing,which seriously affect the quality of the castings so that they do not meet the quality requirements.Therefore,it's necessary to redesign the die casting process according to the shape,size,defect position and defect type found in the original die casting products.In this thesis,the shrinkage defects of the end cover and side cover of the electric connector are reduced through improving the die casting process and using the DOE(Design of Experiment)orthogonal test to determine the most optimal die casting process parameters.By this,the quality of casting products is improved.Under the condition of considering the influence of various factors on the quality of the casting,the shrinkage cavity volume is taken as the experimental index,and based on the DOE orthogonal test,the injection speed,filling velocity,pouring temperature,and tool temperature are used to simulate the flow field and temperature field in nine groups of orthogonal experiments.By the simulation results,the shrinkage cavity volume is analyzed by the range analysis method.It is indicated that the impact degree on shrinkage cavity volume is orderly the injection speed,pouring temperature,filling velocity and tool temperature.The optimal parameters of the die casting process based on the results of the orthogonal experiment are numerical simulated.The results show that,as to the end cover casting,the best result is obtained when the injection speed,filling velocity,pouring temperature,tool temperature are 0.20m/s,31m/s,650°C and 230°C,respectively,and as to the side cover casting,the best result is gained when the injection speed,filling velocity,pouring temperature and tool temperature are 0.12m/s,32m/s,640°C and 230°C,respectively.The shrinkage defects in the end cover and side cover of electric connector shells are distributed in the exhaust and gating systems.Die casting experiments of the end cover and side cover have been done respectively.Then,the die castings are sectioned by the wire cutting and the internal quality of the castings is observed.And no shrinkage defects are found in the products of the castings.