The Die-casting Forming Numerical Simulation Of Motorcycle Engine Left Cover And The Analysis Of Die Failure

The left cover of the Motorcycle engine which has complex structure requires highquality demand of appearance and achieves a certain strength and hardness. A higherrequest was put forward to the die casting process. This paper was based on the problemsof low yield, the failure of the die and more shrinkages existing in the casting during theproduction process of the motorcycle engine left cover. The casting simulation softwareAnycasting was applied to assist in the optimization design of die structure, theoptimization of process parameters，the analysis of the die the failure, aiming at improvingthe quality of castings and increasing production efficiency.According to the current process conditions，The filling process and solidificationprocess of the casting was simulated by Anycasting. The results showed that there existedthe phenomenon combined of eddy current and the trapped gas in the filling process.Defect prediction results were in conformity with actual.Based on the simulation results,the die structure was optimized. In order to avoid the eddy current phenomenon during thefilling process， the channel size and the feeding way was changed. For the purpose ofreducing the trapped gas in the filling process, the thickness of the ingate was changed. Thecooling channel was designed to improve the internal heat circulation of the die andimprove the quality of the casting and the production efficiency.The position of theoverflow was adjusted and the local cooling device was increased to enhance the exhaustcapacity and local temperature adjustment ability of the die system.The orthogonal test was designed by pouring temperature, filling velocity, slow andfast shot distance as the factors influencing the quality of castings.From the experimentresults the optimal parameters were obtained.the pouring temperature is640℃, the fillingvelocity is3m·s-1, slow and fast shot distance is350/70.The range results showed that theeffects of pouring temperature on the quality of the products is the most significant; thesecond is the filling velocity, finally is slow and fast shot distance. According to theorthogonal test data，the effect of these three factors on the quality of the products wasanalyzed.The optimization of casting was carried out and compared with typical section of theoriginal process.The results showed that the shrinkage and the shrinkage porosity had been greatly improved. Through analyzing the ingredient of material, hardness, microstructureof the failure location, morphology of the failure parts, energy spectrum and the simulationof the die temperature distribution which was combined with practical processparameters.We can conclude that the reason for the die failure is the result of the internalstress caused by thermal cycle and erosion of the molten metal.