Numerical Simulation And Process Optimization Of Tilting Casting For Aluminum Intake Pipe Of Diesel Engine

Intake pipe is an important part of diesel engine,its main function is to evenly distribute the air to each cylinder.In order to meet the requirements of automobile lightweight design,more and more automobile manufacturers use aluminum alloy instead of cast iron to make diesel engine intake pipe.Compared with conventional gravity casting,permanent mold tilting casting has the advantages of more reasonable solidification sequence,smooth filling,smooth exhaust and stable quality,which has been used in the production of intake pipe parts by most manufacturers.However,in the tilting casting of aluminum alloy intake pipe,most of the manufacturers refer to the traditional experience for trial production many times.The production efficiency is low,the casting defects are difficult to predict and eliminate,the product quality is difficult to control,and the rejection rate is high.Casting CAE is an important method to predict casting defects,analyze and control forming process and optimize forming process.Aiming at the quality problems of aluminum alloy intake pipe of a six cylinder engine in Weichai,the numerical simulation analysis and process optimization of aluminum alloy intake pipe casting process were carried out by using Pro CAST.The specific research work and results are as follows:(1)The alloying component of ZL107 alloy was measured by spectrometer,and the influence of chemical elements on the properties of the alloy was analyzed.The composition and mass fraction of ZL107 alloy were input on JMat Pro to obtain the thermophysical parameters of ZL107 alloy.Based on the analysis of ZL107 alloy phase diagram and actual production,the pouring temperature of ZL107 aluminum alloy was determined to be 720 ℃.(2)According to the original process,the numerical simulation analysis of the tilting casting process of ZL107 aluminum alloy intake pipe shows that the shrinkage and shrinkage hole defects appear in many thick parts of the casting,which is consistent with the defects found in the actual production.The causes of the casting defects were obtained.The simulation validity of the casting process of ZL107 aluminum alloy intake pipe tilting casting by Pro CAST software was proved.(3)The orthogonal numerical simulation experiment scheme of the intake pipe tilting molding was designed and the orthogonal numerical simulation was completed.According to the results of the orthogonal simulation,the influence of the process parameters on the casting defects was analyzed.It is found that different pouring process parameters have different influence on the volume of shrinkage and shrinkage hole.The influence of mold temperature > pouring temperature > tilting speed >pouring cup temperature;The optimum process parameters were obtained: pouring temperature 740 ℃,top mold preheating 400 ℃,bottom mold preheating 350 ℃,tilting speed 9.0 °/s and pouring cup preheating 300 ℃.(4)The casting technology of ZL107 aluminum alloy intake pipe was improved by using the numerical simulation results: chilling the thick wall,modifying the structure of pouring and riser system and insulating the pouring riser system.According to the improved process and optimized process parameters,the numerical simulation of aluminum alloy intake pipe tilting casting was carried out.It is found that the solidification sequence of the optimized casting was reasonable,and the shrinkage porosity caused by local hot spot disappeared.The purpose of process optimization was achieved,and verified by actual production.The actual production efficiency and casting yield are improved.