Study On Investment Casting Technology Of Automobile Wheel Based On Numerical Simulation

This paper aims at the problems of long research and development cycle,high production cost,cumbersome machining,limited modeling structure of more or less existing wheel manufacturing processes at home and abroad.With the finite element numerical simulation software as the tool,the 3D printing white mold combined with the gypsum mold investment casting process is proposed.through the design of wheel,calculation of pouring system,simulation analysis of different schemes,optimization of orthogonal test parameters,3D printing white mold,casting pouring and performance inspection,a series of process schemes are studied,it is planned to explore a production method that is more suitable for the customization of single sets or small batches of personalized wheel,which enriches the production process and improves the economic benefits and market competitiveness.The main research contents are as follows:(1)Using three-dimensional modeling software to draw a three-dimensional modeling drawing of the wheel,centering on the size and structural characteristics of the wheel,the process design of the plaster casting of the wheel is carried out,and the processes such as the shrinkage rate of the casting,the casting slope,the casting fillet and the machining allowance are determined Parameters,design and theoretical calculation of the pouring system and riser,and put forward three pouring schemes of bottom injection,side injection and top injection.(2)Based on the finite element numerical simulation software,through the comparative analysis of filling process,solidification process and probability defects of three different pouring schemes.The results show that: there are large shrinkage cavity defects at the wheel disc of the bottom pouring scheme,and the corresponding wheel axle hole position can not guarantee its mechanical properties;compared with the bottom pouring scheme,there are shrinkage cavity defects at the wheel disc of the side pouring scheme,the hole defect volume is small,but the overall mechanical properties of the casting can not be guaranteed,the top pouring scheme has completed the feeding effect on the slag collection of the casting,and the casting has no obvious defects,so the scheme is determined to be the actual production pouring scheme.(3)There are designed three factors and three levels orthogonal experiments to optimize the pouring temperature,preheating temperature and pouring speed of the top pouring scheme.The range analysis shows that the pouring temperature has the greatest influence on the casting defects,followed by preheating temperature,and the pouring speed is the smallest.The optimal production process parameters are determined: the pouring temperature is 735?,the preheating temperature is 270?,and the pouring speed is 15cm/s.(4)Using 3D printing technology to obtain the white film prototype of the wheel,through the process of wax dipping,gypsum grouting and baking at 45? for the second time at low temperature to prepare the gypsum shell,casting and cutting the redundant casting system under the condition of vacuum degree less than0.02 MPa.Through the performance test of the wheel casting,X-ray examination shows that there are no obvious pinholes,shrinkage porosity and shrinkage cavity,cracks,strip bifurcation and other defects in the wheel.The mechanical property test shows that the tensile strength of the sample is 255 MPa,the yield strength is 235 MPa,and the elongation is 8%,which satisfies the requirements of the specified performance index.It is verifies the feasibility of manufacturing wheel by 3D printing white mold with gypsum investment casting technology.