Numerical Simulation And Craft Researching Of Die-casting Filling And Solidification Process Of Automotive EGR Valve Seat

The Automotive EGR valve seat is an important part of exhaust gas recirculation system.Structure of the seat is complex,the quality will also affect service life of automobile waste recycling system directly.In traditional pressure casting process of automobile EGR seat,design of die casting process is usually based on experience of the designer.Therefore,it needs continuous tryout and adjustment,which greatly increases the manufacture lead time for the product,and reduces the die casting manufacture efficiency.In additional,quality of the automobile EGR valve seat is always poor.In order to improve the quality of automotive EGR valve seat,and make it meet the development tendency of automotive lightweight,this paper analyzed the structure of automobile EGR valve seat according to the working environment,and uses computer numerical simulation technology to simulate the mold filling and solidification process.Numerical simulation can not only simulate the process of die casting,but also predict the location and number of defects quite precisely.Designers can modify the die casting process according to the simulation results,which can effectively shorten the production trial cycle,and also ensure the quality of castings,prevent or reduce defects.In this paper,numerical simulation of mold filling and solidification process for automobile EGR valve seat was carried out.According to the simulation results,corresponding die casting process scheme was selected.Taking the pouring temperature,mold preheating temperature,injection rate,gate length,gate width and gate thickness as factors,taking the solidification time,filling time,volume of gas and shrinkage as evaluation indexes to establish six factors and three levels orthogonal matrix.Using ProCAST numerical simulation software to run numerical simulation for 18 groups orthogonal experiment,afterwards according to the simulation results,determine the final die casting process scheme and the optimized technological parameters.The optimal gate size according to the simulation are: inner gate length is 2.5mm,inner gate width is 17 mm,and gate thickness is 2.6mm;The optimal technological parameters are : Injection speed is 1m/ s,mold preheating temperature is 190?,and the filling temperature is 620?.Based on the optimal process parameters and die casting process scheme,use AutoCAD software to design the mould of the automotive EGR valve seat.Samples were manufactured by casting,and metallographic experiment was implemented on samples.Results show the manufactured valve seat qualified,which proves the correctness of the simulation results,and can be applied to real production.