Research On Casting Simulation And Thermal Deformation Of Aluminum Alloy Shock Absorber Tower

As a connecting part between the shock absorber and the car body,the shock absorber tower is under very complicated working conditions and bears very large loads.Aluminum alloy shock absorber tower has become one of the research contents of automobile lightweight in recent years because of its light weight and high strength.Aluminum alloy shock absorber tower needs strengthening structure because of hollow structure,considering its structure and performance requirements,it is appropriate to use the casting process to manufacture it.There are many kinds of casting processes,each has its own advantages and disadvantages.However,the low-pressure die casting process has the advantages that the casting parameters can be adjusted,the quality of the produced castings are pretty good and the cost is relatively low,so this paper intends to use the lowpressure die casting process to simulate the casting of aluminum alloy shock absorber tower.Low-pressure die casting is a process in which molten metal is charged into a metal cavity under gas pressure and formed into a casting under a certain pressure.During the filling process,there may be phenomena such as air entrapment,insufficient pouring and excessive fluctuation of the molten metal,which leads to serious defects such as shrinkage and porosity of the casting,so it is necessary to optimize the filling process parameters.At the same time,the process of the metal changes from liquid to solid will release a large amount of heat,which involves the thermal deformation of the casting,and affects the installation of the parts.Therefore,the thermal deformation is one of the important issues determining the quality of the casting.The research in this paper will be carried out in the following three aspects:(1)According to the spatial arrangement of the shock absorber tower,following the structural design principle under the low-pressure die casting process,and combining the characteristics of the aluminum alloy material,the three-dimensional model of the aluminum alloy shock absorbing tower is designed.The strength and stiffness of the aluminum alloy shock absorber tower are verified by finite element analysis to ensure that its performance meets the requirements.(2)Based on the structural characteristics of the shock absorber tower,the casting system will be designed,the pressure and time of the five stages in the filling process will be calculated,and the pressure process curve will be drawn.ProCast is used to simulate the filling and solidification process of the shock absorber tower.Exploring the influence of process parameters such as pouring temperature of metal liquid,preheating temperature of mold and the time of filling stage on the porosity volume of castings,and finding a better combination of parameters by orthogonal test to ensure the quality of aluminum alloy shock absorber castings.(3)The mechanism of thermal deformation of castings will be studied by analyzing the structural factors such as casting radius,ribs,length and width,and the influence of material parameters such as elastic modulus and thermal expansion coefficient on deformation.Based on the deformation mechanism,the thermal deformation control and optimization scheme of the shock absorber tower is proposed.The low-pressure die casting simulation of the modified shock absorber tower is carried out to ensure that the entire filling process is stable,and the porosity volume after the complete solidification is small.Finally,the finite element analysis of the thermal deformation of the shock absorber tower before and after the structural modification to ensure the effectiveness of the proposed thermal deformation control scheme.