Research On Numerical Simulation Of The Low Pressure Die Casting Of Automobile Aluminum Alloy Parts

The technology of low-pressure casting is a sophisticated casting method, which advantages are the casting size of high precision, filling smoothly, impurities in casting are little and subsequent processing of the casting is little and so on. Based on the above advantages, the technology of low pressure casting has been widely used in the automotive industry. However, the products are produced by the technology of low pressure casting which prone to shrinkage or cold traps in the actual production process, because the forming factors of technology of low-pressure casting(such as the preheating temperature of mold, pouring’ temperature, filling’s pressure, etc.) are controlled precisely then be able to produce high quality products. With the development of computer simulation technology, computer simulation technology can solve this problem before the actual production of castings can determine the optimum forming process parameters, which can drop the cost of product.Making use of casting simulation software ProCAST for the simulation study of the low-pressure casting of the process of filling and solidification of the end cover ofengine and the automotive transmission housings, combining the basic theory of numerical simulation of filling and solidification process, analyzing the low-pressure casting that the results of simulation of the process of filling and solidification to predict shrinkage and other defects of casting, optimizing casting gating system and the process parameters, establishing a reasonable technology program to meet the business needs of the actual production.The research of several aspects of the paper are as follows:1.Using Solidworks software to build three-dimensional solid modeling of the separator disk of brake and gearbox’s shell, citing third-party software of Geomesh Environment to repair 3D model, so that the model can be successfully imported into MeshCAST to complete finite element model.2. Making use of casting CAE software ProCAST for a variety of casting processes of the separator disk of brake’s simulation, the optimum parameters for the actual number of program was pouring. The result shows that the test castings are basically consistent with the simulation result which proved the reliability of numerical simulation of low pressure die casting, which lay on foundation of low pressure casting process for determining the best case basis of the gearbox.3. According to the characteristics of the gearbox housing of car, designed two gating systems of four inner gates and six inner gates. simulation studies show that the four inner gate of the gating system more conducive to the casting solidification feeding, six inner gate casting gating system more conducive to the smooth filling, by the pros and cons of both gating system shell casting defects amount to be judged under the gearbox, it uses four inner gates to the introduction of the molten metal pouring system is more reasonable.4. On the base of adopting gating system of four inner gates, basing on the numerical simulation of multiple of low-pressure casting process parameters, analyzing the flow field and temperature field of the process of filling and solidification, finding when the temperature of mold is up to 360 ℃, pouring temperature is 710℃, the compression speed is 0.0016Mpa/s, the casting of gear’s shell will get best quality.