The Simulation Analysis On Low Pressure Die Casting Of The 3S4G Engine Cylinder Head And The Study On The Heat Balance Of Dies

As the important component of the vehicle system, the quality of the engine cylinder head influences directly the performance and production cost of the car. The manufacture level of the engine cylinder head is the important sign of the national manufacturing industry. They have represented the development level of a national auto industry. Facing the enormous pressures of the improvement of the market requirement for the cylinder head casting, the domestic and international enterprises adopt different casting methods and casting technology to improve the quality of the engine cylinder head, and used the computer-aided technology to modify and optimize casting technology.The paper studied the low pressure die casting process of 3S4G engine cylinder head via numerical simulation. According to the solidification principle of low pressure die casting process, the paper studied the solidification process of 3S4G engine cylinder head via numerical simulation with Anycasting software. The problem has been found in the existing method, and the research was carried on the element which influenced the quality of the castings assisted by numerical simulation. The following is the optimization methods:①Changing the pressure parameters to ensure the steady filling and effective solidification feeding. The changed key parameters include the lift time of 12s, the holding pressure of 1.53 kgf/cm2.②Setting up the cooling pipes to ensure the sequence solidification. The added pipes include ten water cooling pipes in the upper mould, three water cooling pipes in the side-mould, and two wind cooling pipes in the lower mould.③Changing the preheating temperature of the mould to ensure the sequence solidification. The parameters include 250℃of the upper mould, 390℃of the lower mould.④Add the heat insulation sleeve on the runner to ensure the runner becomes the last solidification area.The paper also studied the hot spot forming tendency during solidification of AC4B Aluminum alloy in permanent mould casting with the dies of different wall thickness via numerical simulation with Anycasting software. The results show that:①In a single cycle casting, the increase in the thicknes(s3mm～18mm) enhances the cooling ability of the mould and promotes balanced solidification in a certain degree.②In multi-cycle Casting, the thickened die-wall gradually loses its localized chilling effect. In contrast, the die with a decreased wall thickness in a certain range is easier to achieve the desired solidification balance.③During the cycle casting, the mould has already achieved the heat balance after the 7th cycle casting. The heat balance temperature of the reference sample is 182℃.