Numerical Simulation Of Die Casting Process For A-alloy Cylinder Block Of Automobile Engine

Die casting is a metal forming method with high production efficiency, high production quality and high precision. In this paper, the A-alloy engine cylinder block is regarded as the research object. The software ProCAST is employed to simulate the filling and solidification process for die casting. Through the study of numerical simulation, it can guide to fix a more reasonable die casting process, improve the casting quality and reduce the time of design the mold, and then can guide actual production.The cylinder block is a dissymmetrical structure and different height and thickness die casting. It is very difficult to product. In this paper, based on the structure of cylinder block, the gating system and overflow well are designed. Based on the process of die-casting and technical parameters, the cold-chamber die casting machine J11110G is chosen. Then two different gating position projects are designed. The virtual mold technology of ProCAST is employed to simulate the process. Through comparing with the forming of gas trapping and shrinkage porosity in the two projects, the project whose gating position is on the bottom of cylinder block and whose pouring angle is 45 degree is chosen.By use of orthogonal test design, how the injection speed,pouring temperature and mold temperature effects the casting shrinkage porosity forming is studied. The results show that mold temperature is the most significant influence factor, injection speed takes the second place, and pouring temperature is the least significant influence factor. The project that injection speed 4.5m/s, pouring temperature 680℃, mold temperature 240℃is the best one that the shrinkage porosity is the least. Then, three projects that the gate dimension is 579mm2, 600mm2, 621mm2 respectively are simulated and analyzed. The results show that the project of gate dimension 621mm2 is the best one that casting defect is the least. Finally, the die-casting mold and two different cooling channels are designed.The heat balance and thermal stress of the die-casting mold is studied. The results show that adopting a good cooling channel project, the mold temperature can be controlled in a reasonable range and the thermal stress of the mold can be reduced greatly.Based on the numerical simulation study, an appropriate process parameter can be fixed: gating position is on the bottom of cylinder block and pouring angle is 45 degree, injection speed 4.5m/s, pouring temperature 680℃, mold temperature 240℃, gate dimension 621mm2, the cooling channel crossing the core. This process can reduce the gas trapping and shrinkage porosity, and prolong the mold operating life.