消失模负压群铸时大小件之间“争铁液”问题的探讨及应用

Discussion and Application of Vying Liquid Metal between Big and Small Castings of EPC's Group Casting

运用流体力学、传热学原理,分析群铸时液态金属在各型腔内的流动情况,揭示出争铁液现象不仅在大小件混铸时发生,在多个内浇道浇注系统中群铸相同铸件,甚至仅一个铸件仍存在这一现象。顶注不产生争铁液现象,底、侧注时减少横浇道同时充填铸件的数量,使横浇道内金属流速增加越慢,越不易出现争铁液问题。直浇道放在铸件群中部、分层群铸时优先向下层供液,有利于减少相互争铁液现象。

The flow status of liquid metal in the sand box of group casting was discussed according to the fluid mechanics and heat transfer theory. Not only does the appearance of vying liquid metal happen when group casting between the big and small castings, identical castings in the multiple gates system appear too, even one casting. The appearance of vying liquid metal is undetected when top casting is adapted. Decreasing in value of cross gates and moulds brings the speed of liquid metal slowly. The more slowly the speed-up, the few problem appear. The lower of group casting is overflowed on the condition of downsprue in midst, It is favorable for reducing chances of mutual vying liquid metal.