降低油底壳压铸件废品率的工艺改进

Technological Improvement of Decreasing Reject Percentage of Die Casting Oil Sump

在油底壳压铸工艺中,原浇注系统采用扇形浇道、分区填充,产品气孔、缩孔严重,总泄漏率达21%。通过切断渣包集中排气,改变横浇道,增加局部冷却,减少加工余量,产品外观改善,泄漏率略有降低,但内部品质没有改观,总泄漏率仍高达18%。压铸过程模拟后,发现易于卷气、缩孔导致泄漏的部位,采取调整进浇位置和溢流槽位置、适当增大压铸机二快速度、减少留模时间等措施,产品内部质量大为改观,总泄漏率降至2%,总废品率也由原来的24.5%降至现在的5.1%。

The shrinkage hole formed at oil sump by pouring liquid aluminum alloy from A direction,resulting in the leakage rate of the oil sump more than 20%. The position where shrinkage hole easily exist was determined by numerical simulation and product validation. Based on above analysis,the processing parameters and position of overflow tank were adjusted with adopting B direction pouring,eliminating obviously shrinkage hole defects and improving the quality of die castings.