壳型填铁丸工艺条件下凸轮轴凝固温度场测试及分析

Testing and Analysis of Temperature Field of Camshaft during Solidification Produced by Shell Mold with Iron Shot Backing

为找出壳型填铁丸底注立浇工艺国产化捷达轿车凸轮轴生产中热裂缺陷产生的原因,对该工艺下凸轮轴的凝固温度场进行了测定。结果表明:在该工艺条件下,充填过程中温度损失速度较快,达到14℃/s;凸轮轴的凝固顺序为从上往下,冒口径封闭的时间较早,起不到很好的补缩作用,促进了热裂缺陷的产生,这为铸造工艺的改进提供了实验依据。

To disclose the reasons of hot-tearing of camshaft produced by bottom gating system and vertical casting process, the temperature field of the camshaft under the above technique conditions was tested. The test results show that the decreasing speed of temperature is fast during filling, which is 14°C per second. The solidification sequence of camshaft is from top to bottom. The time to close of riser-neck is easier, so riser could not feed very well, which contributes to the hot-tearing of the upper set of cam of the camshaft. The test basis was provided to improve casting technique in the future.