改善缸盖内腔清洁度的措施

介绍了缸盖内腔的结构,分析了内腔粘砂和披缝等缺陷的产生原因,认为导致靠近热节部位粘砂的原因是该部位靠近内浇道,受热时间长,铁液冲刷力较大;气门座之间的部位产生披缝和粘砂的原因是该部位砂芯很薄,组装砂芯个数多等原因造成局部配合间隙大。最后通过采取以下措施使缸盖内腔质量得到改善:(1)在粘砂部位涂抹含有锆英粉等高耐火性能材料的涂料膏;(2)增加易粘砂部位涂料次数,局部增加涂层厚度;(3)采用性能稳定的原砂配制水套用芯砂。

Measures to Improve Inner Cavity Cleanness of Cylinder Head

The inner cavity configuration of the cylinder head casting was introduced and the reasons causing defects such as burning-on and finning etc were analyzed. It was considered that the reason causing burning-on near to the hot spot was that this location was near to the ingates and therefore,had been heated for a long time,and the iron melt stream force washing this location was relatively strong;the reason causing finning and burning-on in the area between gas valve seats was that the core thickness at this area was very thin,and the cores assembly was consisted from a large number of cores and resulting that the gap between cores being locally too big. Finally the inner cavity quality of the cylinder head has been improved by adopting following measures：（1）applying the location easy to be burned-on with the coating paste containimg high refractory material such as the zircon quartz;（2）increasing thickness of the coating layer by using pre-coating method;（3）preparing the core sand with raw sand having stable properties.