论砂型铸造铸件下箱优先设置

Discuss on Lower Case Setting Priority in Sand Casting

简述了发动机缸盖类铸件、轮类铸件、框架类铸件、泵壳阀类致密性铸件等几种典型铸铁件采用将铸件分割置于上、下型的做法,甚或是铸件全部设置于上型的工艺方案,分析了其容易导致气孔、浇不足、冷隔、缩孔、缩松、错边等铸造缺陷的原因。采用铸件全部设置于下型的工艺方案后,因其具有型腔排气充分、可优化设计浇注系统、可优化设置冒口系统、铸件错箱缺陷少、铸件加工余量少等优点,生产实践表明,采用此工艺后铸件合格率大幅提高,可获得内部组织更加致密、外形更加美观的高品质铸件。

The casting division crafts of several typical cast iron like engine cylinder head castings,wheel castings,frame castings, pump casing valve dense castings into mold cover half and bottom half or all in mold cover half was briefly described. The reason of casting defects like blowholes,misrun,cold shut,shrinkage cavity,porosity and mismatching were analyzed. The process plan of putting all cast in the bottom half mold can optimize gating system and riser system while reduce the allowance and mismatching. It is proved in actual production that the pass rate of casting increased a lot and make the refinement microstructure, good shaped, high-quality castings available by using this technology.