491型发动机缸体、凸轮轴砂芯制芯工艺及模具设计

Sand Care Making Technology and Mould Design for Cylinder Blolck and Camshaft of Model 491 Engine

选用酚醛树脂覆膜砂热芯盒法制作进口491型发动机缸体、凸轮轴砂芯．以国产28025多用途射芯机作为首选机型设计模具。采用水冷射嘴，保证砂芯不残留射口砂柱，射砂方向保证细窄部位成型。模具采用四开模具结构，综合采用倾斜分型、弧面及阶梯分型结构。梯型芯头稳固砂芯，无顶芯机构，采用人工直接取芯。

Hot sand core box method with phenolic resin coated sand is choiced to make sand cores of cylinder block and camshaft of model 491 engine. Domestic model Z8025 multi-application core machine is adopted as the first choice machine type to design mould. Water cooling injection nozzle is used to make sure that no sand stem of injection nozz1e remains on core. Sand injection di-rection is so determined that fine and narrow part of core can be formed complete. Mould is of a construction to be opened on four sides,separating manners of inclind,stepped and arc shaped are comprehensively used. There is core head for fixing the sand core,and no stripping mechanism but direct manual core fetching.