一种能提升重型柴油机铝活塞毛坯铸造成品率的模具改进技术

An Improved Die Technology for Improving the Casting Yield of Heavy Duty Diesel Engine Aluminum Piston Blank

重型柴油机铝活塞同普通汽油机铝活塞相比有许多不同,重型柴油机铝活塞的重量是普通汽油机的5~8倍,为了提高耐磨性能,铸造时需要在柴油机铝活塞毛坯中镶嵌合金耐磨圈。重型柴油机气缸中燃烧产生的热量非常高,需要对活塞进行强制冷却,为此目的还需要在柴油机铝活塞毛坯内部开设内冷油道。重型柴油机铝活塞铸造存在合金耐磨圈镶嵌位置左右偏移、上下移位,与铝合金结合面脱落。活塞盐芯铸造过程中存在安放位置上浮、开裂,与铝合金结合面飞边严重,铸造成品率低等问题。针对重型柴油机铝活塞难以做到高率、高成品率铸造的问题,深入研究铸造工艺与模具结构关系,多次铸造实验和探索,改进外模外形结构、加工工艺,改变芯模、盐芯销组件结构。获得了一种能大幅度提升重型柴油机铝活塞毛坯铸造成品率的模具改进技术。

There are many differences between heavy duty diesel engine aluminum piston and common gasoline engine aluminum piston.The weight of heavy duty diesel engine aluminum piston is 5~8 times of that of common gasoline engine.In order to improve the wear resistance,it is necessary to insert alloy wear ring in aluminum piston blank of diesel engine during casting.The heat produced by combustion in the cylinder of heavy duty diesel engine is very high,so the piston needs to be forced cooled.For this purpose,it is also necessary to set up an internal cooling oil channel inside the aluminum piston blank of the diesel engine.In heavy duty diesel engine aluminum piston casting,the inlaying position of alloy wear ring is shifted from left to right,up and down,and the joint surface with aluminum alloy falls off.There are some problems in the casting process of piston salt core,such as floating and cracking,serious flash on the joint surface with aluminum alloy,and low casting yield.In view of the problem that it is difficult to cast aluminum piston with high yield and high yield for heavy duty diesel engine,the relationship between casting process and die structure is studied in depth,casting experiments and exploration are carried out for many times to improve the external mold structure and processing technology,and to change the core mold and salt core pin assembly structure.A die improvement technology which can greatly improve the casting yield of heavy duty diesel engine aluminum piston blank was obtained.