在柴油机和 LPG(液化石油气 )发动机中采用轻型活塞极大地提高了发动机的效率。然而 ,在这些发动机中使用铝活塞 ,其缺点是 :压缩环槽易迅速磨损。这一缺点可采用铝镶铸工艺 ( Al- fin process)来克服 ,即 :先在铸型中将铸铁活塞环定位 ,再将铝水浇入。然后在镶环上加工出压环 The use of lightweight pistons in diesel and LPG (liquefied petroleum gas) engines has greatly increased engine efficiency. However, the use of aluminum pistons in these engines has the disadvantage that the compression ring grooves tend to wear quickly. This disadvantage can be overcome by the Al-fin process, which involves locating the cast iron piston ring in the mold and then pouring aluminum water. Then in the ring machining ring