GB1337732A - Method of casting pistons - Google Patents

Abstract

1337732 Casting composite pistons ASSOCIATED ENG Ltd 19 April 1971 [21 Jan 1970] 22935/73 Divided out of 1337731 Heading B3F A method of casting a piston in a tubular die formed of an upper part 21 and a lower part 22, comprises separating said upper and lower parts, locating a pre-heated insert 27 in the lower part 22, introducing molten metal into the lower part to cover the insert, bringing the upper and lower parts together and, while introducing further molten metal into the die applying a coolant to the die starting at the base and increasing the length of the die subjected to the cooling action as the level of the metal in the die rises. The die is pre-heated by burners 40 and is cooled by a spray ring 41 and a spray head 37. Molten metal is supplied from a tundish 32 through conduits 34. As the molten metal rises, the die and spray head 37 are lowered relative to the conduits 34 and spray ring 41. The lowering may be controlled by a level sensing device so as to maintain the outlets 35 of the conduits 34 either just above or below the surface of the metal. Directional solidification of the metal occurs. The annular insert 27 is provided with a tapered lower face 30 and is supported by means 29. The bottom of the die may be provided with cooling fins. A sand core is supported within the die by a diametrically extending pin 36a.