| 摘要 |
PURPOSE:To prevent penetration of a molten metal into a cooling hole and deformation and to provide a denser, stronger and lighter piston in aluminum casting of the piston by forming a core for internal cooling of a molten salt casting, disposing the core in a casting mold and performing high-pressure casting. CONSTITUTION:Molten salt 31 is poured into the core mold 26 in a molding flask 25 and an annular molten salt core 21 is manufactured. The core 21 is held by a suitable means, for example, by a holding material 20 to a cast annular member 19 having wear resistance and is thus disposed in a casting mold for a piston. Molten aluminum 34 is cast A' under high pressue into a casting mold 11 by a plunger 14. The core 21 prevents penetration and deformation with the high-pressure aluminum and therefore said core forms a good cooling hole. The piston structure is made dense by the high-pressure pouring, by which the strength is improved and the weight is reduced. The insert salt is washed away through a suitable cast hole 35. |
