| 摘要 |
PURPOSE:To ensure dimensional accuracy of a piston and reduce its manufacturing cost, by forming the piston in fine composition with high specific gravity further a combustion chamber left as holding a casting surface. CONSTITUTION:A piston, using a vertical type pressurization casting device, charges inside a preheated metal mold for gasoline engine piston casting under pressure with a melted alloy consisting of 13-16% Si, 0.8-4.0% Cu, 1.0-3.0% Ni, 0.6-1.3% Fe and the rest of Al. After the metal mold is charged with the alloy, local pressurization is applied to a thickness part. Here the piston, in order to form a combustion chamber 2 left as holding a casting surface, uses a metal mold of tungsten alloy material with high thermal conductivity further cools the metal mold to decrease its temperature by water cooling or the like, forming especially fine chilled composition 6. |
