| 摘要 |
PURPOSE:To prevent the generation of scabs and to obtain a defectless casting by using refractory bricks for at least part of a sand mold core for forming a sprue and plural radial runners from the bottom of the sprue into the hollow part of a vertical centrifugal casting mold. CONSTITUTION:The molten metal flowing in the runners 4 extending radially from the sprue bottom exerts the large face pressure to the surface of a gate 5 particularly opposite from the rotating direction of the mold and therefore the sand on the surface is scraped away and the scabs 6, 7 are generated. The refractory bricks having the higher face pressure resistance than the face pres sure resistance of the sand mold are therefore used. The refractory bricks are required to be used in the form of a molding in order to withstand the high face pressure and may be fixed shape bricks 8 to be embedded into part of the gate 5 of the sand mold or the entire part of the gate 5 may be made of the refractory bricks. If the bricks 8 are made into a fixed size, the bricks are usable as general-purpose bricks and if the entire part of the gate 5 is made of the refractory bricks, the sand inclusion is thoroughly prevented without sand spilling to the core bottom, etc. |
