| 摘要 |
PURPOSE:To easily execute the venting and to prevent the development of blow casting by composing of an expendable pattern forming venting hole. CONSTITUTION:The pattern 12 is laid in granule 6 together with a runner 2, gate 3 and riser 4, and at the same time of pouring molten metal from a sprue 2a, the molten metal is poured into the pattern 12 through the gate 3, and the pattern 12 is burnt and gasified. The gas generated by burning and gasifying is easily exhausted to the air through venting hole 13 formed in the expendable pattern 12 and through the riser 4. In this way, the development of defects, such as blow casting, etc., is prevented, and extremely thick shape or thin casting is formed and the full mold product having good quality is obtd. |
