| 摘要 |
PURPOSE:To surely execute even the molding having the narrow part and the depression part, by molding a reducing pressure mold by fitting an insert having a sloping face with the prescribed angle at the narrow part of the cavity. CONSTITUTION:A main pattern 1 and an auxiliary pattern 2 are matched and the cavity having the narrow part at the upper part thereof is formed and a molding film 5 is adsorbed. And, the insert 6 having the sloping face with larger angle than the angle of repose of the granular material for the lower face thereof, is fitted at the lower part of the auxiliary pattern 2. Then, the flask is laid to fill up the granular material 8 and a shield film 9 is covered, to harden under the reducing pressure and to form the drag. At the same time, the cope is formed and after forming the cavity by matching the both molds, molten metal is poured to obtain the product. Therefore, even if, in case of existence of the sloping face having the smaller angle than the angle of repose of the granular material or the depression part for the upper face of the cavity, the sure molding of the reducing pressure mold is obtd. |
