| 摘要 |
PURPOSE:To mold simultaneously a top mold and a bottom mold in molding a gas curable casting mold by forming patterns for top and bottom molds with a central partition board as a boundary on the same molding board, putting the board in a molding flask, packing the molding sand in the flask and curing the sand with gas. CONSTITUTION:A partition plate 4 having the height slightly lower than a molding flask 3 is erected at the center of a molding board 2 in the stage of forming a casting mold by the molding sand consisting of a top mold and a bottom mold. A pattern 5 for the top mold as well as a pattern 6 for a sprue, runner and gate are formed on the left side thereof, and recesses 7 for forming dowels are punched at four corners. A pattern 8 for the bottom mold is formed on the right side, and projecting parts 9 for forming dowel holes are provided at four corners. A molding flask 3 is disposed on such molding board 2, and gas curable molding sand is packed therein, whereafter gas such as CO2 is passed through the sand to cure the sand mold. The flask 3 and the board 2 as a pattern plate are removed from the cured casting mold 13, and the mold is bisected to the right and left from the crack generated by the plate 4. The bisected molds are exactly combined with dowels 11 and dowel holes 12, whereby the casting mold is obtd. |
