| 摘要 |
PURPOSE:To prevent lack of strength of a casting mold and molding defect by inserting a rammer into the cavity through the aperture at the top surface while the aperture at the bottom surface of a core box packed therein with green sand is held closed and opening the aperture at the bottom surface upon descending to a prescribed position so that the tip of the rammer is projected to a prescribed size. CONSTITUTION:A rammer 46 is inserted into the cavity 8 of a mated core box 6 packed therein with green sand to compress and cure the green sand and thereafter the rammer 46 is removed from the box 6, by which the green sand core in molded. The aperture at the bottom surface of the box 6 packed therein with the green sand is closed by a mechanism 18 for opening and closing a shielding plate in this stage and the rammer 46 is inserted through the aperture at the top surface into the cavity 8. When the rammer 46 moves to the prescribed position of the cavity 8, the mechanism 18 is actuated to open the aperture at the bottom surface. The rammer 46 is further lowered so that the tip thereof is projected from the aperture at the bottom surface. |
