| 摘要 |
<p>PURPOSE:To enable production of a hollow core having excellent strength and collapsing property after use by using green sand by packing the green molding sand into a cavity formed of top and bottom metallic molds, inserting a rammer therein to compress and harden the green sand. CONSTITUTION:Green sand is charged through a supply port 14 into a blow tank 13 in the stage of producing a core for casting by using green sand. A mating cylinder 1 is then moved upward to move upward a bottom metallic mold 3 for the core thereby mating the same with a metallic mold 9 in the upper part. A vent plate 19 is lowered by a cylinder 21 to the opening 18a of the mated mold, and a rammer 22 is ejected to press the plate 19 to said opening 18a. The green sand in the tank 13 is blown and packed into the cavity of the mated mold. The bar 22 is retreated and the plate 19 is pulled; at the same time, the rammer 22 is pushed into the green sand in the cavity. The green sand inserted therein with the rammer 22 is pressed and compressed toward the wall of the cavity, whereby the sand is hardened. The rammer 22 is finally pulled and the core having the hollow part is removed from the metallic mold.</p> |
