| 摘要 |
<p>PURPOSE:To enable molding of a core with step having uniform strength and good dimensional accuracy by push-compressing part packed in recessed part with step in a preforming body into the desired core shape from upper and lower sides and molding the desired core. CONSTITUTION:A cavity shaped with upper and lower metallic molds 21, 4, compressed lower mold 6 and blow metallic mold 31 is made to the state forming the recessed parts having excess thickness for compression at upper and lower parts of the recessed parts 5, 22 having the same shape as outer shape of the desired core C. Successively, by working a blow tank 30, the green sand is blown and packed into the cavity, and a preforming body having a little larger than the desired core C to upper and lower directions is molded. Successively, the compressed upper mold 23 is positioned at upper part of the upper metallic mold 21 and stopped. Further, a downward cylinder 36 is worked as extending and after inserting the compressed upper mold 23 into the penetrating hole with step of the upper metallic mold 21, a squeeze cylinder 8 is worked as extending, too. By this method, the compressed upper and lower molds 23, 6 are further inserted into penetrating holes with step and the stoppers 35, 10 are abutted on the upper and lower metallic molds 21, 4, respectively, and extending work is stopped. By this working, the preforming body is compressed to the excess parts with the compressed upper and lower molds 23, 6 to compress and form to the desired core C shape.</p> |
