| 摘要 |
PURPOSE:To obtain a titled shell which hardly requires finishing by blowing sand for shell molding into a metallic mold provided with hollow groove of the hourglass section formed between the joint parts of a pair of molds and heating the sand to cure the same then cutting away the projecting line part on the outside, polishing the inside projecting line part of the shell core obtd. in such a manner and subjecting the same to insert casting into a main metallic mold. CONSTITUTION:The sand 1 for shell molding is blown into the metallic mold 2 having the inside hollow groove 8 and the outside hollow groove 9 to the joint parts 5, 6 of a pair of the molds 5, 6 and is heated to cure. The outside projecting line part 12 is broken from the resultant shell core 10 and the part where the density of the sand 1 is thin is removed together with a flash. The inside projecting line part 11 remaining to the core 10 is then polished away and thereafter the core is put into the master metallic mold 13 and is subjected to insert casting. The casting a14 of the hollow object which has no ruggedness on the inside surface of the hollow part 15 and requires hardly finishing is thus obtd. |
