| 摘要 |
PURPOSE:To obtain a neck down core having an excellent rupture characteristic by manufacturing a core of a heat insulating material or joining a heating element to the core consisting of the heat insulating material or adhering a sand mold to the body side of the casting. CONSTITUTION:A heat insulating core 10 formed of a refractory material and inorg. and org. fiber and binder materials is provided between a casting body 2 and a riser part 1 and if the thickness T of the core is made the same as the thickness of a sand mold core, the diameter N1 in the neck part 11 of the core 10 is made considerably smaller than in the case of the sand mold core. Since the core has good heat insulating property, the feeding of the riser 1 is good and the rupture characteristic of the riser 1 by hammering is remarkably improved. The much better result is obtd. if a heating material 17 is adhered to the inside of the core 10. The deflectless casting is thus manufactured. |
