JPS6444244A - Pouring production of sand core - Google Patents

Abstract

PURPOSE:To easily produce a sand core having an intricate surface shape by pouring a fluid system sand prepd. by kneading proper ratios of water and water glass into a water permeable core mold consisting of split molds and removing the additive water by centrifugal dehydration, then blowing CO2 to the core mold. CONSTITUTION:The system sand having the cement milk-like flowability is prepd. by kneading about 10vol.% water glass of a slightly excess ratio and water of nearly the same ratio. This system sand is poured through a pouring port 3 and is packed into the core 1 consisting of the water permeable split molds provided with numerous fine pores 2 through which the water bleeds out. The addive water in which nearly the excess ratio of the water glass is dissolved is then removed by a centrifugal dehydrator 4 to eliminate the flowability. CO2 is blown into the core mold 1 to solidify the water glass and thereafter, the mold 1 is split and the product is taken out. The sand core having the intricate surface shape is thereby obtd. without requiring skill.