STRUCTURE OF DOWN SPRUE IN METALLIC PATTERN CASTING MACHINE

摘要

PURPOSE:To obtain casting product having stable quality by adjusting reduction or expansion of runner area at lower part of down sprue by an adjusting mechanism to supply pure molten metal into a cavity. CONSTITUTION:The cavity 10 is formed by approaching the upper die 3 and each pattern 4, 5 to the lower die 2 by extending working rods 6-8 and at the same time, the adjusting mechanism 14 is reduced and a sleeve 12 is descended to a position, where a lower moving regulating body 14b collides with a stopper 14a. Next, at the time of supplying the molten metal into a pouring cut 13, as the lower part 11a of down sprue 11 is reduced, the staying time of molten metal in the down sprue 11 is delayed, and so the impurities, such as gas and slag, etc., mixed or generated into the molten metal, floats up to the upper side of down sprue 11. Further, the massive solid impurities are hindered at small gap part of the lower part 11a, to pour the pure molten metal into the cavity. In this way, the pure molten metal is supplied into the cavity and the casting product having stable quality is obtd.