Cambered core positioning for injection molding

摘要

Disclosed is a system for precisely locating a cambered ceramic core within the cavity of an injection molding die, such as is used to form patterns for lost wax method casting of gas turbine airfoils. A combination of at least two independent sets of locators are used: one set of at least three is fixed and contacts the periphery of the core while the other set of at least two is movable and engages the centerline of the core. The two sets independently limit the various degrees of core freedom and maintain its position during injection molding. The concave side of the core is preferably contacted by the fixed locators since this biases deviations into the convex side of the part from which excess deviant material is more readily moved.