MANUFACTURE OF LOST FOAM PATTERN WITH NC MACHINING

摘要

PURPOSE:To shorten machining and manufacturing time and to improve accuracy of a pattern by machining a fitting part of the patter for constituting parts at the same time of manufacturing the main pattern with an NC machining. CONSTITUTION:A block of foamed styrene is machined with the NC machining to obtain lost foam pattern 2 for casting metallic mold. The pattern 2 is composed of the metallic mold part 3 and a thick plate like base plate part 4 formed at base part thereof, and at both side face 5 of the base plate part 4, the pattern for constituting parts, e.g., the fitting parts 6 to the base patterns 7 for fitting hooks for hanging the metallic mold, are bored. At the time of executing the NC machining to the pattern 2, machining position and machining to the fitting part 6 are beforehand programmed so as to execute the machining at the same time, and based on the program, at the same time of machining to the metallic mold part 3 and the base part 4 in the pattern 2, the fitting part 6 is bored. Into this fitting part 6, the pattern for constituting parts, e.g., small diameter shaft part 7b of the base pattern 7 for fitting the hook for hanging the metallic mold and having tapered head part 9a is inserted, and stuck and fixed with adhesive, and the fitting base pattern 7 is formed with the same material as the pattern 2. By this method, the main pattern fitting the pattern for constituting parts is obtd.