Workpiece manufacturing method, involves axially compressing molding blank by sealant in end and simultaneously sliding to final dimension when inner fluid pressure is increased beyond flow limit of material

摘要

The method involves inserting a tubular hollow profile molding blank into a two-piece tool. The blank is subjected with high inner fluid pressure in an inner side and is widened in the gravure or complete workpiece-geometry of the tool. The blank is sealed at ends during opening of the tool and is set under internal pressure which is less than flow limit of material. The tool is closed after setting of negative pressure. The blank is axially compressed by a sealant in an end and is simultaneously slid to final dimension when inner fluid pressure is increased beyond the flow limit.