Method for expanding tubular blanks

摘要

A method and apparatus for expanding a tubular workpiece which includes mounting the workpiece in a lower die, filling the workpiece with fluid and engaging the upper portion of the workpiece with an upper die. The upper die is moved downwardly acting to physically compress the workpiece. The dies are additionally configured to form an internal pressure cavity such that further downward displacement of the upper die creates an internal pressure forcing the workpiece outwardly into the desired end configuration.