APPARATUS AND METHOD FOR HYDROFORMING

摘要

An apparatus and method for forming a complex-shaped frame member from a blank tube (20) having opposed ends are provided. The blank tube is placed in a first cavity (22) on a lower die (12). An upper die (14) is lowered from an open position to a close proximity to the lower die. The upper die has a second cavity (24) aligned with the first cavity. A pair of sealing units seal (32) the opposing ends of the blank tube, and a fluid delivery means for communicating a fluid into the tube. A fluid control means (56) pressurizes the fluid in the tube to a low pressure level. A position determining means determines a distance separating the upper die in the closed position from said lower die in the lowered position. A lower die lifting means (36) raises the lower die from the lowered position the determined distance to the lifted position. The fluid control means then pressurizes the fluid in the tube to expand the tube to conform to the forming cavity.