摘要 |
PROBLEM TO BE SOLVED: To provide a hydroforming method capable of forming a tube upto a large expansion ratio without causing a burst or buckling and also to provide a die for the purpose of implementing the method. SOLUTION: In the hydroforming method in which a metallic tube 1 is added with an inner pressure and a thrusting force in the tube axial direction after mounted in the dies 7, 8 and clamped, the metallic tube is expanded in one cross-sectional direction and then expanded in the direction right-angled to the preceding cross-sectional direction. Otherwise, after expanded in one cross- sectional direction, the metallic tube is expanded in the direction right-angled to the preceding direction in the cross section to form an intermediate product, with the intermediate product mounted on the die for the final product shape for hydroforming. COPYRIGHT: (C)2004,JPO
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