HYDROFORMING METHOD FOR HOLLOW PRODUCT USING MULTI-LAYERED TUBE

• Main Authors: JOO, BYEONG DON, MOON, YOUNG HOON, KIM, SANG YOON
• Format: Patent
• Language: English; Korean
• Published: 21.08.2014
• Subjects: MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVINGMATERIAL; PERFORMING OPERATIONS; PUNCHING METAL; TRANSPORTING; WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS ORPROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL

The present invention relates to a method for manufacturing a hollow hydraulic molded product by using a multi-pipe comprising: (a) a step of mounting multi-pipe assembly, where a hollow inner tube having multiple flow path holes in a radial shape is inserted into a hollow outer tube, inside a mold; (b) a step of injecting a fluid into the inner circumferential surface of the inner tube; (c) a step of applying a liquid pressure to the inner circumferential surface of the outer tube by discharging the fluid to the flow path hole of the inner tube; and (d) a step of completing a molded product having a desired form of the outer circumferential surface while the outer tube is expanded and plastic deformed. The present invention has an effect of markedly improving form accuracy and forming a hollow product of a multi-pipe regardless of formability of the inner tube by hydroforming by applying the pressure to the inner circumferential surface of the outer tube by discharging a fluid through a flow path hole formed in the inner tube of the multi-pipe assembly, and forming a hollow product having a desired outer form by selectively plastic deforming the outer tube without changes in a form of the inner tube.