MANUFACTURING METHOD FOR HOLLOW TUBES HAVING U-SHAPED BENT PARTS AND MANUFACTURING DEVICE FOR HOLLOW TUBES HAVING U-SHAPED BENT PARTS

• Main Authors: IGUCHI KEINOSUKE, MIZUMURA MASAAKI, WADA MANABU
• Format: Patent
• Language: English; Japanese
• Published: 26.01.2017
• 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

PROBLEM TO BE SOLVED: To provide a method and a device for efficiently manufacturing hollow tubes having U-shaped parts with a high productivity, as well as easily obtaining hollow tubes having small intervals between respective parallel parts, as well as small apex curvature radii.SOLUTION: A method for manufacturing hollow tubes uses a metal die having a groove into which a tube stock is inserted, and which is formed between a die member constituting an upper die and a die member constituting a lower die, wherein a recessed part is formed at one side of at least one of the upper and lower die members, continued to a space inside the groove, and recessed toward inside of at least the other one of the upper and lower die members, and an ejection member capable of move back and forth to the recessed part through the space inside the groove, is disposed at the other one of the die members. The method for manufacturing hollow tubes comprises: placing the tube stock in the groove; applying a liquid pressure into the tube stock: at the same time, while applying a pressure along an axis line (axial-pressing) from both end parts, advancing the ejection member from the other one of the die members toward the inside of the recessed part to push-in an intermediate part of the tube stock in a longitudinal direction into the recessed part, so as to form the U-shaped bent part of the tube-stock in the recessed part.SELECTED DRAWING: Figure 5 【課題】高い生産性でＵ字曲がり部分を有する中空管を効率的に製造することができ、しかもＵ字曲がり部分の平行部間間隔や頂部曲率半径が小さい中空管を容易に得ることができる方法および装置を提供する。【解決手段】上型を構成する型部材と下型を構成する型部材との間に素材管が挿入される溝部が形成され、上下の型部材の少なくとも一方に、溝部内の空間に連続しかつ他方の型部材の内部に向かって窪む凹部が形成され、前記他方の型部材の側には、溝部内の空間を経て凹部内に向けて進退し得る突き出し部材が設けられた金型を用いる。そして溝部に素材管を配置し、その素材管内に液圧を加えるとともに、両端部からその軸線に沿って加圧（軸押し）しながら、他方の型部材の側から突き出し部材を凹部内に向けて進出させて、素材管の長手方向の中間部を前記凹部内に押し込み、これにより凹部内に素材管のＵ字曲がり部分を形成する。【選択図】図５