| 摘要 |
PROBLEM TO BE SOLVED: To provide a bending apparatus for a pipe of a rectangle cross-section which resolves the problem that the cross-sectional shape of a bending part is easily deformed to a trapezoid shape, while a breaking easily occurs in the bending outside portion and a thickness reduction easily occurs in the bending outside portion. SOLUTION: The bending apparatus has a bending die 1, a cramp 2, a pressing die 3 and a die pressing means 4. The bending die can be divided into a fixing part 1A and a movable part 1B. The bending apparatus has a bending-die movable part pressurization means 6 which can press the movable part to a web height part 15 of the rectangle cross-section pipe 10. A rotary draw bending is carried out by using the apparatus while applying any one or both of a web reduction pressure and a width reduction pressure. COPYRIGHT: (C)2009,JPO&INPIT
|
