公开(公告)号：US3902344A

公开(公告)日：1975-09-02

申请号：US45678774

申请日：1974-04-01

Applicant: ROLLMET INC

Inventor： STUART JAMES M

IPC: B21D7/025 ,  B21D7/16

CPC classification number: B21D7/162 ,  B21D7/025

Abstract: Large diameter thin-walled pipe is bent by a ram pushing the pipe forward axially and a bending arm forcing the forward end of the pipe to follow a curved path. A heater mounted in a plane passing through the center of the bend heats the pipe in a narrow bending zone to a temperature substantially reducing the yield strength of the metal. Heat input and cooling are adjusted around the periphery of the bend to provide uniform temperatures irrespective of changes in pipe wall thickness resulting from the bending. The flexure axis of the bend may be moved inward or outward along the bend radius by pulling or retarding with the pivotal bending means, or may be fixed by providing relatively cool spots in the heated band at the desired location of the flexure axis. Guide means are provided which may pre-deform the pipe laterally to compensate for lateral deformation during bending or may prevent deformation during bending. The portion to be bent may have a different diameter or thickness to compensate for changes in dimensions resulting from bending.

Abstract translation: 大直径的薄壁管由一个推动管道向前推动的压头弯曲，并且弯曲臂迫使管道的前端跟随弯曲的路径。 安装在通过弯曲中心的平面中的加热器将管道在窄弯曲区域加热至大大降低金属屈服强度的温度。 热输入和冷却围绕弯曲周边进行调节，以提供均匀的温度，而不管由弯曲导致的管壁厚度的变化。 弯曲的弯曲轴线可以通过利用枢转弯曲装置拉动或延伸而沿着弯曲半径向内或向外移动，或者可以通过在弯曲轴线的期望位置处在加热带中提供相对较冷的位置而被固定。 提供引导装置，其可以横向预先变形管道以补偿弯曲期间的横向变形，或者可以防止弯曲期间的变形。 要弯曲的部分可以具有不同的直径或厚度以补偿由弯曲引起的尺寸变化。

公开(公告)号：US3896649A

公开(公告)日：1975-07-29

申请号：US44788674

申请日：1974-03-04

Applicant: ROLLMET INC

Inventor： STUART JAMES M

IPC: B21D7/16 ,  B21D9/07

CPC classification number: B21D9/073 ,  B21D7/162

Abstract: Large diameter thin-walled pipe is bent by a ram pushing the pipe forward axially and a bending arm forcing the forward end of the pipe to follow a curved path. A pair of gas burners mounted inside and outside the pipe in a plane passing through the center of the bend heat the pipe in a narrow bending zone to a temperature substantially reducing the yield strength of the metal.

Abstract translation: 大直径的薄壁管由一个推动管道向前推动的压头弯曲，并且弯曲臂迫使管道的前端跟随弯曲的路径。 在穿过弯曲中心的平面内安装在管道内部和外部的一对气体燃烧器将管道在窄弯曲区域加热至显着降低金属屈服强度的温度。