Method for bending a metal pipe
AssigneeDai-Ichi High Frequency Co., Ltd.
InventorsShumpei Kawanami, Yasuo Watanabe, Susumu Hanyo
Life of this patent
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Abstract
A method and hot bending apparatus for metal pipes in which the temperature of the pipe is kept constant during "gradation bending". The temperature may be adjusted by adjusting the power applied to the heater, or alternatively by adjusting the relative movement of the pipe with respect to the heater. While a feedback system may be utilized, a predetermined program is preferred under control of a microprocessor.
Claims8
In the method of hot bending a metal pipe in which the pipe is passed through a heating zone in a heating/cooling unit while a bending movement is applied and thereafter through a cooling zone in the heating/cooling unit adjacent to the heating zone, and in which the radius of curvature of the bend is larger than the desired radius in the initial and terminal (relatively smaller angle) portions of the bend and greater than the desired radius in the relatively larger angle intermediate portion of the bend, the improvement in which the temperature of the pipe while in the heating zone is maintained a constant.
An apparatus for hot bending a metal pipe in which the pipe is passed through a heating zone in a heating/cooling unit while a bending movement is applied and thereafter through a cooling zone in the heating/cooling unit adjacent to the heating zone, and in which the radius of curvature of the bend is larger than the desired radius in the initial and terminal (relatively smaller angle) portions of the bend and smaller than the desired radius in the relatively larger angle intermediate portion of the bend, the improvement in which the temperature of the pipe while in the heating zone is maintained a constant, the improvement comprising means for maintaining the temperature of the pipe while in the heating zone a constant.
Dependencies are inferred from the claim text.