To provide a method hot-bending a metallic tube by which the flattening of the metallic tube is suppressed with a device arranged inside the metallic tube and also this suppression is performed while preventing the generation of irregular temperature rising in the short section of the metallic tube heated to the red heat temperature.
When the metallic tube 1 which is passed through an induction heating coil is forward moved by a thrust from the rear and hot-bending the metallic tube 1 heated to the red heat temperature in the short section by heating is hot-bent by bending moment produced by a thrust as driving force, the generation of the irregular temperature rising in the short section of the metallic tube heated to the red heat temperature is prevented by inserting and arranging a stiffening device 10 in which a plurality of cylinders 11 of bar bodies are provided connectively in the direction of the center line of the tube into inside the metallic tube 1, receiving the contracting load in the C-T direction generated when the metallic tube 1 is bent in load receiving parts 22, 23 provided at both ends of each cylinder 11 through attachment members 20, 21 and composing these load receiving parts of a non-conductive refractory material.
SHIRAISHI TATSUMI
IMOTO TAKUHIRO
JPS5015773A | 1975-02-19 | |||
JPS591026A | 1984-01-06 | |||
JP2004141474A | 2004-05-20 | |||
JP2003164918A | 2003-06-10 |
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