To effectively prevent the generation of the buckling during the bending at small radius of a thin-walled tube of large diameter by a hot bender such as a high frequency bender.
In a bending method, the angle β of the neutral axis is obtained so as to give the compression side working ratio in a range not to generate the buckling on a web side in terms of a rigidity coefficient to be given by the characteristic of a work and its bending radius. An annular part to be heated to bend is split into a plurality of sections (-90°∼θ2, θ2∼θ3, θ3∼+90°) in its circumferential direction, and the temperature distributions (T1, T2, T3) are formed for each section to keep the neutral axis at the position of the angle β. Generation of the buckling can be prevented thereby.
| JPS5357173 | HOLLOW CRANKKSHAFT AND METHOD OF FABRICATING THE SAME |
| JPH11267765 | METHOD AND DEVICE OF BENDING MATERIAL |
| JPS5925570 | [Title of the device] Pipe vendor |
SUMIKAWA JUNJI
SHIRAISHI YASUKAZU
TOMINO KEISUKE
HITACHI ENG SERVICE
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