METHOD OF INDUCTION BENDING OF PRESSURE-RESISTANT PIPE WITH VERY THICK WALL AND LARGE DIAMETRE Russian patent published in 2017 - IPC B21D7/04 B21D7/16 B21D43/00 

FIELD: machine engineering.

SUBSTANCE: in the initial phase t1 the initial tangential portion of the pipe is thermally treated due to the fact that the initial tangential portion is moved through the inductor without gripping by the bending clamp. At the end of the initial tangential portion, by the time t2, the pipe feeding is stopped and the inductor is moved opposite to the feeding direction along the pipe, while the bending clamp is closed on the pipe. In order to introduce bending in the phase t3, the inductor's displacement rate is reduced to zero and the inductor is moved to its bending position and simultaneously the pipe feeding starts. In the phase t4, a pipe bend is made at a constant pipe feeding rate. In the phase t5, the pipe feeding rate is reduced, and the inductor is accelerated against the feeding direction, and the bending clamp is opened. In the phase t6, the final tangential portion is heated as a result of further supply of the inductor in the opposite direction.

EFFECT: prevention of the negative effect of the deformation process on the material strength in the tangential portions of the pipe.

6 cl, 4 dwg