METHOD FOR COMBINED PIPE ENDS UPSETTING Russian patent published in 2019 - IPC B21J5/08 B21K21/12 

FIELD: machine building.

SUBSTANCE: invention relates to pipe production. Deformation of heated pipe end is carried out on press in four operations using two repositionable detachable matrices and three puncheons. At the first operation, external upsetting with cylindrical part is made with diameter equal to required outer diameter of upset end, and with transition part with external conic surface with length equal to required length of transition zone on inner surface of pipe. At the second operation, the inner cylindrical part is formed in the same matrix by deforming the cylindrical part obtained at the first operation to reduce the inner diameter to the required value. At the third operation, the internal extended elongated transition zone of the pipe is formed by forcing in the second matrix having a cavity with a conical part, the whole part of the pipe upset on the first operation with an external conic surface. In the fourth operation, the cylindrical part of the pipe end upset at the previous operations is deformed in the matrix with reduction of the inner diameter to the required one.

EFFECT: higher quality of produced pipes.

1 cl, 9 dwg