MACHINE FOR MANUFACTURING WELDED STEEL PIPES AND METHOD FOR HANDLING THE SAME MACHINE

摘要

The present invention is that a machine for manufacturing welded steel pipes, in which an edge bending roll for constraining under pressure a strip from its pipe edge portions to the boundaries between the pipe edge portions and its pipe side portions to bend the strip a first center bending roll for constraining under pressure the pipe side portions to bend the pipe side portions, second to fourth center bending rolls for constraining under pressure the strip from the boundaries between the pipe side portions and its pipe bottom portion to the pipe bottom portion and applying lateral pressure to the pipe from both sides to bend the boundaries and the pipe bottom portion and a plurality of cage rolls arranged on both the sides of these center bending rolls, first and second fin pass rolls for further forming under pressure the pipe, are arranged in order from the upperstream side to the downstreamside of a roll forming process. And at least the edge bending roll, the first center bending roll, the first and second fin pass rolls each has a driving means provided thereon, and all the upper rolls of the first to fourth center bending rolls are set in one housing, and all the down roll stands of the first to fourth center bending rolls or all the down roll stands of the second to fourth center bending rolls are set on one common sub-base plate.