Research On Flexible Roll Forming Technology Of Longitudinal Welded Pipe Roll

Cage roll forming technology is widely used in the production of welded pipe, especially in flexible change of welded pipe forming. Forming quality of welded pipe has been improved than the traditional roll forming. The issues about the key design technology of cage roll forming applied in welded pipe forming was researched in this paper, specifically as follows:(1) Principles and characteristics of the cage roll forming was summarized, structural characteristics of the cage roll forming machine analyzed; The deformation characteristics of strip during roll forming process was also described as a theoretical basis for this research paper.(2) Analyzed characteristics of three kinds of traditional roller diagram design method and proposed three-radius bending cage roll forming design method; Calculated Φ50mm、 Φ60mm、Φ70mm three-diameter welded pipe roller diagram design parameters according three-radius bending cage roll forming design method and drew roller diagrams.(3) Calculated shape parameters and position parameters of rolls installed at preforming rack and precision forming rack of three different diameters of the pipe; According to the ideal touch boundary conditions between the line forming outer row roll and strip edge, established a method for solving position parameters of all outer row rollers by curve fitting; Calculated position parameters of all outer row rollers for forming Φ50mm welded pipe by the method mentioned above; Calculated the other two kinds of diameter pipe position parameters of outer row rollers according to the tilt angle invariance principle; Through this work, got a set of shape parameters and position parameters of all kinds of rolls.(4) The entire cage roll forming process of Φ50mm welded pipe was simulated by dynamic explicit elastic-plastic finite element method. The deformation behavior of strip in different flexible forming sections has been analyzed from different aspects such as formed shape, transverse and longitudinal plastic strain and relative curvature; The reasonableness of roll forming roller diagram was also verified.