Rectangle Steel Pipe forming method The tube Forming approach is called bending , square and Rectangle steel pipe forming the way it is called bent. There are two kinds of bending forming basic methods : solid curve and the empty corners.
1 , solid curved
Real bend, suggests that it is compacted bend, bend real tube outer wall and the inner and outer roller compacted way .
1 ) the real advantage of a rebound small bend , forming accurate and precise as long as the roll , inside corner molding R more accurate.
2 ) there is a real drawback bending tensile / thinning effect . First, the real tension generated at the bend will bend , stretch effect makes shortening the length of the longitudinal bend lines ; Second , solid curved fold at metal thinning due to stretching .
2 , air bend
Empty curved pipe through the outer wall of the one-way roller and the contact with the material forming the bending moment , the empty curved bending line will generate compressed , the compression effect makes longitudinal bend lines stretch , bend occurs at the metal accumulation thickening, this is an empty curved compression / thickening effect .
1 ) air bends the advantage is that you cannot be real curved edge length when folded , such as square and Rectangular steel pipe top / side synchronous bending and finishing . Air bend can also be bent R <0.2t of wall angles without breakage .
2 ) air bends drawback is square and Rectangle steel pipe in the top / side synchronous air bends , because the upper roller and a lower roller while generating pressure molding force beyond the critical point easily , causing instability concave edge , and also affect the stable operation of units and forming quality . This is an empty square and a Rectangle steel pipe and pipe bending molding different characteristics.
In practice, these two basic methods, square and Rectangular tube forming products should be based on reasonable process needs to be configured to position . It should be noted curved molding solid stretch / thinning effect and air bend forming compression / thickening effect of the quality of the product , otherwise it will cause Rectangle Pipe concave side molding , finished pipe longitudinal warping and difficult to rectify straight .
