| 摘要 |
A forming roll for pipe mill in continuous roll forming, which includes a curved surface similar to curved surfaces with various curvatures required for forming a pipe in an intended pipe diameter range so as to enable reasonably and naturally plastic deformation of a flat web material but has a roll sectional shape so constructed as not to need any high technique for a forming roll support mechanism and control of the mechanism. For the purpose of using the forming roll in common at respective roll stands in a desired step of a forming line when manufacturing pipes of different pipe diameters in a specified range, for example, of two to three times, a longitudinal cross section of the forming roll is defined by an envelope curve involving a novel concept whereby manufacture of pipes of different pipe diameters is made possible in respective steps such as breakdown pass, cluster, fin pass, squeeze, correction in a diametrical or axial direction and the like. Thus the invention relates to a forming roll which can attain improvement in accuracy of outer diameter, reduction of roll mark, in particular, simplification of a mechanical systems such as roll supporting and positioning mechanisms and ease of positional control of the roll, and the envelope curve can provide a clamp device capable of grasping pipes of different sizes at the same curved surface with a stabler and greater force for different purposes such as cutting without producing scratches on product surfaces. |
