Round pipe steel component arc clod curving forming mould

Abstract

The present invention is an improvement to the arc-shaped cold-bending forming die of round tubular steel members, and particularly relates to an arc-shaped cold-bending forming die for round tubular steel members with a diameter of φ>800 mm, and is characterized in that each die includes a die support plate and more than two movable arcs Composed of mold petals, the total arc length of each petal arc closed envelope is greater than the half-circle arc length of the bent steel pipe. The mold flaps open the combined mold, which greatly increases the envelope surface of the steel pipe being bent, effectively reducing the wrinkling and flattening distortion of the steel pipe during bending. It is used for the bending of larger diameter steel pipes, such as the bending of φ800-1524mm steel pipes, and the cold bending of thicker wall steel pipes, as well as mobile bending, repeated bending trimming, or turning over and back pressing when the bending amount is too large, and the work efficiency can be improved. The work efficiency is 3-5 times. The surface of the bent steel pipe is smooth without indentation and no obvious folds. The depth of the inner R zone is less than 1mm. Both the degree h and the nominal outer diameter D are not greater than 2%, and the ratio of the wave distance A to the wave degree h is not greater than 10, which effectively controls the deformation of the elbow.

Description

technical field [0001] The invention relates to an arc-shaped cold-bending forming die for a round tubular steel member, in particular to an arc-shaped cold-bending forming die for a round tubular steel member with a diameter of φ>800mm. Background technique [0002] The arc-shaped steel round pipes commonly used in steel structural parts are usually welded first to make round straight pipes, and then bent into the required arc shape by arc bending. In the steel structure industry, round straight pipe steel members are bent into curved pipes. The commonly used processing methods are: [0003] Intermediate frequency heating elbow: the heating ring (about 40mm wide) is sleeved on the steel pipe, heated at the bending part of the steel pipe (800-850°C), and then the heated steel pipe is bent in a very narrow width under the action of external force to form arc. Although this kind of hot bending method has the advantage of no deformation or little deformation of the roundne...

AI Technical Summary

Problems solved by technology

Although this kind of hot bending method has the advantage of no deformation or little deformation of the roundness of the steel pipe after bending, it has the disadvantage of this method: the minimum bending radius must be 5 times or more than the outer diameter of the bent steel pipe, and it is difficult to achieve a smaller diameter. The bending of the arc; secondly, after the bending, there is obvious crushing and wrinkling at the heating bend and the cooling straight; thirdly, the high temperature heating of the steel will have an adverse effect on the material, especially for high-strength steel The impact will be greater; in addition, it is difficult to control the heating temperature, and it is difficult to bend the pipe if the heating is not enough. Excessive heating will easily cause overheating, and lead to a large number of oxide scales on the heating part, resulting in thinning of the steel pipe thickness and affecting the strength.

The disadvantage of this structural mold is: the surface of the mold to the steel pipe is less than half a circle (the ratio of the diameter of the steel member to the wall thickness is relatively large, and the bending pressure of the cold press is large, and the strong downward pressure is very easy to bend. During pipe bending, the inner arc of the steel pipe will be wrinkled, and the flattening and distortion in the diameter direction, referred to as crushing and wrinkling, will affect the strength of the steel member. Axial movement and bending, the arc quality of the bend is not ideal

Therefore, the cold bending of round pipes with large diameters such as φ>800mm or more has not been effectively solved in the steel structure industry and has become a major technical problem in the industry

Images