RU2025162C1 - Method of manufacturing box-section welded beams - Google Patents

Abstract

FIELD: plastic working of metals. SUBSTANCE: method involves forming bent profiles from blank by making periodically interrupted ribs extending along double-thickness-strip lines intended to be bent; forming double-thickness strips by bending along the line extending through rib axis of symmetry; effectuating welding along protruding portions of Z-shaped edges. Prior to making periodically interrupted equal-length ribs, peripheral portion of strip is tucked in and portion of blank adjoining central portion of profile wall is tucked out in the direction opposite to that of peripheral portion of strip. EFFECT: increased service life of beam by providing windows for discharge of condensate. 2 cl, 5 dwg, 1 tbl

Description

 The invention relates to the processing of metals by pressure and is intended for use in the manufacture of box-shaped beams from bent profiles. In the manufacture of box-section beams from bent profiles with shelves of double thickness, including perforated ones, profiles are welded together along the edges of the shelves.

A known method of manufacturing box-section beams for shelving (UK application N 1336653, class E 04 C 3/04, published. 07.11.73), according to which the box-shaped beam is made of two grooved bent profiles having bent parts on the flanges. When assembling, the grooved profiles are rotated 180 ^° one relative to the other, as a result of which their flanges overlap, and the bent parts of one profile overlap the edges of the other.

 The disadvantage of this method of manufacturing the beam is that the beam is made without holes for removing condensate, which reduces its durability due to corrosion.

 A known method for the production of box-section beams with hollow shelves used in shelving and frames (US patent N 4002000, CL E 04 C 3/30 3/10, publ. 11.01.77), which is made of two bent profiles, each of which contains a pair of parallel flanges. The outer surfaces of the flanges of the second profile are spaced one from the other at a distance equal to the distance between the inner surfaces of the flanges of the first profile. The flanges of the second profile mutually overlap almost completely, forming a closed beam. During operation, condensation accumulating inside promotes corrosion and reduces the durability of the beam.

 Closest to the technical nature of the invention is a method for the manufacture of beams of closed section [1] made of bent profiles of a C-shape by welding the shelves of the profiles with each other.

 The disadvantage of this method of manufacturing the beam is that in the manufacture of the beam from lightweight, including perforated profiles, condensate is collected in the beam, helping to reduce its durability due to corrosion and additional holes are required to remove it.

 The aim of the invention is to increase the durability of the beam by making holes in the shelves to remove condensate, as well as reducing the complexity of its manufacture.

 For this, in the manufacture of a box-section beam, initially, at the places of future bends of double-thickness shelves, corrugations are periodically repeated along the length of the corrugations, the formation of double-thickness shelves is made by bending along the line passing through the axis of symmetry of the corrugations, and welding along the protruding sections of the zigzag edges. At the same time, it is advisable to bend the peripheral section of the future shelf before periodically repeating corrugations along the length of the corrugation, and bend the workpiece section adjacent to the central section of the profile wall to the side opposite to the bending.

 In FIG. 1 shows a box-section beam with holes for removing condensate; in FIG. 2 is a diagram of the formation of a bent profile with shelves of double thickness and periodically repeating corrugations; in FIG. 3 is a diagram of rolls for performing periodically repeating corrugations; in FIG. 4 - profile with zigzag edges; in FIG. 5 is a diagram of the formation of a bent profile with periodically repeating corrugations performed after bending the peripheral sections of the shelf.

 For the manufacture of box-shaped beams 1 (see Fig. 1) with holes 2 for condensate removal, profiles 3 with shelves 4 of double thickness are initially formed in the mill rolls. On the steel spaced cross-section (perforated) billet 5 in the I transition (Fig. 2) in the places of future folds of shelves 4 of double thickness, periodically repeated corrugations 6 are formed in rolls 12 and 13 (Fig. 3). Then, in the II transitions (Fig. 2), double-thickness shelves are formed sequentially by bending along a line passing through the axis of symmetry of the corrugations 6.

 At the same time, in the II-VII junctions, peripheral elements 7 of the shelves 4 are formed by folding, and then in the VIII-X junctions, the folding of the elements 8 of the shelves 4 relative to the profile wall 9 is formed. In the XI transition after the manufacture of the profile with a zigzag edge 10 (Fig. 4), the edges 11 of the peripheral sections 7 of the shelves 3 with the wall 9 are welded, which provides sealing of the shelves, as well as an increase in the service life of the beams.

 Then the profiles are welded into the beam along the protruding sections of the zigzag edges 10 of the shelves 4 with the formation of holes 2 in the belts of the beam between the protruding sections. The execution of initially periodically repeating corrugations 6 on the workpiece 5 formed at the places where future shelves 4 adjoin bent profiles 3 adjoin each other in the beam will subsequently form a zigzag edge 10, welding along the protruding sections of which adjacent profiles will allow the formation of holes 2 in the girdle beams for removal of condensate without additional labor in one process stream and without violating the continuity of the metal, and, therefore, does not reduce the bearing capacity of the beam.

 In addition, this method allows the formation of holes 2 to remove condensate without violating the tightness of the hollow shelves 4.

 In this case, before performing periodically repeating corrugations 6, it is advisable to bend the peripheral section of the future shelf 4, and the billet section adjacent to the central section of the profile wall 9 is bent to the side opposite to the bend.

 Bending the peripheral section 7 of the future flange 4, and then bending the adjacent section to the central section of the profile wall 9 in the direction opposite to the bending, allows corrugations 6 to be periodically repeated exactly at the junction of the hollow shelves 4 when welding the profiles 2 into the beam 1. In addition , such a shaping scheme simplifies the process of folding the peripheral sections of the profile shelves, provides access for both rolls (lower and upper) to the bending points during the formation of the corrugations and allows them to be molded qualitatively. In addition, the design of the rolls in the first transitions is simplified.

 The described method can be implemented during the formation of profiles in the rolls of a roll forming mill and does not require special devices for implementation.

 According to the technology developed on the basis of the described method, a bent profile 50 x 25 x 27 x 2 mm with double thickness shelves and periodically repeating corrugations was made on a roll forming mill 1-4 ... 50-300. The molding mode is shown in table 1.

 To obtain a finished profile, and then a box-section beam according to the described method, eleven technological transitions were required, and then profiles were welded on a separate stand into a beam with holes for removing condensate.

 The implementation of the box-section beam with holes in the belts 1.5-2 times increases its durability, since the condensate formed in it does not accumulate between the profiles and in the cavity of the shelves, and the possibility of corrosion is minimized.

According to the calculated data and experimental verification, the proposed method for manufacturing a box-shaped beam provides an increase in the durability of the beam by 1.5-2 times by making holes in the shelves to remove condensate without violating the tightness of the hollow shelves;
reduces the complexity of manufacturing the beam by 20 ... 30% due to the holes for removing condensate in a single process stream, excluding the time-consuming operations of making these holes.

Claims (2)

 1. METHOD FOR MANUFACTURING A WELDED BEAM OF A SHAPED SECTION, including the manufacture of bent profiles with double-thickness shelves bent at right angles by sequential shaping from a sheet blank and butt welding of the shelves of the profiles to each other, characterized in that, in order to increase durability by making windows to remove condensate, initially on the workpiece in places of future folds of double-thickness shelves, periodically repeating corrugations are formed, the formation of double-thickness shelves is made of bom along a line passing through the symmetry axis of the corrugations and produce a weld on protruding portions of the zigzag edges.  2. The method according to claim 1, characterized in that before performing periodically repeating corrugations, the peripheral section of the future shelf is bent, and the workpiece section adjacent to the central section of the profile wall is bent to the side opposite to the bend.

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