RU1831396C - Bent s-shaped profiles process - Google Patents

Abstract

The invention relates to the processing of metals by pressure, in particular to the production of cold-formed sections of rolled metal. The purpose of the invention is to reduce metal consumption and improve the quality of profiles. The method for producing a bent C-shaped profile consists in bending the workpiece by rolls with the formation of a curved wall, folding with release of the shelves and vertical walls in rough, intermediate and finishing passes from contact with the upper roll and characterized in that the folding of the shelves in the intermediate passes to an angle of 60 ° lead with a release angle of 4-5 °, vertical walls in the intermediate passages are bent at angles of 15-20 °, in the first finishing pass, the shelves are bent to 90 °, and in the second finishing pass, they are bent by 1 ° and the final folding of the vertical walls is carried out with the simultaneous release of the top of the curved wall, while in the last finishing pass the shelves are additionally bent by 0.5-1.0 °, pinching the top of the wall with rolls. The number of aisles in which shelves and vertical walls are freed has been increased. 1 ill. cl

Description

The invention relates to the processing of metals by pressure and can be used in the production of sectional bent profiles for special purposes.

The purpose of the invention is to reduce the consumption of metal and rolls and to improve the quality of profiles of this configuration.

A well-known technology for the production of a bent C-shaped profile with a corrugated wall of 5BUx140x40x5 mm provides for the release of foldable shelves in the XII and XIII intermediate passages and in the XIX-XX fair passages, and the release of vertical walls (partial and complete) in the XIV-XX intermediate and fair passages. For the manufacture of the profile, 19 forming stands are required (which leads to a large consumption of rolls), and the relatively large width of the finished shelves (40 mm) causes excessive consumption of the metal of the workpiece. The essence of the invention is that the number of passages in which the shelves and vertical walls are freed is increased: shelves in six passages (UX), vertical walls (partially and completely) in all passages where they are bent, except for XII. The value of the angle of liberation of the shelves (when bending them in intermediate passages to 60 °) is taken within 4 ... 5 °. The angles of bending of the vertical walls in the intermediate passages are larger than those of the prototype (15 ... 20 ° versus 7 ... 16 °), aikhdogibkudo90 °

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produced in the first finishing pass (without kinking inward, as in the prototype); the shelves are bent in the last two passages to a smaller angle, and without backward bending, simultaneously releasing the top of the curved wall in the penultimate pass and clamping it with rollers in the last one.

This technology improves the geometry of the profiles, reduces the number of forming stands (ie, roll consumption) and reduces the width of the finished shelves (it is 16 mm or four profile thicknesses, which are less than the accepted ratios with a corresponding reduction in metal consumption. Improvement of the geometry of the profile occurs due to the optimal combination of passages with tight bending (in contact with both rolls) and with the release, as well as the release of the top of the curved wall in one of the finishing passes and the reduction of the bend angles of the polo to.

A pilot test of the invention was carried out on a 2-8x100-600 semi-continuous bending mill of the Magnitogorsk Iron and Steel Works. For this, when molding in 13 cells of a C-shaped special profile 100x55x4 mm used as a road fence, its main dimensions (B, H, VP, RI and R2), as well as the values of longitudinal twisting and curvature (tolerances on dimensions B) were fixed , Н, RI and R2 ± 1.5 mm, inc ± 12.0 mm; permissible curvature not more than 0.1% of the profile length, permissible twisting to 1 ° per 1 m of length and not more than 10 ° for the entire profile length) . Profiles formed by this method in 98.5% of cases had dimensions and geometry within tolerances, and more than 50% of profiles had deviations from the nominal dimensions within half tolerances (this gives increased dimensional accuracy),

Profiling according to the prototype method was also carried out in 19 cells of the same mill of the indicated C-shaped profile. Sorting by size, curvature and twisting amounted to 12% and only 23% of the profile fit within half tolerances. Thus, the experiments confirmed the advantages of the proposed method over the prototype.

According to this technology, C-shaped profiles with a similar configuration were also rolled on a 2-8x100-600 mill; 120x65x4.5 mm (thickness 4.5 mm), 130x67x5 mm and 140x70x5.5 mm; their quality level was approximately the same as when molding special technology 100x55x4 mm using this technology.

The drawing shows a diagram of the molding of a C-shaped profile according to the proposed method (Roman numerals - pass numbers; passages II, V and - not shown).

The moldable strip 1 of thickness S in the draft closed gauges I-III is bent to form a curved wall consisting of a horizontal vertex 2 and side inclined elements 3, as well as shelves of profile 4, and the strip is in contact with both top 5 and lower 6 rolls (shown by a thin line) over the entire width, which provides maximum control over the geometry of the intermediate section of the profile; bending angles of the side elements 3 walls - a ... az, shelves -.

In IV-VI intermediate passages, only the shelves 4 are bending to the corner (the formation of a curved wall - corrugation is completed in III pass) with release angles of 4 ... 50 (in the V pass, since in the VI pass the upper roll is made without conical elements ) This allows high-quality formation of shelves of small width.

In VI 1-X intermediate passages, only the side (vertical) walls of profile 7 are bent to angles 5i ... 64 within 15-20 °. In this case, the section being formed, in addition to shelves 4, is in contact with the lower roll 5 in all these passages, and with the upper roll 6 - only part of the length of the walls 7 being bent (the shelves 4 are free from contact with both rolls), which avoids unnecessary stresses in places of bending of the shelves, providing the necessary straightness and absence of crack formation.

In the first finishing pass XI, the shelves are bent to an angle of 90 ° due to contact with the upper roller (their formation is completed), and the vertex 2 of the curved wall also contacts the upper roller, which ensures its straightness; the vertical walls and the curved wall continue, as in previous passages, to contact the lower roll.

In the second (XII) and last (XIII) finishing passes, the shelves are bent inward at an angle of 5-2.0 ° (in the latter, by 0.5 ° ... 1.0 °), preventing their springing after leaving the mill. In the XII passage, bending of the vertical walls is completed (the lower places of their bending are freed from contact with the rolls to prevent crack formation) with the simultaneous release of the top of the curved wall from contact with the upper roll, which reduces the longitudinal twisting of the profile. In the last pass

(XIII), in order to control the height h of the corrugation, the top 2 is jammed by the rolls. Bending radii of the finished profile RI and R2.

As experiments have shown, deviations from the indicated values of the angles a, f, y and 6 lead to an inevitable deterioration of the geometry and a decrease in the accuracy of the dimensions of the finished profiles, which proves the optimality of these values.

EXAMPLE 1. A C-shaped special profile with dimensions mm, mm, mm, mm, MM, mm and mm is formed in 13 cells, of which 1-111 are draft, IV-X are intermediate and XI-XIII - fair. The values of the bending angles along the aisles: -, II- N1-03 45 °; IV- at 4 °; V- at 4 °; VI- (VII- IX-X-; XII- wi 1o: XIII-, 5 °.

PRI me R 2. Similar modes of bending the same profile, but at 5 ° and.

The technical and economic effectiveness of the proposed method in comparison with the prototype is to reduce the cost

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the number of passes, which reduces the consumption of rolls by 40-50%, reducing the consumption of metal (by reducing the width of the shelves) by 2-3% and increasing the yield of profiles with increased accuracy.

Claims (1)

SUMMARY OF THE INVENTION A method for producing bent C-shaped profiles, which consists in gradually bending the profile elements in the rolls to form a curved wall and freeing the shelves and vertical profile walls from contact with the upper roll in rough, intermediate and finishing passes, characterized in that. the shelves are bent in intermediate passages to an angle of 60 °, with an angle of release of 4 ... 5 °, in the first finishing pass they are bent to an angle of 90 °, in the second - they are bent by 1 °, and in the last finishing pass the shelves are additionally bent by 0.5-1 °. pinched the top of the wall with rolls, the vertical walls in the intermediate passages are bent by 15-20 °, and their final folding is performed in the second finishing pass with the simultaneous release of the top of the curved wall. F I