RU2124410C1 - Formed section and formed section manufacture method - Google Patents

Abstract

FIELD: plastic working of metals, in particular, production of cold-reduced special-purpose sections. SUBSTANCE: formed section has horizontal wall with trapezium-shaped corrugation, inclined side walls and horizontal strips of predetermined size. Strips have flanges of width equal to 4.0-4.5 of section thickness. Flanges are inclined downward at an angle of 68-72 deg relative to strips. Inclination angle between side and horizontal walls is 100-104 deg. Corrugation height is 0.18-0.22 of section height, and corrugation width is 0.39-0.43 of horizontal wall width. Method involves sequentially forming side walls of section in roughing, intermediate and finishing passes; forming corrugation on horizontal wall of section and simultaneously limiting shifting of strip in roughing passes. Corrugation is formed only in roughing passes and tray-shaped profile is formed in intermediate passes, with strip motion being limited in first intermediate pass and bending radius of corrugation member being simultaneously reduced to predetermined value. Flanges on strips are bent downward in finishing passes with minimum bending angle of 2 deg in penultimate finishing pass and maximum bending angle of 32 deg in terminating finishing pass. Flange bending radius is made equal to radius provided in first finishing pass with following reducing it by 2.0-2.5 times in two subsequent passes and increasing it to predetermined value in terminating pass. Section produced by such method may be used for manufacture of main highway guardrails. EFFECT: reduced metal usage and decreased number of rolls employed for production of such sections, improved quality of sections and enhanced reliability in operation. 3 cl, 2 dwg, 1 ex

Description

 The invention relates to rolling production and can be used in the manufacture of shaped cold-formed profiles.

 Shaped (high-quality) bent profiles of the most diverse configuration of the cross section and for various purposes (including for fencing highways) are obtained on special roll forming mills by sequentially bending the strip blank elements with rolls. The assortment of produced bent profiles is most fully presented in the reference book, under the editorship of I. S. Trishevsky. Bent profiles of hire. M .: Metallurgy, 1980, p. 147 - 301, and the modern technology of profiling, for example, in the book under the editorship of I.S. Trishevsky. Production of bent profiles (equipment and technology). M .: Metallurgy, 1982, p. 243 - 262.

 Known bent profile (corrugated sheet), the end protrusions of which are given such a shape that the cutout at one end of the sheet corresponds to the protrusion at the other end (see US Pat. GDR N 146206 class F 28 F 3/06 from 01/28/81) . The disadvantage of this profile is the impossibility of its use as a road fence of highways due to its insufficient rigidity (resistance to bending and twisting).

 Closest to the claimed is a profile with a trapezoidal corrugation N 18 - 15, given in the manual under the editorship of I.S. Trishevsky. Production and application of bent profiles of hire. M .: Metallurgy, 1975, p. 501.

 This profile contains a horizontal wall with a trapezoidal corrugation in the middle of its width and inclined side walls and is characterized by the presence of horizontal shelves mating with the side walls. The disadvantage of this profile is its lack of transverse rigidity, which makes it impractical to use it to enclose motorways.

A known method for the production of bent profiles with flanges, in which to improve the profile geometry, the flanging and the side wall are bent at the same angles, and when the angle reaches ~ 70 ^o at different angles with a gradual decrease in the difference in angles from 20 to zero (see.with. USSR N 360130 class B 21 D 5/08 from 01/18/73). The disadvantage of this method is the inability to obtain with its help high-quality profiles with flanges tilted down on horizontal shelves.

 Closest to the claimed method is the calibration of a special profile of 202 x 40 x 3 mm, given in the book of A.P. Chekmarev and V. B. Kalugsky. Bent profiles of hire. M .: Metallurgy, 1974, p. 119 - 120 and fig. 64.

 The shaping of this profile is carried out by sequentially bending the elements of the formed strip in rough, intermediate and finishing passes and is characterized by the fact that the formation of the corrugation on the horizontal wall and the folding of the side walls in the rough passages are performed simultaneously with the restriction of the lateral displacement of the strip by the flanges of the lower rolls. The disadvantage of this technology is the inability to obtain with its use the inventive bent profile with the required geometry.

 Profiles for highway road fences are used either as racks or as horizontal bars connecting racks. To assemble such profiles, holes are punched in them in certain places. Therefore, any distortion of the geometry of the profiles (bending, twisting, striping, etc.) complicates their assembly and increases the consumption of metal, which leads to the presentation of the geometry of the increased requirements set forth in TU 14-101-360-96 "Cold-formed profiles for road fences of highways "

 An object of the invention is to increase the operational characteristics of bent profiles used for highway road fences and the prevention of defects in their geometry, as well as reducing the consumption of metal and rolls in the production of these profiles.

To solve this problem, a bent profile containing a horizontal wall with a trapezoidal corrugation, inclined lateral shelves of predetermined values, further comprises flanging shelves with a width equal to 4.0 ... 4.5 profile thicknesses, and inclined downward at an angle of 68 ^o .. .72 ^o to the shelves, and the angle of inclination between the side and horizontal walls is 100 ^o ... 104 ^o , while the height of the corrugation is 0.18 ... 0.22 of the height of the profile, and the width of the corrugation is 0.39. . . 0.43 width of the horizontal wall; in the method for producing said bent profile by successively bending the elements of the moldable strip in rough, intermediate and finishing passes, including folding the side walls and forming a corrugation on the horizontal wall of the profile while limiting the lateral displacement of the strip in the rough passages, only corrugation is formed in these passages, in the intermediate the passages carry out the shaping of the trough profile with the limitation of the lateral displacement of the strip in the first such passage with a simultaneous decrease in rad whiskers bending elements corrugation to a predetermined value, and in the finishing pass bends flanging on the shelves downwards with a minimum angle hem 2 ^o in the penultimate and a maximum angle of 32 ^o in the last finishing pass, the bending radius flange returns makes equal to the target in the first finishing pass to decrease its 2.0 ... 2.5 times in two subsequent passes and increasing to a predetermined value in the last pass.

 The essence of the technical solution found is to optimize the geometrical parameters of the bent profile (its maximum liquid with a minimum cross-sectional area), as well as to use an increased number of calibers in its production with limited lateral displacement of the formed strip by the lower roll flanges and such bending angles and bending radii of the flanges by horizontal shelves that provide the required dimensions and profile geometry.

In addition, the use of the maximum (32 ^o ) bending angle of the flanges in the last finishing pass and changing their bending radii from a given value to a minimum with a subsequent increase to a given radius in the same passage causes hardening of the bending sections, which leads to an increase in the stiffness of the profile as in the transverse and in the longitudinal directions.

 In FIG. 1 shows a cross section of the inventive bent profile, and in FIG. 2 - a scheme of its profiling (Roman numerals - serial numbers of passes; the most characteristic of them are shown).

A profile of thickness S, with width B and height H (see Fig. 1) contains a horizontal wall 1 with a trapezoidal corrugation 2 located in its middle, inclined side walls 3, horizontal shelves 4 adjacent to them and inclined to the shelves at an angle β = 68 ^o ... 72 ^o flanges 5, the width of which is b ₀ = (4.0 ... 4.5) S.

The angle between the horizontal and side walls α = 100 ^o ... 104 ^o , and the height of the corrugation h = (0.18 ... 0.22) H and its width b _g = (0.39 ... 0.43) b _s (b _s is the width of the horizontal wall).

 The profile is formed in 14 passes, of which I-IV-draft, V-X-intermediate and XI-XIV-finishing. All rough passages and the first intermediate (V) limit the lateral displacement of the formed strip 6 (see Fig. 2) due to the so-called “closing” of calibers by the flanges 7 of the lower rolls 8.

 In draft passages I-IV, only corrugation 2 is formed by increasing the bending angles γ of its side faces 9 and sequentially decreasing the bending radii R. In the first intermediate (V) pass, the formation of a trough section with horizontal shelves 10 that are horizontal in all passes and formation ends corrugation. In this case, the bending angle δ of the side walls of the profile increases sequentially until the specified angle is reached in the last intermediate (X) passage with a simultaneous decrease in the bending radii R 'between horizontal 1 and side walls 3 to a final value in the X passage.

In the first finishing (XI) pass, the bending down of flanges 5 on the shelves 4 begins, with the minimum bending angle Δφ = 2 in the penultimate (XIII), and the maximum angle Δψ = 32 ^o (Δφ is the "partial" bending angle per pass or difference the bending angles of this profile element in two adjacent passages) - in the last finishing pass (XIV). In this case, the bending radius of the flanges R '' is equal to the one specified in the first finishing pass (XI), in the XII and XIII passes it decreases by 2.0 ... 2.5 times and in the last XIV pass increases to the specified value.

 An experimental verification of the proposed technical solution was carried out on a roll-forming mill 2 - 8 x 100 - 600 of OJSC Magnitogorsk Iron and Steel Works. For this purpose, both individual profile parameters (material - st., 3.20PS) were varied, as well as profiling parameters (number of closed gauges, bending angles of individual elements along the aisles and bending radii). The obtained bent profiles were tested at Yuzhuralavtoban PKF CJSC for rigidity during their bending and torsion, comparing the results with similar tests of the profile selected as the closest analogue (with equal cross-sectional areas and the same thickness S).

 The bent profile with the claimed parameters during testing showed rigidity 22–38% higher than that of the known profile, the first of them, due to the presence of flanges, lacked undulation of the shelves and the width of profile “B” was more stable. The increase in the width of the shelves and the angle of their downward slope did not significantly increase the rigidity, but led to an increase in the width of the workpiece (i.e., to an additional consumption of metal) and to the need to increase the number of passes to 15 (i.e., to an increase in the consumption of rolls). Similarly, an increase in the size of the corrugation slightly increased stiffness, but increased the consumption of metal. A decrease in the angle α led to a decrease in the resistance of the profile to longitudinal twisting, and an increase in α to an increase in the number of passes during profiling to 15–16 with a slight increase in the resistance to longitudinal twisting.

Reducing the number of “closed” gauges to three or four led to the “reforming” (shift of the centers of radii) of the bending places during the formation of the corrugation and to sorting the profiles. At the beginning of the shaping of the trough section in rough passages, it became necessary to fix the position of the corrugation by pinching it with rollers (as in the well-known calibration - see above), which sharply increased tool wear. "Alignment" of the flanging angle of the flanges per pass (i.e., more than 2 ^o and less than 32 ^o ) reduced the stiffness of the profiles during testing (obviously, by reducing the degree of hardening of the bending sections). At the same time, there was a need for the formation of bending sections of flanges with either constant or successively decreasing radii.

 Thus, the experiments confirmed the acceptability of the claimed objects for solving the task and their advantages over the known objects.

 The feasibility study showed that the use of the proposed bent profile of road fences of motorways reduces operating costs (by increasing the service life of stiffer profiles with improved geometry) by no less than 20%, and profiling it by the proposed method reduces metal consumption, on average , by 15% while reducing the consumption of tool (rolls) by approximately 17%.

Example
Curved profile 360 x 100 x 4 mm for road fences of highways from st. 3 has the following cross-sectional parameters (see FIG. 1):
S = 4 mm, B = 360 mm, H = 100 mm, b ₀ = 4.25 S = 4.25x 4 = 17 mm, b _c = 196 mm, h = 0.2H = 0.2x100 = 20 mm, b _g = 041xb _s = 0.41x196 = 80 mm, b _p = 58 mm, α = 102 ^o , β = 70 ^o , R = 10 mm, γ = 76 ^o .

 The profile is used as longitudinal bars attached to the racks of the fence.

 The mentioned profile is made in 14 passes, and all draft (four) of them and the first intermediate (V - see Fig. 2) are made with the closure of calibers by the flanges of the lower rolls.

(далее угол

(далее угол

Формирование корытного сечения начинается в V и заканчивается в X проходах; формирование гофра осуществляется в I-V проходах; подгибка отбортовок - в XI - XIV проходах.Values of the bending angle of the profile elements along the aisles:

(further angle

(further angle

The formation of the trough section begins in V and ends in X passes; corrugation is carried out in IV passes; bending of flanges - in XI - XIV passes.

Bending radii along the aisles (mm):
IR = 57; II-R = 28; III-R = 17; IV-R = 12; VR = 10 (hereinafter R = const = 10 mm), R '- blunt (i.e. its value is more than 60 mm); VI-R '= 37; VII-R '= 21; VIII-R '= 15; IX-R '= 11; XR '= 10 (hereinafter R' = const = 10 mm); XI-R '' = 10; XII-R ″ = 4; XIII-R ″ = 4; XIV-R '' = 10.

Claims (2)

1. A bent profile mainly for road fences of motorways, comprising a horizontal wall with a trapezoidal corrugation, inclined side walls and horizontal shelves of predetermined values, characterized in that it further comprises flanging shelves with a width of 4.0 - 4.5 profile thicknesses, and inclined downward at an angle of 68 - 72 ^o to the shelves, and the angle of inclination between the side and horizontal walls is 100 - 104 ^o , while the height of the corrugation is 0.18 - 0.22 of the height of the profile, and the width of the corrugation is 0.39 - 0.43 width of the horizontal wall. 2. A method of manufacturing a bent profile by sequentially preparing the elements of the formed strip in rough, intermediate and finishing passes, including bending the side walls and forming a corrugation on the horizontal wall of the profile while limiting the lateral displacement of the strip in draft passes, characterized in that only corrugation, in the intermediate passages, a trough profile is formed to limit the lateral displacement of the strip in the first such pass with simultaneous ensheniem bending radii elements corrugation to a predetermined value, and in the finishing pass bends flanging on the shelves downwards with a minimum angle hem 2 ^o in the penultimate and a maximum angle of 32 ^o in the last finishing pass, the bending radius flange returns makes equal to the target in the first finishing pass, reducing it is 2.0 - 2.5 times in two subsequent passes and increasing to a predetermined value in the last pass.

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