RU1811426C - Method of making bent shaped section - Google Patents

Abstract

Using; SUMMARY OF THE INVENTION In the processing of metals by pressure, in particular for the production of cold-formed profiles, SUMMARY OF THE INVENTION: The side elements of the profile are bent sequentially along transitions with the formation of rounded sections at a constant distance I between the centers of the roundings. In the penultimate transition, the profile elements are bent, and in the last transition, they are bent by 0.5, .. 2.0 ° with simultaneous narrowing and expansion of the profile, changing the value of I by 1; 0 ... 1.5% compared with the original value. 3 ill.

Description

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The invention relates to the processing of metals by pressure and can be used in the manufacture of cold-formed shaped sections.

The aim of the invention is to improve the quality of bent shaped profiles of a certain sectional configuration by improving their geometry.

This goal is achieved by the fact that during sequential bending of the side profile elements with the formation of rounded sections with a constant distance I between the centers of curvature, in the penultimate passage these elements are bent, and in the last pass they are bent by 0.5 ... 2, 0 ° with simultaneous narrowing and expansion of the profile, changing the value of I by 1.0,., 1.5% compared with the original value.

In the analysis of known technical solutions not found that combination

features of a method that distinguishes the claimed technical solution from the prototype. Therefore, it can be concluded that the distinguishing features of the invention have significant differences.

The essence of the method is to remove the residual stresses in the formed profile and improve its geometry due to deformation of the opposite sign, which is achieved by alternating narrowing and expansion of the profile in the last calibers, as well as by simultaneous bending of the inclined elements and their bending to the specified angles. Obviously, the values of the transverse strain and the bending-bending angles cannot be randomly selected and their value is most expediently determined experimentally.

The method of unbending folded elements is known and is used to eliminate end defects in piece profiles.

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channeling channels. However, at the same time, in the case of animals, the total bending angles of the inclined elements do not exceed the specified finite) values and, secondly, the narrowing-broadening of the profile occurs without changing the distance between the centers of curvature of the adjacent sections.

Therefore, the known technique does not bring the desired effect when improving the geometry of shaped bent profiles having more than two curves (moreover, part of them

- with relatively large radii - from 7 to 10 strip thickness), for example, with a W-shaped cross section (profile of the road fence), especially with continuous profiling.

An experimental verification of the production method on continuous and semi-continuous roll forming mills (respectively. 1-4x50-300 and 2-8x100-600) of the Magnitogorsk Iron and Steel Works in the manufacture of 10-11 passes of shaped profiles of a road fence (with a W-shaped cross section - SM-FIG. 1) thickness S 2-3 mm, width B

280-320 mm, height H 75-87 mm with I 182-198 mm, R (7-10) 5 and with angles of inclination of the side elements o: and (3 within

52 ° -62 ° from steels with Ok 47 kgf / mm2. In the experiments, we varied the value of the inflection and bending angles of the inclined profile elements, as well as the value A of the relative change in the parameter, evaluating the results by the number of profiles with high (W) profiling accuracy.

The highest level of quality (VT-54-73% yield, the rest profiles of increased (PT) accuracy of cross-sectional dimensions) are achieved in those cases when 0.5 ... 2.0 ° and А 1.0, .. 1, 5%, and the above-described operations to relieve residual stresses were carried out in the penultimate and last passes.

At 0.5 ° and A 1%, like at 2 ° and A 1.5%, the quality level of the profiles decreased: VT output - 20-48%, the rest - PT and NT (normal profiling accuracy), which at lower the values of y and A are explained by insufficient removal of residual stresses (a spring of bent elements was observed), and with large y and A excessive plastic deformation of profile elements,

In addition, the proposed operations were carried out (with optimal values of mind A) not in the last two passes, but 2-4 passes before the finishing (last): the output of BT profiles did not exceed 42%,

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A control profiling was also carried out according to the prototype method (see above): the yield of BT profiles was 46%, PT - 31%, the rest - NT profiles. Thus, the experiments confirmed the acceptability of the technical solution found to achieve the goal and its advantages over the prototype object,

FIG. 1-3 illustrate a method of manufacturing a bent shaped profile along the aisles ...

This profile has a W-shaped cross section, consisting of external 1 and internal 2 inclined lateral elements, interconnected by rounded 3 with radii R, the distance between the centers of which is I; in the middle of the profile also rounded 4 radius R. The angle of inclination of the elements 1 to the horizontal - a,

-elements 2 - / 3; elements 1 may contain flanging edges 5 with an angle of inclination e. The width of the finished profile is B, the highest height is H, the height along the edges

- h N, thickness - S.

The method is implemented as follows ...

The profile (see pos. 1) with the given values a, / 3 and (in all previous passes I const) is set in the penultimate caliber, in which the inclined elements 1 and 2 are bent at an angle a - a / 3 - / 3 0.5 ... 2.0 °, and the value of I using the forming elements of the rolls is reduced by 1.0 ... 1.5% (to G - see pos. II). Then the profile enters the last gauge of the mill and obtains the final dimensions (pos. Hi) due to the expansion of elements 1 and 2 by 0.5 ... 2.0 ° and the expansion of the cross section with an increase in Г by 1.0 ... 1.5 % (up to I). If the profile has flanging edges, then the magnitude of their kink in the penultimate passage should also be in the range of 0.5 ... 2.0 °.

Example 1. A shaped bent profile with a W-shaped cross section with dimensions (see figure 1): B - 306 mm, I 194 mm, H - 83 mm, h 80 mm, R 24 mm, S 3 mm, and / 3 55 ° and 5 81 °, is formed from st.ZKP in 10 passes. The cross-sectional dimensions after the 8th pass correspond to those indicated, except 50 70 ° .. .-. In the penultimate (9th) pass, the inclined elements are bent by 0.5 ° (up to a f - 55.5 °, 5 81.5 °) with a simultaneous decrease in I by 0.011 0.01x194 1 mm. In the last (10th) pass, all elements are unbent by 0.5 ° (to a, (5 81 °) and increased I 192 mm to 194 mm, the yield of BT profiles is 52%, the rest is PT.

PRI me R 2. The same profile is formed in the same way, but at 1 ° (a 56 °, (51 82 °), and D 1.25% (G 194 - 194-0.0125 194-2.5 mm 191.5 mm). The yield of BT profiles is 70%. The rest is PT.

Example 3. The same profile is formed with at 2 ° (57 ° 6 83 °) and, 5% (1 194-194-0.015 194-3 191 mm). The yield of BT profiles is 60%, the rest is PT.

The technical and economic advantage of the claimed object over the prototype is to improve the quality of shaped bent profiles such as road fencing by improving their geometry.

According to the central laboratory of MMK, the use of the technical solution found on roll forming mills of the plant 1-4 and 2-8 in production

of said profiles will increase the yield of rolled products with high profiling accuracy by an average of 17%.

Claims (1)

SUMMARY OF THE INVENTION A method for manufacturing a bent shaped profile by successively bending its side elements with the formation of rounded sections at a constant distance I between the centers of curvature, characterized in that, in order to improve the quality by improving the shape, profile elements in the penultimate pass they are bent, and in the latter they are bent by 0.5 ... 2 ° with a simultaneous narrowing and expansion of the profile, changing the value of I by 1.0 ... 1.5% compared with the original value.