RU2375137C1 - Forming method of special bent profile - Google Patents

Abstract

FIELD: mechanics.

SUBSTANCE: invention refers to metal deformation process, namely to manufacturing procedure of cold-formed rolled profiles. Edge sections are bent one by one as to width of flat workpiece so that inclined side elements are formed. At that, in the above sections there formed are triangular corrugations. In the first three forming passages there formed is channel with horizontal flanges and its side flanges are inclined at an appropriate angle to horizontal. And starting with the fourth passage, these horizontal flanges are bent downwards till finite angle in the seventh passage is reached and also, side flanges formed before are bent to a certain angle so that horizontal flanges are formed in the sections bent downwards.

EFFECT: profile of the required geometry in a minimum number of forming passages.

1 dwg, 1 ex

Description

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

Such profiles are made by the method of continuous or piece profiling on multicell mills of the type 1 ÷ 4 × 50 ÷ 300 and 2 ÷ 8 × 100 ÷ 600.

The profiling technology on such mills is described in sufficient detail, for example, in a book under the editorship of I. Trishevsky “Production of bent profiles. Equipment and technology ", M.," Metallurgy ", 1982, S. 243-262. This technology, as a rule, consists in the use of bending angles of specific values for individual elements of the formed profile, as well as in a certain sequence of bending angles in the mill stands.

A known method for the production of bent sections of rolled products, mainly channels, in which in the first two passes the bending is carried out with the minimum allowable radius, which is increased in the third pass, and after that the bending is carried out with gradually decreasing bending radii (see AS USSR No. 1409372). However, this method is only suitable for producing equal-channel channels.

The closest analogue to the claimed method is a method for the production of bent trough profiles by bending the edge sections of the workpiece with the formation of inclined side elements, characterized in that the folding of the profile shelves is carried out simultaneously with the bending of the said side elements to an angle of 45 ° ... 60 °, and is completed after the bending is completed these elements (see AS USSR No. 1669613). The disadvantage of this method is the relatively large number (9) of passes, which increases the labor costs for the production and consumption of rolls.

The technical task of the present invention is to obtain the profile of the desired geometry for the minimum possible number of forming passes.

To solve this problem, in the method of forming a bent special profile by sequentially bending the edge sections along the width of the strip blank with the formation of inclined side elements, when forming on the edge sections of triangular corrugations in the first three forming passes, they form a trough profile with horizontal shelves when its side shelves are tilted at an angle 55 ° to the horizontal, and after the fourth passage, the horizontal shelf is folded down to reach the final angle β _n = 61 ° in the seventh passage with simultaneous oh podgibkoy previously formed lateral legs to an angle α = 61 ° bend to form at the bottom portions of the horizontal flange returns.

The sequence of operations of the proposed method is obtained empirically and is empirical.

The essence of the proposed technical solution is to optimize the sequence of operations that allows you to get the profile of the desired geometry and with a more complex cross-section than the trough profile, for a smaller number of passes.

The inventive method is illustrated by the diagram in the drawing (Roman numerals - numbers of passes).

In the passages I ... III, a trough profile is formed that contains a horizontal wall 1, inclined side flanges 2 and horizontal shelves 3, and the bending angles of the shelves 2 consistently increase from α ₁ = 20 ° to α ₃ = 55 °. In the IV pass, the bending of the shelves 3 down begins with the simultaneous continuation of the bending of the shelves 2 up, and the formation of flanges on these shelves also begins; while flanges 4 maintain their horizontal position in all passages - from IV to VII (final).

In the passage IV, the folding of the shelves 2 ends α ₄ = α = 61 ^o ; the bend of the horizontal shelves 3 begins with an angle β ₁ = 15 ° and ends with a final angle β _n = β = 61 °. The finished profile has two triangular corrugations 5 and horizontal flanges 4 at the edges. The height of the corrugations is H, their width is in _g , and the width of the flanges is “c” with profile thickness S.

Experimental verification of the proposed method was carried out on a bending mill 2 ÷ 8 × 100 ÷ 600 OJSC "Magnitogorsk Iron and Steel Works". For this purpose, when forming the profile shown in Fig. 1 with a thickness S = 2 ... 3 mm and with a flanging width of = 5 ... 8 mm, the sequence of forming of its constituent elements and the angle α ₃ (from 50 ° to 60 °) were varied ), evaluating the results by the quality of the geometry of the profile with the number of passes 6 ... 8, the number of which was determined by the values of the angle of folding of the side shelves 2 and the angle of inflection of the shelves 3.

The best results (the required geometry of the profile with the optimal number of 7 passes) are obtained using the proposed method. Deviations from the recommended profiling scheme worsened the achieved indicators. Thus, an increase in the bending angles per pass and a decrease in the number of passes to 6 led in some cases to cracking at the corrugation tops, especially at S = 3 mm.

With a decrease in the bending angles per pass and an increase in the number of passes, the geometry of the profiles remained the same as with the recommended profiling scheme, but the consumption of rolls and labor costs for production increased. The method chosen as the closest analogue (see above) was not used in the experiments because of the knowingly large number of passes with the negative consequences arising from this.

Thus, an experimental verification confirmed the acceptability of the technical solution found to achieve the goal and its advantage over a known object.

Feasibility studies have shown that the implementation of the present invention on high-quality roll forming mills similar to the mill 2 ÷ 8 × 100 ÷ 600 of OJSC MMK will reduce labor costs for the production of this special profile by at least 10% with a corresponding increase in profit from sales rental.

Concrete example

The special bent profile 234 × 180 × 30 × 2 mm shown in Fig. 1 (see) has dimensions: width β _n = 234 mm, distance between corrugations L = 180 mm, their height H = 30 mm and profile thickness S = 2 mm. The width of the corrugations in _g = 44 mm, the width of the flanges in = 5 mm, α = 61 °.

Profiling mode (bending angle values: α ₁ = 20 °, α ₂ = 40 °, α ₃ = 55 °, α ₄ ... α = 61 °; β ₁ = 15 °, β ₂ = 40 °; β ₃ = 55 ° ; β _n = 61 °.

All bending radii are R = 3 mm.

Claims (1)

A method of forming a bent special profile, including sequentially bending the edge sections along the width of the strip billet with the formation of inclined side elements, characterized in that they are formed on the edge sections of the triangular corrugations, in the first three passes they form a trough profile with horizontal shelves and tilting its side shelves at an angle 55 ° to the horizontal, and since the fourth passageway said horizontal shelf is folded down to reach the final angle β _n = 61 ° in the seventh passage from one belt podgibkoy previously formed lateral legs to an angle α = 61 ° to form sections at the bend down horizontal flange returns.

Images