RU2040991C1 - Bent section production method - Google Patents

Abstract

FIELD: metal pressure forming. SUBSTANCE: method comprises steps of making a bent section, having asymmetrical configuration of its cross section, with one flange to inside and other flange, turned to outside, five bending zones, providing four convex and one concave three-member portion, the last portion being fifth bending zone in direction to inside from the flange; performing rotation of a web of the section, joined with its third and forth bending zones in direction to inside from the flange in technological shaping transitions relative to an apex of the third bending zone of the section from its any flange in direction, opposite to a direction of flange bending up, in order to provide in the last transition a final rotation angle, whose value is being calculated according to a given relation. EFFECT: enhanced quality of complex-shape bent section. 1 cl, 7 dwg, 2 tbl

Description

 The invention relates to pressure machining of sheet material using rolls of a special shape and is intended for use mainly in ferrous metallurgy, as well as in transport, tractor and agricultural machinery and shipbuilding.

 The manufacture of bent profiles with an asymmetric configuration of the cross section in the rolls is associated with great difficulties due to asymmetric deformation of the metal, causing helical twisting, longitudinal deflection and a change in the main dimensions of the cross section along the length of the profile. To prevent and eliminate these defects, various molding methods are used, which provide for an increased number of technological transitions, the use of dressing and untwisting of profiles during their manufacturing, heating of the initial workpiece and other techniques. However, these methods in some cases do not find application due to the complexity of the design of the roll calibers, an excessive increase in the number of technological transitions, the use of additional equipment for heating and dressing profiles. Then the specified quality of the profiles is not ensured due to their helical twisting and longitudinal deflection, the fibrousness of the edges of the shelves and other defects.

 There is a method of manufacturing asymmetric bent profiles [1] according to which, in order to ensure high-quality molding of profiles due to the increased accuracy of their geometric dimensions, in each rough technological transition, the profile shelves are simultaneously bent in opposite directions to the corners, providing equal horizontal displacements of the edges of the shelves, in the finishing technological transitions at the same time bend a large shelf of the profile and in the opposite direction turn the wall of the profile relative to The tops of the bending place adjacent to the large shelf, in the finishing technological forming transitions, return the profile wall to the molding plane, and then deform the profile to the specified configuration.

 A significant drawback of this analogue is the obtaining in some cases of low quality profiles due to the lack of mutual balancing of the form-changing moments of all profile elements for all technological forming transitions.

 There is also a known method of manufacturing bent unequal channels of the channel type [2] according to which, in order to improve the quality of the profiles by preventing them from twisting, a corner with a shelf is formed in the first technological transitions, the width of which is equal to the width of the larger profile shelf, and in the last transitions, after molding angle between the wall and the larger profile shelf, return the profile wall to the molding plane and bend the smaller shelf to the specified configuration.

 The main drawback of the second analogue (as well as the first one) is the obtaining in some cases of low quality profiles due to the lack of mutual balancing of the total (cross-sectional) shape-changing moments for all technological forming transitions.

 The closest in technical essence to the claimed one is the method of manufacturing unequal hollow bent profiles [3] selected as a prototype, according to which, in order to prevent helical twisting of the profiles, their shaping is carried out due to equal horizontal displacements of the workpiece edges in the axial plane of each technological forming transition.

 A significant disadvantage of the prototype and both analogues is that in the manufacture of closed bent profiles with an asymmetric cross-sectional configuration, with one shelf inward of the profile and with the other outward, with five bending places forming four convex and one concave three-element sections of the profile, and a concave three-element section the profile forms its fifth place of bending, counting from the side of the shelf into the profile; in some cases, low-quality profiles are obtained due to their helical twisting, extending beyond Ustimov limits. To obtain profiles with helical twisting within acceptable limits due to the mutual balancing of all shape-changing moments applied to all flat elements in all technological transitions, it is necessary to bend the flat profile elements at different angles and in the last technological forming transition to fix the profile position in space.

So, for example, the profiling mode in the manufacture of a closed bent profile 105x50x65x35x2 mm with an asymmetric cross-sectional configuration, with one shelf inside the profile and the other outward, with five bending places forming four convex and one concave three-element sections of the profile, and the concave three-element section of the profile forms its fifth place of bending, counting from the side of the shelf inside the profile, from low alloy steel 10KHSND (with the widths of flat elements and the reamers of the bending places located between them b ₁ 13.5 mm, b ₂ 65.1 mm, b _3, b _5, b _7, b _9, b _11, 7.7 mm, 53.0 mm b _4, b _6, 37.4 mm, 23.0 mm b _8, b ₁₀ 17.4 mm, an inner radius of bending of places r 4 mm, the final bending angles of the bending points α _k = β _k = δ _k = ε _k = μ _k = 90 ^° , the metal thickness of the initial billet S2 mm and the width of the initial billet B _zag. 248 mm), determined according to the prototype method, is given in table 1.

The profile was formed by the roll method on a 2.5x x200.550 roll forming mill. Due to the lack of specific instructions in the description of the prototype on the procedure for bending flat profile elements and the magnitude of their bending angles in the manufacture of bent profiles with an asymmetric cross-sectional configuration, with one shelf inside the profile and the other outside, with five bending places forming four convex and one concave three-element sections of the profile, and the concave three-element section of the profile forms its fifth bend, counting from the side of the shelf into the profile, according to the prototype method, the procedure for bending oskih profile elements on transitions and the limit value for the angle hem passageway (20 ^a) were taken the same as in the manufacture of the profile according to the proposed method.

 In the first master technological transition, the initial billet was directed along the roll forming mill.

In the second fifteenth technological forming transitions, the places of profile bending were formed by multi-transition folding of flat profile elements. At the same time, two places of profile bending were formed in the second technological forming transition, in the third seventh three places of bending, in the eighth four places of bending, in the ninth and fifteenth all five places of bending of the profile. Angles bending places in the last bending strip fifteenth molds transition equaled end corners bending places ready _to profilyaα = β _a = δ _a = ε _a = μ _k = ^90. In this transition, the profile was molded to the specified configuration. The rotation angles γ _t of the profile wall with a width of b ₈ in the second fourteenth technological forming transitions were determined by the method of expert evaluations; the final angle of rotation γ _to the same profile wall in the last fifteenth technological molding transition was determined based on the principle of equal horizontal displacements of the edges.

To obtain the finished profile 105x x50x65x35x2 mm, 15 technological transitions were required. The helical twisting of the finished profile was 2 ^o 30 '3 ^about 1 m length, which goes beyond the requirements of GOST 8281-80 "Cold-bent steel. Channel bars are unequal. Assortment" (permissible helical twisting 1 ^about 1 m 1 length).

 The aim of the invention is to improve the quality of the profiles by reducing their helical twisting relative to the longitudinal axis.

b₁α_к+

b₁+

b

+

b₁+

b

-

b₂+

b

+b

,
(1)
где α_к= δ_к=ε_к=μ_к=β_к конечные углы изгиба соответственно первого, второго, третьего, четвертого и пятого мест изгиба профиля, считая от полки внутрь профиля;
b₁ ширина полки внутрь профиля;
b₂ ширина полки наружу профиля;
b₃, b₅,b₇,b₉,b₁₁ ширина разверток мест изгиба профиля с конечными углами изгиба соответственно α_к,δ_к,ε_к, μ_к,β_к;
b₄, b₆, b₈, b₁₀ ширины стенок профиля соответственно первой, второй, третьей, четвертой, считая от полки внутрь профиля;
В_заг ширина исходной заготовки;
m 0,95.1,1 эмпирический коэффициент.The goal is achieved by the fact that, when forming the profile in the rolls by multi-junction turning the profile wall relative to the top of the bending point adjacent to this wall in the direction opposite to the bending direction of one of the profile shelves and simultaneously multi-junctioning the remaining flat profile elements to its specified configuration, turning the profile wall associated with its third and fourth places of bending, counting from the shelf into the profile, is carried out in technological forming transitions relative to the top of the bend profile with a finite bending angle ε _k in the direction opposite to the direction of the folding of the shelves until the final turning angle γ _{k is} reached in the last technological forming transition, the value of which is calculated by the formula γ _k

b ₁ α _to +

b ₁ +

b

+

b ₁ +

b

-

b ₂ +

b

+ b

,
(1)
where α _k = δ _k = ε _k = μ _k = β _{k the} final bending angles of the first, second, third, fourth and fifth places of the profile bending, respectively, counting from the shelf into the profile;
b ₁ shelf width in profile;
b ₂ shelf width to the outside of the profile;
b ₃ , b ₅ , b ₇ , b ₉ , b _{11 the} width of the reamers of the bending points of the profile with finite bending angles, respectively, α _k , δ _k , ε _k , μ _k , β _k ;
b ₄ , b ₆ , b ₈ , b _{10 the} width of the walls of the profile, respectively, of the first, second, third, fourth, counting from the shelf into the profile;
In the _zag width of the original blank;
m 0.95.1.1 empirical coefficient.

М $\genfrac{}{}{0ex}{}{\text{(}}{\text{t}}$ ^фс)=0
(2) где t номер технологического формующего перехода;
М_t ^(фс) суммарный (по поперечному сечению формуемой полосы) формоизменяющий момент, приложенный к формуемой полосе в t-том технологическом формующем переходе;
n количество всех технологических формующих переходов.To ensure helical twisting of the finished profile within acceptable values, it is necessary and sufficient that the system of total (along the cross-section of the moldable strip) shape-changing moments applied to the moldable strip in all technological transitions be balanced, i.e. so that equality holds

M $\genfrac{}{}{0ex}{}{\text{(}}{\text{t}}$ ^fs) = 0
(2) where t is the number of technological forming transition;
M _t ^(fs) total (over the cross-section of the moldable strip) form-changing moment applied to the moldable strip in the t-th technological molding transition;
n the number of all technological forming transitions.

S²l_t,1 +

Jb_i(Δα_t-Δγ_t,1)S³
(3)
М $\genfrac{}{}{0ex}{}{\text{(ф)}}{\text{t,1}}$ _,c

S²l_t,1 +

J(B_заг-b₁)Δγ_t,1,S³
(4)
М $\genfrac{}{}{0ex}{}{\text{(фс}}{\text{t,1}}$ ⁾=М $\genfrac{}{}{0ex}{}{\text{(ф)}}{\text{t,1}}$ _,n-М $\genfrac{}{}{0ex}{}{\text{(ф)}}{\text{t,1}}$ _,c

JS³(t₁Δα_t-B_загΔγ_t,1)
(5)
где М^(ф) _t,1,n формоизменяющий момент, необходимый для формоизменения полки внутрь профиля и прилежащего к ней места изгиба, конечный угол изгиба которого α_к, на участке главного перехода t-того технологического формующего перехода при формовке только этого места изгиба профиля;
М ^(ф) _t,1,c- формоизменяющий момент, необходимый для формоизменения места изгиба профиля, конечный угол изгиба которого α_к, и многоэлементного участка полосы, состоящего из полки наружу профиля, его четырех стенок и мест изгиба, расположенных между ними, на участке плавного перехода t-того технологического формующего перехода при формовке только места изгиба профиля, конечный угол изгиба которого α_к;
М^(фс) _t,1 суммарный (по поперечному сечению формуемой полосы) формоизменяющий момент, необходимый для формоизменения всех элементов профиля на участке плавного перехода t-того технологического формующего перехода при формовке только места изгиба профиля, конечный угол изгиба которого α_к; l_t,1 длина активной зоны участка плавного перехода места изгиба профиля, конечный угол изгиба которого α_к, при формовке только этого места изгиба в t-том технологическом формующем переходе;
Δα_t изменение угла изгиба за проход места изгиба профиля, конечный угол изгиба которого α_к, при формовке только этого места изгиба, в t-том технологическом формующем переходе;
Δγ_t,1 угол поворота за проход стенки шириной b₈, при формовке только места изгиба профиля, конечный угол изгиба которого α_к, в t-том технологическом формующем переходе;
σ_т предел текучести материала заготовки;
S толщина металла заготовки;
J модуль упругости второго рода материала заготовки.When forming only one profile bending point, the final bending angle of which is α _k , by bending the shelf inward of the profile and simultaneously turning the multi-element section of the profile consisting of the shelf outward of the profile, its four walls and bending places located between them in opposite directions, forming changes necessary for the shaping of all strip elements in each t-th technological molding transition, to a first approximation, while holding the molded bend at a constant level in the adjacent t-th and (t-1) th technological forming transitions are determined by dependencies
M $\genfrac{}{}{0ex}{}{\text{(f)}}{\text{t, 1}}$ _{, n}

S ² l _{t, 1} +

Jb _i (Δα _t -Δγ _{t, 1} ) S ³
(3)
M $\genfrac{}{}{0ex}{}{\text{(f)}}{\text{t, 1}}$ _{, c}

S ² l _{t, 1} +

J (B _zag -b ₁ ) Δγ _{t, 1,} S ³
(4)
M $\genfrac{}{}{0ex}{}{\text{(fs}}{\text{t, 1}}$ ⁾ = M $\genfrac{}{}{0ex}{}{\text{(f)}}{\text{t, 1}}$ _{, n} -M $\genfrac{}{}{0ex}{}{\text{(f)}}{\text{t, 1}}$ _{, c}

JS ³ (t ₁ Δα _t -B _zag Δγ _{t, 1} )
(5)
where M ^(f) _{t, 1, n is the} shape-changing moment needed to shape the flange inside the profile and the adjacent bending point, the final bending angle of which α _to , on the main transition section of the t-th technological forming transition when forming only this profile bending point ;
M ^(f) _{t, 1, c} is the shape-changing moment necessary to shape the place of bending of the profile, the final bending angle of which α _to , and the multi-element section of the strip, consisting of a shelf outside the profile, its four walls and the places of bending located between them, on the smooth transition section of the t-th technological molding transition when forming only the profile bending point, the final bending angle of which α _k ;
M ^(fs) _{t, 1} total (along the cross section of the strip being formed) shape-changing moment necessary to shape all the profile elements in the smooth transition section of the t-th technological forming transition when forming only the profile bending point, the final bending angle of which α _to ; l _{t, 1} length of the active zone of the smooth transition section of the profile bending point, the final bending angle of which is α _k , when only this bending point is molded in the t-th technological molding transition;
Δα _{t is the} change in the bending angle over the passage of the profile bending point, the final bending angle of which α _k , when forming only this bending point, in the t-th technological molding transition;
Δγ _{t, 1} angle of rotation for the passage of the wall with a width of b ₈ , when forming only the bending point of the profile, the final bending angle of which α _k , in the t-th technological molding transition;
σ _{t the} yield strength of the workpiece material;
S is the thickness of the metal workpiece;
J is the elastic modulus of the second kind of workpiece material.

JS

b₁ +

b

-B

(6)
М $\genfrac{}{}{0ex}{}{\text{(фс}}{\text{t,3}}$ ⁾

JS

b₁ +

b

-B

(7)
М $\genfrac{}{}{0ex}{}{\text{(фс}}{\text{t,4}}$ ⁾

JS

b₂ +

b

-B

(8)
М $\genfrac{}{}{0ex}{}{\text{(фс}}{\text{t,5}}$ ⁾

JS³[b₂Δβ_t-B_загΔγ_t,5]
(9) где М_t,2 ^(фc), M_t,3 ^(фc) M_t,4 ^(фc), M_t,5 ^(фc) суммарные (по поперечному сечению формуемой полосы) формоизменяющие моменты, необходимые для формооизменения всех элементов профиля на участке плавного перехода t-того технологического формующего перехода при формовке только одного места изгиба профиля, конечный угол изгиба которого соответственно δ_к,ε_к,μ_к,β_к;
Δδ_t Δε_t Δμ_t Δβ_t изменения углов изгиба за проход мест изгиба профиля, конечные углы изгиба которых соответственно δ_к,ε_к,μ_к,β_к, при формовке только каждого из них в t-том технологическом формующем переходе;
Δγ_t,2 Δγ_t,3 Δγ_t,4 Δγ_t,5 углы поворота за проход стенки профиля шириной b₈ при формовке только одного места изгиба профиля, конечный угол изгиба которого соответственно δ_к,ε_к,μ_к,β_к, в t-том технологическом формующем переходе. При одновременной формовке всех пяти мест изгиба профиля рассматриваемого типа имеем
М $\genfrac{}{}{0ex}{}{\text{(}}{\text{t}}$ ^фс)=М $\genfrac{}{}{0ex}{}{\text{(фс}}{\text{t,1}}$ ⁾+М $\genfrac{}{}{0ex}{}{\text{(фс}}{\text{t,2}}$ ⁾+М $\genfrac{}{}{0ex}{}{\text{(фс}}{\text{t,3}}$ ⁾-М $\genfrac{}{}{0ex}{}{\text{(фс}}{\text{t,4}}$ ⁾+M $\genfrac{}{}{0ex}{}{\text{(фс}}{\text{t,5}}$ ⁾

JS

b₁Δα_t+

b₁+
+

b

+

b₁ +

b

-

b₂ +

b

+b₂Δβ_t-B

(10)
Δγ_t=Δγ_t,1+Δγ_t,2+Δγ_t,3-Δγ_t,4+Δγ_t,5
(11)
где М_t ^(фc) суммарный (по поперечному сечению формуемой полосы) формоизменяющий момент, необходимый для формоизменения всех элементов формуемой полосы на участке плавного перехода t-того технологического формующего перехода при одновременной формовке всех пяти мест изгиба профиля;
Δγ_t угол поворота за проход стенки профиля шириной b₈ при формовке всех мест изгиба профиля в t-том технологическом формующем переходе.Similarly to the previous one, for the remaining four places of the profile bend, we write:
M $\genfrac{}{}{0ex}{}{\text{(fs}}{\text{t, 2}}$ ⁾

Js

b ₁ +

b

-B

(6)
M $\genfrac{}{}{0ex}{}{\text{(fs}}{\text{t, 3}}$ ⁾

Js

b ₁ +

b

-B

(7)
M $\genfrac{}{}{0ex}{}{\text{(fs}}{\text{t, 4}}$ ⁾

Js

b ₂ +

b

-B

(8)
M $\genfrac{}{}{0ex}{}{\text{(<figure-callout id="5" label="fs t" filenames="00000106.png,00000108.png" state="{{state}}">fs </figure-callout>}}{\text{t}}$ ⁾

JS ³ [b ₂ Δβ _t -B _zag Δγ _{t, 5} ]
(9) where M _{t, 2} ^(fc) , M _{t, 3} ^(fc) M _{t, 4} ^(fc) , M _{t, 5} ^{(fc) are the} total (along the cross section of the strip being formed) shape-changing moments necessary for the shape change of all elements profile on the smooth transition section of the t-th technological molding transition when forming only one bending point of the profile, the final bending angle of which, respectively, δ _k , ε _k , μ _k , β _k ;
Δδ _t Δε _t Δμ _t Δβ _t changes in the bending angles during the passage of the profile bending points, the final bending angles of which respectively are δ _k , ε _k , μ _k , β _k , when only each of them is molded in the t-th technological molding transition;
Δγ _{t, 2} Δγ _{t, 3} Δγ _{t, 4} Δγ _{t, 5} angles of rotation per passage of the profile wall with a width of b ₈ when forming only one bend of the profile, the final bending angle of which, respectively, δ _k , ε _k , μ _k , β _k , in the t-th technological forming transition. With the simultaneous formation of all five places of profile bending of the type in question, we have
M $\genfrac{}{}{0ex}{}{\text{(}}{\text{t}}$ ^fs) = M $\genfrac{}{}{0ex}{}{\text{(fs}}{\text{t, 1}}$ ⁾ + M $\genfrac{}{}{0ex}{}{\text{(fs}}{\text{t, 2}}$ ⁾ + M $\genfrac{}{}{0ex}{}{\text{(fs}}{\text{t, 3}}$ ⁾ -M $\genfrac{}{}{0ex}{}{\text{(fs}}{\text{t, 4}}$ ⁾ + M $\genfrac{}{}{0ex}{}{\text{(fs}}{\text{<figure-callout id="5" label="t" filenames="00000106.png,00000108.png" state="{{state}}">t</figure-callout> 5}}$ ⁾

Js

b ₁ Δα _t +

b ₁ +
+

b

+

b ₁ +

b

-

b ₂ +

b

+ b ₂ Δβ _t -B

(10)
Δγ _t = Δγ _{t, 1} + Δγ _{t, 2} + Δγ _{t, 3} -Δγ _{t, 4} + Δγ _{t, 5}
(eleven)
where M _t ^{(fc) is the} total (over the cross-section of the moldable strip) shaping moment necessary for shaping all the elements of the moldable strip in the smooth transition section of the t-th technological molding transition while simultaneously molding all five places of profile bending;
Δγ _{t is the} angle of rotation for the passage of the profile wall with a width of b ₈ when forming all places of profile bending in the t-th technological molding transition.

М $\genfrac{}{}{0ex}{}{\text{(}}{\text{t}}$ ^фс)

JS

b₁α_к+b₁ +

b

+

b₁ +

b

-

b₂ +

b

× μ_к+b₂β_к-B

(12)

Δγ_t=γ_к
(13)
Из (2) и (12) следует
γ_к

b₁α_к+

b₁ +

b

+

b₁ +

b

-

b₂ +

b

+b

(14)
На основании экспериментальных исследований имеем:
γ_к

b₁α_к+

b₁ +

b

+

b₁ +

b

-

b₂ +

b

+b

(1)
где m=0,95.1,1 эмпирический коэффициент.Summing the shape-changing moments M _t ^(fc) for all technological forming transitions, we obtain:

M $\genfrac{}{}{0ex}{}{\text{(}}{\text{t}}$ ^fs)

Js

b ₁ α _to + b ₁ +

b

+

b ₁ +

b

-

b ₂ +

b

× μ _k + b ₂ β _k -B

(12)

Δγ _t = γ _k
(13)
From (2) and (12) it follows
γ _to

b ₁ α _to +

b ₁ +

b

+

b ₁ +

b

-

b ₂ +

b

+ b

(fourteen)
Based on experimental studies, we have:
γ _to

b ₁ α _to +

b ₁ +

b

+

b ₁ +

b

-

b ₂ +

b

+ b

(1)
where m = 0.95.1.1 is an empirical coefficient.

 Therefore, in the manufacture of closed bent sections of rolled products with an asymmetric cross-sectional configuration, with one shelf inward of the profile and with the other outward, with five places of bending, forming four convex and one concave three-element sections of the profile, and the concave three-element section of the profile forms its fifth place of bending, counting from the side of the shelf into the profile, according to the proposed method, the system of total (along the cross section of the moldable strip) form-changing moments applied to the moldable in all technological forming transitions, it is balanced, which, in turn, provides helical twisting of bent profiles of the type described within acceptable values and achieving the goal of improving the quality of profiles by reducing their helical twisting relative to the longitudinal axis.

 According to the information available to the applicant in the known solutions there are no signs similar to those that distinguish the proposed technical solution from the prototype, which allows us to conclude that it meets the criterion of "inventive step".

For the technological forming transitions to rotate the profile wall with a width of b ₈ relative to the top of the bending point, the final bending angle of which ε _к , in the direction opposite to the direction of the shelf bending inside the profile until reaching the final turning angle γ _k in the last technological forming transition, it is necessary and sufficient to provide the presence of conical elements with corresponding angles between the generators and the axis in the set of rolls for the manufacture of the profile.

The difference in the proportionality coefficient m in formula (1) is due to the lack of consideration of the strain hardening of the metal of the profile bending points when calculating the shape-changing moments applied to the formed strip. The selection of this coefficient is based on the following considerations:
1) when the coefficient m is less than 0.95, in some cases there is a helical twisting of the finished profile, the value of which is outside the permissible limits, in the direction from the shelf inside the profile to the shelf outside the profile;
2) with a coefficient m greater than 1.1, in some cases there is a helical twisting of the finished profile, the values of which are outside the permissible limits, in the direction from the shelf to the outside of the profile to the shelf inside the profile.

 The analysis of the proposed method for the manufacture of bent profiles with an asymmetric cross-sectional configuration, with one shelf inside the profile and the other outward, with five bending places, forming four convex and one concave three-element sections of the profile, the concave three-element section of the profile forming its fifth bending position, counting from the side of the shelf into the profile, indicates that the method is industrially applicable and a positive effect in the implementation of the invention will be obtained due to mutual balances the total (along the cross section of the formed strip) form-changing moments applied to the formed strip in all technological forming transitions.

Figure 1 shows a diagram of the molding of a bent profile with an asymmetric cross-sectional configuration, with one shelf inward of the profile and with the other outward, with five places of bending, forming four convex and one concave three-element sections of the profile, and the concave three-element section of the profile forms its fifth place of bending , counting from the side of the shelf into the profile;
In FIG. 2 is a cross-section of a finished closed bent profile with an asymmetric cross-sectional configuration, with one shelf inward of the profile and with the other outward, with five bending points forming four convex and one concave three-element sections of the profile, the concave three-element section of the profile forming its fifth bending position, counting from the side of the shelf into the profile;
In Fig. 3, an auxiliary scheme for determining the angle of rotation for the passage Δγ _{t, 1} of the profile wall with a width of b ₈ when forming only the bending point of the profile, the final bending angle of which is δ _k , in the t-th technological molding transition;
In FIG. 4 is an auxiliary scheme for determining the angle of rotation for the passage Δγ _{t, 2} , of the profile wall with a width of b ₈ when forming the bending point of the profile, the final bending angle of which is δ _k in the t-th technological molding transition;
In Fig. 5, an auxiliary scheme for determining the angle of rotation for the passage Δγ _{t, 3} of the profile wall with a width of b ₈ when forming only the bending point of the profile, the final bending angle of which ε _k , in the t-th technological molding transition;
In Fig.6, an auxiliary scheme for determining the angle of rotation for the passage Δγ _{t, 4} of the profile wall with a width of b ₈ when forming only the bending point of the profile, the final bending angle of which μ _k , in the t-th technological molding transition;
In Fig. 7, an auxiliary scheme for determining the angle of rotation for the passage Δγ _{t, 5} of the profile wall with a width of b ₈ when forming only the bending point of the profile, the final bending angle of which β _k , in the t-th technological molding transition.

b₁α_к+

b₁ +

b

+

b₁ +

b

-

b₂ +

b

+b

где α_к, δ_к,ε_к,μ_к,β_к конечные углы изгиба соответственно первого, второго, третьего, четвертого и пятого мест изгиба профиля, считая от полки внутрь профиля;
b₁ ширина полки внутрь профиля;
b₂ ширина полки наружу профиля;
b₃, b₅,b₇,b₉,b₁₁ ширина разверток мест изгиба профиля с конечными углами изгиба соответственно α_к,δ_к,ε_к,μ_к,β_к;
b₄, b₆, b₈, b₁₀ ширины стенок профиля соответственно первой, второй, третьей, четвертой, считая от полки внутрь профиля;
В_заг ширина исходной заготовки;
m 0,95.1,1 эмпирический коэффициент.In the manufacture of bent profiles with an asymmetric cross-sectional configuration, with one shelf inward of the profile and with the other outward, with five places of bending, forming four convex and one concave three-element sections of the profile, and the concave three-element section of the profile forms its fifth place of bending, counting from the side of the shelf inside the profile, according to the proposed method, by molding the profile in rolls due to multi-junction rotation of the profile wall relative to the top of the bending point adjacent to this wall in the direction and opposite to the bending direction of one of the profile shelves, and simultaneous multi-transition bending of the remaining flat profile elements to its predetermined configuration, the profile wall, conjugated with its third and fourth bending points, counting from the shelf into the profile, is rotated in technological forming transitions relative to the top of the place bending the profile with the final bending angle ε in _a direction opposite to the hem flange before reaching the last molds transition ending angle Rotating γ _k, the value of which is calculated by the formula
γ _to

b ₁ α _to +

b ₁ +

b

+

b ₁ +

b

-

b ₂ +

b

+ b

where α _k , δ _k , ε _k , μ _k , β _{k are the} final bending angles of the first, second, third, fourth, and fifth places of the profile bending, respectively, counting from the shelf into the profile;
b ₁ shelf width in profile;
b ₂ shelf width to the outside of the profile;
b ₃ , b ₅ , b ₇ , b ₉ , b _{11 the} width of the reamers of the bending points of the profile with finite bending angles, respectively, α _k , δ _k , ε _k , μ _k , β _k ;
b ₄ , b ₆ , b ₈ , b _{10 the} width of the walls of the profile, respectively, of the first, second, third, fourth, counting from the shelf into the profile;
In the _zag width of the original blank;
m 0.95.1.1 empirical coefficient.

 In the technological master transition 1, the initial billet 1 is moved along the roll forming mill.

In the intermediate forming transitions 11, an intermediate asymmetric profile of the channel type is formed. In this case, a bending point 2 of the profile is formed with a finite bending angle α _k , bending the shelf 3 of width b ₁ by the angle α _t , and 4 with a finite angle μ _t , bending the shelf 5 of width b ₁₀ + b ₁₁ + b ₂ by the angle μ _t ; a wall 6 with a width of b ₄ + b ₅ + b ₆ + b ₇ + b _{8 is} maintained in the flatness of the molding MM.

In the intermediate forming transitions III, IV, V, an intermediate asymmetric trough-type profile is formed with one shelf 7 of width b ₂ . In this case, bending points 4 and 8 are formed with finite bending angles μ _k and β _k , bending the shelf 7 and wall 9; bending points 4 and 8 by bends at the angles μ _t and β _t . The place of bend 2 was bent in transitions III, IV by an angle α _t until a final angle of bending α _k in transition V.

In intermediate forming transitions VI, an intermediate asymmetric profile is formed with one flange inside the profile and the other outward, with four bending places forming three convex and one concave three-element sections of the profile, the latter forming its fourth bending position, counting from the shelf inside the profile. In this case, bending points 4, 8 and 10 are formed by bending the wall 9 at an angle μ _k , the shelf 7 at an angle β _k and the wall 11 with a width b ₄ at an angle δ _t .

In intermediate forming transitions VII, an intermediate asymmetric profile is formed with one flange inside the profile and the other outward, with five bending places forming four convex and one concave three-element sections of the profile, the concave three-element section of the profile forming its fifth bending point, counting from the shelf into the profile . In this case, bending points 10 and 12 are formed with finite bending angles δ _k and ε _k , bending the wall 11 by an angle δ _t and turning the wall 13 with a width of b ₈ by an angle γ _t until reaching the final bending angles δ _to ε _k and the final angle of rotation γ _{to the} wall 13 of width b ₈ , the value of which is calculated according to dependence (1).

 The proposed method can be implemented using a device containing a set of rolls for the manufacture of a bent profile with an asymmetric cross-sectional configuration, with one shelf inward of the profile and with the other outward, with five bending places forming four convex and one concave three-element sections of the profile forms its fifth place bending, counting from the side of the shelf into the profile.

So, for example, the profiling mode in the manufacture of a bent profile 105x x50x65x35x2 mm with an asymmetric cross-sectional configuration, with one shelf inward and with the other outward, with five bending points forming four convex and one concave three-element sections of the profile, from low alloy steel 10 HSND ( with the widths of flat elements and reamers of bending points located between them b ₁ 13.5 mm, b ₂ 65.1 mm, b ₃ b ₅ b ₇ b ₉ b ₁₁ 7.7 mm, b ₄ 53.0 mm, b ₆ 37 , 4 mm, b ₈ 23.0 mm, b ₁₀ 17.4 mm, inner radius of bending places r 4 mm, final bending angles of bending places α _to = β _k = δ _k = ε _k = μ _to 90 ^° , the metal thickness of the initial billet S 2 mm and the width of the initial billet B _zag 248 mm), determined according to the proposed method, are given in table 2.

 The profile was formed in a continuous way on a roll forming mill 2.5 x x 200.550.

 In the first technological master transition 1, the initial workpiece was moved along the roll forming mill.

In the second forming transition 11, an intermediate asymmetric channel profile profile was formed. In this case, the bending profile sections 2 were formed by bending the shelf 3 with a width of b ₁ at an angle α ₂ 4 ^о , and 4, bending the shelf 5 with a width of b ₁₀ + b ₁₁ + b ₂ by an angle μ ₂ = 15 ^о , the wall 6 with a width of b ₄ + b ₅ + b ₆ + + b ₇ + b _{8 was} held in the MM molding plane.

In the third-fifth III, sixth IV and seventh V forming transitions, an intermediate asymmetric trough-type profile was formed with one shelf 7 of width b ₂ . In this case, the bending points 4 and 8 were formed, bending the shelf 7 and the wall 9; places of bending 4 and 8 were bent at angles μ _t and β _t . Bending place 2 was bent in the transitions III, IV an angle α _t to reach a final bending angle α _to ⁹⁰ ° in the transition V.

 In the eighth forming transition VI, an intermediate asymmetric profile was formed with one shelf inward of the profile and with the other outward, with four bending places forming three convex and one concave three-element sections of the profile, the concave three-element section of the profile forming its fourth bending position, counting from the shelf into the profile .

In this case, the bending points 4, 8 and 10 were formed by bending the wall 11 of width b ₄ to an angle β _t and bending the places of bending 4 and 8 to the final bending angles μ _k = β _to 90 ^° .

b₁α_к+

b₁ +

b

+

b₁ +

b

-

b₂ +

b

+
+b

=

[13,5·90^°+(13,5+7,7+53,0)·90^°+(13,5+7,7+53,0+
+7,7+37,4)·90^°-(65,1+17,4+7,7)·90^°+65,1·90^°]62^°43′.72^°38′
Приняли γ_к 70^о, m 1,06.In the ninth to fifteenth forming transitions VII, VIII, an intermediate asymmetric profile was formed with one flange inside the profile and the other outward, with five bending places forming four convex and one concave three-element sections of the profile, and the concave three-element section of the profile forms its fifth bending position, counting from the shelf into the profile. In this case, the bending points 10 and 12 were formed by bending the wall 11 by an angle δ _t and turning the wall 13 with a width of b ₈ by an angle γ _t until reaching the final bending angles δ _k = ε _to 90 ^° and a final angle of rotation γ _{to the} wall 13 of width b ₈ . The value of the final angle of rotation γ _{to was} calculated according to the dependence (1)
γ _to

b ₁ α _to +

b ₁ +

b

+

b ₁ +

b

-

b ₂ +

b

+
+ b

=

[13.5 · 90 ^° + (13.5 + 7.7 + 53.0) · 90 ^° + (13.5 + 7.7 + 53.0 +
+ 7.7 + 37.4) · 90 ^° - (65.1 + 17.4 + 7.7) · 90 ^° + 65.1 · 90 ^° ] 62 ^° 43′.72 ^° 38 ′
Took γ _to 70 ^about , m 1,06.

To obtain a finished profile of 105x50x65x35x2 mm with an asymmetric cross-sectional configuration, with one shelf inside the profile and the other outward, with five bending places forming four convex and one concave three-element sections of the profile, from 10KHSND low-alloy steel, according to the proposed method, 15 technological transitions were required. Helical twisting of the finished profile was ^about 0 20 ^'0 ° 50' to 1 m length, which is within the requirements of GOST 8281-80 "cold-formed steel. Channel bars unequally. Range" (permissible helical twisting ^about 1 per 1 m length).

According to the test data on the roll forming mill 2.5x200.550, the proposed manufacturing method allows, in comparison with the prototype:
a) improve the quality of bent profiles with an asymmetric cross-sectional configuration, with one shelf inward of the profile and with the other outward, with five bending places forming four convex and one concave three-element sections of the profile, the concave three-element section of the profile forming its fifth bending point, counting from the sides of the shelf inside the profile by reducing their helical twisting (for example, in the manufacture of a bent profile 105x50x65x35x3 mm from low alloy steel 10HSND according to the proposed method the second twisting relative to the axis of the axis was 0 ^about 20 '0 ^about 50' per 1 m of length, in the manufacture according to the method of the prototype 2 ^about 30 '3 ^about 1 m length);
b) expand the assortment of complex asymmetric bent profiles (due to profiles whose production has not been mastered previously due to technological difficulties).

 The proposed method does not adversely affect the state of the environment.

 The economic effect will be obtained by improving the quality of bent profiles by reducing their helical twisting.

Claims (1)

METHOD FOR MANUFACTURING BENT PROFILES with an asymmetric cross-sectional configuration, with one shelf inside the profile and the other outward, with five bending places forming four convex and one concave three-element sections of the profile, the concave three-element section of the profile forming its fifth place from the side of the bend inside the profile, including forming the profile in the rolls by multi-junction turning the profile wall relative to the top of the bending point adjacent to this wall in the direction opposite to the phenomenon of bending one of the shelves of the profile, and simultaneous multi-transition bending of the remaining flat elements of the profile to its predetermined configuration, characterized in that the rotation of the wall of the profile associated with its third and fourth places of bending, counting from the shelf into the profile, is carried out in technological forming transitions relative to the top Profile bending points with the final bend angle ε in _a direction opposite to the hem flange, until the last mold by moving the end angle Orochi γ _k, the value of which is calculated depending on

where α _k , δ _k , ε _k , μ _k , β _{k are the} final bending angles of the first, second, third, fourth, and fifth places of the profile bending, respectively, counting from the shelf into the profile;
b ₁ shelf width in profile;
b ₂ shelf width to the outside of the profile;
b ₃ , b ₅ , b ₇ , b ₉ , b _{1 1 the} width of the reamers of the bending points of the profile with finite bending angles, respectively, α _k , δ _k , ε _k , μ _k , β _k
b ₄ , b ₆ , b ₈ , b _{1 0 the} width of the walls of the profile, respectively, of the first, second, third, fourth, counting from the shelf into the profile;
B _{z a d the} width of the original workpiece;
m 0.95 1.1 empirical coefficient.

Images