RU2044584C1 - Nonsymmetrical formed section manufacturing method - Google Patents

Abstract

FIELD: plastic working of metals. SUBSTANCE: method involves turning second wall of section, beginning from peripheral bending portion, whose final bending angle is part of right-hand portion of nonsymmetric zone, in technological forming transition parts relative to apex of third bending portion, beginning from bending portion whose final bending angle is part of right-hand portion of nonsymmetric zone, in the direction of bending strip of section mated with fourth bending portion, beginning from bending portion, whose final angle makes right-hand part nonsymmetric zone, till final angle of turning is obtained in final technological forming transition part, with final angle of turning being calculated by formula recited in Specification. EFFECT: increased efficiency in obtaining nonsymmetrical formed sections of tray type articles. 6 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 waviness of the edges of the shelves and other defects.

 There is a method of manufacturing bent profiles with vertical walls of different lengths [1] according to which, in order to increase productivity and reduce energy consumption during gradual bending of walls along transitions in rolls, equal bending moments are applied to both bent vertical walls, in the bending process a bending point adjacent to a larger vertical wall, stretch in the tangential direction.

 The main disadvantage 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.

 Closest to the proposed technical essence is the method of manufacturing unequal bent profiles [2] selected as a prototype, according to which, 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 analogue is that in the manufacture of asymmetric bent profiles of the trough type in some cases, profiles of low quality are obtained due to their helical twisting that goes beyond the permissible limits. To obtain profiles with helical twisting within acceptable limits, it is necessary to determine the value of the final angle of rotation of the profile wall not from the condition of equal horizontal displacements of the edges of the shelves, but from the condition of mutual balancing of the total (along the cross-section of the formed strip) form-changing moments for all technological forming transitions.

So, for example, the profiling mode in the manufacture of an asymmetric profile 53x112x3.9 mm trough type of mild steel St3kp (with the widths of flat elements and the reamers of the bending points located between them b ₁ 17.7 mm, b ₂ 14.7 mm, b ₃ 9, 1 mm, b ₄ 31.5 mm, b ₅ 12.6 mm, b ₆ 43.2 mm, b ₇ 10.3 mm, b ₈ 0, b ₉ 13.7 mm, bend radius r 7 mm, final bending angle α of bending places 59 _to ^about 34 ', β 89 _to ^about 52', δ = 82 _to ^about 20 ', ε ^I _to 67 ^for 22', the initial billet s 3,9 mm thick metal and the initial billet width B _zag = 153.0 mm) determined by the method of the prototype, are given in table 1.

Here: β is _the final bending angle of the bending profile, which is included in the right-hand side of inequality (1);
ε _k , δ _k , α _{k the} final bending angles of the first, second and third places of the profile bending, respectively, counting from its bending location, the final bending angle of which β _to
b _{1 the} width of the flange profile associated with its place of bending, the final bending angle of which α _to
b _{2 the} width of the other profile shelf;
b ₃ , b ₅ , b ₇ , b _{9 the} width of the reamers of the bending points of the profile with finite bending angles, respectively, α _k , δ _k ε _k β _k ,
b ₄ , b ₆ , b _{8 the} width of the walls of the profile, respectively, of the first, second and third, counting from the place of bending with a finite bending angle α _to .

 The profile was formed in a continuous way on a roll forming mill 1 4 x 50 300 from a roll billet.

Due to the lack of information on the number of technological transitions and the values of the bending angles of the bending places in all transitions (except the last one) when manufacturing a profile using the prototype method, they were determined by the method of expert evaluations and taken equal to the values of the corresponding parameters when manufacturing the profile according to the proposed method. A similar technique was applied with respect to the angles of rotation of the wall with a width of b ₆ in the first seven transitions.

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

In the second eighth technological forming transitions, the profile was formed by multi-junction turning of the profile wall with a width of b ₆ until the final turning angle γ _k = 25 ^° , obtained from the equality of horizontal displacements of the edges of the shelves, and multi-jib folding of the remaining flat profile elements in the last eighth technological forming junction. At the same time, in the second technological forming transition, an intermediate profile was formed with three bending points; in the remaining technological forming transitions, a profile was formed with all four bending points.

The bending angles of the bending places in the last eighth technological molding transition were equal to the final bending angles of the bending places of the finished profile α _to 59 ^° 34 ', δ _k = 82 ^° 20', ε _k , 67 ^° 22 ', β _to 89 ^° 52'.

To obtain the finished asymmetric bent profile 53x112x3.9 mm trough type according to the prototype method, eight technological transitions were required. The helical twisting of the finished profile was 1 ^about 20'-1 ^o 50 'per 1 m of length, which goes beyond the requirements of GOST 8281-80 "Cold-bent steel. Channel bars are unequal. Sortamet" (permissible helical twisting of 1 ^about 1 m 1 length).

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

- b₁α_k+(b₁+b₃+b₄)δ_к+ (b₂+b₈+b₉)ε_к+b

, где β_к конечный угол изгиба другого периферийного места изгиба профиля;
δ_к, ε_к конечные углы изгиба соответственно второго и третьего мест изгиба, считая от места изгиба профиля с конечным углом изгиба α_к;
b₁ ширина полки профиля, сопряженной с его периферийным местом изгиба, конечный угол изгиба которого α_к;
b₂ ширина другой полки профиля;
b₃, b₉ ширина разверток мест изгиба профиля с конечными углами изгиба соответственно α_к, β_к
b₄, b₈ ширина стенок профиля, сопряженных с его местами изгиба, конечные углы изгиба которых соответственно α_к, β_к
В_заг ширина исходной заготовки;
m 0,95.1,1 эмпирический коэффициент.To do this, when forming a profile in rolls by multi-junction turning the wall of the profile relative to the top of the bending point adjacent to this wall in the direction of folding one of the shelves of the profile and simultaneously multi-jibing the remaining flat elements of the profile to the specified configuration of its cross section, rotation of the wall of the profile conjugated with its places bending, which bending finite angles δ and ε _{to to} perform a process of forming the transitions relative to the top profile bending points, the curvature of which end angle _to about δ, in the direction of hem flange profile conjugate with its peripheral bending place, the final bending angle α _to that part of the left side of
b ₁ α _k + [0.5B _zag - (b ₂ + b ₃ + b ₄ )] δ _k , + (b ₂ + b ₈ + b ₉ ) xε _k > b ₂ β _k (1) until reaching the latter technological forming transition of the final angle of rotation γ _{to the} value of which is calculated by the dependence
γ _to

- b ₁ α _k + (b ₁ + b ₃ + b ₄ ) δ _c + (b ₂ + b ₈ + b ₉ ) ε _c + b

where β is _the final bending angle of another peripheral location of the bending profile;
δ _to , ε _{to the} final bending angles of the second and third places of bending, respectively, counting from the place of bending of the profile with a finite bending angle α _k ;
b _{1 the} width of the profile flange associated with its peripheral bending location, the final bending angle of which α _to ;
b _{2 the} width of the other profile shelf;
b ₃ , b _{9 the} width of the reamers of the bending points of the profile with finite bending angles, respectively, α _k , β _k
4 b, ₈ b wall section width, its conjugate with bending locations, the final bending angle α _for which respectively, β _to
In the _zag width of the original blank;
m 0.95.1.1 empirical coefficient.

M $\genfrac{}{}{0ex}{}{\text{(}}{\text{t}}$ ^фс)= 0, (3) где М_t ^(фс) суммарный (по поперечному сечению полосы) формоизменяющий момент, приложенный к формуемой полосе в t-ом технологическом формующем переходе;
t номер технологического формующего перехода;
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 strip cross-sections) form-changing moments applied to the mold, strip in all technological transitions, be balanced, i.e. so that equality holds

M $\genfrac{}{}{0ex}{}{\text{(}}{\text{t}}$ ^fs) = 0, (3) where M _t ^{(fs) is the} total (along the strip cross-section) forming moment applied to the formed strip in the t-th technological molding transition;
t number of technological forming transition;
n the number of all technological forming transitions.

σ_тS²l_t,1+

Yb₁(Δα_t-Δγ_t,1); (4)
M $\genfrac{}{}{0ex}{}{\text{(ф)}}{\text{t,1}}$ _,c=

σ_тS²l_t,1+

Y (B_заг-b₁)Δγ_t,1; (5)
M $\genfrac{}{}{0ex}{}{\text{(фс}}{\text{t,1}}$ ⁾ M $\genfrac{}{}{0ex}{}{\text{(ф)}}{\text{t,1}}$ _,n M $\genfrac{}{}{0ex}{}{\text{(фс)}}{\text{t,1,}}$ _c

Ys³(b₁Δα_t- B_загΔγ_t,1), (6) где М_t,1,n ^(ф) формоизменяющий момент, необходимый для формоизменения периферийного (по исходной заготовке) места изгиба профиля с конечным углом изгиба α_к и сопряженной с этим местом изгиба полкой шириной b₁ на участке плавного перехода t-го технологического формующего перехода при формовке только места изгиба профиля с конечным углом изгиба α_к;
М_t,1,c ^(ф) формоизменяющий момент, необходимый для формоизменения периферийного (по исходной заготовке) места изгиба профиля с конечным углом изгиба α_к и многоэлеметного участка полосы, содержащего стенку профиля шириной b₆ на участке плавного перехода t-го технологического формующего перехода при формовке только места изгиба профиля с конечным углом изгиба α_к
M_t,1 ^(ф) суммарный (по поперечному сечению формуемой полосы) формоизменяющий момент, необходимый для формоизменения всех элементов профиля на участке плавного перехода t-го технологического формующего перехода при формовке только места изгиба профиля с конечным углом изгиба α_к;
_lt,1 длина активной зоны участка плавного перехода места изгиба профиля с конечным углом изгиба α_к при формовке только этого места изгиба в t-ом технологическом формующем переходе;
Δ α_t изменение угла изгиба за проход периферийного (по исходной заготовке) места изгиба профиля с конечным углом изгиба α_к при формовке только этого места изгиба в t-ом технологическом формующем переходе;
Δ γ_{t, 1} угол поворота за проход стенки профиля шириной b₆ при формовке только периферийного (по исходной заготовке) места изгиба профиля с конечным углом изгиба α_к в t-ом технологическом формующем переходе;
σ_т предел текучести материала;
s толщина металла исходной заготовки;
Y модуль упругости второго рода материала заготовки.When forming only one peripheral (in the initial workpiece) place of bending of the profile with a finite bending angle α _to by bending a shelf with a width of b ₂ and a multi-element section of a strip containing a wall of a profile of width b ₆ , the shaping moments necessary for shaping all elements of the strip in each t- at the first approximation, while holding the moldable bending place at a constant level in the adjacent t-th and (t-1) -th technological transitions, are determined by the dependencies
M $\genfrac{}{}{0ex}{}{\text{(f)}}{\text{t, 1}}$ _{, n} =

σ _t S ² l _{t, 1} +

Yb ₁ (Δα _t -Δγ _{t, 1} ); (4)
M $\genfrac{}{}{0ex}{}{\text{(f)}}{\text{t, 1}}$ _{, c} =

σ _t S ² l _{t, 1} +

Y (B _zag -b ₁ ) Δγ _{t, 1} ; (5)
M $\genfrac{}{}{0ex}{}{\text{(fs}}{\text{t, 1}}$ ⁾ M $\genfrac{}{}{0ex}{}{\text{(f)}}{\text{t, 1}}$ _{, n} M $\genfrac{}{}{0ex}{}{\text{(fs)}}{\text{t, 1,}}$ _c

Ys ³ (b ₁ Δα _t - B _zag Δγ _{t, 1} ), (6) where М _{t, 1, n} ^{(ф) the} shaping moment necessary for shaping the peripheral (in the initial workpiece) bending location of the profile with a finite bending angle α _to and a shelf with a width of b _1, coupled to this bending point, in the smooth transition section of the t-th technological forming transition when forming only the bending point of the profile with a finite bending angle α _k ;
M _{t, 1, c} ^{(f) the} shaping moment necessary for shaping the peripheral (in the initial blank) bending location of the profile with a finite bending angle α _k and a multi-element strip section containing a profile wall of width b ₆ in the smooth transition section of the t-th technological molding transition when forming only the bending profile with a finite bending angle α _to
M _{t, 1} ^(f) total (along the cross section of the strip being molded) shape-changing moment necessary for the shape-changing of all profile elements in the smooth transition area of the t-th technological forming transition when forming only the profile bending point with a finite bending angle α _к ;
_{lt, 1} length of the active zone of the smooth transition section of the profile bending point with a finite bending angle α _k when only this bending point is molded in the t-th technological molding transition;
Δ α _{t the} change in the bending angle over the passage of the peripheral (in the initial workpiece) place of the profile bending with the final bending angle α _to when forming only this bending place in the t-th technological forming transition;
Δ γ _{t, 1} angle of rotation for the passage of the profile wall with a width of b ₆ when forming only the peripheral (in the initial workpiece) bending location of the profile with a finite bending angle α _k in the t-th technological molding transition;
σ _{t the} yield strength of the material;
s metal thickness of the initial billet;
Y is the elastic modulus of the second kind of workpiece material.

Ys

(b₁+b₃+b₄)Δδ_t-B

; (7)
M $\genfrac{}{}{0ex}{}{\text{(фс}}{\text{t,3}}$ ⁾=

Ys

(b₂+b₈+b₉)Δε_t-B

; (8)
M $\genfrac{}{}{0ex}{}{\text{(фс}}{\text{t,4}}$ ⁾=

Ys

(b₂Δβ_t-B

; (9) где М_t,2 ^(фс), М_t,3 ^(фс), M_t,4 ^(фс) суммарные (по поперечному сечению формуемой полосы) формоизменяющие моменты, необходимые для формоизменения всех элементов профиля на участке плавного перехода t-го технологического формующего перехода при формовке только одного места изгиба профиля, конечный угол изгиба которого соответственно δ_к ε_к β_к
Δ δ_t Δ ε_t Δ β_t изменения углов изгиба за проход мест изгиба профиля, конечные углы изгиба которых соответственно δ_к ε_к β_к при формовке только каждого из них в t-ом технологическом формующем переходе;
Δ γ_{t, 2}, Δ γ_{t, 3}, Δ γ_{t, 4} углы поворота за проход стенки профиля шириной b₆ при формовке только одного места изгиба профиля, конечный угол изгиба которого соответственно δ_к ε_к β_к, в t-ом технологическом формующем переходе.Similarly to the previous one, for the remaining three places of profile bending, we write
M $\genfrac{}{}{0ex}{}{\text{(fs}}{\text{t, 2}}$ ⁾ =

Ys

(b ₁ + b ₃ + b ₄ ) Δδ _t -B

; (7)
M $\genfrac{}{}{0ex}{}{\text{(fs}}{\text{t, 3}}$ ⁾ =

Ys

(b ₂ + b ₈ + b ₉ ) Δε _t -B

; (8)
M $\genfrac{}{}{0ex}{}{\text{(fs}}{\text{t, 4}}$ ⁾ =

Ys

(b ₂ Δβ _t -B

; (9) where M _{t, 2} ^(fs) , M _{t, 3} ^(fs) , M _{t, 4} ^(fs) total (along the cross section of the strip being formed) shape-changing moments necessary for the shape-changing of all profile elements in the smooth transition section t- of the technological forming transition when forming only one profile bending point, the final bending angle of which, respectively, δ _to ε _to β _to
Δ δ _t Δ ε _t Δ β _t changes the bending angles for the passage of the places of bending of the profile, the final bending angles of which, respectively, δ _to ε _to β _to when forming only each of them in the t-th technological forming transition;
Δ γ _{t, 2} , Δ γ _{t, 3} , Δ γ _{t, 4} angles of rotation for the passage of the profile wall with a width of b ₆ when forming only one bending point of the profile, the final bending angle of which, respectively, δ _to ε _to β _k , in the t technological forming transition.

Ys

-b₁Δα_t+ (b₁+b₃+b₄)Δδ_t-
(b₂+b₈+b₉)Δε_t+ b₂Δβ_t- B

; (10)
Δ γ_t Δ γ_{t, 1} + Δ γ_{t, 2} Δ γ_{t, 3} + Δ γ_{t, 4}, (11) где М_t ^(фс) суммарный (по поперечному сечению формуемой полосы) формоизменяющий момент, необходимый для формоизменения всех элементов формуемой полосы на участке плавного перехода t-го технологического формующего перехода при одновременной формовке всех четырех мест изгиба профиля;
Δ γ_t угол поворота за проход стенки профиля шириной b₆ при формовке всех мест изгиба профиля в t-ом технологическом формующем переходе.With the simultaneous formation of all four places of bending of the trough type profile, 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 $\genfrac{}{}{0ex}{}{\text{(fs}}{\text{t, 4}}$ ⁾ =

Ys

-b ₁ Δα _t + (b ₁ + b ₃ + b ₄ ) Δδ _t -
(b ₂ + b ₈ + b ₉ ) Δε _t + b ₂ Δβ _t - B

; (10)
Δ γ _t Δ γ _{t, 1} + Δ γ _{t, 2} Δ γ _{t, 3} + Δ γ _{t, 4} , (11) where М _t ^{(fs) is the} total (along the cross section of the strip being formed) form-changing moment necessary for the change of all elements of the formed strip at the smooth transition section of the t-th technological forming transition while simultaneously forming all four places of profile bending;
Δ γ _{t the} angle of rotation for the passage of the profile wall with a width of b ₆ when forming all places of profile bending in the t-th technological forming transition.

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

Ys

-b₁α_к+ (b₁+b₃+b₄)δ_к-(b₂+b₈+b₉)×ε_к+ b₂β_к- B

; (12)

= γ_к. (13)
Из (3) и (12) следует
γ_к

- b₁α_k+(b₂+b₃+b₄)δ_к+ (b₂+b₈+b₉)ε_к+b₂β_к- B

(14)
На основании экспериментальных исследований имеем
γ_к

- b₁α_k+(b₁+b₃+b₄)δ_к+ (b₂+b₈+b₉)ε_к+b₂β_к- B

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

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

Ys

-b ₁ α _k + (b ₁ + b ₃ + b ₄ ) δ _k - (b ₂ + b ₈ + b ₉ ) × ε _k + b ₂ β _k - B

; (12)

= γ _k . (13)
From (3) and (12) it follows
γ _to

- b ₁ α _k + (b ₂ + b ₃ + b ₄ ) δ _c + (b ₂ + b ₈ + b ₉ ) ε _c + b ₂ β _c - B

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

- b ₁ α _k + (b ₁ + b ₃ + b ₄ ) δ _c + (b ₂ + b ₈ + b ₉ ) ε _c + b ₂ β _c - B

, (2) where m is 0.95.1.1 empirical coefficient.

From geometric relationships
δ _k > 2 γ _k (15)
From (14) and (15) it follows
b ₁ α _k + [0.5 B _zag (b ₁ + b ₃ + b ₄ )] δ _k + + (b ₂ + b ₈ + b ₉ ) ε _k > b ₂ β _k (1)
Thus, in the manufacture of asymmetric bent profiles of the trough type according to the proposed method, the system of total (cross-sectional) shape-changing moments applied to the formable strip in all technological transitions is balanced, which in turn provides helical twisting of asymmetric bent profiles of the trough type within acceptable values and achieving the stated goal of improving the quality of asymmetric bent profiles of the trough type 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".

To implement in technological forming transitions the rotation of the profile wall conjugate to its bending points, the final bending angles of which are δ _k and ε _k relative to the top of the profile bending point, the final bending angle of which is δ _k in the direction of the bending of the profile shelf conjugated with its peripheral bending place, the final bending angle α _to which is included in the left-hand side of inequality (1), before reaching the final turning angle γ _{to the} last technological forming transition, it is necessary and sufficient to provide for the presence of conical elements with the 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 (2) from unity 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 was carried out on the basis of the following considerations:
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 profile shelf of width b ₁ to its shelf of width b ₂ ;
when the coefficient m is greater than 1.1, 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 profile shelf of width b ₂ to its shelf of width b ₁ .

 The analysis of the proposed method for the manufacture of asymmetric bent profiles of the trough type indicates that the method is industrially applicable and a positive effect in the implementation of the invention will be obtained due to the mutual balancing of the total (across the cross section of the moldable strip) shaping moments applied to the moldable strip in all technological transitions.

In FIG. 1 shows a diagram of the molding of an asymmetric bent profile of a trough type according to the proposed method; figure 2 finished asymmetric profile, cross section; figure 3 auxiliary scheme for determining the angle of rotation for the passage Δ γ _{t, 1} of the profile wall with a width of b ₆ when forming only one bending point, the final bending angle of which α _to , in the t-th technological forming transition; figure 4 auxiliary scheme for determining the angle of rotation for the passage Δ γ _{t, 2} of the profile wall with a width of b ₆ when forming only one bending point, the final bending angle of which δ _to in the t-th technological forming transition; figure 5 auxiliary scheme for determining the angle of rotation for the passage Δγ _{t, 3} of the profile wall with a width of b ₆ when forming only one place of bending, which ε _to , in the t-th technological forming transition; Fig.6 auxiliary scheme for determining the angle of rotation for the passage Δ γ _{t, 4} of the profile wall with a width of b ₆ when forming only one bending point, the final bending angle of which β _to , in the t-th technological forming transition.

- b₁α_k+(b₁+b₃+b₄)δ_к+ (b₂+b₈+b₉)ε_к+b

, (2) где β_к конечный угол изгиба другого периферийного места изгиба профиля;
δ_к, ε_к конечные углы изгиба соответственно второго и третьего мест изгиба, считая от места изгиба профиля с конечным углом изгиба α_к;
b₁ ширина полки профиля, сопряженной с его периферийным местом изгиба, конечный угол изгиба которого α_к
b₂ ширина другой полки профиля;
b₃, b₉ ширина разверток мест изгиба профиля с конечными углами изгиба соответственно α_к, β_к
b₄, b₈ ширина стенок профиля, сопряженных с его местами изгиба, конечные углы изгиба которых соответственно α_к, β_к
В_заг ширина исходной заготовки;
m 0,95.1,1 эмпирический коэффициент.In the manufacture of asymmetric bent profiles of the trough type according to the proposed method by forming the profile in rolls due to multi-transition of the profile wall relative to the top of the bending point adjacent to this wall in the direction of folding one of the profile shelves and simultaneous multi-transition folding of the remaining flat profile elements to the given configuration of its cross section , rotation of the profile wall, associated to its bending places, the final bend angles _to which the δ and ε _to carry out in process ormuyuschih transitions relative to the top profile bending points, final bending angle δ _in which, in the direction of hem flange profile conjugate with its peripheral bending place, the final bending angle α _to that part of the left side of
b ₁ α _k + [0.5B _zag - (b ₁ + b ₃ + b ₄ )] δ _k + + (b ₂ + b ₈ + b ₉ ) ε _k > b ₂ β _k (1)
until the final angle of rotation γ _{to the} value of which is calculated from the dependence in the last technological forming transition
γ _to

- b ₁ α _k + (b ₁ + b ₃ + b ₄ ) δ _c + (b ₂ + b ₈ + b ₉ ) ε _c + b

, (2) where β is _the final bending angle of another peripheral bending profile;
δ _to , ε _{to the} final bending angles of the second and third places of bending, respectively, counting from the place of bending of the profile with a finite bending angle α _k ;
b _{1 is the} width of the profile flange associated with its peripheral bending location, the final bending angle of which α _to
b _{2 the} width of the other profile shelf;
b ₃ , b _{9 the} width of the reamers of the bending points of the profile with finite bending angles, respectively, α _k , β _k
4 b, ₈ b wall section width, its conjugate with bending locations, the final bending angle α _for which respectively, β _to
In the _zag width of the original blank;
m 0.95.1.1 empirical coefficient.

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

In technological forming transitions II, III, IV and V, an asymmetric bent profile of the trough type is formed. At the same time, bending points 2 5 are bent at angles, respectively, δ _t ε _t β _t, α _t until the final bending angle V reaches the final bending angles δ _to ε _to β _to, α _to This is ensured by folding the shelves 6 and 7 and the side walls 8 and 9 and turning the central wall 10 relative to the top of the bending point 2 by the angle of rotation γ _t until the final angle of rotation γ is reached in the last technological forming transition V _{to the} value of which is calculated by the formula (2).

 The proposed method can be implemented using a device containing a set of rolls for the manufacture of an asymmetric bent profile of the trough type.

So, for example, the molding mode in the manufacture of an asymmetric bent profile 53x112x3.9 mm trough type of low-carbon steel St3kp (with the widths of flat elements and the reamers of the bending points located between them b ₁ 17.7 mm, b ₂ 14.7 mm, b ₃ 9 , 1 mm, b ₄ 31.5 mm, b ₅ 12.6 mm, b ₆ 43.2 mm, b ₇ 10.3 mm, b ₈ 0, b ₉ 13.7 mm, bend radius r 7 mm , final bending angle of bending of places α = 59 _to ^about 34 ', β 89 _to ^about 52', δ = 82 _to 20 ^o ', ε = 67 _to ^about 22', the initial billet s 3,9 mm thickness and width of the metal original billet In _zag 153.0 mm), determined according to the proposed method, is given in tab l.2.

Prior to the formation of the profile, the indexation of its elements was checked by substituting the numerical values of the profile dimensions into the inequality (1)
b ₁ α _k + [0.5V _zag (b ₁ + b ₃ + b ₄ )] δ _k + + (b ₂ + b ₈ + b ₉ ) ε _to 17.7 ˙59.6 ^о + [0.5.153 0
- (17.7 + 9.1 + 31.5)] ˙82.3 + (14.7 + 0 + 13.7) 67.4 14.7˙89.9 ^o b ₂ β _c
The validity of the inequality confirmed the correctness of the indexing of the profile elements.

- b₁α_k+(b₁+b₃+b₄)δ_к+ (b₂+b₈+b₉)ε_к+b

=

- 17,7× 59,6^°+ (17,7+9,1+31,5)·82,3-(14,7+0+
+ 13,7)·67,4+14,7·89,9

= 19^°34′.22^°40′
Приняли γ_к 22^о, m 1,068.The formula (2) determined the value of the final angle of rotation
γ _to

- b ₁ α _k + (b ₁ + b ₃ + b ₄ ) δ _c + (b ₂ + b ₈ + b ₉ ) ε _c + b

=

- 17.7 × 59.6 ^° + (17.7 + 9.1 + 31.5) 82.3- (14.7 + 0 +
+ 13.7) 67.4 + 14.7 89.9

= 19 ^° 34′.22 ^° 40 ′
Took γ _to 22 ^about , m 1,068.

 The profile was formed in a continuous way on a roll-forming mill 1-4x50-300 from a roll billet.

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

In the second eighth technological forming transitions II, III, IV and V, an asymmetric bent profile of the trough type was formed. When this bending points 5 February flexed at angles of _{δ t ε t β t, α} t to achieve the eighth last molds transition V finite angle bend α _k = 82 ^to 20 ', δ _k = 67 ^o 22', β _to 89 ^o 52 ', α _to 59 ^o 34'. It is provided, bending the flange 6 and 7 and side walls 8 and 9 and the rotating central wall 10 relative to top bending points 2 of the turning angle γ _t to achieve the eighth last molds transition V finite rotation angle γ _to 22 ^o, the magnitude of which is calculated by formula (2).

To obtain a finished asymmetric bent profile 53x112x3.9 mm trough type according to the proposed method, it took eight technological forming transitions. The helical twisting of the finished profile was 0 ^o 30 '0 ^o 50' per 1 m of length, which is within the requirements of GOST 8281-80 "Cold-bent steel. Channel bars are unequal. Assortment" (permissible helical twisting of 1 ^about 1 m length).

According to the test data on the roll forming mill 1 4x50 300, the proposed manufacturing method allows, in comparison with the prototype:
improve the quality of formed sections of asymmetrical type Korytnyi by reducing their helical twisting about the longitudinal axis (e.g., in the manufacture of asymmetrical curved profile 53h112h3,9 Korytnyi type mm mild steel St3kp the proposed method was 0 helical twisting ^about 0 ^o 30'-50 '1 m length, in the manufacture of the method of the prototype 1 ^about 20'-1 ^o 60 'per 1 m of length);
expand the assortment of complex asymmetric bent profiles (due to profiles whose production has not been mastered earlier 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 asymmetric bent profiles of the trough type and expanding the range of manufactured profiles.

Claims (1)

METHOD FOR MANUFACTURING ASYMMETRIC BENT PROFILES of trough type, including forming a profile in rolls of a multi-transition turn of a profile wall relative to the top of a bending point adjacent to this wall in the direction of folding one of the profile shelves and simultaneously multi-transition folding of the remaining flat profile elements to a predetermined cross-sectional configuration that the rotation of the profile wall, associated to its bending places, the end of which the angles δ and ε bending _{to k,} performed in the forming process x transitions relative to the top profile bending points, final bending angle δ _in which, in the direction of hem flange profile conjugate with its peripheral bending place, the final bending angle α _to that part of the left side of
b ₁ α _k + [0.5B _zag - (b ₁ + b ₃ + b ₄ )] δ _k + (b ₂ + b ₈ + b ₉ ) ε _k > b ₂ β _k ,
until reaching the final turning angle γ _k in the last technological forming transition, the value of which is calculated from the dependence

where β is _the final bending angle of another peripheral location of the bending profile;
δ _to , ε _{to the} final bending angles of the second and third places of bending, respectively, counting from the place of bending of the profile with a finite bending angle α _k ;
b _{1 the} width of the profile flange associated with its peripheral bending location, the final bending angle of which α _to ;
b _{2 the} width of the other profile shelf;
b ₃ , b _{9 are the} widths of the reamers of the bending points of the profile with finite bending angles, respectively, α _k , β _k ;
₄ b, ₈ b wall section width, its conjugate with bending locations, the final bending angle α _for which respectively, β _k;
B _{z a d the} width of the original workpiece;
m 0.95 1.1 empirical coefficient.

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