RU2036037C1 - Bending shape production method - Google Patents

Abstract

FIELD: metal machining. SUBSTANCE: successive bending of strip billet by rollers with formation of horizontal and vertical walls, seats and flanging is exercised. During rough machining passes they exercise formation of vertical wall, located on side of flanging, with simultaneous bending of two adjacent to it slope members. Since first intermediate pass they begin simultaneous formation by rollers horizontal members of horizontal wall and spaced from flanging seat and by slope members - second vertical wall, second seat and adjacent to it flanging. During all intermediate passes they use upper roller, that has diameter of its member, that forms place of bending between second seat and located on side of flanging vertical wall, bigger than diameter of member, that forms place of bending between spaced from flanging seat and second vertical wall. To prevent strip longitudinal twisting and horizontal damages, vertical rollers are contacting the strip all over the surface of flanging. EFFECT: bending shape production method is used in metal machining. 1 dwg

Description

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

 A known method of manufacturing a bent profile, including sequentially bending the strip billet through the rolls of the roll forming mill with the formation of horizontal and vertical walls, shelves and flanges and passing the strip between the vertical rollers of the mill, while the horizontal wall and one of the shelves are formed by horizontal roll elements, and the formation adjacent to this shelf vertical wall and flanging inclined elements.

 The disadvantage of this method is the impossibility of obtaining an asymmetric profile with one flanging and shelves of different lengths, as well as the relatively large number of necessary forming passes.

 The objective of the invention is to reduce labor costs in the production of asymmetric profiles having one flanging, and to improve their quality.

 To do this, in the known method for the production of a bent profile, including sequentially bending the strip billet through the rolls with rolls of a roll forming mill with the formation of horizontal and vertical walls, shelves and flanges and passing the strip between the vertical rollers of the mill, while the horizontal wall and one of the shelves are formed by horizontal roll elements , and the formation of a vertical wall adjacent to this shelf and flanging by inclined elements, in the manufacture of asymmetric profiles, I have their one flanging, in rough passages simultaneously form a vertical wall located on the flanging side, and bend two inclined elements adjacent to this wall, horizontal elements of the rolls form a shelf remote from the flanging, and the formation of this shelf begins with the first intermediate passage simultaneously with the formation horizontal wall adjacent to this flange of the vertical wall, flanging and associated with flanging of the horizontal shelf, which is formed by inclined elements with the roll rollers, the contact of the vertical rollers with the flanging is carried out over its entire surface, and in all intermediate passages the upper roll is used, with the diameter of the element forming the place of bending between the flange located on the flanging side and the vertical wall, larger than the diameter of the element forming the place of bending between flanging the shelf and its associated vertical wall.

 The essence of the invention lies in the fact that an asymmetric profile of complex configuration in rough (first three) passages is formed as a zeta profile (only one of the vertical walls is formed), and the formation of the remaining elements begins the first intermediate pass. After this and all subsequent passes, the flanging during the passage of the strip between the vertical rollers contacts one of them along its entire length, and the places of bending of the strip adjacent to the formed vertical walls are located at different levels in all intermediate passages. As a result of this, the longitudinal twisting of the finished profiles beyond the tolerance is eliminated and it becomes possible to reduce the number of forming stands due to the use of greater than the known method, private (per pass) bending angles of some elements.

 In this case, vertical rollers along with the transfer of the strip from one stand to another are also used to create “braking” forces of different sizes along the edges of the moldable strip, which prevents both longitudinal twisting and horizontal curvature of the strip due to the asymmetry of the profile cross section.

 The shaping in draft passages (with closed gauges) of a zeta cross section with the formation of one of the vertical walls is aimed at creating a maximally rigid intermediate profile that is resistant to lateral displacements and vertical deflection, and the position of the lower bend of the strip is constant in all passes. The location of the bending points adjacent to the vertical walls at different levels helps to equalize the torques of the opposite direction, affecting the edges of the formed strip.

 The drawing shows a diagram of the formation of the profile along the aisles.

 The method is as follows.

 In draft (I-III) passes, the workpiece is folded by rolls (gauges covered by the lower roll flanges) with the formation of a Z-shaped section containing the vertical wall 1 located on the flanging side and the inclined branches 2 and 3 adjacent to it. In the first intermediate (IV) the passage begins the simultaneous formation of horizontal walls 4 and shelves 5, as well as the second vertical wall 6 and the second shelf 7 adjacent to the flange 8.

 In all passages, starting with IV, the flange 8 is in contact with the left (in the drawing) vertical roller 9 along its entire length, and the shelf 5 with the right roller 10 is only edged.

The diameters D _{1 of the} elements of the upper roll forming the bend point O ₁ between the vertical wall 1 and the profile shelf 7 are larger in all intermediate passages (IV-V) of the diameter D _{2 of the} elements forming the bend point O ₂ between the second vertical wall 6 and the shelf 5.

In the pre-finishing (VII, VIII) and finishing (IX) passages D ₁ = D ₂ .

 The radii of the bending points are successively reduced along the aisles. The bending angles of the elements of the cross section in the aisles: α, β, γ, δ and θ, moreover in the IV, V, VI and VII passes β> θ, and in the VIII and IX passes β = θ.

Forming axis VV and forming level XX pass through point O ₁ .

 An experimental verification of this method was carried out on a continuous roll forming mill 1-4x50-300 of the Magnitogorsk Iron and Steel Works when rolling an asymmetric profile 145x46x3 mm from 3sp steel in nine forming stands. Various calibration options were tested with an assessment of the quality of bent profiles for the output of rolled products of high (VT) and increased (PT) dimensional accuracy.

 The best results (yield profiles BT 23% PT 51% rest normal (OT) dimensional accuracy) were obtained using the proposed method (Fig. 1).

The transfer of the beginning of simultaneous bending of all elements to an earlier stage of the profiling process (III and II passes), as well as to a later stage (IV pass), deteriorated the quality indicators (yield of BT profiles 3-15% PT 32-47% the rest from), part of the profiles had increased longitudinal twisting (more than 1 ^about 1 m length and more than 10 ^about the entire length of the rod).

 The quality indicators also worsened when the flanges were in contact with the vertical roller only with its own edge: up to 5% of the profiles had increased twisting and curvature was greater than the norm (more than 0.1% of the rod length).

 The distortion of the geometry of the profiles was also observed when the diameters of the elements forming the bending points between the vertical walls and the shelves in the intermediate passages were equal, i.e. at the same angles of bending of the vertical walls in these passages.

 When molding a profile according to the prototype method with the simultaneous bending of all elements, starting from the first pass, the results were obtained: yield of rolled VT 9% PT 26% of the rest from, and up to 6% of the profiles had increased longitudinal twisting, and molding was carried out in 11 stands .

PRI me R. Profile 145x46x2 with dimensions (Fig. 1) r = 6 mm, B = 145 mm, b ₁ = 42 mm, b ₂ = 33 mm, H = 46 mm, h = 32 mm and S = 3 mm is formed in 9 passes with the following parameters:
Iα = γ = 10 ^o , β = 20 ^o ;
IIα = γ = 15 ^o , β = 30 ^o ;
IIIα = 25 ^° , β = 45 ^° , γ = 15 ^° ;
IV (all elements simultaneously Hem) α = ^{25 °,} β = ⁶⁰ °, δ = ^{45 °,} θ = ^{20 °,} D ₁ = 46 mm, D ₂ = 433 mm
Vα = ²⁰ °, β = ^{65 °,} δ = 55 ^°, θ = ^{40 °,} D ₁ = 477 mm, D ₂ = 453 mm
VIα = ^{15 °,} β = ^{75 °,} δ = ^{70 °,} θ = ⁶⁰ °, D ₁ = 477 mm, D ₂ = 466 mm
VIIα = 10 ^о , β = 80 ^о = δ, θ = 78 ^о , D ₁ = D ₂ 477 mm,
VIIIα = 2 ^about , δ = 90 ^about , β = θ = 88 ^about , D ₁ = D ₂ = 478 mm;
IX β = δ = θ = 90 ^° ; α = 0 ^about , D ₁ = D ₂ = 478 mm

 The proposed method for the production of a bent profile allows to reduce the labor costs for the manufacture of the profile and improve its quality.

Claims (1)

 METHOD FOR PRODUCING BENDED PROFILE, including sequentially bending the strip blanks with rolls of the roll forming mill with the formation of horizontal and vertical walls, shelves and flanges and passing the strip between the vertical rollers of the mill, while the horizontal wall and one of the shelves are formed by horizontal roll elements, and the formation of the adjacent to this shelf of the vertical wall and flanging inclined elements, characterized in that in the manufacture of asymmetric profiles, having x one flanging, in rough passages simultaneously form a vertical wall located on the flanging side, and bend two inclined elements adjacent to this wall, horizontal elements of the rolls form a shelf remote from the flanging, and the formation of this shelf starts from the first intermediate passage simultaneously with the formation horizontal wall adjacent to this flange of the vertical wall, flanging and associated with flanging of the horizontal shelf, which is formed by inclined elements with the roll rollers, the contact of the vertical rollers with the flanging is carried out over its entire surface, and in all intermediate passages, an upper roll is used, the diameter of the element of which forming the bend between the flange located on the flanging side and the vertical wall is larger than the diameter of the element forming the bending place between the flanging the shelf and its associated vertical wall.

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