SU1634347A1 - A method for manufacturing bent rolied sections - Google Patents

Abstract

The invention relates to the processing of metals by pressure and is intended for use in forming bent rolling profiles, mainly of the type of channels with a constant height of the flange, consisting of extreme sections with wide and narrow walls of constant width and an average section with a wall of variable width connected to the extreme sections help transition sites. The purpose of the invention is to improve the quality of the profiles by eliminating profile reshaping. In the process of forming the profile, simultaneously with the application of the shaping forces, the shaping forces are applied to the inner surface of the shelves at curvilinear parts of the bend sites along the entire length of the workpiece at an angle determined by the calculated dependence and shear force to the inner surface of the bends in the middle section and transition areas . The profile shelf at the transition sites is molded along the radius determined by the calculated dependence. The application of the shaping force only to the inner surface of the bend points at an angle to the vertical prevents the roll skew. 5 silt (L S

Description

The invention relates to the processing of metals by pressure and is intended for use in forming bent rolling profiles, mainly of the type of channels with a constant height of the flange, consisting of extreme sections with a wide and narrow wall of constant width and an average section with a wall of variable width connected to the extreme sections with help transition sites.

The aim of the invention is to improve the quality of the profiles by eliminating their reshaping.

Figure 1 shows a profile with a variable length of the wall; figure 2 is a view of And figure 1; FIG. 3 is a kinematic diagram of a working stand of a mill for forming a channel with a variable wall width; Fig. 4 is a diagram of the application of forces when forming a channel with a variable length of the wall; Fig. 5 is a diagram for determining the angle c.

In the process of forming a profile with a variable length of the width of the wall, it is advisable to apply a force from the inner surface of the profile only on curved sections.

about with

with

(places of bending) along its entire length: on narrow 1 and wide 2 sections of constant width, sections 3 and A of the transition and middle section 5 of variable width - at a calculated angle of 0 to the vertical axis.

At the same time, shearing forces are applied, displacing the forming elements of the upper and lower rolls, as sections 3, 5 and 4 pass through the cage, the shape of the flange profile in each transition is curved in plan for the calculated radius R in sections 3 and 4 of the transition, and in section 3 inward profile, in section 4 - outward.

The angle is determined from the calculated dependence

in arctg PK-slna) / (p5PH + PKCosai) 1 (1) and the radius R of the shelf bend in the plan is determined by the dependence

R 1kr / / 2 - arctg (ctg y / sin GQ), (2) where Pk is the force applied when forming to the outer surface of the shelf;

05 - the total angle of the shelf bend in the 1st technological transition;

PH - the force applied when forming to the outer surface of the wall;

y is the angle of transition of a section with a narrow wall to a section with a variable wall;

1Kr - the length of the curved in terms of parts of the shelf in the transition areas.

If the shelf is bent upside down (at the transition from narrow to medium to the outside, and at the transition from medium to wide inside), the smoothness of the profile shape is disturbed, on the shelf at each transition site there are two additional folds in the transition, which leads to a decrease bearing capacity profile. At the same time, the presence of zones with different sign deformations, with complex bending in both static and dynamic mode of operation, to the occurrence of cracks. The quality of the profiles is reduced.

As shown by the data of experimental verification as a result of using the proposed method for forming

channel 200 (250) x 90x4 mm with a variable length along the wall width did not occur reshaping. The length of the curved part of the shelf in the transition section was

30 ± 1 mm, while in the basic method ± b mm.

Thus, the use of the proposed method will improve the quality of the profiles by eliminating the reshaping

shelves in a section with a variable width of the wall, the deviation of the length of the curved shelf from the nominal (30 mm) is ± 1 mm, whereas for the production by a known method to ± 6 mm.

f o rm u l a i z o brie n i

Method for the production of curved rolled profiles of the type of channels with variable wall width and constant width of the shelf containing the extreme parallel sections

and an inclined section located between them, conjugated with extreme ones by means of curvilinear in terms of transitional sections, including application of shaping forces to profile elements and places

bending and shearing forces in the middle and transition areas, characterized in that, in order to improve the quality of the profiles, the effort to form each bend is applied from the inner surface only in a curvilinear section over the entire length of the profile at an angle to the vertical axis in the cross sectional plane, determined from the expression

0 arctg (Pk-sin (A) / (0.5 Rn + Pk cos a),

where RK is the force applied when forming to the outer surface of the butt;

PH is the force applied to the outer surface of the wall;

a - the total angle of the shelf bend in

1st technological transition,

and the magnitude of the radius of curvature of the flange in the transitions and the lengths of the arcs of these portions are assumed to be constant at each transition and equal to

5 finished profile.

FIG.

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0 FIG. five

Claims (1)

Claim A method for the production of bent profiles of the type of channels with a variable width of the wall and a constant width of the shelf, containing extreme parallel sections and placed between them inclined section, conjugated with extreme through curved in terms of transition sections, including the application of forming forces to the profile elements and places of bending and shear forces on the middle and transition sections, characterized in that, in order to improve the quality of the profiles, the molding force of each bending point is applied from the side of the inner surface only on a curved section along the entire length of the profile at an angle Θ to the vertical axis in the plane of the cross section, determined from the expression 0 = arctan [(Pk · sip sd) / (0.5 Pn + Pk cos cq)], where Pk is the force applied during molding to the outer surface of the shelf; Rn is the force applied to the outer surface of the wall; SP is the total angle of the shelf bending in the l-th technological transition, and the radius of curvature of the shelf in the transition sections and the length of the arcs of these sections are taken at each transition to be constant and equal to their values on the finished profile. Figure 2