SU1417958A1 - Method of bending thin-walled sections - Google Patents

Abstract

The invention relates to the processing of metals by pressure, in particular, to the technology of manufacturing parts by the method of bending by stretching. The purpose of the invention is to improve the quality of bending and expansion of the field of application. The cross section of the profile before the flexible one is divided into separate sections. Different sections of the cross section of the profile are reported by various longitudinal deformations. The magnitude of the bend is determined from the difference in the longitudinal deformations in the cross sections of the profile. The direction of the bend is set by applying tensile forces to that portion that is external to the center of curvature. The amount of bending is controlled by changing the size of the clamped areas. By combining the pattern of clamping sections of the profile with the trimming of the bending copy machine, it is possible to obtain details of the spatial configuration. 1 3.p. f-ly, 3 ill. x (L

Description

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The invention relates to the processing of metals by pressure, in particular, to the technology for the manufacture of parts by the method of bending with p-stiffening.

The purpose of the invention is to improve the quality and expand the scope.

FIG. 1 shows the process of bending an LL profile, for example, a U-shaped cross section; Fig. 2 illustrates the process of adjusting the amount of bending; in fig. 3 is a process of changing the direction of bending.

The initial profile blank, for example, a U-shaped section of length 1, is conventionally divided around the perimeter of the cross section into sections, the number of which can be arbitrary. In this example, the number of plots) gri, which are denoted by the pos. I, 2 and 3 (Fig. 1a). In order to carry out the process of bending, for example, only section 1 of the cross section of the profile is clamped at the ends with a force (p, and applying to this section are pulling forces P equal in magnitude and opposite in direction (Fig. 1b), since section 1 stretched by the value of 2 fl, -1, sections 2 and 3 (in this example, the side shelves) due to the fact that they are not clamped 5 grades by a different size the smaller the farther away the edges of these sections are from the clamped section 1. In the In this case, the extreme ends of these sections will be stretched to This is confirmed by the diagram of the distribution of stresses along the height of the section P9lok profile.

Gd will always be less than /, due to the fact that, to the non-pressed, sections 2 and 3, across the cross section, the tensile force P is transmitted not directly through the clamping elements, but through the clamped section 1, i.e. The clamped section 1, when stretched out, is not longitudinally unclamped, and as the unclamped sections move away from the closed ones, this interrelation decreases, i.e. stretching unclamped areas seems to be slowed down and a shift of material layers occurs in uncompressed sections of the cross section of the profile.

After removing the tensile forces P due to the difference in elastic stresses and residual longitudinal deformations (and -Jj) in different parts of the cross section of the profile, the workpiece will be bent in a direction less than height 82

plots and take the form shown in FIG. 1b, i.e. the portion to which the clamping force Q is applied and the tensile force P (zone I) is external to the center of curvature.

The curvature of the curved part is the greater, the greater the difference in residual longitudinal deformations of the clamped and non-pressed sections of the cross section of the profile, i.e. it can be adjusted by the size of the clamped areas. With additional partial clamping

side shelves profile, i.e. when za-. press profile, besides section 1, also in part of sections 2 and 3, when stretched by reducing the size of unclamped sections, we will get more,

than in the case of the clamp according to FIG. 1, the elongation of the ends of the non-pressed sections Lz 1e-1 L 12-1 (Fig. 2a), and, consequently, the smaller difference between the residual core deformations of the clamped and non-pressed zones, i.e. u -u u- U2

the lesser curvature of the part, and the direction of the bend (Fig. 2b) is preserved similarly to FIG. 1c. I ..

To change the direction of the bend of the workpiece, it is necessary to change the area of application of the clamping Q and the pulling forces P.

For example, to change the plane are flexible by 90 ° compared to the bend shown in FIG. 1c and 26, clamping and longitudinal tensile forces P must be applied to one of the side shelves of the profile (Fig. 3a), then after removing the stretching, the workpiece. bent in the direction of the opposite side flange (Fig. 3b). By combining the above-mentioned schemes for clamping profile sections with trimming around bending copiers, it is possible to obtain details of the spatial configuration.

Claims (2)

1. A method of bending thin-walled profiles by applying a deformation to one of the sections of the cross section of the profile, characterized in that, in order to improve quality when bending profiles of complex section and expanding the field of application, before deformation, the cross section of the profile is divided into separate the sections, the deformation is carried out by clamping and subsequent stretching of individual sections, while the direction of bending is determined by clamping and applying tensile forces to that section of the profile that is outside visas. 2. The method according to p. 1, This is because the magnitude of the bend is controlled by changing the size of the clamped sections. tz ; f1 / g. J FIG. 2 / ff Y