SU1685569A1 - Method for making corrugated shapes - Google Patents

Abstract

The invention relates to the processing of metals by pressure and can be used in the production of cold-formed corrugated rolled sections. The purpose of the invention is to reduce the consumption of metal with optimal quality profiles. The flat actual blank is preliminarily determined by the average actual thickness and width of the flat sections, taking into account the ratio of the average actual and minimum allowable thicknesses and sizes of these sections on the finished profile. Then, the flat areas are subjected to transverse stretching by bending along an arc of a circle in the direction opposite to the direction of stretching of the corrugations. The magnitude of the bending radius of these areas is determined from the calculated dependence. The method allows to reduce the metal consumption. 1 il.

Description

with

with

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

The aim of the invention is to reduce the consumption of metal with optimal quality profiles.

The drawing shows a diagram of the implementation of the method.

The average actual thickness of the workpiece is pre-determined as follows.

On each roll of the workpiece (mainly cold rolled strip) fed to the mill 0.5-2.5 x 300-1500 (on which the proposed method is implemented), the theoretical weight (mass) of the roll of nominal thickness hH and the conversion factor K, equal to the ratio theoretical Pt and actual pf roll weights.

In turn

PT LBH mon y, and

RF L Vf Lf y, where L is the length of the strip in the roll;

Vn and Vf are, respectively, nominal and actual bandwidths; 7.85 - steel density;

Bf is the average actual thickness of the strip.

It's obvious that

K A L BH NU Vn tin Russia L Vf gkru Vf-Nf

Since the rolls come only with a cut edge, the width of the strip varies in the roll very slightly (within 1 mm) and Bf is determined by one measurement (roll width).

Then bf Vn r1H / Bf K.

about

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In addition to the average actual thickness of the workpiece Ff, the width of the flat workpieces bi, b2 is predetermined. Bz and b4 ... bn considering their sizes on the finished profile bi, b2. Bz, b4 ... bn and coefficient

broadening K

.u -j, where h - the minimum thickness of the strip

Bz b

bi

B - -

(b + b2 + bh + b4) Weag-bc

R 2:

(bj + b2 + b3 + b4)

about

where Vzag - the width of the workpiece without

Ku

Ryny two extreme technological corrugations and taking into account the coefficient of broadening;

Vvra is the width of the sweep of the section of the finished profile.

In the pitch roughing pass, the flat portions of the preform 1 are subjected to transverse stretching of their bending along an arc of a circle of radius R. The value of which is determined by the dependence

0.22 b (hi + hi 2/3)

7VhJ-h2

where b is the width of the corresponding area of the workpiece, mm;

R is the bending radius of a part of the workpiece with width b.

At the same time, the near-fringe areas 2 are clamped by rolls (for example, with the formation of technological corrugations).

The portions of strip 3 corresponding to the vertices of future corrugations are formed by radii r R, as a result of which the thickness in these places will be somewhat less than on flat sections of bi-bs (the thickness of the bend points on the finished profiles x is not controlled). In subsequent transitions, the corrugations 4 are formed with the release of the edge sections 2. The finished profile 5 has a thickness hn 2: R. Technological corrugations can be cut off or (if the metal is sufficiently plastic), smooth out in finishing passes.

The magnitude of the radius r can be taken equal to (1.7-2) rk (critical bending radius).

0

five

0

five

thirty

35

40

Example. Corrugated profile 735 x 23 x 2 mm from st. 09Г2 has a scan section with a length of 801 mm. The average actual thickness of the workpiece is 1.95 mm, the minimum thickness of the strip (and profile) is 1.82 mm h, i.e. the strip can be broadened 1.95: 1.82-1.07 times and take the workpiece with a width of 801: 1, mm, and taking into account the sweep width of the two technological corrugations, 749 + 215-779 mm (after forming these corrugations are removed).

The parameters of the finished profile bi. b2, b3 and b4 / (figs are respectively 170, 250, 250 and 65 mm.

The width of the flat widened areas of the workpiece: bi: ba: b3: b4 - bi: b2: Lz: b4 34: 50: 50: 13, i.e. bi - 173 mm, b2 - Lz 255 mm, 04 - 66 mm.

The magnitude of the bending radii: g 2gk 2 0.44 2 - 1.8 mm; RI - 0,22b4 (RV + h2 / 3) / h Vh | h2 147MM.R2 R3 216 MM; R4 is 60 mm (the R values are taken to be minimal in order to ensure the greatest broadening of the flat areas and, thus, maximum metal savings).

The technical and economic advantage of the described method over the known method is to reduce the metal consumption by approximately 3%.

Claims (1)

Invention Formula A method of making corrugated profiles, including the forming of corrugations and plastic transverse stretching of the workpiece by bending the flat sections along an arc of a circle, the radius of which is determined by the calculated dependence, in the direction opposite to the stretching of the corrugations, in order to reduce the metal consumption at optimum quality profiles, the magnitude of the bending radius of flat areas of the workpiece R is determined by the dependence RS 0.22 b (hj + h 2/3) L Vhl - h; where h $ is the average actual thickness of poloO1 ( h - the minimum allowable thickness of the strip (profile) mm; b - the width of the flat areas of bending of the strip blank, mm. at, OG 3 at m ... jt -. g 4-fe / r  05 3 3 J Ј L-2