RU2230620C2 - Roll grooved pass system in shape bending mill - Google Patents

Abstract

FIELD: plastic metal working, particularly manufacture of cold bent cut-through shapes.

SUBSTANCE: system of roll grooved passes for forming equal-flange cut-through angle includes rough, intermediate and final passes formed by means of upper and lower rolls mounted with gap and having predetermined width B of grooved pass. Rough grooved pass is closed by means of flanges of lower roll. Novelty is that barrel of upper roll of finish rolling stand has three members; mean of said three members is in the form of disc having cutting-through members arranged along disc generatrix. Members for cutting-through have predetermined contour and width of working portion δ = (0.10 - 0.14)B; they are mounted at angular pitch 30 -36 degrees. Lower roll of said roll grooved pass has circular cylindrical turning in the middle of roll barrel; width of said turning Δ = (1.01 - 1.03)δ. All roll passes behind rough pass are open ones.

EFFECT: enhanced effectiveness of process for manufacturing shapes with high accuracy of making cut-trough portions in zone of bending angle.

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Description

The invention relates to rolling production and can be used in the manufacture of varietal cold-formed profiles for special purposes.

High-quality bent profiles, including angular ones, are produced on specialized roll forming mills by passing a strip blank through two-roll calibers, which are usually divided into draft, intermediate and finishing. The rolls of calibers consist of cylindrical-conical elements that carry out successive, in the direction of rolling, bending (shaping) of individual sections of the workpiece with the formation of the desired final section. The set of individual calibers for the production of a particular profile is called a system. The system used for profiling equal-angled corners is given, for example, in the book under the editorship of I.S. Trishevsky “Production of bent profiles (equipment and technology)”, M., “Metallurgy”, 1982, p.246-247 and fig. Xvii. 3.

If the gauge system has an additional perforated caliber, then it is suitable for the production of bent section profiles with perforations, i.e. with through holes of various shapes formed without removing part of the metal into waste.

A known gauge system for the production of bent unequal channels, in which all the intermediate gauges are made with the flange of the upper roll, located on the side of the smaller diameter of the conical element of greater width (see RF patent No. 2025164 class. In 21 D 5/06 from 03.25.92 g.). A known gauge system (mill) for profiling corners, in which the upper rolls of all stands except the first forming one, is made with a cylindrical symmetrical belt of a certain width at the top of the forming rounding (see AS USSR No. 1690892, class B 21 D 5 / 06/10/10/98).

A disadvantage of the known gauge systems is the impossibility of obtaining bent grooved corners with their help.

The closest analogue to the claimed object is a gauge system (roll calibration) for the manufacture of an equilateral perforated angle of 45 × 2 mm, given in the book of I. S. Trishevsky et al. “Perforated profiles”, M., “Metallurgy”, 1972, p. 133 and Fig. 52b. This system contains draft, intermediate and finishing calibers formed by the upper and lower rolls installed with a clearance, and is characterized in that the first three calibers are made with closing by the flanges of the lower rolls. The disadvantage of the described system is the impossibility of guaranteed obtaining with its help high-quality notched corners.

Indeed, since this system is designed only for forming a pre-perforated strip, when bending the grooved workpiece to obtain an equal-hollow corner with grooves on its top, crushing (closing) of such grooves can occur in the case of lateral displacement of the strip, which is especially true for a crescent (curved in the horizontal plane) of the strip.

An object of the invention is to obtain high-quality bent corner profiles with notches in the bend and reducing the cost of their production.

To solve this problem, in a gauge system of a roll mill containing draft, intermediate and finishing calibers formed by clearance of upper and lower rolls with a given gauge width B, the draft gauge is made with closed flanges of the lower roll, the barrel of the upper roll of the finishing stand contains three elements of which the middle one is made in the form of a disk with perforated elements of a given shape installed along its generatrix and with the width of the working part δ = (0.10 ... 0.14) V, located with an angular pitch of 30 ... 36 °, and neither the last roll of this caliber is made with a circular cylindrical groove in the middle of the roll barrel, the width of which is Δ = (1.01 ... 1.03) δ, and all calibers are made open after the draft.

The above mathematical dependences are obtained as a result of processing experimental data and are empirical.

The essence of the technical solution found lies primarily in the location of the caliber in which the profile is cut: it is located after the forming stands, which ensures that the cuts are made exactly at the corner bend. In addition, the middle element of the upper roll of the last caliber is made with perforated elements located along its generatrix at a certain distance, the width of the working part of which is determined by the width of this caliber. These elements are located opposite the cylindrical groove of the lower roll, the width of which depends on the specified width of the elements.

The drawing shows the inventive system of calibers designed for the manufacture of bent grooved corners.

The system contains four calibers (I ... IV), of which I - draft, II and III - intermediate forming and IV - finishing (perforated) caliber. Each gauge contains upper 1 and lower 2 rolls with rolling diameters, respectively D and d, the same for all calibers, installed with a gap S equal to the nominal thickness of the profiled strip. Each roll consists of conical (upper) and cylinder-conical (lower) elements, and, on the upper rolls of I ... III caliber, a forming radius of the same value R.

I caliber is made with closing flanges 3 of the lower roll, the remaining calibers are open. The angle of inclination α of the conical generatric gauges sequentially increases along the course of rolling to a given final value α3.

The upper roll of the IV stand contains a middle element 4 with a diameter Dp, the width of the working part of which δ = (0.10 ... 0.14) of the width B of the caliber. This element can be made, for example, in the form of a gear, the teeth of which (not shown in the drawing), installed with an angular pitch of 30 ... 36 °, have a predetermined shape and are punched in a formed strip of notches. Between the cylinder-conical elements of the lower roll, a cylindrical element (disk) 5 is placed, as a result of which a circular groove is formed with a width Δ = (1.01 ... 1.03) δ, which includes the protrusions (teeth) of the element 4 of the upper roll. The slotted elements of this roll can also be made in the form of separate rollers of a given shape, installed in the grooves of the element 4.

During profiling, the strip is centered by 3 gauge I flanges, as well as by vertical rollers located in the inter-stand spaces of the mill. The formed strip is set in the finishing gauge IV, where the punching of the arched notches without bending the shelves of the corner is carried out.

An experimental verification of the proposed technical solution was made in the manufacture of art. 3 kp of slotted equal-angle corners with a thickness of 0.8 ... 1.5 mm and with a shelf width of 90 ... 110 mm in ZAO “Rolled - Bent Profile” of Magnitogorsk Iron and Steel Works.

It is established that high-quality notched corners are obtained using the proposed system of calibers. Such corners can be bent along a predetermined radius to obtain parts of the hermetic packaging of rolled strip steel.

A decrease in the angular step (less than 30 °) in some cases caused cracks in the region of arched grooves during subsequent bending of the profiles, and its increase (more than 36 °) made the distance between the grooves on the packaging details of the rolls unreasonably large, which corroded some of the metal during transportation to the consumer.

The experiments showed that the width of the working part of the glazed elements (it determines the height of the arched grooves, as well as the conditions of crack formation) and the ratio between the specified width and the width of the cylindrical groove of the lower roll of the last stand (it determines the quality of the metal cut during the formation of grooves) are very important.

The suitability of the gauge system, chosen as the closest analogue, for obtaining high-quality bent corners with notches at the place of their bend was also tested. When forming a billet pre-cut in the middle of its width in six calibers, of which I ... III were made with closing them with lower rolls, it was not possible to obtain high-quality profiles suitable for use as packaging parts for rolled steel. In addition, the roll consumption was approximately 1.5 times greater, which accordingly increased the cost of profiling.

Thus, an experimental verification confirmed the acceptability of the technical solution found to fulfill the task and its advantages over a known object.

According to ZAO “Complex of New Technologies”, the use of the proposed gauge system for the production of the above-described perforated bent corner profiles will reduce the cost of their manufacture by at least 60%, which will accordingly increase the profit from their sale.

Concrete example

The system of calibers of a roll forming mill for forming an equal-flange notched corner 100 × 1.2 mm from st. 3 kp contains draft (I), two intermediate (II and III) and fine (perforated, IV) calibers (see drawing). Rolling roll diameters: D = 477 and d = 190 mm; the value of R = 2 mm, the angles of inclination of the conical generatric calibers - α ₁ = 20, α ₂ = 40, α ₃ = 46.

Caliber I is made with the flanges closing the lower roll, the remaining calibers are open, IV gauge with a width of B = 142 mm contains a middle element on the upper roll with a diameter of Dp = 500 mm and a width of δ = 0.12 V≈17 mm, along the generatrix of which with angular 32.5 ° steps performed II notched protrusions. The lower roll of this caliber is made with a circular cylindrical groove, the width of which is Δ = 1.02δ = 17.35 mm.

Claims (1)

The gauge system of a roll forming mill for forming an equal-flange notched corner, containing draft, intermediate and finishing calibers formed by clearance of the upper and lower rolls with a given gauge width B, while the draft gauge is made with closed flanges of the lower roll, characterized in that the barrel of the upper roll is finished the stand contains three elements, of which the middle one is made in the form of a disk with perforated elements of a given shape installed along its generatrix and with the width of the working part δ = (0.10 ... 0.14) V, set with an angular step of 30 ... 36 °, and the lower roll of this caliber is made with a circular cylindrical groove in the middle of the roll barrel, the width of which is Δ = (1.01 ... 1.03) δ, and all calibers are made open after draft .