SU1015961A1 - Section bending mill stand - Google Patents

Abstract

1. CLUTCH OF THE DEFICIENT MILL, containing upper and lower wapes. with pentral elements and lateral conical elements, characterized in that, in order to reduce roll wear, the centrifugal element of the upper roll is concave, and the lower one is axial, while the lower roll is provided with inclined platforms connecting the central element with lateral conical elements, and the angle of inclination of the generatrix of the conical surface is lateral; of the upper part of the upper roll, is greater than the angle of inclination of the generatrix of the conical surface of the lower element of the lower roll by an amount of 5-6.

Description

2. A cage according to claim 1, 1, 2, and 2, so that each of the slopes of the lower roll is perpendicular to the bisector of the angle between the cylindrical and the horses of the roll, and its width is determined from the following relation

. 2 ..- coe% (R + 5

0 -G - i7 "

S1M i

de p. - radius of curvature of the upper roll;

S the size of the gap between the rolls, is equal to the thickness of the strip to be formed;

angle of hemming of the conical surface of the side element of the lower roll;

, S, the size of the gap between the rollers at the junction of the conical and central elements; minimum relative compression profile.

The invention relates to the processing of metals by pressure, in particular to equipment for profile bending machines. The known roll forming mill stand containing upper and lower rollers, made with central parts, in the form of a barrel and lateral conical elements. The disadvantage of the known stand is abrupt wear of the roll elements. The purpose of the invention is to reduce roll wear. For this purpose, in the stand of the roll forming mill containing the upper and lower rolls with central elements and lateral conical elements, the central element of the upper roll is made concave, and the lower one is cylindrical, while the lower roller is equipped with inclined planes connecting the central element with lateral conical elements, and the angle of inclination of the forming conical surface of the side element of the upper roll is greater than the angle of inclination of the conical surface of the side element of the lower roll forming an amount of 5-6. In addition, each inclined area of the lower roll is perpendicular to the bisector of the angle between the cylindrical and conical elements of the roll, and its width is determined by the dependence of, g and 5-ay aL / g (R-fS) 3 77/1 K - rounding radius top roll; 5 - - the size of the gap between the rolls is equal to the thickness of the strip to be formed; v is the angle of the hem of the forming concave, surface of the side element of the lower roll; g is the size of the gap between the rolls at the junction of the conic and central elements; g, - the minimum relative compression profile. FIG. 1 shows the proposed roll forming mill stand for the production of a bent channel with the bending of the bending places in thickness during molding; in fig. 2 — node I in FIG. 1. The cage consists of the upper 1 and lower 2 rolls, which are set with a gap to pass the forming strip 3 with a thickness S. The upper roll has a concave barrel, the diameter of which begins to decrease immediately after rounding on the roll, and conical (side) elements with an angle of inclination to the horizontal and rounding radii (bending radii) R. The lower roll has a cylindrical barrel, conical elements with an angle of inclination about the horizontal, and crimping inclined elements 4, which are straight, forming which is perpendicular to the bisector of angle R between the barrel and the conical elements of the lower roll. The crimping elements are located at the junction of the barrel and the conical elements of the lower roll and have a width S, When the moldable strip enters the gap between the rollers 1 and 2 forming the caliber, its extreme elements (flanges) are bent at an angle determined by the angle of inclination conical elements of the lower roll to the horizontal. If the rolls are installed with a gap .9,; the value of which is equal to the nominal thickness of the strip 3 and the distance between the straight line a, tangent to the rounded tops of the upper roll and the breaking barrel of the lower roll (Fig. 1), then. the inner radius of the bend points of the channel; vein ft, and these bend points are crimped with a minimum degree of crimping for a given radius, defined by the width O of the crimped element. If it is necessary to increase the reduction, the roll gap is reduced by moving the upper roll down. The smallest bending point thickness S, which coincides with the angle bisector, also decreases, but due to the concave type of the upper roll and the difference in angle values and od, this roll continues to contact with the moldable strip only along the radii of curvature (the contact area increases slightly). As a result, the wear of the barrel and the side elements of the upper roll is reduced. If the perpendicular bisectrix of the angle p forming the & element element, then the relationship between the values of cG R I oL is determined geometrically as follows. From the SOB and AEDV (Fig. 2) follows that. 1% 180 ° - oi, u.f) QC, i TIirin of the inclined crimping area of the E F caliber: cG 2ED t 2VD, --tgoC -tor 4 (from LEDV). But VDOV-TO, and TO: R +5 and ABOUT OA.-cogr-B (from. D); i.e. cr-Bf - 2UR S): COsi- (RW), 2tl -S-C05 | (): S1M Thus, at nominal, the gap between the rolls is equal to the thickness of S psios the thickness of the bend of the profile, measured by the bisector of the angle p is equal to - cG. dL S - () .- C05 -R- | ig Experimental check of the proposed roll-up mill stand is performed on a 2-8x1OO-6OO mill when forming a 120x60x6 channel bar from 09G2 steel. Opening of the bend points is carried out in the 4th stand of the mill. For this purpose, several sets of rolls of the proposed design are produced, differing in individual sizes. The upper rolls of the 4th stand are prepared in five variants: with the angle of conical elements equal to 47.49-52 1614, but with the same barrel deflection (tangent to the places of curvature of the rolls make up the horizontal). The radius of rounding for all rolls is 25 mm. The lower roll of the 4th stand has an angle of about 45, i.e. the total angle of the hem in this stand is also equal to 45 °. In places of contact with the barrel and side elements of the lower roll (in the corners of the gauge) there are crimping inclined elements with a width of 14.2 mm and a slope angle (in the first series of experiments) 3 22.5. Such an implementation of the crimping elements provides at nominal clearance and thickness of the workpiece; (6 mm) relative compression of 8- O, O5 5%, Rolling roll diameters; top (minimum, in the middle of the barrel) - 258 mm, bottom 652 mm. Since the wear of the lower roll for all variants of manufacturing the upper rolls remains approximately the same (crimping elements are pre-borized, which determines their high wear resistance), only the upper rolls of the rollers for each value of the angle oL are determined: during initial reduction (5%) and at 10, 15 and 20% to increase the local production of conical elements (in mm, with the help of probes) after 200 tons of rolled metal. In the rolling process, the thickness of the sections of the profiles is also periodically fixed (value 5). The results are as follows: when crimping bending points with a value of 5% (the value is within 5.65-5.8 mm), the wear of the upper rolls after 200 tons of rolled stock is practically absent for all sets of these rolls with angles oi. 47-52} 10% - the wear of the side elements of the upper rolls is 1.0-1.5 mm, and at ~ 15%, the strip is drilled due to its pinching with the rollers; of. 49, 10% of the wear O, 8-1.2 mm, but at P 3.5% the strip often gets stuck and the pinching process is unstable 50, E 10% of the sediment is O, 5-1, O mm, -: 15 % - wear 1.31, 7 mm, t - 20% - blocking of the band; 51 °, E 10% - wear value О,, 7 mm, E 15% - wear 0.8-1.4 mm, g 20% - wear is 1.5-2, О mm | from / to 62, f 10% wear 0.3-6.6 mm, 15% wear, 5-O, 9 mm, 20% wear is 1.3-1.8 mm, but for the most part

The profiles appear wavy on KjpoK fkam shelves.

Thus, experiments have shown that the best results are achieved at oi 50 and 51, i.e. when the difference in the magnitudes of the angles oi ° C is 5-6.

Next, for the stand with the upper roll, which had the angle “, two lower rolls are made with the inclination angles of the crimping pads 15 ° to 30 °. At 15, the strip is stopped in the rolls of the yoke at 10%, and in the stand with T DZ

R

It is not possible to obtain a bend compression of more than 1.7-2.5 (the crowd of the crimped places 9 5.85-5.9 mm).

Experimental rolling results show that using the present invention when profiling channel bars with crimping bending thickness (for example, in order to improve their geometry) reduces the wear of the work rolls while adjusting the reduction rate by changing the roll gap.

Claims (2)

1. A crate of a roll forming mill comprising upper and lower rolls with central elements and side conical elements, characterized in that, in order to reduce wear of the rolls, the central element of the upper roll is concave and the lower one is cylindrical, while the lower roll is provided with inclined platforms connecting the central element with the side conical elements, and the angle of inclination of the generatrix of the conical surface of the side element of the upper roll is greater than the angle of inclination of the generatric conical surface of the side element nta of the lower roll by 5-6 °. 2. The cage according to claim 1, with a lorn, in that each inclined 'flat roll of the lower roll is perpendicular to the bisector of the angle between the cylindrical and conical elements of the roll, and its width is determined from the following relationship 2 LEI-e. -Co <5 ~ (p. + S ') _where p. _ radius of curvature of the upper • roll; S is the size of the gap between the rollers, equal to the thickness of the formed strip; about - utop bending generatrix of the conical surface of the side element of the lower roll; G = €, S ~ the gap between the rolls at the junction of the conical and central elements; £ - minimum relative profile compression.