RU2188729C2 - Drive system of multistand shape bending mill - Google Patents

Abstract

FIELD: plastic metal working, namely equipment for making bent rolled shapes. SUBSTANCE: light-weight drive unit of multistand shape bending mill is designed for transmitting torque to upper and lower rolls and it includes engine, reduction gear, tension apparatus, powered upper and lower sprockets, additional sprockets and endless chain embracing upper and lower sprockets along S-shaped curve. Each of upper and lower sprockets is mounted on separate shaft in bearing unit at level of respective working roll. Bearing units of upper sprockets may be vertically moved by predetermined height. All separate shafts by means of pin couplings are joined with working rolls with possibility of operative disconnection of any coupling and respective roll. Additional sprockets are mounted under lower sprockets and they are designed for correcting tension of endless chain. EFFECT: enlarged manufacturing possibilities, lowered cost of drive exploitation. 3 cl, 3 dwg, 1 ex

Description

 The invention relates to rolling production and can be used in the manufacture of high-quality bent profiles of relatively small sizes.

 For the manufacture of high-quality bent profiles (corners, channel, trough, Z-shaped, etc.), special mills are used, usually containing 8 ... .14 two-roll stands. Depending on the size of the initial billet, roll forming mills are divided into several types: light, medium and heavy. The drive of modern roll forming mills contains an engine, gearbox, gear stands, couplings, spindles and its features are described in sufficient detail, for example, in the book under the editorship of I.S. Trishevsky "Production of bent profiles (equipment and technology)", M., "Metallurgy", 1982, p. 146-149.

 A significant drawback of roll forming mills with such a drive is a large number of intermediate parts and assemblies, the rotation of which consumes a significant proportion of the energy of the engines, which reduces the efficiency drive, makes its manufacture and operation more expensive.

 Known drive machine for roller forming, carried out from an electric motor through a chain drive, and the first upper roll is made idle (see US Pat. US 3529461, CL 21 D 5/08 from 09/22/70). The drawback of the drive is the possibility of slipping the rolls and jamming the strip in the first, not completely drive stand.

 Also known is the drive of a roll forming mill with an endless chain enveloping the upper and lower sprockets of different diameters mounted on the ends of the work rolls along an S-curve (see Japanese Pat. Pat. 1832, class 12 C 221.3 of January 27, 69). The disadvantage of this device is the drive of all rolls (upper and lower) of the mill, which increases their wear and increases the likelihood of surface defects on the profiles.

 The closest in technical essence to the claimed invention is the drive of a multi-unit roll forming mill of light type with upper and lower work rolls, designed to transmit torque to said work rolls and comprising a motor, gearbox, tensioner, power upper and lower sprockets, additional sprockets and an endless chain enveloping the force upper and lower stars by the S-shaped curve (RU 2110350 С 1, 05/10/1998, В 21 D 5/06).

 A drawback of the drive of this design is the need to stop the mill and change the location of its tensioning device, not only when changing the diameters of the rolls (for example, after regrinding during repair), but also when changing to a strip (blank) of a different thickness, when a change in the roll gap is necessary. A similar operation is performed and, if necessary, disable (enable) one or more rolls. All this leads to an increase in downtime of the mill and to a higher cost of operation of its drive, which will be the greater, the wider the assortment of produced bent profiles.

 The technical problem solved by the invention is the expansion of technological capabilities and cheaper operation of the drive rolls of a light mill for the production of high-quality bent profiles.

 To solve this problem, the drive of a multi-cage roll forming mill of the light type with upper and lower work rolls, designed to transmit torque to the said work rolls and contains an engine, gearbox, tensioner, power upper and lower sprockets, additional sprockets and an endless chain enveloping the power upper and S-shaped lower sprockets equipped with separate shafts and bearings; each power sprocket is mounted on a corresponding separate shaft in the support at a level corresponding to of the working roller, the supports of the power upper sprockets are mounted to move vertically to a predetermined height, all individual shafts are connected via finger couplings to the work rolls with the ability to quickly disconnect any of the finger couplings from the work roll, and additional sprockets are located under the power lower sprockets to ensure infinite chain tension adjustments.

 The finger coupling of a separate shaft of each power upper sprocket is made with half-couplings made with four elongated holes located at an equal distance from the centers of the half-couplings, while the axes of the opposite holes of the half-couplings of each said coupling are perpendicular to one another, and the fingers of the finger couplings of the individual upper power shafts and lower sprockets are installed in the holes of finger couplings provided for them with the possibility of sliding.

 Elongated holes are made with the same difference in length and width equal to a given value.

 The essence of the proposed technical solution lies in the fact that, firstly, the power sprockets are located not at the ends of the mill shafts, but autonomously, which allows them not to be removed or transported during transshipment of the rolls. This reduces sprocket wear. Secondly, when varying the number of drive rolls, there is no need to change the location of the tensioner. Thirdly, when changing the roll gap (switching to a different thickness of the workpiece), the difference in the levels of the upper rolls and sprockets is compensated by the design of the upper couplings (the presence of elongated holes and sliding fingers in them), and the chain tension is adjusted (if necessary) by some movement of additional stars. All this extends the technological capabilities of the drive, reduces the cost of its manufacture and operation while reducing wear on the chain, power sprockets and idler wheel assembly.

 Figure 1 shows the location of the drive and idler wheels and sprockets of the inventive drive; figure 2 - arrangement of power sprockets in the bearings and couplings connecting the drive to the working shafts; figure 3 - the location of the holes on the upper couplings.

The torque from the engine 1 (see figure 1) through the gearbox 2 and the drive wheel 3 through an infinite chain 4 is transmitted to the power upper 5 and lower 6 sprockets. Due to the S-shaped chain coverage of each pair of sprockets, they rotate in opposite directions, providing the desired direction of movement of the formed strip (shown by the middle arrow). The magnitude of the ratio of the diameters of the upper and lower sprockets (i = D / d) is equal to the ratio of the rolling (main) diameters of the mill rolls: D _k / d _k - see figure 2.

 Each of the power sprockets (5 and 6) is mounted on a separate shaft - top 7 or bottom 8 (see figure 2); shafts are mounted in bearings 9 and 10 on bearings (not shown); the ends of the sprocket shafts and the working shafts 11 and 12 of the mill are connected by upper 13 and lower 14 finger couplings, each of which contains two coupling halves. The working shafts are placed on bearings in pillows 15 and 16 installed in the stands of stands (not shown); on the working shafts formed forming elements 17.

 The upper supports 9 of the power sprockets can be moved vertically with the help of set screws 18, freely passing through these supports and screwed into the holes of the lower supports 10. At the outlet of the mill there is a tension wheel 19 (see Fig. 1), which, like the power supports sprockets mounted on the foundation beam 20 (only two pairs of supports are shown - at the inlet and outlet of the mill). From the bottom, supports of additional sprockets 21 are fixed to this beam, correcting the tension of the chain 4.

 The fingers 22 (see Fig. 3) of the upper and lower couplings are made in such a way that they can be easily removed and installed in the couplings (this is achieved by choosing, for example, the running "landing" of the fingers in the holes and the presence of special heads on the fingers). Moreover, as shown by an experimental verification of the proposed drive (see below), the "slack" of the fingers in the holes of the coupling at low profiling speeds on a light mill (0.5 ... 0.8 m / s) does not cause any difficulties in the operation of the drive (and the mill).

 Each of the upper coupling halves has four elongated holes 23 (see Fig. 3), i.e. their length "l" is greater than the width "b" by an amount depending on the difference between the minimum and maximum thicknesses of the profiled workpiece; at the same time, the axes of the same holes (for example, xx and x'x ') in two connected coupling halves are perpendicular to each other, which allows rotation to be transmitted to the rolls at a certain displacement of the coupling centers due to the sliding of fingers 22 in the holes. The distances from the centers O1 of all the holes to the center of both coupling halves are the same and equal to "a".

 The bearings of the sprockets, drive and tension wheels of the drive and stand of the mill are installed on separate foundation beams (20 and 24 - see figure 2), which favorably affects the accuracy of profiling, as the inevitable vibration of the drive is not transmitted to the shaft of the mill, which also contributes to the "slack "fingers in the couplings.

 When switching from one thickness of the formed strip to another, it is enough only to raise (or - lower) the additional drive sprockets 21; the same operation can be sufficient even with a small change in the rolling diameters of the rolls and a constant strip thickness. With changes in roll diameters greater than the difference in values (l-b), it is necessary to move vertically the supports 9 of the upper sprockets and the tension wheel 19 horizontally. To disconnect the corresponding mill roll from the drive, you should disconnect its coupling halves and sprockets by removing fingers 22 from the couplings.

 An experimental verification of the inventive drive was carried out during comparative tests of the proposed technical solution and the well-known (see description of the drive according to RF patent 2110350 above) on a twelve-unit roll-forming unit 0.5-2.5 • 30-250 CJSC “Rolled-bent profile” of Magnitogorsk Iron and Steel Works. Comparative tests showed that the wear resistance of the power sprockets of the proposed drive was 1.4 ... 1.8 times greater than that of a drive of known design, and the chain was almost 30%. In addition, the wear of the sliding surface of the tension wheel of the proposed drive has decreased almost twice. All this led to a reduction in operating costs of this drive (compared to the known one) by an average of 1.6 times, and the transition from the maximum (2.5 mm) workpiece thickness to the minimum (0.5 mm) reduced mill downtime by 2, 0 .. .2.5 times, which allowed to increase its productivity.

 It was also determined the optimal number (4) of holes in the upper couplings, giving a "smooth stroke" of the drive. With a larger number of holes, it is necessary to increase the dimensions of the couplings due to their weakening by the holes.

 Thus, the experiments confirmed the acceptability of the claimed object for solving the task and its technical and economic advantages over the known technical solution.

 According to the data of the Central Laboratory of OJSC Magnitogorsk Iron and Steel Works, the use of the proposed drive on multi-roll forming mills similar to the 0.5-2.5 unit will reduce the cost of redistribution in the production of high-quality bent profiles (by reducing the labor costs for operating and repairing the drive) not less than than 20%, which accordingly will increase profits from the sale of finished products.

Concrete example
The lightweight mill of 0.5-2.5 • 30-250 contains 12 Duo stands with a “pitch” between them of L = 800 mm and is intended for profiling a workpiece with a thickness of 0.5 ... 2.5 mm and a width of 30 ... 250 mm from steel with a tensile strength of up to 50 kgf / mm ² .

 Mill drive - chain, from an induction motor with an adjustable speed and a power of 45 kW; maximum profiling speed (strip workpiece movement) - 0.8 m / s.

 The mill drive is mounted on a separate foundation beam and contains (except for the engine) a gearbox, a drive wheel, a tensioning device, 12 pairs of power sprockets with i = 2,3 and 4 distance sprockets. The drive uses an endless single-row roller chain with a pitch of 25.4 mm, capable of withstanding a breaking load of 6500 kg and alternately covering the upper and lower power sprockets in an S-shaped curve.

 Each of these sprockets is mounted in an individual support on the shaft, at one end of which a coupling is mounted, connected by fingers φ == 14-0.16-0.33 mm to a coupling half on the working shaft of the mill. Moving the upper bearings of the power sprockets in a vertical plane - using the set screws to a distance of 25 mm.

 In each upper coupling half, 4 elongated holes are made with l = 17 mm, b = 14 + 0.2 mm, the distance from the centers of which to the centers of the coupling halves is a = 68 mm; the axes of the same name connected by the fingers of the coupling halves are perpendicular to each other.

Claims (3)

 1. The drive multi-roll forming mill of the light type with upper and lower work rolls, designed to transmit torque to the said work rolls and comprising a motor, gearbox, tensioner, power upper and lower sprockets, additional sprockets and an endless chain enveloping the power upper and lower sprockets along an S-shaped curve, characterized in that it is provided with separate shafts and bearings, each power sprocket is mounted on a corresponding separate shaft in the support at a level corresponding to its working roll, the supports of the power upper sprockets are mounted to move vertically to a predetermined height, all individual shafts are connected by means of finger couplings to the work rolls with the ability to quickly disconnect any of the finger couplings from the work roll, and additional sprockets are located under the power lower sprockets to ensure infinite chain tension adjustments.  2. The drive according to claim 1, characterized in that the finger coupling of the individual shaft of each power upper sprocket is made with half-couplings made with four elongated holes located at an equal distance from the centers of the half-couplings, while the axes of the opposite openings of the half-couplings of each said coupling are located perpendicular to one another, and the fingers of the finger couplings of the individual shafts of the power upper and lower sprockets are mounted in the sliding holes of the finger couplings provided for them.  3. The drive according to claim 2, characterized in that the elongated holes are made with the same difference in length and width equal to a given value.

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