SU1733136A1 - Roll unit of four-high rolling mill - Google Patents

Abstract

The invention relates to rolling production and m. used to increase the flatness of sheets and strips on continuous and reversing mills. SUBSTANCE: annular grooves are made on the inner surface of the work roll barrels and the cylindrical surface of the liners adjoining it, and the groove steps are interconnected by mathematical dependence. 4 il.

Description

The invention relates to rolling production and can be used to improve the accuracy of geometrical dimensions and improve the shape of sheets and strips on continuous and reversing hot and cold rolling mills.

The roll unit of the rolling stand is known in the composition of the working, support and intermediate rolls, each of which is mounted between the respective working and support rolls with the possibility of axial movement. The disadvantages of the known design of the roller unit include the impossibility of promptly adjusting the cross-section of the bands during the rolling process, as well as limiting the technological possibilities of adjustment due to the effect of the adjusting device on the strip edges.

Closest to the present invention is a roll rolling mill assembly comprising a roller in contact with the rolled metal, which contains

a neck and a hollow barrel with a device placed inside C /) to regulate it ее the outer generatrix, made in the form of a short cylindrical liner moving along the axis. The disadvantage of the device is the low efficiency and limited technological capabilities of adjusting the profile of the strip due to the need to move the liner to the CO for considerable distances.

The purpose of the invention is to increase the efficiency and expand the technological capabilities of adjusting the transverse Q profile and the shape of rolled strips.

To achieve this goal, in the roll unit of the quarto rolling stand, which includes support rolls installed by cushions in the openings of the beds, as well as work rolls, each of which contains necks and a hollow barrel with an adjustable outer profile and an outer barrel forming device inside the barrel cavity made in the form of a rolling along the axis

The cylindrical liner barrels according to the invention have annular grooves on the inner surface of the work roll barrels and the cylindrical surface of the liner associated with it, and the groove steps are related by

tb te

n

n +1

where those - the step of the grooves on the inner surface of the barrels of the work rolls;

tB - step grooves on the outer surface of the liner;

n is the number of grooves on the length of the generatrix of the inner cavity of the barrel.

Figure 1 shows the roll unit of the quarto stand, general view; Fig. 2, 3 shows the relative position of the grooves made on the inner surface of the barrels and the surface of the liners adjacent to it; Fig. 4 shows a graphical distribution of stiffness along the length of the roller assembly with different variants of the position of the liners in the upper and lower work rolls.

In the windows of the bedding station 1 (Fig. 1), using support pillows 2 and 3, support 4 are installed, as well as workers 5 and b rolls interacting with rolled metal 7. The barrels of work rolls are provided with axial cylindrical cavities in which cylindrical liners 8 are placed and 9 with the possibility of movement in the axial direction. The cavities Yu and 10 separated by liners and cavities 11 and 11 independently of one another are connected by axial channels 12, 13, autonomous sources of high-pressure liquid.

On the inner surface of the work roll barrels, annular grooves (Fig. 2.3) are made with a width b, evenly distributed along the cavity length with a step t6. On the outer forming surface of the cylindrical liners are made annular grooves of width b with step

tB te

n

n + 1

where n is the number of grooves on the length of the generatrix of the inner cavity of the barrels.

The inserts 8 and 9 are placed in the roll barrels with the possibility of axial movement by an amount equal to at least one step of the grooves te.

Roller node rolling stand quarto works as follows.

When rolling the strip in the stand, the profile of the work rolls is caused, in particular, by the distribution of deformations in the contacts

0

five

0 5

0 5

0 5

0

five

Work roll - liner. In this case, the magnitude of the contact deformation is proportional to the pressure qi (i 1, 2n) in the conjugate

parts of the cylindrical surfaces of the liner and barrel of the work roll (Fig.2.3).

In turn, the contact pressures qi are determined by the length (1.2, ..., n) of the contact areas of the work roll - insert, delimited by grooves.

Since the groove pitch on the inner surface of the roll barrel te exceeds the pitch of the grooves on the cylindrical surface of the liner t.v. n, ln-1, ln-2, ... (figure 2) exceed the lengths of the contacts in the middle of the booster In / 2, In / 2, ln / 2 + 1, In / 2-nd

Accordingly, the pressure in the middle of the roll barrel is qn / 2, Qn / 2, qn / 2 + 1, qn / 2 + 1 .... higher than the pressure at its edges x qi, q2, qa, ... and qn, qn-i, qn-2

Thus, the rigidity of the work roll in the middle of the barrel is lower than at its edges, and when the strip is rolled, the roll acquires a concave shape.

If it is necessary to change the nature of the profiling of the work roll 5, working fluid is fed into the cavity 10J (or 10) through the channel 12 (or 12), under the pressure of which the insert 5 moves 0.5 steps te to the right (or left). In this case (Fig. 3), the lengths of the contacts on the edges of the barrel are less than the lengths of the contacts in its middle, the pressure in the contacts is the work roll - liner is higher on the edges of the roll barrel and lower in its middle, and the roll acquires convex profiling.

The transverse profile of the strip is adjusted as follows.

Previously, before rolling the strip, by feeding the working fluid into the cavity 10 or 10, the insert 8 is moved so that its grooves take up relative to the grooves of the roll 5 the position shown in FIG. Insert liner at the same time

9 in the position shown in FIG. With this combination of inserts, the sections of the roll barrel 5 (Fig. 4a) with increased rigidity SB (curve a, Fig.46) are opposite the sections of the lower roll 6 with reduced rigidity Ce (curve b, figv), which equalizes the total rigidity roller knot along the length of the roll barrels (line a, figg). The strip is then rolled.

When rolling a strip with wavy edges, the flatness sensor generates a control pulse, under the action of which the actuator (conventionally not shown in the drawings) through channel 12

supplies the working fluid to the cavity 10 of the upper roll 5, as a result of which the insert 8 moves to the right by the value te / 2. In this case, the distribution of stiffness Cs along the length of the work roll 5 is described by curve b (fig.4b), which, in combination with the initial distribution of stiffness Ce along the length of roll 6 (curve b, figv) gives the distribution of the total stiffness C of the roller assembly curve b (Figg). Tightening of the middle sections of the roller unit while loosening its edges increases compression and stretching of the strip in the middle of its cross section, which corrects the initial and deflection parameters.

In the case of rolling a stripped strip (a wave in the middle), the working fluid through the channel 13 is fed into the cavity 11 of the roll 6, under pressure of which the insert 9 moves to the right by the value t6 / 2. In this case, the distribution of rigidity Ce over the length of roll 6 is described by curve a (fig.4b), which, in combination with the initial distribution of rigidity Cs along the length of roll 5 (curve a, figb), gives the distribution of the total hardness of the roll knot along curve b ( Figd). As a result of the increase in crimping of the edges of the strip, its original defect is corrected.

Regulation of the absolute value of non-uniformity of reduction is provided by synchronous movement of the inserts 8 and 9 in opposite directions by a value within (0 ... t6 / 2).

For example, with the distribution of the stiffnesses of the upper roll along curve b (fig.4b) and the lower roll along curve c (figv), the non-uniformity of the total distribution of stiffness C is significantly reduced (curve r, fig.4g).

With simultaneous movement of inserts in one direction, asymmetric defects of the transverse profile and strip shapes are provided, namely: a wave on the left edge, a wave on the right edge, a box on the left, a box on the right, etc.

The speed of adjustment in the roll knot in question is determined by the groove pitch. The smaller the groove pitch, the higher the speed. For example, when installing electromagnetic piston pumps in the necks of work rolls with barrels and liners diameters of 500 and 350 mm, respectively, and groove pitch te 10 mm, 15 mm and 20 mm, the time required to move the liner by te / 2 is 0.12 ... 0.2; 0.20 ... 0.28; 0.25 ... 0.32 s, respectively.

The limits of the transverse profile of the strip, which are adjustable in the proposed roller assembly, depend on the ratio of the width of the groove to the step of their execution. For example, for the above parameters of the barrel and liner of the work roll with a load of 10 kN for every millimeter of the length of contact between the strip and the work roll and the ratio of the groove width to the step of making the grooves b / te 0.3, the maximum limits of adjustment of the transverse profile of the strip are 0.025 mm.

Thus, this roll unit of the quarto rolling stand provides an expansion of the technological capabilities of adjusting the cross-section of the rolled strips, as well as increasing the speed of adjustment in the rolling process.

Claims (1)

Invention Formula A roll hanger of a quarto rolling stand containing pillows, supporting and work rolls installed in them, having necks and a hollow barrel with a device for adjusting the barrel forming profile in the form of a rolling cylindrical liner, characterized in that in order to adjust the cross-section of the rolled strip , annular grooves are made on the inner surface of the work roll barrels and the cylindrical surface of the liners adjoining it, and the groove steps are interconnected and property  IB step grooves on the outer surface of the liners, mm; te is the groove pitch on the inner surface of the work roll barrels, mm; n - the number of grooves on the length of the generatrix of the inner cavity of the barrel. F g.T. YU