RU40225U1 - SHEET ROLLING QUARTO CART - Google Patents

Abstract

The utility model relates to the processing of metals by pressure and can be used on sheet mills for hot and cold rolling. The technical problem solved by the utility model is to increase the resistance of the backup rolls of sheet rolling stands of the quarto due to the equalization of roll pressures. The essence of the utility model lies in the fact that the quarto sheet-rolling stand equipped with a system for regulating the profile of the strips of an axial movable convex-concave work rolls is characterized in that the rolls are profiled in accordance with the dependence of the z-coordinate of the roll roll barrel profile, mm; a - amplitude (half of the total convexity - concavity of the profile), mm; L is the length of the barrel of the backup roll, mm; x - coordinate along the length of the roll of the backup roll, mm

Description

The utility model relates to the processing of metals by pressure and can be used on sheet mills for hot and cold rolling.

Known sheet rolling stand quarto (roll unit), in which the extreme sections of the backup rolls are made on a quadratic parabola, and the transitional sections of the work rolls from the barrel to the ends are made with a radius of 0.04-0.08 diameter of the working roll [1].

The disadvantage of this stand is the uneven distribution of the roll pressure due to the mutual discrepancy between the barrels forming the working and backup rolls, which negatively affects the stability of the latter.

The closest analogue is the quarto sheet rolling mill [2], equipped with a system for regulating the strip profile by axial sliding of convex-concave work rolls, in which the work rolls have a profile described by a polynomial, and the support rolls are cylindrical with bevels of 100 mm each.

The disadvantage of this stand is also the uneven distribution of the roll pressure due to the mutual discrepancy between the barrels forming the working and backup rolls, which negatively affects the stability of the latter. Calculations performed using a mathematical model show that this unevenness is from 30% to 90% along the length of the barrel from the maximum. The latter is confirmed by the wear data of the backup rolls.

The technical task of the proposed utility model is to increase the resistance of the backup rolls of sheet rolling stands of the quarto due to the equalization of roll pressures.

The solution to this problem is achieved by the fact that in a sheet rolling stand

quarto, equipped with a system for regulating the profile of the strips by axial sliding of convex-concave work rolls, profiling of the backup rolls is made in accordance with the dependence:

where z _O is the ordinate of the profile of the roll roll, mm;

a - amplitude (half of the total convexity - concavity of the profile), mm;

L is the length of the barrel of the backup roll, mm;

x - coordinate along the length of the roll of the backup roll, mm

Figure 1 presents the General scheme of sheet rolling stand quarto with backup rolls with the proposed profiling. Figure 2 shows the wear curve of the backup roll of a two-stand reversing mill of OJSC MMK with the existing and proposed profiling.

The sheet rolling mill quarto has work rolls with the possibility of their axial movement to regulate the profile of the rolling and backup rolls made in accordance with the proposed dependence (figure 1). Such profiling substantially equalizes roll pressures, and thereby reduces wear.

During the rolling process, the convex sections of the work rolls are in contact with the corresponding concave sections of the support, profiled according to the proposed dependence, and the concave sections are convex. Thus, the alignment of the roll pressures occurs, and therefore the wear is reduced.

Example:

Two-stand reversive mill of OJSC MMK. The length of the backup roll barrel is 1750 mm. Profiling of work rolls is made according to:

z _P = a ₃ x ³ + a ₂ x ² + a ₁ x,

where z _P is the ordinate of the profile of the barrel of the work roll, mm,

x - coordinate along the length of the roll of the backup roll, mm,

and ₃ , a ₂ , a ₁ - polynomial coefficients,

and the profiling of the backup rolls is cylindrical with bevels along the edges of the barrel. As a result of this profiling, the wear of the backup rolls is uneven with a maximum corresponding to the convexity of the work roll (FIG. 2).

Using the mathematical model, we determined the necessary value of the parameter a of the proposed profiling of the backup rolls a = 0.07 mm, profiling was also performed with edge bevels. The result was a significant reduction in wear of the backup rolls by 30% from 0.27 mm to 0.18 mm, as well as a more uniform nature of the output (figure 2).

Sources of information:

1. A.S. No. 1405925.

2. VTI 101-P-ChL 5-505-2002. Production of cold-rolled strips on a two-stand reversible mill in LPC-5 of OJSC MMK.

Claims (1)

The quarto sheet rolling mill, equipped with a system for regulating the profile of the strips by axial sliding of convex-concave work rolls, characterized in that the profiling of the backup rolls is made in accordance with the dependence

where Z _about - the ordinate of the profile of the roll roll, mm; a - amplitude (half of the total convexity-concavity of the profile), mm; L is the length of the barrel of the backup roll, mm; x - coordinate along the length of the roll of the backup roll, mm