JP2539487B2 - Rolling method of rolling mill with asymmetric crown roll - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a rolling method for a sheet rolling mill, and more particularly to a rolling mill having an asymmetric crown roll suitable for extending roll life of a rolling mill employing an asymmetric roll. Regarding the rolling method.

[Conventional technology]

Regarding a rolling mill that shifts and rolls asymmetric crown rolls, there is one described in Japanese Patent Laid-Open No. 56-30014, but there is no description about measures for the life of the reinforcing rolls outside thereof. .

[Problems to be Solved by the Invention]

The above-mentioned prior art does not consider measures against wear of the reinforcing rolls, and there is a problem that the amount of rolling until the rolls are replaced decreases due to wear of the reinforcing rolls.

An object of the present invention is to provide a pair of upper and lower asymmetric crown rolls having different roll profiles on the left and right sides of the roll as viewed from the center of the roll length direction and a pair of upper and lower asymmetric crown rolls supporting the roll length. In the rolling direction of a rolling mill having a pair of upper and lower reinforcing rolls whose roll profile from the center to the end of the roll is equal to the left and right of the roll, prolongs the life of the reinforcing rolls and increases the rolling amount until the reinforcing rolls are replaced. Especially.

[Means for solving the problem]

The above-mentioned purpose is that the roll profile extending from the center of the roll length direction to the end of the roll has a pair of upper and lower asymmetric crown rolls that are different on the left and right of the roll, and the pair of upper and lower asymmetric crown rolls are supported to support the center of the roll length direction. In the rolling direction of a rolling mill having a pair of upper and lower reinforcing rolls whose roll profile toward the end of the roll is equivalent to the left and right of the roll, the upper and lower sides of the pair of upper and lower asymmetric crown rolls without changing the direction in the roll length direction. , Or changing the orientation of the pair of upper and lower asymmetric crown rolls in the roll length direction, or the second upper and lower reversed the relationship of the upper and lower roll profiles of the first pair of asymmetric crown rolls. The pair of the asymmetric crown rolls and the first pair of upper and lower asymmetric crown rolls may be replaced with each other. Accordingly, the asymmetrical profile is inverted in the roll longitudinal direction, by rolling, are achieved.

[Action]

By sequentially reversing the asymmetric crown roll, the maximum load portion of the reinforcing roll is not concentrated on the operating side or the driving side, but is dispersed in two places, the operating side and the driving side, so that the wear amount is dispersed, The amount of rolling until the replacement of the reinforcing roll is increased.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS.

1 and 2 show an example of a 4-high rolling mill. In this figure, the upper and lower work rolls 2 and 3 are processed by a roll having an asymmetric S-shaped profile, and their axial movements are made substantially equal to each other in the opposite directions, whereby the shape of the rolled material 6 or the strip width The directional plate thickness distribution is controlled. Top and bottom rolls
A few profiles don't have to be S-shaped,
There are various types such as a single trapezoid and a convex shape having a non-uniform curvature.

At the time of rolling, as shown by the load distribution and velocity distribution in FIG. 2, the load is nonuniform due to the asymmetric crown of the work roll, and the maximum load portion 5 is generated at a position deviated from the center of the plate width direction. Not only that, but there is a speed difference in the axial direction of the roll. Further, since the diameter of the work roll changes in the axial direction, for example, a speed difference occurs between the upper reinforcing roll 1 and the upper work roll 2 over the entire length of the contact portion, causing slippage. The uneven load distribution and the speed difference cause asymmetric wear.

By the way, in general, work rolls are not only frequently replaced, but also materials with high hardness are selected. Since it takes a long time to replace, it is generally not a good idea.

According to the present invention, in the state shown in FIG. 1 in the preceding state, if the upper and lower work rolls 2 and 3 have a combination shown by the solid line, the upper and lower work rolls 2 and 3 after the roll change. Is a combination as shown by the broken line. That is, a combination of upper and lower work rolls, which has a profile in a reversed relationship with the preceding upper and lower work rolls 2 and 3, is used. This moves the maximum load from 5 to 5 '. By doing so, the wear of the surface of the reinforcing rolls 1 and 4 is dispersed.

FIG. 3 shows a case of a 6-high rolling mill. In this case, the intermediate rolls 7 and 10 are shifted in place of the work rolls shown in FIGS.

It should be noted that the roll generally has a bearing box at its end, which often differs between the operating side and the drive side, and the end of the roll itself often differs between the operating side and the drive side. . Therefore, it is practical to combine the roll with the bearing box in which the upper and lower relations have been reversed in advance in the roll shop, instead of reversing the roll from the upper or lower side or the operating side in the assembled state with the bearing box.

〔The invention's effect〕

According to the rolling method of the present invention, a pair of upper and lower asymmetric crown rolls having different roll profiles on the left and right sides of the rolls as viewed from the center of the roll length direction and a pair of upper and lower asymmetric crown rolls are respectively supported. In the rolling direction of a rolling mill that has a pair of upper and lower reinforcing rolls whose roll profile from the center to the end of the roll as viewed from the center of the roll length is the same on the left and right of the roll, the contact portion between the reinforcing roll and the asymmetric crown roll is dispersed to reinforce. It is possible to disperse the worn portion of the roll, extend the life of the reinforcing roll, and increase the amount of rolling until replacement of the reinforcing roll.

[Brief description of drawings]

FIG. 1 is a schematic view of a four-high rolling mill showing an embodiment of the present invention, FIG. 2 is a view showing a state of load distribution and speed distribution in FIG. 1, and FIG. 3 is another embodiment of the present invention. It is an outline figure in the case of a 6-high rolling mill which shows an example. 1 ... Upper roll, 2 ... Upper roll, 3 ... Lower roll, 4 ... Lower roll, 6 ... Rolling machine, 7 ...
Upper middle roll, 8 ... Lower middle roll.

Claims (1)

(57) [Claims] 1. A pair of upper and lower asymmetric crown rolls having different roll profiles on the left and right sides of the rolls as viewed from the center of the roll length direction, and a pair of upper and lower asymmetric crown rolls respectively supporting the roll profile to support the roll length direction. In a rolling method of a rolling mill having a pair of upper and lower reinforcing rolls whose roll profile from the center to the end of the roll is the same on the left and right of the roll, a pair of upper and lower asymmetric crown rolls without changing the direction in the roll length direction. Replacing the top and bottom, or changing the direction of the pair of upper and lower asymmetric crown rolls in the roll length direction, or the first roll of the first pair of upper and lower asymmetric crown rolls of the second roll profile relationship is reversed. Replacing the pair of upper and lower asymmetric crown rolls and the pair of first upper and lower asymmetric crown rolls And by, said asymmetric profile is inverted in the roll longitudinal direction, the rolling method of rolling mill having asymmetric crown roll, which comprises rolling.