JPH01306003A - Method for rolling in rolling mill using asymmetrical roll - Google Patents

Abstract

PURPOSE:To reduce wear of reinforcing rolls and to increase rolling amounts up to roll changing by using asymmetric rolls in a rolling mill and reversely changing their position at proper times. CONSTITUTION:As for roll changing of work rolls 2, 3 having asymmetric profile such as S-shape, etc., the rolls 2, 3 are reversed in a combined position shown by the broken lines. A max. loaded part between the rolls 2, 3 and rein forcing rolls 1, 4 is moved from a position 5 to a position 5' by reversing the combined position shown by continuous lines to a position shown the broken lines and performing rolling. Thus, surface wear of the rolls 1, 4 is distributed and is symmetrized. Hence, wear of the rolls 1, 4 is reduced because the rolls 1, 4 are made of a comparatively soft material. Therefore, a rolling amount to a next changing time of the rolls 1, 4 is increased.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a rolling method for a plate rolling mill, and in particular to a rolling method using an asymmetric roll that is suitable for extending the life of a rolling mill that uses an asymmetric roll. Concerning rolling method.

[Conventional technology]

Regarding a rolling mill that shifts and rolls asymmetric rolls, there is one described in Japanese Patent Application Laid-Open No. 56-30014, but there is no mention of measures for the lifespan of the outer reinforcing rolls, etc.

[Problem to be solved by the invention]

The above-mentioned conventional technology does not take measures against the wear of the reinforcing roll, and there is a problem in that the amount of rolling until the roll is replaced is reduced due to the wear of the reinforcing roll.

An object of the present invention is to distribute the contact parts between the reinforcing roll and the asymmetric crown roll at two locations, thereby dispersing the worn parts, and thereby increasing the life of the reinforcing roll (rolling amount until the roll is replaced).

[Means to solve the problem]

The above object is achieved by sequentially reversing the asymmetric rolls when changing them. In practice, this is achieved by replacing the previously used combination of vertically asymmetrical rolls with a vertically reversed combination of asymmetrical rolls when exchanging the asymmetrical rolls.

[Effect]

By sequentially reversing the asymmetric rolls, the maximum load on the reinforcing roll is not concentrated on the operating side or the driving side, but is dispersed between the operating side and the driving side, so the amount of wear is dispersed and the reinforcement roll is The amount of rolling until the rolls are replaced is increased.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

FIGS. 1 and 2 show an example of a four-high rolling mill.

In this figure, the upper and lower work rolls 2 and 3 are subjected to roll processing with an S-shaped asymmetric profile, and the axial movement of the upper and lower work rolls is made approximately equal and in opposite directions, thereby changing the shape of the rolled material 6 or the plate. The thickness distribution in the width direction is controlled. The profiles of the upper and lower rolls 2 and 3 do not necessarily have to be S-shaped, but may have many shapes such as a single trapezoid, a convex shape with non-uniform curvature, etc.

During rolling, as shown in the load distribution and speed distribution in Figure 2, there is an asymmetry in the load due to the asymmetry of the 5 work rolls, and the maximum load portion 5 only occurs at a position offset from the center in the width direction of the sheet. Instead, a speed difference occurs in the axial direction of the rolls. Further, since the work roll diameter changes in the axial direction, a speed difference occurs over the entire length of the contact portion between, for example, the upper reinforcing roll 1 and the upper work roll 2, causing slippage.

Uneven load distribution and speed differences result in asymmetric wear.

By the way, in general, work rolls are not only replaced frequently but also made of a material with high hardness, so that problems are less likely to occur, but reinforcing rolls are not only made of a relatively soft material, but also It is generally not a good idea to replace it because it takes a long time.

According to the present invention, if the combination of the upper and lower work rolls 2 and 3 shown in solid lines is used in the preceding state in FIG. are the combinations shown by the broken lines. That is, the top has a profile that is inverted from the preceding upper and lower work rolls 2.3.

A combination of lower work rolls. As a result, the maximum load section moves from 5 to 5'. This prevents asymmetrical wear of the surfaces of the reinforcing rolls 1, 4 over their entire length.

Figure 3 shows the case of a 6-high rolling mill.
Instead of the work roll in the figure, the intermediate roll 7.10 may be shifted and turned upside down.

In addition, the roll generally has a bearing box at its end,
Not only is this often different between the operating side and the driving side, but the ends of the roll itself are often different between the operating side and the driving side. Therefore, rather than flipping the roll upside down or from the operation side to the driving side while assembled with the bearing box, it is practical to combine the roll and the bearing box with the vertical relationship reversed in advance at a roll shop.

〔Effect of the invention〕

According to the present invention, the wear of the reinforcing roll is dispersed and symmetrical, so that the amount of rolling until the reinforcing roll is replaced can be increased.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a four-high rolling mill showing an embodiment of the present invention, and FIG. 2 is a load distribution in FIG. 1. FIG. 3, a diagram showing the state of speed distribution, shows another embodiment of the present invention, and is a schematic diagram in the case of a six-high rolling mill. 1...Top reinforcement roll, 2...Top work roll, 3...
- Lower work roll, 4... Lower reinforcing roll, 6... Rolling machine, 7... Upper intermediate roll, 8... Lower intermediate roll.

Claims (1)

[Scope of Claims] 1. A rolling method in a rolling mill using asymmetric rolls, characterized in that the asymmetry is appropriately reversed in the rolling mill using asymmetric rolls. 2. The rolling method using a rolling mill using asymmetric rolls according to claim 1, wherein the reversal is performed by an asymmetric roll.