JPH0732002A - Rolling method - Google Patents

Abstract

PURPOSE:To reduce the thrust force and to miniaturize the device by crossing an upper work roll and a lower work roll, forming this cross angle into an angle so that the thrust force acts at its maximum, and shifting the upper and lower work rolls to the acting direction of this thrust force. CONSTITUTION:Roll crossing means to cross only upper and lower work rolls 1, 2 or to cross the upper and lower work rolls and the upper and lower back up rolls 23, 24 mutually at the same time, and roll shifting means to shift the upper and lower work rolls 1, 2 are installed. The upper work roll 1 and lower work roll 2 are mutually crossed so that the thrust forces act from taper rolling parts 1a, 2a of the upper work roll and the lower work roll toward non-tapered ends respectively, the upper work roll 1 and lower work roll 2 are shifted respectively to the acting directions of this thrust forces, after completing this shift, the cross angle is formed in a cross angle required for controlling sheet crown of a strip and the strip 10a is rolled. Therefore, the thrust force is made small and the friction of the work rolls is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of rolling a strip material by crossing a work roll alone or a pair of a work roll and a backup roll and further shifting the work roll.

[0002]

2. Description of the Related Art In a cold continuous rolling mill, in order to prevent the influence of wear of work rolls on the strip shape and to improve the strip passability of steel strip, the steel strip is gradually narrowed from the preceding strip steel. Continuous rolling is performed by welding to the strip steel of width.
FIG. 5 is a front view showing the concept of an example of the roll shift rolling machine of the rolling equipment described above, and FIG. 6 is a plan view showing a VI-VI view of FIG.

As shown in FIGS. 5 and 6, the upper work roll 21 is pressed down by an upper backup roll 23.
And the lower work roll 22 that has been pressed down via the lower backup roll 24 are respectively shifted according to the strip width W1 of the strip steel 10a by the upper and lower roll shift devices of the rolling mill (not shown). To roll. The upper and lower work rolls 21 and 22 are provided with taper portions 21a and 22a, respectively, at one end of the barrel portion. By rolling both edge portions of the strip steel 10a with the respective taper portions 21a and 22a, edge drop is achieved. Is intended to be improved. As shown in FIG. 6, when the succeeding narrow steel strip 10b connected by the welded portion 10c comes, the upper work roll 21 and the lower work roll 2 corresponding to the plate width W2 thereof.
2 is shifted by upper and lower roll shift devices (not shown) to roll the narrow strip steel 10b.

[0004]

However, in the conventional apparatus, when the narrow strip steel 10b comes, the upper and lower work rolls 21 and 22 must be rapidly and significantly shifted in order to shorten the plate shape defective portion as much as possible. There is. Therefore, the roll shift force Sh at the time of start-up becomes considerably large, and the roll shift device also has a large capacity, so that the manufacturing cost of the rolling mill increases.

Particularly, in the case where the upper and lower work rolls 21 and 22 are crossed, if the direction of the thrust force acting on the upper and lower work rolls 21 and 22 by the roll cross is opposite to the shift direction, the required roll The shift force Sh further increases.

[0006]

A rolling method according to the present invention comprises an upper work roll and a lower work roll each having a tapered rolling portion formed at one end of the barrel portion in the opposite direction.
The upper and lower backup rolls that reinforce the pair of upper and lower work rolls are provided, and only the upper and lower work rolls or a roll cross means for simultaneously crossing the upper and lower work rolls and the upper and lower backup rolls, and a roll for shifting the upper and lower work rolls In a rolling mill provided with a shift means, the upper work roll and the lower work roll so that thrust forces respectively act from the taper rolling portion of the upper work roll and the lower work roll toward the non-tapered end portion. By crossing each other, the upper work roll and the lower work roll are respectively shifted in the acting direction of the thrust force, and when this shift is completed, the cross angle is formed to a cross angle necessary for plate crown control of the strip material. It is characterized by rolling.

[0007]

[Function] The upper work roll and the lower work roll are crossed at a required cross angle to control the plate crown of the strip, and the taper rolling portions of the upper work roll and the lower work roll are used to control the edges of the strip. Roll the strip while preventing edge drops.

At this time, thrust force acts on the upper work roll and the lower work roll by the cloth, and the acting direction is always constant. A strip having a narrower width than that of the preceding strip is connected to the rear end of the strip, and when the narrow strip comes, the cross angle becomes the maximum for the upper work roll and the lower work roll. It is formed at an angle at which the thrust force acts, and the upper and lower work rolls are respectively shifted according to the plate width so that the upper taper rolling portion and the lower taper rolling portion are located at both edge portions of the narrow strip material.

At this time, since the upper work roll and the lower work roll are rapidly and drastically shifted in order to shorten the edge drop portion of the running strip, a large roll shift force is required, but the upper and lower work rolls are required. Since the force shifts in the same direction as the acting thrust force, the roll shift force actually required is reduced by the thrust force as compared with the case where the upper and lower work rolls are not crossed. When this roll shift is completed, the upper and lower work rolls are formed to have a cross angle required to control the plate crown of the subsequent narrow strip, which is generally smaller than the thrust force, and the narrow work roll is formed. Roll the strip material.

[0010]

FIG. 1 is a front view showing the concept of a rolling mill for cold rolling in which only work rolls are crossed and shifted according to the first embodiment of the present invention, and FIG. 2 is a view taken along line II--II of FIG. It is a top view shown.

In FIGS. 1 and 2, 1 is an upper work roll, 2 is a lower work roll, both of which are opposite to the direction of the thrust force Tb received from the backup rolls 23 and 24, and are barrel portions in mutually opposite directions. An upper taper rolling portion 1a and a lower taper rolling portion 2a are provided at the ends. The roll cross device of a rolling mill (not shown) causes the rolls to cross each other, and the upper and lower roll shift devices (not shown) shift them in opposite directions. The upper and lower backup rolls 23 and 24, which are parallel to each other, reinforce each other. Has been done.

In order to control the strip crown of the strip steel 10a, the upper work roll 1 and the lower work roll 2 are crossed with each other at a required cross angle θ, and further, the strip width thereof is prevented in order to prevent edge drop of the strip steel 10a. Depending on W1, the upper taper rolling portion 1a and the lower taper rolling portion 2a are set so as to be located at both edge portions of the strip steel 10a, and the strip steel 10a is rolled while preventing edge drop.

During this rolling, the upper work roll 1 and the lower work roll 2 receive thrust force μ from the strip steel 10a.
s · P (μs: thrust coefficient, P: rolling load) and thrust force μ received from the upper and lower backup rolls 23, 24
b.P (.mu.b: thrust coefficient) are acting respectively, and this acting direction is always constant.

The thrust force μb · P received from the backup rolls 23 and 24 is larger than the thrust force μs · P received from the strip steel 10a, and since the two act in opposite directions, the difference in thrust force μb actually acts.・ P-
It becomes μs · P.

The thrust coefficient (thrust force / rolling load ratio) μs received from the strip steel 10a and the thrust coefficient μb received from the upper and lower backup rolls 23 and 24 differ depending on the roll roughness of the upper and lower work rolls 1 and 2, the lubricating oil specifications and the like. However, when the cross angle θ is approximately 0.2 to 0.6 °, the maximum value is obtained. When the cross angle θ is greater than this, the thrust coefficients μs and μb
Becomes saturated.

When the cross angle θ increases, the strip steel 10
Since the slip with a becomes large, the wear of the upper and lower work rolls becomes large. At the rear end of the strip steel 10a, the narrow strip steel 10
b is connected by the welded portion 10c. When the narrow strip steel 10b comes, the upper and lower work rolls 1 and 2 are acted by the maximum thrust force μb · P−μs · P, for example, 0.
The upper and lower work rolls 1 and 2 are positioned at both edge portions of the narrow strip steel 10b in accordance with the plate width W2, with the upper and lower work rolls 1 and 2 crossing each other at a cross angle θ of 3 °. To shift each.

At this time, the upper work roll 1 and the lower work roll 2 are rapidly and drastically shifted in order to shorten the edge drop portions of the running strip steels 10a, 10b as much as possible, so that a large roll shift force is required. However, since the thrust force difference μb · P−μs · P shifts in the same direction as the acting direction, the roll shift force Sh actually required is the same as that in the case where the upper and lower work rolls 1 and 2 are not crossed. It becomes smaller by the force difference μb · P−μs · P.

Next, when the roll shift is completed after passing through the welded portion 10c, the upper and lower work rolls 1 and 2 are required to control the plate crown of the narrow strip steel 10b, for example, 0.1 °.
To a cross angle θ and the narrow steel strip 10b is rolled.

FIG. 3 is a front view showing the concept of a rolling mill for cold rolling in which a work roll and a backup roll are crossed in a pair and the work roll is shifted, which is a second embodiment of the present invention. FIG. It is a top view which shows the IV-IV view of FIG.

In this second embodiment, the upper work roll 11
Since the upper backup roll 13, the lower work roll 12, and the lower work roll 14 and the lower backup roll 14 are crossed in pairs to form a required cross angle θ, the upper and lower work rolls 11 and 12 have upper and lower backup rolls when rolling the strip steel 10a. The thrust force μb · P from 13, 14 does not act, and the preceding strip steel 10a or the subsequent narrow strip steel 10b
Only the thrust force from μs · P acts.

Therefore, as shown in FIGS. 5 and 6, the positions of the upper taper rolling portion 11a and the lower taper rolling portion 12a are the first.
If it is the same as the embodiment, the crossing direction of the upper and lower work rolls is opposite to that of the first embodiment, and the direction from the end of the barrel portion provided with the upper taper rolling portion 11a and the lower taper rolling portion 12a to the end of the non-tapered barrel portion. The test force μs · P acts on.

Therefore, the roll shift force Sh actually required for shifting the upper and lower work rolls 11, 12 is smaller by the thrust force μs.P than when the upper and lower work rolls 1, 2 are not crossed.

[0023]

According to the present invention, the upper work roll and the lower work roll are crossed with each other so that the thrust force acts from the taper rolling portion of the upper work roll and the lower work roll toward the non-tapered end. , By forming this cross angle to the angle at which the thrust force acts maximum and shifting the upper work roll and the lower work roll in the direction of this maximum thrust force respectively, the roll shift force actually required rises and falls. The thrust force can be reduced as compared with the case where the work rolls are not crossed. Therefore, the roll shift device can be downsized, and the manufacturing cost of the rolling mill can be reduced.

Further, by forming a small cross angle necessary for controlling the plate crown of the strip after the roll shift is completed, the thrust force can be reduced during rolling, so that the wear of the upper and lower work rolls is reduced. Since the thrust force acts in a fixed direction, the shift position can be stabilized without the occurrence of axial runout of the upper and lower work rolls as in the case where the upper and lower work rolls are not crossed. .

[Brief description of drawings]

FIG. 1 is a front view showing the concept of a cold rolling mill that crosses and shifts only work rolls in a first embodiment of the present invention.

FIG. 2 is a plan view showing II-II view of FIG. 1.

FIG. 3 is a front view showing the concept of a rolling mill for cold rolling in which a work roll and a backup roll are crossed in a pair and the work roll is further shifted in the second embodiment of the present invention.

FIG. 4 is a plan view showing IV-IV in FIG.

FIG. 5 is a front view showing the concept of an example of a conventional roll shift rolling mill.

6 is a plan view showing a VI-VI view of FIG. 5. FIG.

[Explanation of symbols]

 1 ・ 11 Upper work roll 2 ・ 12 Lower work roll 1a ・ 11a Upper taper rolling part 2a ・ 12a Lower taper rolling part 10a Strip steel 10b Narrow strip steel 10c Welding part 13 ・ 23 Upper backup roll 14 ・ 24 Lower backup roll μb・ P Thrust force received from backup roll μs ・ P Thrust force received from strip steel P Rolling load Sh Roll shift force θ Cross angle

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location // B21B 37/00 BBP 37/28

Claims (1)

[Claims] 1. An upper work roll and a lower work roll each having a tapered rolling portion formed at one end of the barrel portion in opposite directions, and a pair of upper and lower backup rolls for reinforcing the upper and lower work rolls are provided. A rolling mill provided with only the upper and lower work rolls or a roll cross means for simultaneously crossing the upper and lower work rolls and the upper and lower backup rolls with each other, and a roll shift means for shifting the upper and lower work rolls, wherein the upper work roll and the lower work roll are provided. The upper work roll and the lower work roll are crossed with each other so that the thrust force acts from the taper rolling part toward the non-tapered end, and the upper work roll and the lower work roll are acted on by the thrust force. Direction, and when the shift is completed, the cross angle is changed. A rolling method characterized by forming a cross angle required for controlling a plate crown of a strip and rolling the strip.