JPH0313207A - Multistage rolling mill having integral type backup roll - Google Patents

Abstract

PURPOSE:To control flatness over a wide range by imparting roll crown converged toward one end to one set of rolls and the roll crown curved to the waveform of one wavelength to the other one set, respectively, and reversing the axial directions of the respective crowned roll pairs to allow the axial movement of the rolls. CONSTITUTION:The roll crown converged toward one end is imparted to at least two pieces one set of the rolls (the 1st intermediate rolls) 3, 3 among the work rolls 2, 2, 1st intermediate rolls 3, 3, 2nd intermediate rolls 4, 4 and integral type backup rolls 5, 5 of the multistage rolling mill. The roll crown curved to the waveform of one wavelength is imparted to the other two pieces one set of the rolls (the 2nd intermediate) 4, 4. The axial directions of the respective crowned roll pairs are reversed to allow the axial movement of the rolls. The excellent ability to correct edge drop is obtd. in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a multi-high rolling mill with a capacity equivalent to 20 stages, which has an excellent flatness control function and is capable of applying a high rolling load.

(Prior Art) Cold rolling of difficult-to-work materials such as stainless steel and silicon steel is often performed in multi-high rolling mills such as 12-high and 20-high rolling mills. In such a multi-high rolling mill, since the diameter of the work rolls can be reduced, there is an advantage that a high rolling reduction can be achieved with a small rolling load compared to a conventional vertically arranged rolling mill. However, on the other hand, when the diameter of the work roll is made small, the deflection of the roll becomes large, so there is a drawback that the rolled material is likely to have a defective shape.

Therefore, various solutions have been proposed in the past in order to prevent the occurrence of such shape defects.

One such method is to control the shape of the rolled material by dividing the outermost backup roll into a plurality of parts in the axial direction and adjusting the amount of displacement of each divided roll. However, in this method, the more intermediate rolls are present between the backup roll and the work roll, the more the effectiveness is diminished. However, it was not possible to fully demonstrate its potential.

To improve this point, the
A method of using a work roll bender or an intermediate roll bender together with the above-mentioned backup roll displacement adjustment method was proposed in the above publication. However, this method has the disadvantage that the equipment becomes complicated, and as the roll becomes thinner or the roll barrel becomes longer, the pending force does not work all the way to the center, so the control force remains only at the ends of the rolled material. there were.

Further, Japanese Patent Publication No. 63-207405 and the like proposes a method in which one end of the intermediate roll is tapered and each of the intermediate rolls is shifted independently in the axial direction. However, even in this method, the control force is applied only to a part of the periphery of the taper, and furthermore, there is the added complexity of having to change the taper shape one by one depending on the steel type, plate width, etc.

Further, in Japanese Patent Publication No. 63-30104, etc., a vertically arranged rolling mill is proposed in which the rolls are provided with an S crown that can be approximated by a cubic equation and are shiftable in the axial direction.

The development of such devices has provided considerable control over belly and ear extensions.

However, it is still not sufficient, and improvements in this layer are desired.

In addition, with the above-mentioned device, it is hardly possible to control compound elongation in which quarter elongation, belly elongation, and ear elongation are mixed, so improvements in this area are also desired.

In addition, in conventional multi-high rolling mills, especially 20-high rolling mills,
Partly because the backup roll had to be of a split type in terms of shape control, there was a problem in that a sufficiently high rolling load could not be applied.

Furthermore, when split backup rolls are used, uneven surface pressure between the rolls is likely to occur in the roll axis direction, and the eccentric mechanism is complex, making mill design difficult and the equipment cost high. was left behind.

(Problems to be Solved by the Invention) This invention advantageously solves the above problems, and not only further improves the shape control effect of belly elongation and ear elongation, but also improves quarter elongation and alternate layer compound elongation. The purpose of this project is to propose a multi-high rolling mill with a capacity equivalent to 20 stages, which is capable of correcting complex shape defects and even edge drops, has excellent shape control ability, and is capable of applying a sufficiently high rolling pressure. .

(Means for Solving the Problem) That is, the present invention provides a multi-high rolling mill in which a plurality of first intermediate rolls, second intermediate rolls, and integral backup rolls are sequentially arranged behind a pair of work rolls. At least a set of two rolls selected from a roll group consisting of a work roll, a first intermediate roll, a second intermediate roll, and an integrated bank-up roll is provided with a crown having one end tapered, At least a set of two other rolls also selected from the above roll group,
A roll crown extending over at least one wavelength of the same waveform curve is provided, and for each of the above-mentioned crowning roll pairs,
This is a multi-stage rolling mill that has integral bank-up rolls arranged such that the roll axes are opposite to each other and that are movable in the roll axis and incorporated into a mill housing.

Further, the present invention is a multi-high rolling mill in which a roll bending device is incorporated into the above-mentioned rolling mill.

In this invention, one wave to be applied to the roll, a waveform curve for separation, can be one pitch taken from a sine curve, one pitch taken from a third or higher order function, and These approximate curves are advantageously adapted, but among them, a curve taken out by one pitch from a sine curve and its approximate curve are particularly suitable.

The present invention uses a combination of a roll pair having a crown tapered at one end as described above and a crown extending over at least one wavelength of the waveform curve, thereby achieving an improvement in comparison with the prior art, as described later. Since the shape control ability is greatly improved, the conventional shape control by extruding a split backup roll is no longer necessary, making it possible to use an integrated backup roll. The use of an integral backup roll is something that has been achieved for the first time in this invention.

Hereinafter, this invention will be specifically explained based on the drawings.

1a and b the roll arrangement of a multi-high rolling mill according to the invention is shown in side view and front view.

In the figure, 1 is a rolled material, 2 is a work roll, 3 is a first intermediate roll, 4 is a second intermediate roll, and 5 is two integral backup rolls. Work rolls 2 are arranged, and these work rolls 2
A total of four first intermediate rolls 3, two each behind the
However, behind the first intermediate roll 3, there are a total of six second intermediate rolls 4, three each on the upper and lower sides, and further second intermediate rolls 4.
A total of eight integral backup rolls 5 are installed behind the rolling mill, four each on the upper and lower sides, and these rolls constitute a 20-high rolling mill.

Note that 6 is a roll bending device.

Among these, the first intermediate roll 3 is provided with a roll crown whose one end is tapered, and the second intermediate roll 4 is provided with a roll crown consisting of a waveform curve that can be approximated by l pitches of a sine curve. It has a structure that can be shifted in the direction of the roll axis.

Here, the rolls to which a single taper crown and a sine curve of one pitch are to be given are not limited to the above examples, but include the work roll 2, the first intermediate roll 3, and the second intermediate roll. 4 and backup roll 5 can be freely selected and combined.

In addition to the above-mentioned sine curve and its approximation curve, the waveform curve to be provided may be a waveform curve obtained by extracting one pitch across the coordinate origin from a higher-order equation of 3rd order or higher, or even an approximate curve thereof. It's okay.

Further, the roll shift device may be either hydraulic or electric.

(Function) Figures 2a and 2d show changes in the roll gap when a single tapered roll with one end tapered and ground is installed in the opposite direction to the roll axis and shifted in the axial direction.

As is clear from the figure, the thickness of the plate edge can be adjusted by changing the set value of the length (x) of the edge of the rolled material rolled on the tapered grinding surface, reducing edge drop. Control can be performed effectively.

Next, Figure 3 a''-c shows the changes in the roll gap when a pair of rolls with a corrugated roll crown that can be approximated by one pitch of a sine curve is installed in opposite directions in the roll axis direction and shifted in the axial direction. show.

Figure a shows a case where the pair of rolls are arranged facing each other and the roll gap is constant in the axial direction. The figure shows the case where each roll is moved in the direction of the arrow from state a.
The roll gap is wide at the center and narrow at the ends. In addition, C in the same figure shows a case where each roll is moved in the opposite direction to that in the same figure, and the roll gap is narrow at the center and wide at the ends.

Therefore, by appropriately shifting a pair of rolls provided with a wavy roll crown that can be approximated by one pitch of a sinusoidal curve in the roll axis direction, it is possible to effectively correct the edge elongation and belly elongation.

Next, FIG. 4 shows a comparison of the maximum additional rolling loads when using the conventional split type backup roll and the integrated type backup roll according to the present invention.

As is clear from the figure, when the integral backup roll according to the present invention is used, the reduction is approximately 40% compared to the conventional one.
An increase in rolling load can be expected.

Next, Fig. 5 shows the first part of the 20-high rolling mill shown in Fig. 1 above.
When a pair of rolls provided with a single tapered crown (hereinafter simply referred to as T-crown) is used as an intermediate roll (II IMR), furthermore, one intermediate roll, a second intermediate roll (2IMR), or a backup roll (BIIR) is used.
Using a pair of rolls with a wave-shaped roll crown (hereinafter simply referred to as S-crown) that can be approximated by one pitch of a sine curve, we investigated the shape control ability when each roll was individually shifted appropriately in the roll axis direction. The results are shown in comparison with the case where a split backup roll was extruded.

The shape control ability was evaluated by the difference in elongation Δ2 between the center and the ends of the rolled material and the difference in elongation Δ4 between the center and a part of the quarter.

As is clear from the figure, in the case of T-crown roll shift and S-crown roll shift alone, a certain degree of control can be expected for ear elongation and belly elongation, but there is almost no hope for quarter elongation or alternating layer composite elongation control. .

Note that split backup roll extrusion can only be expected to provide slight control over quarter elongation and alternate layer compound elongation.

Next, FIG. 6 shows the results of an investigation into the shape correction ability when a T-crown roll was used as the first intermediate roll and an S-crown roll was used as the second intermediate roll in the above-mentioned 20-high rolling mill. A comparison will be made with the results of an investigation in which a single tapered roll was used as an intermediate roll, a split roll was used as a backup roll, and a roll bender was also used.

As is clear from the figure, by combining T-crown rolls and S-crown rolls, shifting them appropriately in the roll axis direction, and using an integral backup roll, it is possible to prevent selvage elongation and flattening under large additional loads. Not only will the elongation control effect be greatly improved, but excellent correction ability can be expected for quarter elongation, compound elongation, and even edge drop, and flatness control over a wide range can therefore be realized.

In this invention, the roll pair to which the T crown or S crown should be applied is at least a pair of rolls selected from a roll group consisting of a work roll, a first intermediate roll, a second intermediate roll, and a backup roll. if there is,
Although any roll may be used, it is more preferable that each roll pair is selected from the same type of roll group, that is, a work roll pair, a first intermediate roll group, a second intermediate roll group, and a backup roll group. Also, the control effect is T
The closer the crown and S-crown imparting rolls are to the material to be rolled, the more the arrangement of each pair of rolls is in the order of point symmetry, vertical symmetry, and horizontal symmetry with the material to be rolled as the center.

Furthermore, if a roll bending device is used in combination, the above effects will be further enhanced.

(Example) Example 1 In the 20-high rolling mill shown in FIG.
The second intermediate roll 4 is the crown (3) which can be approximated by a cubic equation as shown in FIG.
1 crown) was used.

Then, while shifting the first intermediate roll and the second intermediate roll in the axial direction, a stainless steel plate having a width of LOOO mm was rolled from a thickness of 1.2 mm to a thickness of 1.0 m+n.

Shape plan views showing the roll arrangement and shape correction ability at this time are shown in FIGS. 9a and 9b, respectively.

In addition, Fig. 9 shows the case where the conventional device is used.
Rolls with a single tapered shape as shown in Figures c are used as the first intermediate roll and second intermediate roll, and these rolls are shifted in the axial direction to perform similar rolling (divided bank-up roll). The results of a survey on the shape control ability when performing this are also shown.

As is clear from FIG. 9, with the conventional device, the shape control ability can only be obtained in a narrow range, and the shape control ability to follow compound elongation and quarter elongation is extremely small. Furthermore, due to the narrow control range, it has been necessary to change the tapered shape of the first intermediate roll or the second intermediate roll depending on the steel type plate width of the rolled material.

On the other hand, when using the device of this invention, it is possible to obtain a wide range of control that can sufficiently handle not only selvage extension and belly extension, but also compound extension and quarter extension. It becomes possible to obtain a plate with a good shape without changing the shape of the intermediate roll for the rolled material.

Example 2 In the same <20-high rolling mill, as shown in Fig. 10a, the work roll had a single tapered crown (T crown) as shown in Fig. 7a, and the first intermediate roll had a no. 1
Figure 10 shows the results of investigating the shape control ability when rolling was carried out in the same manner as in Example 1, with a crown (32 crowns) that can be approximated by one pitch of a sine curve as shown in Figure 1, respectively. .

Example 3 In the same <20-high rolling mill, as shown in Fig. 12a, each of the first intermediate rolls had a round (T-crown) as shown in Fig. 7a, and the second intermediate roll had a round (T-crown) as shown in Fig. 7a. A total of 4 rolls (two sets of upper and lower) located on the outside are equipped with S2 crowns, and a further 4 rolls are located outside of the back 7" o-ru.
Figure 12 shows the results of an investigation into the shape control ability when rolling was carried out in the same manner as in Example 1, with S2 crowns applied to the book rolls.

Example 4 In the same <20-high rolling mill, as shown in FIG. For the four rolls located outside the rolls,
A 32 crown and a T crown are given to each pair of rolls located at a point symmetrical position, and a T crown and an S2 crown are given to each roll pair located at a point symmetrical position to the four rolls located outside the backup roll. Figure 13 shows the results of an investigation regarding the shape control ability when rolling was carried out in the same manner as in Example 1.

(Effect of the invention) Thus, according to the multi-high rolling mill according to the present invention, edge elongation,
Excellent correction ability can be obtained not only for abdominal stretch, but also for quarter stretch, compound stretch, and even edge drop, and therefore flatness control over a wide range can be achieved.

Furthermore, since the multi-high rolling mill according to the present invention can use integrated backup rolls, it is not only possible to apply a larger rolling load than before, but also eliminates uneven surface pressure between the rolls in the roll axis direction. , it also eliminates the need for complicated mill design, which further contributes to cost reduction.

[Brief explanation of the drawing]

Figures 1a and 1b are side views and front views showing the roll arrangement of a 20-high rolling mill to which the present invention is applied, and Figures 2a to 2d show T-crown rolls installed parallel to each other in opposite directions. , Figures 3a and 3c show changes in the roll gap when shifted in the roll axis direction, and Figures 3a and 3c show the changes in the roll gap when the S-crown rolls are installed parallel to each other in the opposite direction and shifted in the roll axis direction. FIG. 4 is a comparison diagram of the maximum additional rolling load when using a conventional split backup roll or an integrated backup roll according to the present invention, and FIG.
Figure 6 shows the shape control ability when a T-crown roll pair or an S-crown roll pair is applied alone to the first or second intermediate roll of a corrugated rolling mill. Figures 7a, b, and c are shape control range diagrams showing the shape correction ability when a T-crown roll is used as the first intermediate roll and an S-crown roll is used as the second intermediate roll at the same time, respectively. Figure 8 is a diagram showing a tapered shape, Figure 8 is a diagram showing a suitable S crown that can be approximated by a cubic formula, Figures a and b in Figures 9 and 10 are respectively a T crown roll and an S crown roll in a 20-high rolling mill. Figure 11 is a diagram showing a suitable S crown that can be approximated by one pitch of a sinusoidal curve. A roll arrangement diagram showing the arrangement of T-crown rolls and S-crown rolls in the machine, and b in the same figure are both shape control range diagrams for each roll arrangement in a of the same figure. ■...Rolled material 2...Work roll 3.
...First intermediate roll 4...Second intermediate roll 5...
・Integrated backup roll 6...Roll benzo ink device Fig. 1 (a7 ('j)) <a> (C) Fig. 5 -1,0 -0,5 Noshino ゛5°! ! ! Dimension Maro if 0

Claims (1)

[Claims] 1. Behind a pair of work rolls, a plurality of first
In a multi-high rolling mill in which an intermediate roll, a second intermediate roll, and an integral backup roll are sequentially arranged, at least one roll selected from a group of rolls consisting of the work roll, the first intermediate roll, the second intermediate roll, and the integral backup roll is provided. A set of two rolls is provided with a crown tapered at one end, while at least another set of two rolls similarly selected from the above roll group,
The mill housing is provided with a roll crown extending over at least one wavelength of the same waveform curve, and in addition, each pair of crowned rolls is arranged such that the roll axis direction is opposite to each other, and is movable in the roll axis direction. A multi-high rolling mill having an integral backup roll, which is characterized in that it is incorporated in. 2. The multi-high rolling mill according to claim 1, comprising a roll bending device.