JPS6011568B2 - rolling mill - Google Patents

Description

[Detailed description of the invention] The present invention relates to a rolling mill.

During strip rolling, the rolls sag due to the rolling load, which requires compensation.

However, in reality, it is necessary to roll materials with different material dimensions and materials, so the rolling loads vary, and the roll sag occurs in a more SI manner. The most important functions required of rolling mills in recent years are:
These are improvements in the plate cross-sectional profile and flatness.

Conventionally, in order to provide this function to a rolling mill, a roll initial crown method and a roll pending method have been used in combination. However, the roll initial crown method requires frequent roll changes, and the roll pending method limits the pending force due to the strength of the roll chock and roll neck, so both methods are used together. However, satisfactory results have not been obtained. In order to solve this problem, a method was proposed in which the rolling mill was made into a six-layer type and the deflection of the work rolls was controlled by shifting the intermediate rolls in the strip width direction. However, this method requires high equipment costs, and because the intermediate rolls are asymmetrical, it is difficult to control the camber of the rolled material, and the rolls are subject to severe wear. Another disadvantage is that it takes several tens of days to convert an existing four-layer rolling mill into a six-layer rolling mill, and the rolling line must be shut down during this period. As yet another means, a variable crown roll (hereinafter referred to as VC roll) has been proposed. This VC role is the first
As shown in the figure, an annular gap 3 is provided between the arbor 1 and the sleeve 2, and a high-pressure medium (for example, water , oil, grease, etc.), and the unit 4 adjusts the pressure of the medium to control the amount of crowning of the roll (the amount of expansion in the diametrical direction of the outside diameter of the roll). Conventionally, VC rolls have been used as grooves on rolls other than the work rolls of multi-roll mills, and although they have the feature of being able to freely change the roll crown during rolling, they cannot handle a stronger rolling force than before. In some cases, the amount of swelling may not be enough to compensate for the amount of swelling.

In recent years, the demand for stronger rolling reduction has been increasing day by day in terms of improving rolling efficiency and quality, and the emergence of a new rolling mill that can meet this demand is eagerly awaited. Furthermore, if the compensation range for roll sagging is expanded, roll wear and thermal
Crown compensation is also possible. Therefore, it is an object of the present invention to provide a rolling mill that enables a smaller rolling machine to achieve a stronger rolling force than conventional rolling mills.

In the rolling mill of the present invention, in order to perform strong rolling, at least one of the upper and lower work rolls is first constructed into a small roll.

When the diameter of the work roll is reduced, the amount of roll sagging becomes larger than that of the conventional roll, so this small-diameter work roll is supported by two intermediate slide rolls, which will be described later. Additionally, at least one of the upper and lower backup rolls is configured as a VC roll to control the plate crown or plate shape. The intermediate slide roll used in the rolling mill of the present invention will be explained with reference to FIGS. 2 and 3.

Two intermediate slide rolls 6 are arranged in parallel on the installation side of the flea work roll 7. Roll 6 is large flea part 61
and a small diameter portion 62. The large portion 61 is formed in a cylindrical shape similar to a normal roll, but the small and light portion 62 is formed in a tapered naper shape or a crown shape. The contour line of the small strain portion 62 may be a straight line or a curved line (for example, a circular arc, a sine curve, a parabola, etc.). The roll 6 is supported so as to be freely movable in all directions. As best shown in FIG. 3, the intermediate slide rolls 6 are arranged parallel to each other at regular intervals in a horizontal plane, with their small diameter portions facing in opposite directions.

The large diameter portion 61 of the roll 6 mainly serves to prevent the small diameter work roll 7 from sagging, and the small diameter portion 62 of the roll 6 primarily serves to prevent edge drop of the rolled material and to increase the effect of roll pending. do. By moving the roll 6 in the axial direction, the edge drop of the rolled material can be controlled even if the width of the rolled sheet changes. Since the intermediate slide roll 6 alone is not sufficient to control the plate crown, a VC roll is used as a backup roll 8.

Since control of the plate crown or plate shape using the VC roll is well known, the explanation thereof will be omitted. The gap 3 of the VC roll may be formed integrally as shown in FIG.
, B and C may be divided into multiple sections. Various combinations of the VC roll and the intermediate slide roll can be considered, one example of which is shown in FIG. For convenience of explanation, the VC roll is shown as a figure, and the intermediate slide roll is shown as a figure. As shown in FIG. 4, a normal intermediate backup roll 9 may be provided between the intermediate slide roll 6 and the backup roll 8. In addition, in FIG. 4B, the backup roll 8 may be a normal roll, and the intermediate backup roll 9 may be a VC role.

Further, since the intermediate roll receives horizontal force from the work roll 7 and the backup rolls 8 and 9, if the intermediate roll does not have sufficient rigidity, a support is provided to suppress mirroring in the horizontal direction. Rolls may be required. 8th
The figure shows an example of how to support intermediate rolls.

FIG. 8A shows the case where the intermediate roll and support roll 13 are assembled into the chock of the backup roll 8, and FIG. 8B shows the case where they are directly attached to the housing. In case A, the support roll 13 also moves up and down in accordance with the up and down movement of the backup roll 8, but in case B, a separate mechanism (not shown) for vertical movement is required. When supporting an intermediate roll, if the support roll 13 can be pushed horizontally, a horizontal bend will be added to the intermediate roll, and the work roll sagging control function will be further improved. do.

In summary, it is ideal to provide the VC roll and the intermediate slide roll on both the upper and lower sides (Fig. 4A), but depending on the rolling conditions, it is possible to provide them on either the upper or lower side. The desired purpose can be fully achieved. FIG. 6 shows an embodiment in which the plate crown, plate shape, or both are controlled.

A shape detector or profile detector 11 is installed on the entry side, exit side, or both sides (in this embodiment, the exit side) of the rolling mill 10 of the present invention, and a plate crown or plate shape detection signal is introduced into the control device 12. The control device 12 compares the test signal with the set value and sends a correction signal to the axial displacement device (not shown) of the intermediate slide roll 6 and the media pressure unit 4 (not shown) of the VC roll as backup roll 8, respectively. (Fig. 1) to control the position in the ball direction and the amount of crown of each roll 6 and 8.The effect will be further expanded if used in conjunction with the existing roll pending.The rolling mill 10 of the present invention is applied to a continuous rolling mill. An example of this case is shown in FIG.

As illustrated, rolling mills 10 do not need to be provided in all stands, nor do rolling mills 10 need to have the same roll configuration. The roll configuration of each rolling mill may be appropriately determined depending on the rolling conditions. Example 1 '1' Rolling Mill A rolling mill with a roll arrangement shown in FIG. 2 was used.

Upper work roll: 25 m in diameter x 1704 m in body length Lower work roll: 58 m in diameter x 1704 m in body length (drive) Upper intermediate slide roll: 300 in diameter (large) x 297 in diameter (small) × Torso length 1704 chest × 2 (driving) Support roll: Diameter 28 mound × Torso length 30 mboard Upper backup roll: Diameter 140 mboard × Torso length 1704 skin VC
Roll, maximum oil pressure 500kg/, maximum expansion amount 0.2
8 legs/radius Lower back-up roll: Diameter 140mm x Body length 1704'21 Rolling method Move the upper intermediate slide roll in the axial direction according to the plate width and set it at the appropriate position to reduce the internal pressure of the VC roll. And the pending force of the pender was controlled to reduce the pressure by 50% or more per pass.

'3' Rolling results Good flatness could be obtained in each pass.

Furthermore, the finishing profile was improved compared to the conventional schedule (approximately 30% per pass). In addition, when rolling was performed while adjusting the horizontal indentation amount of the support roll 13 of this mill, it was possible to sufficiently control the flatness, and
It has been found that the combination of the VC roll and the pending roll can adequately deal with defects in fairly complex shapes.

Example 0 [11 Rolling mill A rolling mill with the roll arrangement shown in FIG. 4 was used.

Upper/lower work rolls (drive): Diameter 5 x body length 4
6 Cape Upper/Lower intermediate slide/roll (drive): Diameter (large) 6W broadside x diameter (small) 58 skins x torso length 460 skins x 2 each
Upper and lower backup rolls: diameter 300 fence x body length 460 skin VC roll, maximum oil pressure 500k9/maximum limit amount 0.15 ribs/radius '21 Rolling method Almost the same as Example 1.

'3' Rolling Results Conventionally, one baby-faced work roll initial crown was required depending on the rolling material, but according to the method of the present invention, all rolling can be done with one pair of straight rolls.

Example m The rolling mill of Example 1 was installed on the side of a 5-stand continuous cold rolling mill. 1, M. Installed on 2 stands, M. 1, M. Strong reduction rolling was performed on two stands.

As a result, it was not possible to increase the thickness of the hot coil. For example, conventional plain thickness 2.3 pieces, 2. The finishing thickness from the bow was rolled to 0.5 ribs and 0.2 sails, respectively, but with the method of the present invention, the finished thicknesses were 3.8 ribs and 4. Finishing thickness 0.5 ribs from the snout,
It was possible to roll each to a thickness of 0.2 skin. The finish profile has also been improved. Example N The rolling mill of Example 1 was installed on a ship with a 68-inch 5-stand continuous rolling mill. Five stands were installed, and the position of the intermediate roll was changed in response to a change in sheet width, and the internal pressure of the VC roll and the pending force of the roll bender were automatically controlled in accordance with the signal from the shape detector.

As a result, we were able to ensure extremely good flatness (steepness of 1% or less, probability of 93%). Example V The rolling mill of Example 1 was converted into a 68-inch 7-stand continuous hot rolling mill. When installed on 7 stands, we were able to ensure better flatness than before.

Furthermore, No. 6, No. When applied to 5 stands and profile control was performed, both the plate crown and edge drop were significantly reduced. As is clear from the above description, according to the rolling mill of the present invention, strong rolling and precise rolling are possible with small and inexpensive equipment.

[Brief explanation of drawings]

FIG. 1 is a half-longitudinal cross-sectional view of a VC roll used in the rolling mill of the present invention. FIG. 2 is a schematic side view of an example of the rolling mill of the present invention. 3 is a plan view of the intermediate slide roll seen from line mm in FIG. 2, and FIG. 4 is a schematic side view showing a modification of the rolling mill of the present invention. FIG. 5 is a schematic vertical sectional view showing a modification of the VC roll shown in FIG. 1. FIG. 6 is a schematic configuration diagram showing the control system of the rolling mill of the present invention. FIG. 7 is a schematic configuration diagram showing an example of a continuous rolling mill using the rolling mill of the present invention. FIG. 8 is a schematic configuration diagram showing an example of a method for supporting intermediate rolls. 6: Intermediate slide roll, 7: Work roll, 8; Backup roll, 1
3; Support Law Nore. Figure 2 Figure 3 Figure 4-Figure 6 Figure 6 Figure 7 Figure 8

Claims (1)

[Claims] 1. In a multiple rolling mill consisting of work rolls and backup rolls, at least one of the upper and lower work rolls is reduced in diameter, and the small diameter work roll is supported by two intermediate slide rolls, A rolling mill characterized in that at least one of the upper and lower back-up rolls is a variable crown roll.