JPH02290604A - Method for rolling metallic strip by four stages rolling mill - Google Patents

Abstract

PURPOSE:To allow the shape control over the entire transverse region of a thin steel strip by allowing stroke ranges up to the parts near the longitudinal centers in the cylindrical parts of back up rolls and disposing the back up rolls in the positions zigzagging with the upper and lower rolls. CONSTITUTION:The right half part of the upper back up roll 2a is formed to a projecting crown shape and the left half part of the lower back up roll 2b is formed to a projecting crown shape when tapered pistons 7 are pulled off after the back up rolls 2a, 2b are ground until the roll surfaces are flattened while the tapered pistons 7 are kept pushed in. The shape control rolling near nearly the entire transverse region is, therefore, possible at the time of the rolling of the thin steel strip if the stroke ranges of the two back up rolls 2a, 2b are respectively extended up to the axial centers of the back up rolls.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method of rolling a metal strip using a quadruple rolling mill equipped with a backup roll having a tapered piston type variable roll crown mechanism. [Prior art] The gI'Kf4 strip used for tinplate has a high flatness from a crystal purchasing perspective in order to meet the quality standards required for tinplate and to improve threadability and increase production efficiency. High requirements. In order to improve the flatness of the thin steel strip, shape control rolling is performed. As a method, a rolling mill is equipped with a roll crown variable mechanism that changes the roll crown of the work roll, and this changes the roll crown of the work roll to control the flatness of the thin steel strip (hereinafter referred to as shape control). That's what I do.

One of the methods for shape-controlled rolling of the thin steel strip described above is a method using a four-layer rolling mill equipped with backup rolls having a tapered piston type variable roll crown mechanism. The backup roll used in this method has a configuration as shown in FIG. That is, the backup roll 31 includes an arbor 32, a sleeve 33 shrink-fitted to the arbor 32, and a hydraulic chamber 3 located at both ends of the arbor 32 and configured by the arbor 32 and the sleeve 33.
4 and a taper piston 35 arranged at 4. To explain this backup roll 31 in more detail,
A hydraulic oil supply passage 36 is provided in the arbor 32, and hydraulic oil for operating the taper piston 35 is sent from a hydraulic oil hydraulic unit 38 to the hydraulic chamber 34 through a rotary joint 37 arranged at the shaft end of the arbor 32.
The taper piston 35 is adapted to be moved in and out in the direction of the roll axis. Further, three slip rings are provided at the other shaft end of the arbor 32, and a piston position sensor 40 is provided in the hydraulic chamber 34. Then, the position signal of the piston position sensor 40 is transmitted to the arbor 32.
Since the signal is sent to the taper piston control block 42 via the piston position sensor signal line 4l and the slip ring 39 provided in the ,
It uses taper piston control. FIG. 6 shows the procedure for grinding the backup roll 31 equipped with the taper piston 35. First, Figure 6 (a
> Push the taper piston 35 toward the center of the roll axis using hydraulic oil, and press the backup roll 3.
Transform 1 into a bone shape. Next, the roll surface is ground in this condition to make the surface flat as shown in Figure 6(b). Then, as shown in FIG. 6(c), the taper piston 35 is pulled out to the outside of the roll axis so that a convex crown is formed on the surface of the roll. FIG. 7 shows the position and roll profile of the tapered piston 35 in the roll axis direction, the profile of the work roll 45, and the plate shape when the shape of the thin steel strip 44 is controlled using the backup roll 31 that has been ground. ru
It shows section j. (1) When the taper piston 35 is at the outermost position from the roll center as shown in Fig. 7(a), the backup roll profile (51) is in its most convex state, and the work roll profile (52) is The convex crown and plate shape (53) are in a state of medium elongation. (2) When the taper piston 35 is in the intermediate position as shown in FIG. 7(b), the backup roll profile (
51) has a slightly convex profile, the work roll profile (52) is flat, and the plate shape (53) is also flat. (c) When the taper piston 35 is pushed farthest toward the roll center as shown in FIG. 7(C),
The backup roll profile (51) has a flat profile, the work roll profile has a concave crown (52), and the plate shape (53) has an ear wave shape. [Problems to be Solved by the Invention] However, in the conventional method of rolling a copper strip using a four-layer rolling mill equipped with a backup roll having a tapered piston type variable opening and crown mechanism, the following problems arise. there were. That is, the hydraulic chambers 34 in which the tapered pistons 35 of the tapered piston variable roll crown mechanism of the backup roll are arranged are symmetrically arranged at positions on both sides of the arbor 32, and the sleeve 33 is shrink-fitted in the center of the arbor 32. Therefore, the central part of the roll is an area that is not affected by the movement of the taper piston. Therefore, as is clear from the graph in Figure 8 showing the change in the indentation amount of the taper piston and the change in roll diameter, no shape control effect can be expected in the widthwise central part of the rolled thin steel strip, especially for narrow width materials. The problem was that shape control effects could not be expected.
This invention solves the above problems of the prior art,
The purpose of the present invention is to provide a copper strip rolling method using a four-layer rolling mill equipped with a backup roll having a tapered piston variable roll crown mechanism that can be expected to have a shape control effect over the entire width direction. [Means for Solving the Problems] A method of rolling a metal strip using a four-layer rolling mill equipped with a backup roll having a tapered piston type variable roll crown mechanism according to the present invention includes the taper piston type variable roll crown mechanism described above. The backup roll is configured such that the stroke range of the backup roll can be extended to near the center in the longitudinal direction of the body of the backup roll, and the backup roll is arranged so that the tapered piston type variable roll crown mechanism is located at alternate positions for the upper and lower rolls, This is a metal strip rolling method that involves rolling the metal strip while controlling its shape over almost the entire width. [Function] A method of rolling a metal strip using a quadruple rolling mill equipped with a backup roll having a tapered piston type variable roll crown mechanism according to the present invention includes changing the stroke range of the tapered piston type variable roll crown mechanism to the back amplifier. The tapered piston type variable roll crown machine is configured so that it can reach up to the center in the longitudinal direction of the roll body, and the backup rolls are arranged so that the sides of the machine are alternately positioned with the upper and lower rolls. It is possible to roll the metal strip while controlling its shape over almost the entire width. Therefore, it is not the case that a shape control effect cannot be expected at the widthwise central part of a rolled thin metal strip, or that a shape control effect cannot be expected for a wide width material, unlike in the past. [Example] Fig. 1 shows a four-layer rolling mill used in a method of rolling a copper strip by a four-layer rolling mill equipped with a backup roll having a tapered piston type variable roll crown mechanism according to an embodiment of the present invention. explain. Figure 1 shows the work rolls la, lb and back rolls a, 2 of this four-layer rolling mill.
It is a vertical cross-sectional view of b. The upper back roll 2a placed on the upper work roll 1a is connected to the arbor 3 and the arbor 3.
It consists of a sleeve 4 that is shrink-fitted to the sleeve 4. At a position located at one end of the arbor 3 (on the right side in FIG. 1), hydraulic chambers 5 and 6 are constituted by the arbor 3 and a recess provided in the sleeve 4, and between the hydraulic chambers 5 and 6 there is a taper piston. 7 is placed. The walls of the hydraulic chambers 5 and 6 are tapered, and the taper piston 7
When the sleeve 4 is pushed toward the center of the roll by applying hydraulic pressure to the hydraulic chamber 5, the outer diameter of the sleeve 4 on the side where the tapered piston 7 is arranged is approximately 1,500μ larger at the outermost end than at the center of the sleeve 4. It is configured so that Further, the lower back-up roll 2b disposed below the lower work roll 1b is composed of an arbor 3 and sleeves 4 arranged alternately with respect to the upper back-up roll 2a. And just like the upper backup roll 2a,
A hydraulic chamber 5 is formed by the arbor 3 and the recess provided in the sleeve 4.
and 6, and a tapered piston 7 is disposed between the hydraulic chambers 5 and 6. The walls of the hydraulic chambers 5 and 6 are tapered, and when the taper piston 7 is pushed toward the center of the roll by applying hydraulic pressure to the hydraulic chamber 5, the side of the sleeve 4 where the taper piston 7 is arranged The outer diameter is approximately 1,500μ larger at the outermost end than at the center of the sleeve 4. A four-layer rolling mill used in a method of rolling a copper strip using a four-layer rolling mill equipped with a backup roll having a tapered piston type variable roll crown mechanism according to an embodiment of the present invention is constructed as described above. Therefore, as shown in Fig. 6 in the prior art section, when the tapered piston is pushed in and the backup roll is ground so that the roll surface becomes flat, when the taper piston is pulled out, the upper backup roll is The right half has a convex crown shape as shown in the cross-sectional view of Figure 2(a), and the left half of the lower backup roll has a convex crown shape as shown in the cross-sectional view of Figure 2(b). Therefore, if the stroke range of the taper pistons of both backup rolls is set to the axial center of each backup roll, shape control rolling can be performed over almost the entire width direction during thin steel strip rolling. The scope of shape control of the thin steel strip mentioned above is schematically shown in comparison with the conventional case as shown in Figs. 3 and 4. That is, the change portion (21) of the roll profile of the backup roll having the conventional tapered piston type variable roll crown mechanism is limited to both end portions of the backup roll as shown by the shaded area in FIG.
While the shape control range W of the thin steel strip is limited to the vicinity of both edges of the scrap strip as in b), in the method of the present invention, the shape control range W of the thin steel strip is limited to the area where the roll profile of the backup roll changes (21).
extends to the axial center of the backup roll as shown in the shaded area in Fig. 4(a), and as a result, as shown in Fig. 4(b)
), the shape control range W of the thin copper strip extends over the entire width direction. In the method of rolling a steel strip using a four-layer rolling mill equipped with a backup mill having a tapered piston type variable roll crown mechanism according to an embodiment of the present invention, shape control rolling can be performed over the entire width as described above. So,
A thin steel strip with good flatness can be manufactured, the quality level required for tinplate can be ensured, and productivity can be increased because the sheet threadability is good.

Note that the present invention is applicable to rolling any metal strip. [Effects of the Invention] According to the present invention, in a method of rolling a metal strip using a four-layer rolling mill equipped with a backup roll having a tapered piston type variable roll crown machine side, shape control can be performed over the entire width direction of a thin metal strip. A rolling method can be carried out.

[Brief explanation of the drawing]

Claims (1)

[Claims] In a method of rolling a metal strip using a four-layer rolling mill equipped with a backup roll having a tapered piston type variable roll crown mechanism, the stroke range of the tapered piston type variable roll crown mechanism is set near the longitudinal center of the body of the backup roll. In addition, backup rolls are arranged so that this tapered piston type variable roll crown mechanism is positioned at alternate positions on the upper and lower rolls, and rolling is performed while controlling the shape over almost the entire width of the metal strip. A method for rolling a metal strip characterized by: