JPH02303602A - Method for rolling metallic strip - Google Patents

Abstract

PURPOSE:To control the shape of a steel strip in the entire area of the transverse direction thereof and according to the width of the steel strip by varying the variable crown range of back-up rolls up to the center in the longitudinal direction of the cylindrical part, setting the variable range so as to stagger alternately with the upper and lower rolls and providing shift mechanisms to the rolls. CONSTITUTION:The upper back-up roll 2a has a projecting crown shape in the right half part and the lower back-up roll 2b has a projecting crown shape in the left half part when tapered pistons 7 are pulled from the pushed-in state. The shape control in nearly the entire area in the transverse direction of the thin steel strip is, therefore, possible if the stroke ranges of the tapered pistons 7, 7 of the back up rolls 2a, 2b are respectively confined up to the center in the axial direction of the back-up rolls 2a, 2b. Since the upper and lower back-up rolls 2a, 2b are provided with the shift mechanisms, the shape control according to the width of the steel strip is executed by shifting the upper and lower back-up rolls 2a, 2b in right and left directions.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a method for rolling a metal strip using a rolling mill equipped with a backup roll having a tapered piston type variable roll crown mechanism.

[Prior art] Thin copper strips used for tinplate, for example, have a high level of flatness from a quality perspective in order to meet the quality standards required for tinplate and to improve threadability and increase production efficiency. This is required. 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). ).

One of the methods for shape-controlled rolling of the thin steel strip described above is a method using a type 4 rolling mill equipped with a backup roll having a tapered piston type variable roll crown mechanism. The backup role used for this method is
The configuration is as shown in Figure 6. That is, the backup roll 31 includes an arbor 32 and a sleeve 33 that is shrink-fitted to the arbor 32. It is comprised of taper pistons 35 located at both ends of the arbor 32 and arranged in a hydraulic chamber 34 made up of the arbor 32 and the sleeve 33. To explain this backup roll 31 in more detail, the arbor 32 is provided with a hydraulic oil supply passage 36, and the hydraulic oil for operating the taper piston 35 is supplied through a rotary joint 37 arranged at the axial end of the arbor 32. It is sent from the hydraulic unit 38 to the hydraulic chamber 34, and the taper piston 35 is moved in and out in the roll axis direction. Further, a slip ring 39 is provided at the other shaft end of the arbor 32, and a piston position sensor 40 is provided in the hydraulic chamber 34. And the digit 1 signal of the piston position sensor 40 is the arbor 3
The taper piston control panel 42 is connected via the piston position sensor signal line 41 and slip ring 39 provided in the
Therefore, the rolling mill operator controls the taper piston using the operation switch 43 while checking this signal.

FIG. 7 shows a procedure for grinding the backup roll 31 equipped with the taper piston 35. First, the 7th [1f
As shown in fl(a), the taper piston 35 is pushed toward the center of the roll axis using hydraulic oil to deform the backup roll 31 into a pin-shaped shape.Next, in this state, the roll surface is ground. 7. Make the surface flat as shown in Figure 7(b). Then, as shown in FIG. 7(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. 8 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 controlling the shape of the thin steel strip 44 using the ground backup roll 31. It shows a relationship.

(1) When the taper piston 35 is located at the outermost position from the roll center as shown in FIG. , plate shape (53)
is in a state of medium elongation.

(2) When the taper piston 35 is in the intermediate position as shown in FIG. 8(b), the backup roll profile (
51) has a slightly convex profile, the one work roll profile (52) is flat, and the plate shape (53) is also flat.

(3) When the taper piston 35 is pushed farthest toward the roll center as shown in FIG. 8(C), the backup roll profile (51) becomes a flat profile, and the work roll profile (52) has a concave crown. The plate shape (53) becomes an ear wave state.

[NM to be Solved by the Invention] However, in the conventional method of rolling a metal strip using a rolling mill equipped with a backup roll having a tapered piston type variable roll crown mechanism, there are the following problems. Namely.

As shown in FIG. 6, the tapered piston 35 of the tapered piston type variable roll crown mechanism of the backup roll 31
The hydraulic chambers 34 are arranged symmetrically on both sides of the arbor 32, and the sleeve 33 is shrink-fitted in the center of the arbor 32, so that the center of the roll does not deform due to the movement of the taper piston. This is an area that is out of reach. Therefore, as is clear from the graph showing changes in the indentation amount of the taper piston and the roll diameter in Fig. 9, no shape control effect can be expected in the widthwise central part of the rolled metal strip, and especially for narrow width materials, the shape is almost impossible to control. #
The problem was that the desired effects could not be expected.

In addition, the crown variable range of the body of the backup roll 31 is fixed, and the shoulder portion (A section) where the crown begins to change in Fig. 9 is also fixed relative to the body, so that it is possible to The position of the shoulder part changes depending on the width of the obi,
Appropriate shape control could not be performed.

This invention solves the above-mentioned problems of the prior art,
It is an object of the present invention to provide a method for rolling a metal strip using a rolling mill equipped with a backup roll having a tapered piston type 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 rolling mill equipped with a backup roll having a tapered piston type variable roll crown mechanism according to the present invention includes rolling a metal strip using a rolling mill equipped with a backup roll having a tapered piston type variable roll crown mechanism. In the method of rolling a metal strip using a rolling mill equipped with Backup rolls are arranged so that the variable roll roll mechanism is located at alternate positions between the upper and lower rolls, and a shift mechanism is provided so that the backup roll can be shifted in the roll axis direction, thereby rolling the metal strip while controlling its shape. This is a method for rolling metal strips.

[Function] The method of rolling a metal strip using a rolling mill equipped with a backup roll having a tapered piston type variable roll crown mechanism according to the present invention includes changing the crown variable range of the tapered piston type variable roll crown mechanism to the body of the backup roll. In addition to arranging the tapered piston type variable roll crown mechanism so that the upper and lower rolls are positioned at alternate positions, the backup roll is shifted in the roll axis direction. To make this possible, a shift mechanism is provided to roll the metal strip while controlling its shape. Therefore, the shape control range of the metal strip extends to the center of the sheet width, and by shifting the backup roll in the axial direction, the shape can be controlled according to the width of the metal strip.

[Example] A four-layer rolling mill used in a method of rolling a steel strip by a rolling mill equipped with a backup roll having a tapered piston type variable roll crown mechanism according to an embodiment of the present invention was constructed as follows.
This will be explained using figures. Figure 1 shows the work roll la of this four-layer rolling mill.

It is a longitudinal cross-sectional view of 1b and back rolls a and 2b.

The upper back roll 2a disposed above the upper work roll 1a is composed of a taper 3 and a sleeve 4 shrink-fitted to the arbor 3. And one end of arbor 3 (
Hydraulic chambers 5 and 6 are formed by the arbor 3 and a recess provided in the sleeve 4 at a position located on the right side in FIG. 1, and a taper 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 sleeve 4
The outer diameter of the sleeve on the side where the taper piston 7 is placed is
The A side end is configured to be approximately 1,500 microns larger than the center portion of the sleeve 4. Also, lower work roll 1b
The lower back roll 2b placed under the arbor 3
and sleeves 4 arranged alternately with respect to the case of the upper backup roll 2a. Similarly to the upper backup roll 2a, the arbor 3 and the recess provided in the sleeve 4 constitute hydraulic chambers 5 and 6.
A tapered piston 7 is arranged 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 sleeve 4
The outer diameter of the sleeve on the side where the taper piston 7 is arranged is about 1500 μ larger at the outermost end than the outer diameter before pushing.

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 variable roll crown mechanism according to an embodiment of the present invention is constructed as described above. Therefore, as shown in Figure 7 in the prior art section, when the backup roll is ground so that the roll surface is flat with the taper piston pushed in, and the taper piston is pulled out, the upper backup roll The right half of the lower backup roll has a convex crown shape as shown in the cross-sectional view of Figure 2 (a), and the left half of the lower back-up roll has a convex crown shape as shown in the cross-sectional view of Figure 2 (b). If the stroke range of the tapered pistons of the 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.

Furthermore, the upper backup roll 2a and the lower backup roll 2b are provided with shift machines that can shift the rolls in the axial direction! (not shown), by shifting the upper back-up roll 2a and the lower back-up roll 2b in the left-right direction as shown in FIG. 3, the shape can be controlled according to the width of the copper strip. I can do it.

FIG. 4 is an improvement on the embodiment shown in FIG. 3, in which the length of the backup roll body is shortened to reduce deformation of the work roll in contact with the end where the tapered piston type variable roll crown mechanism is not provided. In FIG. 5, the aforementioned ends are further tapered to reduce deformation of the work roll. This mechanical taper is greater than the maximum value of the variable roll crown mechanism.
Usually the lowest value. Note that deformation of the work roll may be further reduced by shortening the backup roll body length and tapering the end portion.

In the method of rolling a copper strip using a four-layer rolling mill equipped with a backup roll having a tapered piston variable roll crown mechanism according to an embodiment of the present invention, shape control rolling is possible over the entire width as described above. At the same time, it is possible to control the shape according to the width of the copper strip, so thin steel strips with good flatness can be manufactured, ensuring the quality level required for tinplate, and with good threadability, making production easier. You can increase your sexuality.

The present invention is applicable to intermediate backup rolls of a 6-layer rolling mill and to hot rolling.

[Effects of the Invention] According to the present invention, in a method of rolling a metal strip using a rolling mill equipped with a backup roll having a tapered piston type variable roll crown mechanism, the shape of the metal strip can be controlled over the entire width direction of the metal strip, and the shape of the metal strip can be controlled. Shape control can be performed depending on the width.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of 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 variable roll crown mechanism according to an embodiment of the present invention; FIG. 2 is an explanatory diagram showing the roll crown of the backup roll used in the method of rolling a copper strip according to an embodiment of the present invention, FIG. 4
FIG. 5 is a diagram of another embodiment of the present invention; FIG. 6 is a vertical sectional view of a backup roll having a conventional tapered piston type variable roll crown mechanism; FIG. The figure is an explanatory diagram showing the grinding procedure of a backup roll with a conventional tapered piston type variable roll crown mechanism, and Figure 8 shows the shape obtained by a quadruple rolling mill equipped with a backup roll with a conventional taper piston type variable roll crown mechanism. FIG. 9, an explanatory diagram for explaining controlled rolling, is a graph showing the relationship between the pushing amount of the conventional taper piston and the change in the roll diameter of the backup roll. la, lb...work roll, 2a, 2b...backup roll, 3...arbor, 4...sleeve, 5, 6...hydraulic chamber, 7...
Tapered piston, 8... Taper.

Claims (1)

[Claims] In a method of rolling a metal strip using a rolling mill equipped with a backup roll having a tapered piston type variable roll crown mechanism, the crown variable range of the tapered piston type variable roll crown mechanism can be made close to the longitudinal center of the body of the backup roll. In addition, the backup rolls are arranged so that the tapered piston type variable roll crown mechanism is positioned at alternate positions for the upper and lower rolls, and a shift mechanism is provided so that the backup rolls can be shifted in the roll axis direction. 1. A method for rolling a metal strip, comprising: rolling the metal strip while controlling its shape.