JPH084802B2 - Rolling method for metal strip - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for rolling a metal strip by a rolling mill provided with a backup roll having a taper piston type variable roll crown mechanism.

[Prior Art] For example, a thin steel strip used for tinplate has a high flatness in terms of quality in order to satisfy the quality level required for tinplate and to improve the sheet passing property to increase the production efficiency. Is required. Shape-controlled rolling is performed to increase the flatness of the thin steel strip. As the method, a roll crown variable mechanism that makes the roll crown of the work roll variable is provided in the rolling mill, and thereby the roll crown of the work roll is changed to control the flatness of the thin steel strip. I said).

As one of the methods for performing the shape control rolling of the thin steel strip described above, there is a method using a quadruple rolling mill provided with a backup roll having a tapered piston type variable roll crown mechanism. The backup role used for this method is
The structure is as shown in FIG. That is, the backup roll 31 is located at both ends of the arbor 32, the sleeve 33 shrink-fitted to the arbor 32, and the arbor 32.
It is composed of a tapered piston 35 disposed in a hydraulic chamber 34 composed of a sleeve 32 and a sleeve 33. More specifically, this backup roll 31 is provided with a hydraulic oil supply passage 36 in the arbor 32, and the hydraulic oil for operating the taper piston 35 passes through the rotary joint 37 arranged at the shaft end of the arbor 32. It is sent from the unit 38 to the hydraulic chamber 34, and the taper piston 35 is taken in and out in the roll axial direction. 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. Then, since the position signal of the piston position sensor 40 is sent to the taper piston control board 42 via the piston position sensor signal line 41 provided on the arbor 32 and the slip ring 39, the operator of the rolling mill is While confirming this signal, the operation switch 43 controls the taper piston.

FIG. 7 shows a procedure for grinding the backup roll 31 equipped with the taper piston 35. First, FIG. 7 (a)
As described above, the taper piston 35 is pushed in the direction of the center of the roll axis by the working oil, and the backup roll 31 is deformed into a hook shape. Next, the roll surface is ground in this state to form a flat surface as shown in FIG. 7 (b). Then, as shown in FIG. 7 (c), the tapered piston 35 is pulled out to the outside of the roll shaft so that a convex crown is formed on the surface of the roll.

FIG. 8 shows the position of the taper piston 35 in the roll axis direction and the roll profile when the shape of the thin steel strip 44 is controlled by using the backup roll 31 which is ground in this way.
The relationship between the profile of the work roll 45 and the plate shape is shown.

(1) When the taper piston 35 is on the outermost side from the roll center as shown in FIG. 8 (a), the backup roll profile (51) is in the most convex state, and the work roll profile (52) is the convex crown. , The plate shape (53) is in a state of middle stretch.

(2) When the taper piston 35 is at the intermediate position as shown in FIG. 8 (b), the backup roll profile (5
1) has a slightly convex profile, the work roll profile (52) is flat, and the plate shape (53) is also flat.

(3) As shown in FIG. 8 (c), when the taper piston 35 is pushed most toward the roll center, the backup roll profile (51) becomes a flat profile, the work roll profile (52) becomes a concave crown, The plate shape (53) is in the state of an ear wave.

[Problems to be Solved by the Invention] However, the conventional method for rolling a metal strip by a rolling mill equipped with a backup roll having a taper piston type variable roll crown mechanism has the following problems. That is, as shown in FIG. 6, the hydraulic chamber 34 in which the taper piston 35 of the taper piston type variable roll crown mechanism of the backup roll 31 is arranged is arbored.
Since the sleeves 33 are arranged symmetrically on both sides of the roll 32 and the sleeve 33 is shrink-fitted in the central portion of the arbor 32, the central portion of the roll is an area that is not deformed by the movement of the tapered piston. . Therefore, the ninth
As is clear from the graph showing the amount of indentation of the tapered piston and the change in roll diameter in the figure, the shape control effect cannot be expected in the widthwise central part of the rolled metal strip, and in particular the shape control effect can be expected for narrow width strips. There was a problem that I could not.

Further, since the variable range of the crown of the body of the backup roll 31 is fixed and the shoulder portion (A portion) of the crown in FIG. 9 where the crown begins to change is also fixed to the body, various types of rolled metal can be used. Change the position of the shoulder according to the width of the belt,
It was not possible to perform appropriate shape control.

The present invention solves the above-mentioned problems of the prior art, and provides a method for rolling a metal strip by means of a rolling mill equipped with a backup roll having a taper piston type variable roll crown mechanism capable of expecting a shape control effect over the entire width direction. It is intended to be provided.

[Means for Solving the Problem] A method of rolling a metal strip by a rolling mill provided with a backup roll having a taper piston type variable roll crown mechanism according to the present invention is performed by using a backup roll having a taper piston type variable roll crown mechanism. In a method of rolling a metal strip with a rolling mill provided, the taper piston type variable roll crown mechanism is configured to allow a variable crown range of the backup roll up to near the center of the longitudinal direction of the body of the backup roll. The variable roll crown mechanism arranges the backup rolls so that the upper and lower rolls are located at alternate positions, and the shift mechanism is provided so that the backup rolls can be shifted in the roll axial direction and the metal strip is rolled while controlling the shape. This is a method of rolling a metal strip.

[Operation] A method of rolling a metal strip by a rolling mill provided with a backup roll having a taper piston type variable roll crown mechanism according to the present invention is a method in which the crown variable range of the taper piston type variable roll crown mechanism is set to The taper piston type variable roll crown mechanism is arranged so that the upper and lower rolls are located at alternate positions, and the backup roll is shifted in the axial direction of the roll. A shift mechanism is provided so that it can be rolled while controlling the shape of the metal strip. Therefore, the shape control range of the metal band extends to the center of the plate width, and by shifting the backup roll in the axial direction, the shape control according to the width of the metal band can be performed.

[Embodiment] A quadruple rolling mill used in a method for rolling a steel strip by a rolling mill equipped with a backup roll having a taper piston type variable roll crown mechanism of one embodiment of the present invention will be described with reference to FIG. FIG. 1 is a longitudinal sectional view of the work rolls 1a, 1b and the back-up rolls a, 2b of this quadruple rolling mill. The upper back-up roll 2a arranged on the upper work roll 1a is composed of an arbor 3 and a sleeve 4 shrink-fitted to the arbor 3. The hydraulic chambers 5 and 6 are formed by the arbor 3 and the recess provided in the sleeve 4 at a position located at one end (right side in FIG. 1) of the arbor 3, and the tapered piston is provided between the hydraulic chambers 5 and 6. 7 are arranged. The wall surfaces of the hydraulic chambers 5 and 6 are tapered. When the tapered piston 7 is pressed toward the center of the roll by applying hydraulic pressure to the hydraulic chamber 5, the sleeve on the side of the sleeve 4 where the tapered piston 7 is disposed The outer diameter of the outermost end is larger than the center of the sleeve 4 by about 1,500 μm. Further, the lower back roll 2b arranged below the lower work roll 1b has an arbor 3 and
The upper backup roll 2a and the sleeves 4 are arranged alternately. Then, like the upper backup roll 2a, the hydraulic chambers 5 and 6 are constituted by the arbor 3 and the concave portion provided in the sleeve 4, and the hydraulic chamber 5
A taper piston 7 is arranged between and. The wall surfaces of the hydraulic chambers 5 and 6 are provided with a taper. When the tapered piston 7 is hydraulically pressed into the hydraulic chamber 5 and pushed in the direction of the center of the roll, the sleeve 4 of the sleeve 4 on the side where the tapered piston 7 is arranged is arranged. The outer diameter is configured to be about 1500μ larger at the outermost end than the external system before pushing.

A quadruple rolling mill used in a method for rolling a steel strip by a quadruple rolling mill equipped with a backup roll having a taper piston type variable roll crown mechanism according to one embodiment of the present invention is configured as described above. Therefore, as shown in Fig. 7 of the prior art, when the taper piston is pushed in, the backup roll is ground so that the roll surface becomes flat, and then the taper piston is pulled out. The right half has a convex crown shape as shown in the sectional view of FIG. 2 (a), and the lower backup roll has a convex crown shape as its left half as shown in the sectional view of FIG. 2 (b). Therefore, when the stroll ranges of the taper pistons of both backup rolls are set to the axial center of the backup rolls, shape-controlled rolling can be performed over the entire width direction during thin steel strip rolling.

Further, since the upper backup roll 2a and the lower backup roll 2b are provided with a shift mechanism (not shown) capable of axially shifting the rolls, the upper backup roll 2a and the lower backup roll 2a are provided as shown in FIG. roll
By shifting 2b in the left-right direction, shape control according to the width of the steel strip can be performed.

FIG. 4 is an improvement of the embodiment of FIG. 3, in which the backup roll cylinder length is shortened to reduce the deformation of the work roll in contact with the end without the taper piston type variable roll crown mechanism. In FIG. 5, the above-mentioned end portion is further tapered to reduce the deformation of the work roll. This mechanical taper is usually smaller than the maximum value of the variable roll crown mechanism. The backup roll cylinder length may be shortened and the end portion may be tapered to further reduce the deformation of the work roll.

In the method of rolling the steel strip by the quadruple rolling mill provided with the backup roll having the taper piston type variable roll crown mechanism according to the embodiment of the present invention, the shape-controlled rolling can be performed over the entire width as described above. At the same time, shape control according to the width of the steel strip can be performed, so thin steel strip with good flatness can be manufactured, the quality level required as a tin plate can be secured, and the plate passing property is good for production. You can improve your sex.

The present invention is also applicable to an intermediate backup roll of a six-fold rolling mill,
It can also be applied to hot rolling.

[Effect of the Invention] According to the present invention, in a method of rolling a metal strip by a rolling mill provided with a backup roll having a taper 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 can be controlled according to the width.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a quadruple rolling mill used in a method for rolling a steel strip by a quadruple rolling mill equipped with a backup roll having a taper piston type variable roll crown mechanism according to an embodiment of the present invention, FIG. 2 is an explanatory view showing a roll crown of a backup roll used in a method for rolling a steel strip according to an embodiment of the present invention, and FIG. 3 is a longitudinal sectional view showing a state in which the backup roll is shifted in the present invention. FIG. 4 is a view of another embodiment of the present invention, FIG. 5 is a view of another embodiment of the present invention, and FIG. 6 is a longitudinal sectional view of a backup roll having a conventional taper piston type variable roll crown mechanism,
FIG. 7 is an explanatory view showing a grinding procedure of a backup roll having a conventional taper piston type variable roll crown mechanism, and FIG. 8 is a quadruple rolling mill equipped with a backup roll having a conventional taper piston type variable roll crown mechanism. FIG. 9 is a graph showing the relationship between the pushing amount of the conventional taper piston and the change of the roll diameter of the backup roll, which is an explanatory view for explaining the shape-controlled rolling according to FIG. 1a, 1b …… Work roll, 2a, 2b …… Backup roll, 3 …… Arbor, 4 …… Sleeve, 5,6 …… Hydraulic chamber, 7 …… Tapered piston, 8… Tapered.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-63-220911 (JP, A) JP-B-63-1122 (JP, B2)

Claims (1)

[Claims] 1. A method of rolling a metal strip by a rolling mill equipped with a backup roll having a taper piston type variable roll crown mechanism, wherein a crown variable range of the taper piston type variable roll crown mechanism is set to a longitudinal length of a body of the backup roll. The taper piston type variable roll crown mechanism is arranged so that the upper and lower rolls are located at alternate positions, and the backup roll is shiftable in the roll axis direction. A method for rolling a metal strip, which comprises rolling the metal strip while controlling the shape of the metal strip by providing a shift mechanism.