JPH07144210A - Device and method for reducing deformation on work roll - Google Patents

Abstract

PURPOSE:To provide a device and method for reducing deformation which is caused on the surface of a work roll. CONSTITUTION:A pair of upper and lower work rolls 1, 2 are shifted in the same direction as the revolving shafts; and, in accordance with the deviation of the thickness in the width direction of a metallic strip, which is a rolling stock 3 which has passed through the pair of work rolls 1, 2, rolling is performed while the rolling force imparting to both ends in the direction of each of the revolving shafts of the work rolls 1, 2 is adjusted by the use of rolling cylinders 5a, 5b, as a screw-down device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work roll reducing device and a work reducing method for a work roll used when rolling a metal strip such as a steel strip.

[0002]

2. Description of the Related Art For example, a metal strip such as a steel strip is usually composed of a pair of upper and lower work rolls which are brought into direct contact with a material to be rolled to carry out reduction, and work rolls for preventing the work rolls from being bent or broken. A tandem mill having a plurality of rolling mills provided in combination with two to several backup rolls installed on the back is continuously rolled into a product having a predetermined plate thickness. With such a tandem mill, metal strips having various thicknesses and widths are continuously manufactured.

By the way, the strip width of the material to be rolled is often constant in the same lot, and there are many opportunities to continuously roll the material to be rolled having the same strip width in an actual manufacturing site.

FIG. 4 shows a pair of upper and lower work rolls and a material to be rolled in order to clarify the state of the rolling force applied to the material to be rolled during rolling by enlarging the deflection of the work roll. It is a longitudinal cross-sectional view in a plane orthogonal to the rolling direction. As shown in the figure, the upper work roll 4
1 is an upper backup roll not shown, and lower work roll 42 is a lower backup roll not shown,
Each of the upper work roll 41 and the lower work roll 42 is set to be longer than the plate width of the material 40 to be rolled, so that the upper work roll 41 is pressed. The lower work roll 42 and the lower work roll 42 are bent as shown in FIG.
0 and two corners 40a and 40b and the lower work roll 42 are two corners 40c and 40d of the material 40 to be rolled.
And make strong contact with each other.

Therefore, when a material to be rolled having the same plate width is continuously manufactured by a tandem mill, the upper work roll 41 and the lower work which come into contact with the four corners 40a, 40b, 40c and 40d of the material 40 to be rolled are provided. A so-called plate path, in which the contact surface of each roll 42 and its vicinity partially abnormally wear to form a recess, occurs.

FIG. 5 is a side view of the work roll 50 in which two plate passages 51 and 52 are generated on the surface. When the work roll 50 continues rolling, the plate passages 51 and 52 become deeper. Two strip-shaped plate thickness defects occur in the product metal strip, resulting in poor quality products. in this case,
Since it is necessary to stop the rolling line and replace the work rolls 50, the productivity is remarkably reduced, and the life of the work rolls that can be sufficiently used except for the strip path generating portion is greatly reduced.

Therefore, conventionally, at the manufacturing site, the surface of the work roll is polished while the defective part of the plate thickness is within the allowable range, and the plate path that occurs before the product has a problem is eliminated. It was corresponded by doing. for that reason,
The life of the work rolls is substantially controlled by the degree of the strips that are generated, and the strips are one of the main factors that deteriorate the basic unit of the work rolls.

By the way, it has been said that the so-called shift mill technique proposed by Japanese Patent Publication No. 59-48690 is also effective for reducing the road clearance. 6 (a) and 6
(B) is an explanatory view showing the outline of the present invention.

In the present invention, as shown in FIG. 6A, a pair of upper and lower work rolls 63 and 65 having bending devices 68 and 69 and a pair of upper and lower backup rolls 6 are provided.
When rolling the material 64 to be rolled by a rolling mill in which a pair of upper and lower intermediate rolls 62 and 66 that are shiftable in the rotational axis direction are arranged between the rolling mills 1 and 67, before rolling start,
Upper and lower intermediate rolls 62, 6 depending on the strip width of the rolled material 64
6 has been shifted to left and right symmetrical positions with respect to the center of the rolling mill, and at the time of rolling, as shown in FIG. The thickness is detected, and the upper and lower intermediate rolls 6 are detected based on this difference in plate thickness.
The end position of one of the upper intermediate rolls 62, 66 is shifted in the rotational axis direction along the direction from the large plate thickness to the small plate thickness of the left and right plate thicknesses in the plate width direction so as to shift these upper and lower intermediate rolls 6 from each other.
Rolling is performed by setting the positions of 2 and 66 asymmetrically with respect to the center line of the rolling mill, and originally, it is easy to correct the rolled material 64 in which the strip thickness is not constant at both ends in the strip width direction. However, the reaction force that the work rolls 63 and 65 receive from the material 64 to be rolled in the rotation axis direction is obtained by shifting one of the upper and lower intermediate rolls 62 and 66 in the rotation axis direction. Since it fluctuates, the wear of the work rolls 63 and 65 is dispersed and uniformized in the rotation axis direction, and it has been considered that it is also effective in reducing the plate path. In addition,
6 (a) and 6 (b), reference numerals 70 and 71 both denote load cells for detecting the rolling load.

[0010]

However, as a result of the study by the present inventor, the present invention can surely make the plate thickness uniform at both ends in the plate width direction, but the work roll plate path reducing effect can be obtained. Turned out to be very unlikely in practice.

That is, according to the present invention, in FIG. 6B, the upper intermediate roll 62 or the lower intermediate roll 66 is moved in the rotational axis direction in order to correct the deviation of the plate thickness at both ends in the plate width direction of the material 64 to be rolled. When performing rolling while shifting, one end of the upper and lower intermediate rolls 62 and 66 needs to be aligned with the end of the material to be rolled 64 in the plate width direction. There is a problem in that the pressing force is strongly applied from both the corners of the material 64 to be rolled and the corners of the upper and lower intermediate rolls 62 and 66, so that a strip path is likely to occur in the opposite direction. Therefore, starting from points A and B at which the upper work roll 63 contacts the material 64 to be rolled, and points C and D at which the lower work roll 65 contacts the material 64 to be rolled, respectively, a strip path is generated. .

The present invention has been made in order to solve the problems of the prior art, and more specifically, a work used in continuous rolling of a metal strip such as a steel strip. It is an object of the present invention to provide an apparatus and a method capable of reducing the plate path generated on the surface of the roll.

[0013]

SUMMARY OF THE INVENTION In order to solve the above problems, a work roll path reduction device according to the present invention comprises a pair of upper and lower work rolls which are shiftable in at least the same direction of the rotation axis of the rolling rolls. Depending on the deviation between the roll and the thickness of the metal strip that is the material to be rolled after passing through the work roll, the reduction force exerted on both ends of the work roll in the rotation axis direction can be adjusted respectively. It is characterized in that it is provided in combination with the rolling-down device.

Further, according to the present invention, when a metal strip as a material to be rolled is continuously rolled by at least a pair of upper and lower work rolls among the rolling rolls, the work roll is vertically moved in the same direction as the rotation axis direction. While shifting the pair of work rolls together, according to the deviation of the plate thickness in the plate width direction of the metal strip that is the material to be rolled after passing through the work rolls, rotation of each of the pair of upper and lower work rolls A method for reducing a work path of a work roll, wherein rolling is performed while adjusting a rolling force exerted on both end portions in the axial direction to reduce a work path generated in the work roll.

[0015]

In the work roll path reducing device according to the present invention (hereinafter, simply referred to as "device according to the present invention"),
At least among the rolling rolls, with a pair of upper and lower work rolls that are shiftable in the same direction of the rotation axis, depending on the deviation in the plate width direction of the metal strip after passing through the work rolls, Since a combination of a rolling down device that can adjust the rolling down force exerted on both ends of the work roll in the rotation axis direction is provided in combination, the upper and lower work rolls are both shifted in the same direction during continuous rolling of the metal strip. While rolling, the contact parts with the four corners of the material to be rolled are dispersed in the direction of the rotation axis of the work rolls to disperse and equalize the wear parts generated in the work rolls. The deviation of the plate thickness of the metal strip in the plate width direction due to the non-uniform rolling force in the plate width direction of the rolled material caused by shifting in the same direction of the rotation axis direction Easily and reliably prevented by adjusting the rolling force of.

In the method for reducing the work path of work rolls according to the present invention (hereinafter, simply referred to as "method according to the present invention"), at least a pair of upper and lower work rolls among the rolling rolls are continuously used as the material to be rolled. When rolling the strip, together with shifting the pair of work rolls in the same direction of the rotation axis direction of the work rolls,
According to the deviation of the plate width in the plate width direction of the metal strip after passing the work roll, in order to perform rolling while adjusting the rolling force exerted on both ends of the pair of upper and lower work rolls in the rotation axis direction, The contact parts with the four corners of the rolled material are distributed in the rotation axis direction of the work roll to disperse and equalize the wear parts generated in the work roll, and the upper and lower work rolls are shifted in the same rotation axis direction during rolling. It is possible to easily and reliably prevent the deviation of the thickness of the metal strip in the width direction of the strip due to the non-uniformity of the reduction force in the width direction of the material to be rolled, by adjusting the reduction force of the reduction device. To do.

[0017]

EXAMPLE A case where the apparatus according to the present invention is applied to a four-high rolling mill will be described. FIG. 1 shows a device according to the invention
FIG. 2 is a vertical cross-sectional view showing a configuration of an example when applied to a multi-stage rolling mill, and FIGS. 2 and 3 together show a case where the method according to the present invention is performed by the apparatus according to the present invention shown in FIG. It is a longitudinal cross-sectional view showing the upper and lower work rolls and the material to be rolled.

In FIG. 1, an upper work roll 1 rotatably supported by bearings 7a and 7b and a lower work roll 2 rotatably supported by bearings 8a and 8b are arranged so as to be opposed to each other. The bearings 7a, 7b have shift cylinders 9a, 9
b has shift cylinders 10a, 10 on the bearings 8a, 8b.
b are connected to each other. Shift cylinders 9a, 9
b and the shift cylinders 10a and 10b are actuated in the same direction by the shift signal output from the shift control device 13 to simultaneously shift the upper work roll 1 and the lower work roll 2 in the same direction.

The shift signal is output based on the shift amount and shift timing programmed in advance in the shift control device 13.

An upper backup roll 11 is arranged on the back of the upper work roll 1, and a lower backup roll 12 is arranged on the back of the lower work roll 2. The upper backup roll 11 and the lower backup roll 12 do not shift in the rotation axis direction in this embodiment.

Hydraulic roll-down cylinders 5a and 5b are arranged on the two roll necks on the left and right of the backup roll as part of the roll-down device. The reduction cylinders 5a and 5b are connected to the reduction control device 6, and a reduction signal output from the reduction control device 6 allows independent adjustment of the reduction force exerted on the two roll necks. ,
The pressing force exerted on both ends of the lower work roll 2 in the rotation axis direction is individually adjusted.

Although not shown, the reduction cylinder 5
Each of a and 5b is provided with a hydraulic pressure source for supplying hydraulic oil, a control mechanism for the amount of hydraulic oil supplied, and the like, and a pressure reducing device is configured together with these peripheral devices.

A load cell 4a for detecting a rolling load is provided on two roll necks on the left and right of the upper backup roll 11.
4b is arranged. The detected rolling load is output to the reduction control device 6 as a rolling load signal.

From the reduction controller 6 to the reduction cylinders 5a, 5
The reduction signals output to b are plate thickness gauges (not shown) for measuring the plate thicknesses at both ends in the plate width direction of the material 3 to be rolled, which are provided at the exit sides of the upper work roll 1 and the lower work roll 2, respectively. ), The rolling load signals from the load cells 4a and 4b are added in accordance with the two plate thickness signals output from the above), and the deviation between the two plate thickness signals is determined and output so as to be zero.

The method according to the present invention will be described together with the operation in the case of rolling the material 3 to be rolled by the four-stage rolling mill to which the apparatus according to the present invention having the above structure is applied.

At the start of rolling, the upper work roll 1 and the lower work roll 2 are in the positions shown by the solid lines in FIG. 1, and the upper backup roll 11 and the lower backup roll 11 are given a certain rolling load by the rolling down cylinders 5a and 5b. The material to be rolled 3 is pressed by the rolls 12 and rolled.

When rolling is carried out for a certain period of time shorter than the conventional time from the start of use to roll polishing, the shift control device 1
Shift signals from the shift cylinders 9a, 9b and 1
It is simultaneously output to 0a and 10b. The shift signal is a signal for simultaneously shifting the shift cylinders 9a, 9b and 10a, 10b by a fixed amount in the same direction, and the upper work roll 1 and the lower work roll 2 respectively have bearings 7a, 7b.
And 8a and 8b are simultaneously shifted in the same direction of the rotation axis. In this embodiment, both the upper work roll 1 and the lower work roll 2 are shifted to the right in the drawing and are respectively shifted to the positions indicated by broken lines.

FIG. 2 shows the positional relationship between the upper work roll 1 and the lower work roll 2 and the material 3 to be rolled when the shift is completed. The centers of the upper work roll 21 and the lower work roll 22 in the rotation axis direction are shifted to the right by the shift amount with respect to the center of the rolled material 23 in the plate width direction.

When the rolling is continued in this state, the rolling load applied to both ends of the rolled material 23 in the strip width direction fluctuates due to this shift, and when compared with the left side of the rolled material 23, the rolling load is changed to the right side. Therefore, the rolling load applied to the rolled material becomes large, and there is a possibility that the rolled material 23 that has passed through the upper work roll 21 and the lower work roll 22 may have a deviation in plate thickness at both end portions in the width direction.

In order to prevent this, in the four-high rolling mill to which the device according to the present invention shown in FIG. 1 is applied, the shift of the upper work roll 1 and the lower work roll 2 is started,
The plate thickness at each end of the rolled material 3 in the plate width direction is measured by a plate thickness gauge installed on the exit side of the upper work roll 1 and the lower work roll 2, and two sheets are output from the plate thickness gauge at the end of the shift. A plate thickness signal is output to the reduction control device 6.

In the reduction controller 6, the load cells 4a, 4
Rolling performed at the end of shift by adjusting the rolling force exerted on both ends of the upper work roll 1 and the lower work roll 2 in the rotation axis direction within a range in which the detected value of the rolling load output from b does not exceed the limit value. At this time, the deviation between the two plate thickness signals output from the plate thickness gauge is set to 0.

In this state, if rolling is continued for a certain period of time shorter than the conventional time from the start of use to roll polishing, a shift signal from shift control device 13 is sent to shift cylinders 9a, 9b and 10a, 10b. It is output and the shift cylinders 9a, 9b and 10a, 10b are simultaneously shifted to the left in the drawing by a fixed amount. Therefore, the upper work roll 1 and the lower work roll 2 have bearings 7a and 7b, respectively.
And 8a, 8b are simultaneously shifted in the same direction of the rotation axis by a fixed amount.

FIG. 3 shows the positional relationship between the upper work roll 1 and the lower work roll 2 and the material 3 to be rolled when the shift is completed. The centers of the upper work roll 31 and the lower work roll 32 in the rotation axis direction are shifted to the right with respect to the center of the material to be rolled 33 in the plate width direction by (current shift amount-previous shift amount). For exactly the same reason as described above, unless the amount of reduction exerted on both ends of the upper work roll 31 and the lower work roll 32 in the rotation axis direction is appropriately adjusted, the upper work roll 3
1. There is a possibility that the rolled material 33 that has passed through the lower work roll 32 may have a deviation in plate thickness at both ends in the plate width direction.

In order to prevent this, in the four-high rolling mill to which the device according to the present invention shown in FIG. 1 is applied, the shift of the upper work roll 1 and the lower work roll 2 is started,
The plate thickness gauges installed on the exit sides of the upper work roll 1 and the lower work roll 2 measure the plate thicknesses at both ends in the width direction of the material 3 to be rolled, and two plates output from the plate thickness gauges at the end of the shift. The thickness signal is output to the rolling down control device 6.

In the rolling-down control device 6, the rolling-down force exerted on both ends of the upper work roll 1 and the lower work roll 2 in the rotational axis direction is adjusted in exactly the same manner as described above, and the two plates output from the plate thickness gauge are adjusted. The deviation of the thickness signal becomes zero.

After that, until the next shift signal is output from the shift control device 13, rolling is continuously performed according to the positional relationship among the upper work roll 1, the lower work roll 2 and the material to be rolled 3 shown in FIG. When the next shift signal is output, work roll shift and rolling force adjustment are performed, and this is repeated until the end of rolling.

In this way, when the metal strip, which is the material to be rolled, is rolled by the four-stage rolling mill to which the apparatus according to the present invention shown in FIGS. The plate path generated on the work roll is reduced without causing the plate thickness deviation.

Compared with the prior art in which one of the upper and lower work rolls is shifted in the same direction of the rotation axis based on the deviation of the plate thickness in the plate width direction of the work roll entrance side, FIG. In the apparatus according to the present invention described above, since the upper and lower work rolls 1 and 2 can be periodically shifted at the timing programmed in the shift control device 13, the generation of plate passages on the surfaces of the work rolls 1 and 2 is generated. In addition to significantly reducing the degree, it is less likely to cause conveyance defects such as meandering on the material to be rolled, and it is easy to ensure the plate thickness accuracy of the product.

[0039]

[Modification] The apparatus according to the present invention described with reference to FIGS. 1 to 3 is merely an example of the present invention, and the present invention is not limited thereby.

For example, in the four-high rolling mill to which the apparatus according to the present invention shown in FIGS. 1 to 3 is applied, the backup roll has a structure which does not shift in the rotational axis direction.
If the work roll is shifted in the rotation axis direction as a shiftable structure, the force required for the work roll shift can be reduced, and the occurrence of roll scratches between the work roll and the backup roll can be prevented.

On the contrary, when only the work roll is shifted, the roll crown can be easily adjusted.

In the above embodiment, the work rolls are shifted during rolling. However, the work rolls may be shifted during a stop of the rolling mill between lots without shifting in a certain lot. If shifting is performed when the rolling mill is stopped, there is no fear of conveyance defects such as meandering of the material to be rolled.

The apparatus according to the present invention may be applied to a multi-stage rolling mill other than the 4-stage rolling mill. In this case, not only the work rolls but also the backup rolls and other rolling rolls such as intermediate rolls may be shifted.

The constituent elements may be modified within the scope of the present invention.

[0045]

As described above, the device according to the present invention is
Depending on the deviation of the plate thickness in the plate width direction of the metal strip that is the material to be rolled after passing through the work rolls, a pair of upper and lower work rolls that are shiftable in at least the same direction of the rotation axis of the rolling rolls. Since the work roll is provided in combination with a reduction device that can adjust the reduction force exerted on both ends of the work roll in the rotational axis direction, the work roll can be formed without deviation of the plate thickness at both ends of the metal strip in the plate width direction. It is possible to reduce the board path that occurs in the.

Further, according to the method of the present invention, when the metal strip, which is the material to be rolled, is continuously rolled by at least a pair of upper and lower work rolls among the rolling rolls, A pair of upper and lower work rolls are both shifted in the same direction, and a pair of upper and lower work rolls are rotated in accordance with the deviation in the plate width direction of the metal strip that is the material to be rolled after passing through the work rolls. Rolling can be performed while adjusting the rolling force exerted on both end portions in the axial direction to reduce the plate path generated in the work roll.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing the configuration of an embodiment in which the apparatus according to the present invention is applied to a four-high rolling mill.

FIG. 2 is a vertical cross-sectional view showing upper and lower work rolls and a material to be rolled when a method according to the present invention is carried out by the apparatus according to the present invention shown in FIG.

FIG. 3 is a vertical sectional view showing the upper and lower work rolls and a material to be rolled when the method according to the present invention is carried out by the apparatus according to the present invention shown in FIG.

FIG. 4 is a vertical cross-sectional view in a plane orthogonal to the rolling direction, in which the bending of the work roll is enlarged to clarify the state of the rolling force received by the work roll from the work roll during rolling.

FIG. 5 is a side view of a work roll in which two plate paths are generated on the surface.

6 (a) and 6 (b) are both explanatory views showing an outline of so-called shift mill technology.

[Explanation of symbols]

 1 Upper work roll 2 Lower work roll 3 Rolled material 4a, 4b Load cell 5a, 5b Reduction cylinder 6 Reduction control device 7a, 7b Bearing 8a, 8b Bearing 9a, 9b Shift cylinder 10a, 10b Shift cylinder 11 Upper backup roll 12 Lower backup Roll 13 Shift control device 21 Upper work roll 22 Lower work roll 23 Rolled material 31 Upper work roll 32 Lower work roll 33 Rolled material 40 Rolled material 40a-40d Corner 41 Upper work roll 42 Lower work roll 50 Work roll 51 , 52 plate road 61 upper backup roll 62 upper intermediate roll 63 upper work roll 64 upper work roll 65 lower work roll 66 lower intermediate roll 67 lower backup roll 68 bending device 69 bending device 70 load cell 7 1 load cell

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location B21B 37/62 8315-4E B21B 37/00 145 Z

Claims (2)

[Claims] 1. A pair of upper and lower work rolls of the rolling rolls that are shiftable at least in the same direction of the rotation axis direction, and a plate in the plate width direction of a metal strip that is a material to be rolled after passing through the work rolls. A work roll path reduction device comprising a combination of a reduction device that is capable of adjusting a reduction force applied to both ends of the work roll in the rotation axis direction in accordance with a deviation in thickness. 2. When a metal strip, which is a material to be rolled, is continuously rolled by at least a pair of upper and lower work rolls among the rolling rolls, a pair of the upper and lower work rolls in the same direction as the rotation axis direction of the work rolls. While shifting the rolls together, depending on the deviation of the plate thickness in the plate width direction of the material to be rolled after passing through the work rolls, both ends in the rotation axis direction of the pair of upper and lower work rolls. A rolling path reducing method for a work roll, which comprises rolling while adjusting a rolling force exerted on a portion to reduce the rolling path generated in the work roll.