JP2921779B2 - Asymmetric rolling compensating rolling mill - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling mill, and more particularly to a rolling material such as a hot-rolled steel strip and a rolling mill which is prevented from being bent and rolled.

[0002]

2. Description of the Related Art The meandering of a material to be rolled on a rolling line not only lowers the accuracy of the product, but also damages the rolling mill and its ancillary equipment, and efforts have been made to eliminate this.

[0003] The meandering of the material to be rolled is largely due to the left-right asymmetric rolling of the building, and the left-right asymmetric rolling is attributed to the roll position accuracy.

[0004] For this reason, conventionally, efforts have been made to maintain and manage the machine accuracy within an appropriate range by maintaining the mechanical device that determines the roll position accuracy.

In order to prevent bending and meandering of the steel strip, the meandering amount (displacement between the mill center and the steel strip center) and the direction of the steel strip are measured on the entry side (or immediately below) of the rolling mill, and the shift amount is measured. There is a control method for appropriately changing the difference between the left and right roll opening degrees according to the direction.

As disclosed in JP-A-59-229221, the amount of bending (or upright bending) of the steel strip on the entry side of the rolling mill and the amount of wedge of the steel strip (thickness in the width direction of the steel strip). Distribution, indicating the thickness difference between both ends of the steel strip)
There has been a control method of appropriately changing the difference between the left and right roll opening degrees according to the amount of bending and the amount of wedge, or a method of using a side guide that supports the steel strip from the left and right in addition to this control method.

Further, as disclosed in Japanese Patent Application Laid-Open No. 55-45533, a specific shape parameter value is detected from the shape of the steel strip on the exit side of the rolling mill when controlling the shape of the steel strip during rolling. In some cases, these parameters are adjusted using an intermediate roll and a roll bending adjusting device based on the parameter values. Here, the rolling-down device is used exclusively for adjusting asymmetrical shape defects.

In applying such a shape control technique, control of roll position accuracy is very important. For example, as disclosed in Japanese Utility Model Laid-Open Publication No. 59-110107, a clearance between a rolling mill housing and a roll chock is disclosed. Since there is only a monitoring device, it is very difficult to apply the shape control technology.

[0009]

According to the prior art described above, the bending, uprightness, wedge amount, etc. of the material to be rolled on the entry side of the rolling mill are measured, and the left and right rolls of the rolling mill roll are opened according to the size. In the method of controlling the difference in degree, there is no means for confirming that the rolling mill is controlled by the target control amount, and particularly when the roll axial direction position is vertically asymmetric, the target roll opening There is a problem that an error occurs in the roll opening difference by an amount that is asymmetric with respect to the degree.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and even when the position of a roll in the roll axis direction is asymmetric, a correction in accordance with an error amount due to the asymmetry is performed by the left and right roll opening control. In addition to the above, an object of the present invention is to provide an asymmetric rolling compensating rolling mill capable of achieving a target control amount.

[0011]

SUMMARY OF THE INVENTION The present invention provides a roll position sensor for detecting the displacement of each roll including a work roll in the direction of the roll axis within a gap in terms of machine accuracy, and a method for detecting the displacement of the rolls based on the detected values of these roll position sensors. A calculating device for calculating the asymmetry of the axial position of the roll, and calculating, based on the calculation result, the difference between the left and right roll openings for performing the same rolling as when the roll position is symmetrical, The above object is achieved by an asymmetric rolling compensating rolling mill comprising: a left and right roll opening control device for giving a difference between the left and right roll opening degrees to a roll based on a calculation result of the device.

[0012]

In the present invention, the axial position of each roll of a rolling mill is detected by a roll position sensor, and the roll opening difference is self-corrected by an arithmetic unit based on the detected value, so that the roll position is symmetric. The same symmetric rolling as in the above case can be performed.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

This embodiment, as shown in FIGS. 1 and 2, is an asymmetric rolling compensating rolling mill 1 according to an embodiment of the present invention.
Numeral 0 denotes a 6-high rolling mill, and upper and lower work rolls 1
2, 14; upper and lower intermediate rolls 16 and 18; and upper and lower backup rolls 20 and 22.

Each of the rolls is supported by an operation-side roll chock 12A,... 22A and a drive-side roll chock 12B,.

Further, roll position sensors 12C to 22C for detecting the axial position of each of the rolls on one of the operation side and the drive side are arranged, respectively.

The operation side roll chocks 12A to 22A
The roll-down position of each of the drive-side roll chocks 12B to 22B is adjusted by a drive-side pressure reducer 26, and the drive-side pressure reducer 26 is adjusted.

The output signals of the roll position sensors 12C to 22C are input to the arithmetic unit 28, respectively.

The arithmetic unit 28 calculates the asymmetry of the axial position of the roll on the basis of the detection values of the roll position sensors 12C to 22C. Calculate the difference between the left and right roll opening for rolling as described above, and based on this result,
The operation-side pressing-down device 24 and the driving-side pressing-down device 26 are driven to give a difference in the roll opening degree between the right and left rolls.

Specifically, the work rolls 12, 1
4. Intermediate rolls 16, 18 and backup roll 2
The positions of the rolls 0 and 22 in the roll axis direction are directly measured by the roll position sensors 12C to 22C, and the error in which the position of each roll in the roll axis direction deviates from the point symmetric position is obtained.
The amount of change in roll opening difference at the time of rolling the steel sheet caused by the error amount and direction is predicted and calculated by the arithmetic unit 28, and the roll opening difference opposite to the expected change value is corrected in order to correct the predicted value of change in roll opening difference. Move the roll opening difference in advance with the difference correction amount,
It is intended to suppress the occurrence of a difference in roll opening between the left and right sides during rolling of a steel sheet, and to roll a straight steel sheet.

Also, the bending amount of the steel sheet on the entry side,
The meandering amount, and also when obtaining a straight steel plate by roll opening correction control according to the wedge amount, similarly to the above, by correcting the roll position asymmetry amount by the roll opening difference correction amount, a predetermined amount Control objectives can be achieved.

As shown in FIG.
A, 1B, a 6-high rolling mill 1 including intermediate rolls 2A, 2B and backup rolls 3A, 3B.

When the work roll shift mechanism 4A, 4B and the intermediate roll shift mechanism 5A, 5B are provided in such a six-high rolling mill 1, the roll chocks 3C, 3D of the backup rolls 3A, 3B are moved in the roll axis direction. There are mechanical gaps S4, S5, S6 in the roll chock keeper device 6, the work roll shift mechanisms 4A, 4B and the intermediate roll shift mechanisms 5A, 5B, respectively. For this reason, when the upper intermediate roll 2A is shifted to the drive side and the lower intermediate roll 2B is shifted to the operation side, even if the operation amounts of the upper and lower intermediate roll shift cylinders 7A and 7B are the same in the opposite direction, each roll choke is not required. Are displaced by the amount of the mechanical gap, the symmetry of the roll position is broken as a whole, and the steel sheet 8 is rolled asymmetrically as shown in the figure. As a result, the steel sheet 8 may be bent. State.

In this embodiment, as shown in FIG. 3, all rolls are rolled symmetrically in a correct position, that is, in a state where there is no roll shift.

Next, as shown in FIG. 4, when the lower intermediate roll 18 is shifted to the driving side, the symmetry of the roll position is broken, and the steel sheet is rolled asymmetrically in the left and right direction, causing bending.

That is, when the lower intermediate roll 18 is displaced to the drive side as shown in FIG. 4, the surface pressure distribution between the rolls is larger on the operation side on the lower side and smaller on the drive side, and conversely on the upper side. The driving side is large and the operating side is small,
The distribution of the surface pressure applied to the steel plate is asymmetrical in the left-right direction, which is large on the driving side and small on the operation side, and as a result, a difference between the left and right roll opening degrees is generated.

To cope with this, the axial position of each roll is detected by the roll position sensors 12C to 22C, and the roll opening difference generated from the axial position error is calculated by the arithmetic unit 28. By operating the operation-side pressure reduction device 24 and the drive-side pressure reduction device 26 based on the opening degree difference predicted value,
The roll opening difference prediction value is corrected.

More specifically, as shown in FIG. 5, the rolling amount on the operation side of the roll is made larger than that on the drive side so that the roll opening is parallel to the left and right during rolling on the drive side.

In this embodiment, as described above, when the roll position asymmetry based on the mechanical gap in the roll shift device and the keeper device occurs, this is detected by the roll position sensor, and the roll position asymmetry amount is detected. In this case, since the roll opening difference is corrected in accordance with the condition (1), it is possible to perform symmetrical rolling of the steel sheet in the same state where the roll position is symmetric.

Also, by adjusting the operation of the pack amount, a certain amount of mechanical clearance is allowed in each roll chock, so that it is not necessary to repair the machine accuracy at a large repair cost as in a conventional rolling mill. In addition, the precision of the machine that must be maintained is lower than before, and the repair cost of the machine can be reduced.

In the above embodiment, the present invention is applied to a six-high rolling mill. However, the present invention is not limited to this, and can naturally be applied to a four-high rolling mill. .

[Brief description of the drawings]

FIG. 1 is a front view including a partial block diagram showing an embodiment of an asymmetric rolling compensating rolling mill according to the present invention.

FIG. 2 is a schematic sectional view showing a roll arrangement of the asymmetric rolling compensating rolling mill according to the embodiment.

FIG. 3 is a diagram showing a surface pressure distribution between rolls during symmetric rolling in a state where each roll is parallel.

FIG. 4 is a diagram showing an inter-roll surface pressure distribution when a lower intermediate roll is shifted to a driving side;

FIG. 5 is a diagram showing an inter-roll surface pressure distribution in a state where the displacement of the intermediate roll is compensated for by the present invention.

FIG. 6 is a schematic cross-sectional view showing a state where rolls are shifted in a conventional six-high rolling mill.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Asymmetric rolling compensating rolling mill 12, 14 ... Work roll 16, 18 ... Intermediate roll 20,22 ... Backup roll 12A ... 22A ... Operation side roll chock 12B ... 22B ... Drive side roll chock 12C-22C ... Roll position sensor 24 ... operation side pressure reduction device 26 ... drive side pressure reduction device 28 ... calculation device

Claims (1)

(57) [Claims] 1. A roll position sensor for detecting a displacement of each roll including a work roll in a roll axis direction within a gap on a mechanical accuracy, and an asymmetrical position of the roll in the axial direction based on a detected value of the roll position sensor. And a calculation unit for calculating the difference between the left and right roll opening degrees for performing the same rolling as in the case where the roll position is symmetrical, based on the calculation result, and a roll based on the calculation result of the calculation device. Roll compensating rolling mill, comprising: a left and right roll opening control device for giving a left and right roll opening difference to each other.