JP2005152942A - Shape detection method for cold rolled sheet and shape control method in multi-stage rolling mill - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect a precise sheet shape by correcting a shape detection signal in a sheet edge portion during cold-rolling of a flat sheet, and to control the shape from the sheet shape detection data so as to manufacture the rolled sheet of the target shape in a superior shape precision and in a high productivity. <P>SOLUTION: When each segment 21 of a shape detection roll 20 detects a load received from a rolling sheet and detects the shape of the rolled sheet by treating the detection signal, the detection signal, from a sensor corresponding to the segment 21 whose entire face is not covered by the rolled sheet, is treated correcting the signal using a sheet covering ratio (A/B) of the segment and thus the sheet shape under rolling is detected. The detected shape is compared with the target shape and a sheet shape control means is adjusted so that the sheet shape approximates to the target shape. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method of accurately detecting a plate shape accurately and controlling automatically so as to obtain a target shape after rolling when cold rolling is performed mainly on a thin plate having a thickness of 1 mm or less by a multi-stage rolling mill.

Improving the quality and production efficiency of the rolled material is an important factor for cost reduction. Therefore, various rolling control methods have been developed while increasing the number of rolling mills. As one of the multi-stage rolling mills, a 20-stage Sendier mill is widely known.
For example, as shown in FIG. 1, the 20-stage Sendia mill 10 includes a pair of opposed work rolls 11u and 11d, a total of four first intermediate rolls 12u and 12d that are in contact with the respective work rolls 11u and 11d, and a first A total of six second intermediate rolls 13u, 13d in contact with the intermediate rolls 12u, 12d and a total of eight backup rolls 14u, 14d, 15u, 15d in contact with the second intermediate rolls 13u, 13d. Of the eight backup rolls 14u, 14d, 15u, and 15d, the two backup rolls 15u located at the center of one side have a crown adjusting mechanism. The first intermediate rolls 12u and 12d are tapered at one edge portion of the roll, and are movable in the plate width direction of the rolled material M. By adjusting the crown adjustment mechanism of the backup roll 15u and the shift amount of the first intermediate rolls 12u and 12d, the shape of the rolled material M is controlled.

Various methods have been proposed regarding a mechanism for adjusting the crown of the backup roll 15 u and a method for adjusting the shift amount of the first intermediate rolls 12 u and 12 d for controlling the shape of the rolled material M.
The present applicant also proposed a method for setting or correcting the crown adjustment amount and the intermediate roll shift position of the backup roll in Patent Documents 1, 2, 3, and 4 as a method for controlling the plate shape.

  By the way, even if the above-described control method is adopted, first, it is necessary to know the plate shape more accurately. Various methods have been proposed as a method for detecting the shape of the rolled material. For example, in Patent Document 5, a shape detection roll having a plurality of sensors that are shifted by a predetermined angle in the rotational direction and arranged at a predetermined interval in the axial direction is brought into contact with the rolled material, and the speed of the rolled material Rotating in synchronization with each other, detecting the load received by each sensor from the rolled material, and processing the detection signal to detect the shape of the rolled material, There has been proposed a method for correcting the tension of the material and detecting a more accurate shape. Moreover, in patent document 6, when detecting the load which each sensor receives from the said rolling material, and processing this detection signal and detecting the shape of the said rolling material, of the rolling material which passes the said shape detection roll There has been proposed a method of obtaining a displacement in the plate width direction and correcting the shape based on the displacement to detect a more accurate shape.

JP 2001-137925 A JP 2001-269706 A JP 2003-48008 A JP 2003-48009 A Japanese Patent Laid-Open No. 11-201745 JP 2001-317932 A

However, even if the plate shape is accurately detected by the methods described in Patent Documents 5 and 6 and the plate shape control is performed by applying the methods proposed in Patent Documents 1 to 4, the control is not necessarily performed with high accuracy. Can't do it.
During actual cold rolling, slippage occurs due to deviations in the sheet passing position of the material to be rolled, fluctuations in the sheet width, or from slight deviations in the sheet passing direction of the roll shaft, and from the slight differences in the surface hardness and surface roughness of the sheet material. Since the plate edge position fluctuates due to or meandering, the actual plate shape may not match the detected shape. For this reason, even if the shape control method proposed in Patent Documents 1 to 4 is applied, accurate shape control cannot be performed.

In particular, when a thin plate having a thickness of 1 mm or less is to be cold rolled, it is necessary to make it into an ear plate shape to prevent the plate from breaking. However, depending on the degree of the shape of the ear plate or the balance between the left and right, there may be a case where a rolling trouble occurs due to breakage or narrowing. For this reason, it is difficult to automatically control the rolling shape.
The present invention has been devised to solve such problems. Even when a thin plate material is cold-rolled, an accurate plate shape is detected by edge correction, and the plate shape detection is performed. An object of the present invention is to provide a control method capable of manufacturing a rolled material having a target shape based on data with high shape accuracy and high productivity.

In order to achieve the object of the method for detecting the shape of a cold-rolled sheet material of the present invention, a plurality of segments each provided with a sensor are arranged with a predetermined angle shift in the rotation direction of the sensor and a predetermined interval in the axial direction. The shape detection roll is brought into contact with the rolled material and rotated in synchronization with the speed of the rolled material, the load received by each sensor from the rolled material is detected, the detection signal is processed, and the rolling material When detecting the shape, the detection signal of the sensor in which the rolled material does not cover the entire surface of the segment is corrected by the steel plate coverage of the segment and processed.
The shape control method in the multi-high rolling mill of the present invention is characterized in that the plate shape obtained by the above method is compared with the target shape, and the plate shape control means is adjusted so that the plate shape approximates the target shape. And

According to the present invention, the shape of the edge of the plate is corrected, so that conventionally, cold rolling with significantly improved accuracy compared to the shape detection in which the edge shape detection is not reflected without reflecting the load at the edge of the plate. A shape detection method for a plate material can be provided.
By adopting this shape detection method, the plate shape can be adjusted to the target shape by applying the normal plate shape control means and adjusting the elongation of the desired part while contrasting with the target plate shape. .

  In general, the shape detection roll is configured such that a plurality of segments each having a load sensor are incorporated on one axis at predetermined intervals in the axial direction and shifted by a predetermined angle in the rotational direction. And each segment is rotated in synchronization with the speed of the rolled material while contacting the rolled material, the load received from the rolled material by the sensor of each segment is detected, the detection signal is processed, and the shape of the rolled material Is intended to detect. For example, in a detection roll having an effective measurement width of 1300 mm, 25 segments each having a width of 52 mm are combined in the axial direction. Furthermore, the load received from the rolled material is set so as to be displayed only when the rolled material is in contact with the entire width direction of the specific segment, that is, the entire width of the 52 mm width. For this reason, in the conventional detection method, a dead zone occurs with a maximum width of 52 mm. That is, since the both ends of the material to be rolled do not contact the full width of the specific segment, the shape of the edge is not recognized correctly.

Therefore, in the present invention, in order to minimize the dead zone, the segment in contact with the end of the plate is also set as the detection target segment, and edge correction is introduced based on the steel plate coverage of the segment.
It is intended to calculate the elongation (shape) of the plate edge based on the value obtained by multiplying the segment detection value of the plate edge where the steel plate is only partially in contact with the separately calculated steel plate coverage. .
The “steel sheet coating amount” in this specification means a width in which a cold-rolled steel sheet contacts a specific segment 21 of the detection roll 20 as shown in FIG. Therefore, the “steel plate coverage” is the ratio of the width of the steel plate in contact with the segment width. When the steel plate coverage (A) and the segment width (B) are expressed as shown in FIG. 2, the steel plate coverage (%) is ( A / B) × 100.

  For example, when rolling a coil with a width of 1000 mm, if the coil is set and running at the center of a rolling mill and a shape detection roll, the shape detector with a width of 1300 mm, in which 25 segments with a width of 52 mm are combined, 19 It will run on each load detection segment, and both ends of the coil are in contact with each of 6 mm of 52 mm wide segments. (6/52) × 100 is the steel plate coverage at this time, and the plate end shape can be recognized together with the load detection value detected in the segment in contact with the coil end.

By the way, when it is going to correct | amend the plate | board shape of the both ends of an actual coil in consideration of the said steel plate coverage, if the amount of steel plate coverage is small, the accuracy of the load detection value of a segment will become low. It is presumed that the accuracy of the load detection value falls because it is easily affected by the crown of the steel plate, fluctuation of the plate width, and plate displacement. Therefore, in the coil end shape correction in the shape detector using the 52 mm width segment, the edge correction is introduced when the steel sheet covering amount is 20 mm or more, that is, the steel sheet covering ratio is 38% or more. Is preferred.
That is, the steel plate coverage or the steel plate coverage of the coil both plate end segments is calculated, and when the steel plate coverage or the steel plate coverage is 20 mm or more or 38% or more, the load detection value of the plate end segment is determined as the steel plate coverage. Accordingly, the load value at the plate end is obtained, the difference in elongation is converted from the difference from the load detection value of the other segment, and the plate end shape is further corrected.

  Specifically, it is as follows. That is, when the material M to be rolled as shown in FIG. 3A is placed on the shape detection roll 20 after cold rolling, the load value is detected at each segment 21. When the overall load distribution value is displayed by adding the shape correction term of the plate edge to the detected value of each segment 21, it is as shown in FIG. From this load distribution, when the difference in elongation rate is converted by a normal method and the shape is displayed by the deviation of the elongation rate at each part, the shape is displayed as shown in FIG.

After detecting a more accurate plate shape by such a method, the cold rolling mill is controlled so as to obtain a desired plate shape.
The target shape of the rolled sheet varies depending on the characteristics and thickness of the steel, the usage mode, or the characteristics of the rolling mill. A flat shape is not necessarily preferable. Depending on the mode of use thereafter, medium elongation, ear waves, and edge elongation may be preferable. For example, when trying to cold-roll a high carbon hard material as described above to a plate thickness of 1.0 mm or less, the edge portion of the material to be rolled is likely to be cracked, and the plate crack is generated from that portion, thereby causing a rolling trouble. Easy to wake up. For this reason, it is preferable to obtain a so-called edge-shaped plate having a shape as shown in FIG.

  For example, as described above, in order to obtain a plate having an elongated shape as shown in FIG. 4 from the rolling conditions that can obtain the shape as shown in FIG. The elongation rate of each part is adjusted so that both shapes are approximated as much as possible by controlling the shape actuator such as the control of the shift amount of the intermediate roll 30 as shown and the control of the split backup roll reduction device (not shown). A known method is adopted as the adjustment method itself. In FIG. 5, M is a rolled material and 32 is a work roll.

As described above, in the conventional method, the detection load of the segment of the plate shape detector on which the plate end is placed is not taken into consideration, that is, the shape is displayed in a form excluding the shape of the end, The shape is controlled based on the shape display. On the other hand, in the present invention, since the detection load of the segment of the detector on which the plate end is placed is also corrected and utilized for measurement of the plate shape, the plate end shape is accurately grasped and the accuracy is high. The plate shape can be detected and displayed.
In the shape control method in the multi-high rolling mill of the present invention, the shape of the end portion is also taken into consideration. Therefore, even if the plate end position varies somewhat due to deviations in the plate passing position of the material to be rolled, fluctuations in the plate width, side slip or meandering, the plate shape is less than the conventional method in which the plate end shape is not considered. Control can be performed with high accuracy. Furthermore, when trying to cold-roll a thin plate of a high hardness material, smooth cold rolling can be performed without causing rolling troubles such as plate breakage.

The SK5 material was used as a test material, and a cold-rolled annealed plate having a thickness of 2.0 mm and a width of 932 mm was finished and cold-rolled in 9 passes to a finished thickness of 0.52 mm using a 20-stage Sendier mill.
The plate shape at this time was measured using a detector in which 25 detection segments with a width of 52 mm were combined. The number of detected segments covered by the cold-rolled plate is 932 / 52≈17.92, and the number of segments completely covered is 17. Of the 25 segments, the central 17 segments are completely covered, and the segments on both sides are covered with {(932-52 × 17) / 2} / 52 × 100 = 46%. It will be covered.

FIG. 6 shows the detected shape of the stable portion detected by 17 segments. In FIG. 6, the actual measurement shape measured using a commercially available flatness meter is also displayed.
In addition, this actual measurement shape takes the sample of the same longitudinal direction position as the detection shape of a longitudinal direction position about the same rolling material, and mounts the said steel plate sample on a flat table, on it, it is XY. It is measured by moving the laser in a two-dimensional direction. According to a conventional method, the actual measurement shape is obtained by measuring changes in the swell (ear wave) height and the like of the steel plate by the above-described method, converting this measurement value into a steepness, and further, generating a width direction deviation (I-Unit). ).

Even if the rolled material is the same, the measurement location in the longitudinal direction is different, so the detected shape and the actual measurement shape are slightly different, but the overall profile is well matched.
Furthermore, the segments on both sides of the 17 segments each have a coverage of 46%. Edge correction values converted to width direction deviations (I-Units) by applying a correction based on the coverage to the loads detected in the segments 4 and 22 are indicated by ▲ on both sides in FIG. It can be seen that it is very close to the actual measured shape.

  About the said finish cold-rolled material, after performing shape control like Example 2 mentioned later, the detected shape in the state of edge correction | amendment off and on was separately displayed as FIG. 7, FIG. In FIG. 8, the shape value based on the detection value in each segment is shown as a bar graph, and each bar at both ends is a shape value obtained by edge-correcting the detection value. When the edge correction is off, one of the bars at both ends in FIG. 8 is not detected. However, the actual rolling shape is an ear wave shape from the position in the width direction toward the plate edge, and this portion cannot be detected by the edge correction off, and is a so-called dead zone. When comparing FIG. 7 and FIG. 8, it can be seen that the detection accuracy is remarkably improved by introducing the edge correction.

FIG. 9 shows detected shape values in the edge correction on state at a specific time when the same specimen as used in Example 1 is finish-rolled without performing shape control in the same manner. The target shape is also shown.
Comparing the two, it can be seen that, at this point, the detected shape on the Ws side has not obtained a desired elongation with respect to the target shape.
Since the shape deviation between the detected shape and the target shape is mostly insufficient on the Ws side, the automatic shape control in this case shifts the first intermediate roll to the Ws side so that the end of the Ws plate becomes the extended shape. It is judged and commanded as follows.
FIG. 10 shows the detected shape when rolling is performed by correcting the shape by the automatic shape control described above.
It can be seen that when the shape is corrected by performing automatic shape control with the edge correction turned on, a rolled shape close to the target can be obtained.

Schematic diagram of 20-stage Sendier rolling mill The figure explaining “the amount of covering” and “the covering ratio” of the present invention The figure explaining the aspect which detects plate shape with a shape detection roll Diagram explaining the target edge stretch shape of the plate The figure explaining the situation which shifts an intermediate roll with respect to a material to be rolled and a work roll The figure explaining the difference between the detected shape and the actual measured shape in the example Diagram explaining the detected shape when edge correction is not performed A diagram for explaining the relationship between the detected shape and the target shape when edge correction is performed Example of detected shape when shape control based on edge correction is not performed A diagram for explaining the relationship between a detected shape and a target shape when shape control based on edge correction is performed

Claims (2)

  A plurality of segments each having a sensor are shifted in the rotation direction of the sensor by a predetermined angle and a shape detection roll arranged at a predetermined interval in the axial direction is brought into contact with the rolled material and synchronized with the speed of the rolled material. When the sensor receives the load received from the rolled material by each sensor and processes the detection signal to detect the shape of the rolled material, the rolled material does not cover the entire surface of the segment. The shape detection method of the cold-rolled board | plate material characterized by correct | amending this detection signal with the steel plate coverage of a segment, and processing it.   A plurality of segments each having a sensor are shifted by a predetermined angle in the rotation direction of the sensor and a shape detection roll arranged at a predetermined interval in the axial direction is brought into contact with the rolled material and is synchronized with the speed of the rolled material. When the sensor receives the load received from the rolled material by each sensor and processes the detection signal to detect the shape of the rolled material, the rolled material does not cover the entire surface of the segment. The detection signal is corrected with the steel plate coverage of the segment and processed to detect the plate shape during rolling, and the detected shape is compared with the target shape so that the plate shape approximates the target shape. A shape control method in a multi-high rolling mill characterized by adjusting a control means.

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