JP2008229723A - Rolling control method and rolling control apparatus - Google Patents

Abstract

【Task】
Conventionally, it has been difficult to perform rolling that achieves both edge drop quality and prevention of roll marks on the plate surface due to scratches on the roll at the plate edge.
[Solution]
WR is divided into several virtual regions in the width direction, the plate end is integrated with the rolling length at that position, and within the WR shift region where the edge drop does not exceed the allowable value, the above integrated value is a certain value. The WR shift position is determined so as not to use the region beyond the limit.
【effect】
Both edge drop quality and plate surface quality can be achieved. Furthermore, since the life of the roll itself can be extended, it is possible to reduce the cost for the roll and increase the production amount by reducing the time for roll replacement.
[Selection] Figure 1

Description

  The present invention relates to a rolling control method and apparatus.

  In general, in rolling control, in order to prevent the thickness of the rolled material at the end in the sheet width direction from falling, the edge drop amount measurement value is compared with the target edge drop amount setting value of the steel plate, Based on the comparison calculation value, shift control in the sheet width direction of the work roll of the rolling mill is performed. Such a technique is described in, for example, JP-A-60-12213.

Japanese Patent Laid-Open No. 60-12213

  In such work roll control, when the edge drop control is stabilized, the work roll shift position is not changed. If the roll shift position remains constant, a local force due to the plate end is continuously applied to the portion of the roll surface where the plate end abuts, so that streaks are gradually attached. A so-called roll mark transfer occurs in which the scratched portion of the roll is transferred to the rolled material from the end of the plate, and the surface quality of the plate is deteriorated.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a device capable of suppressing deterioration of surface quality even in edge drop control.

  In order to achieve the above object, the present invention is configured to integrate the work situation by specifying the region of the rolling roll corresponding to the vicinity of the end in the sheet width direction of the material to be rolled.

  Preferably, a storage area in which the roll is divided into several virtual areas in the width direction is provided, and the rolling length at which the plate end portion is located in that area is integrated for each area, and the area is attached by the integrated value. When determining the roll mark level and controlling the roll shift position with edge drop control, shift so that the area where the measured value exceeds a certain value is not used within the shift area that satisfies the allowable range of edge drop. This can be achieved by determining the position.

  Preferably, the work roll is divided into several virtual regions in the width direction, the rolling lengths at which the plate ends are located are integrated, and the integration is performed within the work roll shift region where the edge drop does not exceed the allowable value. The shift position of the work roll is determined so as not to use an area where the value exceeds a certain value.

  According to the present invention, it is possible to suppress the deterioration of the surface quality.

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

  FIG. 1 shows an embodiment of an edge drop control device for a rolling mill to which the present invention is applied. The rolled material 15 is rolled to a desired thickness by the rolling mill stand 1. Details of the rolling mill stand 1 are shown in FIG. An upper work roll 111 and a lower work roll 112 (the upper work roll 111 and the lower work roll 112 are collectively referred to as the work roll 11) are provided across the material 15 to be rolled. Each of the upper work roll 111 and the lower work roll 112 has a taper at the end in the plate width direction. For example, the taper of the upper work roll 111 is provided at the right end, the taper of the lower work roll 112 is provided at the left end, and the taper of the upper work roll 111 and the taper of the lower work roll 112 are opposite to each other. Provide. By providing in this way, edge drop control becomes possible at both ends in the sheet width direction of the material to be rolled.

  The upper work roll 111 and the lower work roll 112 are sandwiched between the upper intermediate roll 121 and the lower intermediate roll 122 (the upper intermediate roll 121 and the lower intermediate roll 122 are collectively referred to as the intermediate roll 12). A backup roll 131 and a lower backup roll 132 (the upper backup roll 131 and the lower backup roll 132 are collectively referred to as the backup roll 13) are provided.

As shown in the figure, the edge drop control device of the embodiment is provided with an edge drop detector 3 installed on the exit side of the rolling mill stand. The edge drop detector 3 calculates the deviation between the plate thickness at the edge drop evaluation point (for example, a position 10 mm from the plate end) and the plate thickness at the plate center (for example, a position 100 mm from the plate end) shown in FIG. To detect. In response to the deviation between the edge drop value measured by the edge drop detector and the target edge drop determined by the target edge drop setting device 5, the edge drop control output computing device 4 converts the edge drop control output to the work roll shift 11 It is calculated as the shift amount. The shift amount (WR shift amount) of the work roll 11 is calculated as the operation side of the distance (ΔW _S ) from the taper start portion of the upper work roll 111 to the end of the material 15 as shown in FIG. The distance (ΔW _D ) from the taper start portion of the work roll 112 to the end portion of the material 15 to be rolled is calculated as the drive side. The rolling length accumulation device 7 for each WR area accumulates the rolling length for each virtual area in the width direction. The WR oscillation output calculation device 8 calculates a work roll oscillation amount ΔW _OC for changing the work roll shift amount (ΔW) based on the integrated value. The edge-up determination device 10 determines a state (edge up) in which the plate thickness at the plate end is thicker than other portions based on the edge drop detection value. The edge-up removal WR shift amount calculation device 11 calculates the work roll shift amount ΔW in order to remove the edge-up. The WR shift control output determining device 9 determines the final control output based on the outputs of the edge drop control output calculating device 4, the WR oscillation output calculating device 8 and the edge up removal WR shift amount calculating device 11. Thereby, the WR shift control device 6 controls the rolling mill stand 1. Details of the edge drop control output computing device 4 will be described.

  The edge drop control of the six-stage rolling mill stand 1 will be described as an example. The edge drop control output computing device 4 performs edge drop control in the rolling mill, and detects the edge drop amount on the delivery side of the rolling mill (plate thickness drop at the end of the plate) from the detection signal from the edge drop detector 3; The amount of operation of the actuator of the rolling mill is calculated according to the difference from the target edge drop given from the target edge drop setting device 5, and the edge drop is controlled. In a 6-stage rolling mill, this actuator has (1) work roll 11 (hereinafter referred to as WR) shift and (2) intermediate roll 12 (intermediate roll; hereinafter referred to as IMR) shift. Controls the amount of edge drop. The WR shift of the work roll 11 and the IMR shift of the intermediate roll 12 are functions for changing the position of the roll in the axial direction. As shown in FIG. 2, the roll one end is tapered (tapered) in advance, so by changing the axial position of the roll, the taper (taper) start point of the roll with respect to the rolled material is changed, Edge drop is controlled by changing the distribution of the crushing force at the end of the rolled material. That is, the edge drop control output calculation device 4 sets the work roll shift amount ΔW so that the edge drop amount detected by the edge drop detector 3 approaches the target edge drop amount set by the target edge drop setting device 5. Calculate.

  Next, the details of the rolling length accumulation device 7 for each WR region and the WR oscillation output calculation device 8 will be described. First, regarding the rolling length integrating device 7 for each WR region, the virtual regions (in,..., I−1, i, i + 1,. i + m). This roll width direction shift position is operated by edge drop control or the like. This shift operation changes the position at which the plate end of the material to be rolled comes into contact with the roll. The WR area accumulator 7 has a storage area for accumulating the rolling length for each virtual area (in,..., I-1, i, i + 1,..., I + m). The rolling lengths of the virtual regions that are in contact with each other are integrated and stored. For the integrated value for each virtual area, the values from the time of roll replacement are integrated (the integrated value is cleared by roll replacement).

The WR oscillation output calculation device 8 calculates a WR oscillation amount ΔW _OC that is a correction amount for the output (WR shift amount ΔW) of the edge drop control output calculation device 4. That is, the WR shift amount is corrected as ΔW + ΔW _OC .

In the WR oscillation output calculation device 8, for each first predetermined rolling length integrated value (for example, every 100 m), the area corresponding to the plate end of the previous work roll 11 and the area corresponding to the plate end of the current work roll 11 are equivalent. It is determined whether the area is the same as above. If they are the same, the WR oscillation amount is calculated so as to move in the same direction as the movement direction from the plate end portion equivalent region of the work roll 11 the previous time to the plate end portion equivalent region of the previous work roll 11. For example, if the region i-1 has moved from the region i-1 to the region i from the previous time to the last time, the WR oscillation amount ΔW _OC is set so that the region corresponding to the plate end of the work roll 11 moves from the region i to the region i + 1 this time. Calculate. According to such control, the work roll 11 moves as shown in FIG. 4B by the WR shift amount ΔW + ΔW _OC .

  If this integrated value exceeds a certain amount (a value sufficiently larger than the first integrated value, for example, 10 km, this is called the second integrated value), there is a possibility that the area of the roll is damaged. Can be judged to be very high. At this time, the shift position of the roll is changed (this shift position changing operation is hereinafter referred to as oscillation).

  As shown in FIG. 4, the edge drop is a reduction amount of the plate thickness at the edge drop evaluation point that is tens of millimeters inside from the end of the plate. Since the roll is tapered as shown in FIG. 4, this edge drop can be controlled by changing the shift position in the width direction. When the shift position is changed inward from the plate end, the edge drop amount decreases, and conversely, when the shift position is changed to the outer side, the edge drop amount increases.

As described above, the roll shift position is changed when the integrated value in a certain region exceeds a certain amount (second integrated value). That is, when moving from the current region i to the region i + 1, if the extended integrated value in the region i + 1 exceeds the second integrated value, the WR oscillation amount ΔW is set so as to move further to the region i + 2. Calculate _OC . By the way, the edge drop has an allowable range unlike the plate thickness control and the like, and if the edge drop is within this range, the shift position of the roll may be changed. That is, as shown in FIG. 4, a WR shift range (maximum WR shift amount WR _max and minimum WR _min ) in which edge drop is allowed is obtained from the edge drop allowable range and compared with the WR shift amount (ΔW + ΔW _OC ). . When the WR shift amount in the region i + 1 scheduled to move is out of the WR shift range, for example, ΔW _OC is calculated so that the region moves in the direction opposite to the region movement from the previous region to the current region. For example, if the previous movement from the area i-1 to the area i is performed, the work roll 11 is controlled to return from the current area i to the area i-1.

  From the viewpoint of reducing the edge drop amount, the region is moved by one region inside the shift. When the integrated value in the area continues to exceed a certain amount, the shift is further changed inward by one area. If the edge drop exceeds the allowable range as a result of continuing this operation, the region is moved outward by one region. The movement toward the outside is repeated, and when the edge drop exceeds the allowable range again, the movement toward the inside is resumed.

  Through the above series of operations, a shift region that satisfies the allowable range of edge drop in one coil is determined. After the shift area is determined, the shift operation is performed so that the amount of the plate edge in each area is as uniform as possible. For example, the current region i-1 is used in FIG. 4 and the next shift operation direction is the region i by the inner shift, but the integrated value has already increased in the region i (the first integrated value). This area is not used, and the shift position is changed up to area i + 1.

  In this way, the shift position is repeatedly changed from the inside to the outside to the inside to the inside, and so on, and this operation is called oscillation.

Next, details of the edge-up determination device 10 and the edge-up removal WR shift amount determination device 11 will be described. The edge-up determination device 10 checks edge-up at the edge drop evaluation point shown in FIG. When edge up is detected, the edge up removal WR shift amount calculation unit 8 calculates a WR shift amount ΔW _EU for removing edge up. Specifically, the WR shift amount ΔW is set to zero or near.

Next, details of the WR shift control output determination device 9 will be described. As the WR shift control output, three control output values of (1) output edge drop control output 4, (2) WR oscillation control output 8, and (3) edge up removal control output 11 are input to the WR shift control output device 9. Is done. When the WR shift control output determination device 9 determines that edge up has occurred based on the detection value of the edge drop detector 3, the output value ΔW _EU of the edge up removal WR shift amount 11 is used as the work roll shift amount. And If there is no edge up, the edge drop amount is outside the predetermined range (edge drop allowable range shown in FIG. 4; however, it may be wider than this allowable range or narrower than this allowable range). If there is, the output value ΔW of the edge drop control output computing device 4 is set as the work roll shift amount. If within the allowable range, the output value ΔW + ΔW _OC of the WR oscillation device 8 is set as the work roll shift amount. In the WR shift control output determination device, priority is given to these three outputs and the final control output is determined. For example, priority 1 is an edge-up removal control output, priority 2 is an outgoing edge drop control output, and priority 3 is a WR oscillation control output. A non-zero output is selected in priority order, and a control output is given to the WR shift control device as a WR shift final control output.

  In addition, the edge drop control output calculating device 4, the target edge drop setting device 5, the WR shift control device 6, the rolling length integrating device 7 by WR region 7, the WR oscillation output calculating device 8, the WR shift control output determining device 9, the edge up Although the determination device 10 and the edge-up removal WR shift amount calculation device 11 have been described as devices, it is needless to say that all or some of them can be operated by software by one or a plurality of calculators. .

  As a result, it is possible to realize rolling that achieves both edge drop and plate surface quality even during edge drop control. In addition, the life of the roll can be extended, and the production cost can be increased by reducing the cost of the roll and reducing the time for roll replacement.

  As described above, the roll length is integrated for each virtual region in the width direction of the WR, and the roll mark is transferred to the rolled material by not using the region where the integrated value exceeds a certain value. By preventing this, it is possible to achieve both stable edge drop products and surface quality of the rolled material, increase the life of the roll, reduce the cost of the roll, and reduce the time for roll replacement.

The whole block diagram of the edge drop control apparatus of a rolling mill. The block diagram of a rolling mill stand. Operation | movement explanatory drawing of the rolling length integration | accumulation apparatus according to WR area | region. Explanatory drawing of WR oscillation operation | movement of a present Example.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Rolling mill stand, 2 ... Rolled material, 3 ... Edge drop detector, 4 ... Edge drop control output calculating device, 5 ... Target edge drop setting device, 6 ... WR shift control device, 7 ... Roll length according to WR area | region Integration device, 8... WR oscillation output calculation device, 9... WR shift control output determination device, 10... Edge-up determination device, 11.

Claims (12)

  In a method for controlling the rolling roll to move in the sheet width direction in order to control the sheet thickness in the vicinity of the sheet width direction end of the material to be rolled, the region of the rolling roll corresponding to the vicinity of the sheet width direction end of the material to be rolled A rolling control method for identifying work numbers and accumulating work conditions, and controlling movement of the rolling roll according to the accumulated conditions.   In Claim 1, the rolling roll equivalent to the sheet width direction edge part vicinity of a to-be-rolled material is divided | segmented into several area | region, a work condition is integrated | accumulated in each area | region, and the movement of the said rolling roll respond | corresponds to each said integration | stacking condition. Controlled rolling control method.   The rolling control method according to claim 2, wherein the integration is an integration of a rolling length.   In Claim 3, when the said rolling length exceeds predetermined value, the movement of the said rolling roll is controlled so that the part of the rolling roll in a corresponding area | region will leave | separate from the plate width direction edge vicinity of a to-be-rolled material. Rolling control method. 2. The rolling control method according to claim 1, wherein the rolling roll corresponding to the vicinity of the end in the sheet width direction of the material to be rolled is divided into a plurality of regions, and the rolling roll is controlled to move stepwise from region to region.   6. The rolling control method according to claim 5, wherein the rolling roll is controlled so as to repeat movement periodically from one direction to another direction.   The rolling control method according to claim 6, wherein control is performed so as to suppress the range of the periodic movement in accordance with a plate thickness tolerance in the vicinity of the end portion in the plate width direction.   2. The rolling roll according to claim 1, wherein the thickness of the material in the vicinity of the end in the width direction of the material to be rolled becomes close to or exceeds the thickness in the direction of the center. Rolling control method for controlling the movement of the steel.   In a rolling control device for controlling the rolling roll to move in the plate width direction in order to control the thickness in the vicinity of the plate width direction end of the material to be rolled, the rolling roll corresponding to the vicinity of the end of the material to be rolled in the plate width direction A rolling control device characterized by comprising an integration means for specifying the region and integrating the work status, and controlling the movement of the rolling roll according to the integration status.   In Claim 9, the rolling roll equivalent to the sheet width direction edge part vicinity of a to-be-rolled material is divided | segmented into several area | region, a work condition is integrated | accumulated in each area | region, and the movement of the said rolling roll is according to each said integration | stacking condition. Rolling control device to control.   The rolling control device according to claim 10, wherein the integration is an integration of a rolling length.   In Claim 11, when the said rolling length exceeds a predetermined value, the movement of the said rolling roll is controlled so that the part of the rolling roll in a corresponding area | region will leave | separate from the plate width direction edge vicinity of a to-be-rolled material. Rolling control device.

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