JP3445199B2 - Thickness control method in rolling mill - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a strip thickness control method in a rolling mill.

[0002]

2. Description of the Related Art Generally, due to asymmetry between a work side and a drive side of a rolling mill, and asymmetry such as material thickness and temperature, a difference in plate thickness between the work side and the drive side occurs and a camber occurs. There are cases. If a camber occurs, a plate having a predetermined size may not be removed, and if a larger camber occurs, the rolling equipment may be damaged, resulting in a loss of operation. Therefore, it is important to control the plate thickness on the work side and the drive side.

As a method for controlling the plate thickness at both ends by adjusting the rolling positions of the work side and the drive side, for example, a method disclosed in Japanese Patent Publication No. 63-29606 is known. In this prior art, two gauge meter formulas relating to the work side and drive side plate thicknesses, or an average gauge meter formula indicating the average of the work side output side plate thickness and the drive side output side plate thickness, and a difference gauge indicating the difference Each of the rolling positions was set by using the two meter types.

[0004]

In the above-mentioned prior art, the rolling positions on both sides are calculated by using the estimated values of the rolling loads or rolling load differences on the work side and the drive side, respectively. However, a rolling load difference occurs due to various causes, and therefore a model for comprehensively estimating the rolling load or the rolling load difference is incomplete, and it is extremely difficult to accurately estimate the model. Also, from the experience that the ratio of rolling load difference to total rolling load (rolling load difference / total rolling load) becomes almost constant, a method of estimating that of the next slab based on the ratio of the previous material is shown. ing. However, for example, when the state of heating deviation caused by the difference in rolling load changes, the ratio inevitably changes, so an error occurs in the estimated value of rolling load difference, and there is a problem that the plate thickness control accuracy decreases. .

Further, in the above-mentioned prior art, the objects to be controlled are the average plate thickness and the work-side and drive-side plate thickness difference, and learning is carried out by comparing the measured plate thickness and those predicted using the gauge meter formula to obtain the gauge meter formula. We are trying to improve the accuracy of. However, as shown in FIG. 1, it is not possible to specify the position at which the average plate thickness is obtained in the rolled material whose plate thickness changes in the plate width direction. Therefore, it is impossible to improve the accuracy of the gauge meter system by learning with the plate thickness measured values at three points including only the plate edge or the plate width center. Further, in order to accurately calculate the average plate thickness, it is necessary to narrow the plate thickness measurement pitch and increase the number of measurement points, but there is a problem in that the cost is increased.

Therefore, an object of the present invention is to provide a method capable of highly accurately controlling the plate thickness without using the "rolling load difference" which is a factor that causes an error.

[0007]

According to the first aspect of the present invention, the plate thickness at the center of the plate width, the plate crown, and the asymmetry amount of the rolling mill are calculated, and the plate thicknesses at both ends are calculated based on these values. This is done based on the knowledge that it is necessary to consider up to now, and that it is not necessary to use the rolling load difference, which was a factor that causes an error, and the calculation can be performed by the “total rolling load”. That is, the feature of the present invention is that the rolling positions of the work side and the drive side of the rolling mill are independently set so that the plate thicknesses at both ends in the plate width direction of the plate material satisfy a preset target value. In relation to the total rolling load, the relation between the work-side and drive-side housing deformations, the deformation amount of the work roll center position of the cylinder and the plate crown amount, the change of each roll diameter at the center position of the work roll and the backup roll The point is to set the work-side and drive-side roll-down positions by using the gauge meter plate thickness model of the plate thickness profile in the plate width direction, which is composed of the amount and the correction amount for the plate thickness at both ends of the plate width.

That is, the present invention uses a gauge meter plate thickness model to give a predicted total rolling load P (known number) and to reduce the work side and drive side to obtain a target plate thickness difference Δh (known number). The positions SW and SD (unknown numbers) are obtained. The gauge meter plate thickness model is represented by the following formula, for example. hC = (SW + SD) / 2 + 2YRR + (YHW + YH
D) / 2 + ΔCR + (OfW + OfD) / 2 hW = hC-Ch + Δh / 2 hD = hC-Ch-Δh / 2 Δh = B (SW-SD + YHW-YHD + OfW-Of
D) / L However, hC, hW, hD: Plate width center, work side, plate thickness SW at the plate thickness defining point on the drive side, SD: Work side, drive side rolling position YRR: Work roll center position Amount of deformation, YRR =
f ₁ (P, ...), P is the total rolling load YHW, YHD: Deformation amount of the housing on the work side and drive side, YHW = f ₂ (P, ...), YHD = f ₃ (P,
......) ΔCR: Change amount OfW of each roll diameter at the center position of the work roll and the backup roll, OfD, OfD: Amount of correction for the plate thickness at the work side and drive side ends Ch: Plate crown, Ch = hC- (hW + hD ) / 2 Δh: Target plate thickness difference between work side and drive side B: Plate width L: Distance between chocks The rolling position is obtained by the following formula. SW = hC + Δh · L / 2B−α−β · L / 2B SD = hC−Δh · L / 2B−α + β · L / 2B where α = 2YRR + (YHW + YHD) / 2 + ΔCR + (O
fW + OfD) / 2 β = (YHW−YHD + OfW−OfD) · B / L Further, the second aspect of the present invention calculates the plate thickness at the center of the plate width and the work side and drive side asymmetry of the rolling mill, By calculating the work-side and drive-side reduction positions based on this, there is no need to use the rolling load difference, which was a factor that has been indispensable and has caused errors, and the sum of the rolling reaction forces of the work-side and drive-side can be eliminated. It was made based on the knowledge that the rolling positions of the work side and the drive side can be calculated with the rolling load.

That is, the feature of the present invention is that the rolling reaction is the sum of the rolling reaction forces generated in the housings of the work side and the drive side during the rolling of the plate material, and the deformation amount of the housings of the work side and the drive side with respect to this rolling load. , And each relational expression of the amount of deformation at the center of the work roll cylinder, the work side and drive side reduction positions where the roll gap at the center position of the work roll before the start of rolling becomes 0, and the work roll and backup that occur after the start of rolling Using a gauge meter formula that consists of the amount of change in each roll diameter at the center position of the roll, the amount of correction for the plate thickness at the center of the plate width, and the amount of correction for the plate thickness difference at both ends of the plate width, Work side and drive so as to protect the difference between the plate thickness at the center position of the given plate material and the work side and drive side edges. Lies in the fact to set the pressure position of the id.

The gauge meter formula is expressed by the following formula. hC = {(SW-S0W) + (SD-S0D)} / 2+
YRR + (YHW + YHD) / 2 + ΔCR + Of1 Δh = {(B-2b) / L} · {(SW-S0W)-
(SD-S0D) + (YHW-YHD)} + Of2 where, hC: thickness of plate width central part, Δh: difference of plate thickness between work side and drive side end, SW, SD: reduction of work side, drive side Position, S0W, S0D: Work-side and drive-side rolling position where the roll gap at the center of the work roll cylinder before rolling is 0, YRR: Deformation amount of the work roll cylinder center with respect to rolling load, YRR = f ₁ ( P, ……), P is the sum of rolling reaction forces generated on the workside and driveside housings, YHW, YHD: Deformation of the workside and driveside housings against rolling load, YHW = f ₂ (P, ……)
, YHD = f ₃ (P, ...) ΔCR: Changes in roll diameters at the center positions of the work roll and backup roll after the start of rolling, Of1: correction amount for the plate thickness at the center of plate width, Of2: work Amount of correction for difference in plate thickness at side and drive side ends, B: plate width of plate material, b: work side, distance between plate thickness defining point at drive side end and plate width end, L: work side, drive The distance between the rolling positions on the side. The rolling positions SW on the work side and drive side,
SD is obtained by solving the simultaneous linear equations consisting of the above expressions of hC and Δh.

Further, according to the third aspect of the present invention, if the rolling positions of the work side and the drive side are calculated based on the plate thickness at the center of the plate width, the plate crown, the work side of the rolling mill, and the asymmetric amount of the drive side, It is not necessary to consider the difference in rolling load, which is a factor that causes errors, and the rolling position, which is the sum of rolling reaction forces on the work side and drive side, can be used to calculate the rolling position on the work side and drive side. It was made by the knowledge.
That is, the feature of the present invention is that the rolling load is the sum of rolling reaction forces generated in the work side and drive side housings during rolling of the plate material, and the work side and drive side housing deformation amounts with respect to the rolling load, and the work rolls. Each relational expression of the amount of deformation in the center of the cylinder and the amount of plate crown, the rolling position of the work side and the drive side where the roll gap at the center position of the roll cylinder before rolling is 0, the work roll and the backup roll that occur after the start of rolling Using the gauge meter formula that consists of the amount of change in each roll diameter at the center of the cylinder and the amount of correction for the plate thickness of the work side and drive side ends, the work side and drive side end of a given plate material are used. The point is to set the work-side and drive-side roll-down positions so as to maintain the plate thickness of.

The gauge meter formula is expressed by the following formula. hW = hC-Ch-Δh / 2 + OfW hD = hC-Ch + Δh / 2 + OfD where hC = {(SW-S0W) + (SD-S0D)} / 2+
YRR + (YHW + YHD) / 2 + ΔCR Δh = {(B-2b) / L} · {(SW-S0W)-
(SD-S0D) + (YHW-YHD)} hW, hD: work side, plate thickness at the drive side end, SW, SD: work side, drive side rolling position, S0W, S0D: work roll before rolling start Of the work side where the roll gap at the center of the cylinder is 0, the rolling position of the drive side, YRR: Deformation amount of the center of the work roll cylinder against the rolling load, YRR = f ₁ (P, ...), P is the work side and the drive Sum of rolling reaction forces generated on the side housing, YHW, YHD: Deformation of the work side and drive side housings against rolling load, YHW = f ₂ (P, ...)
, YHD = f ₃ (P, ...) Ch: Amount of strip crown with respect to rolling load, Ch = f ₄ (P, ...)
...) ΔCR: Change in roll diameter at the center position of the work roll and the backup roll after the start of rolling, OfW, OfD: Amount of correction for the plate thickness at the work side and drive side ends B: Plate width of plate material, b : Distance between plate thickness defining point at work side and drive side end and plate width end, L: Distance between work side and drive side roll-down positions, work side and drive side roll-down position SW,
SD is obtained by solving the simultaneous linear equations consisting of the above expressions of hC and Δh.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION In the first aspect of the present invention, the plate thicknesses hW and hD on the work side and drive side are calculated by subtracting the plate crown Ch from the plate thickness hC at the center of the plate width to determine the work side and the drive side. This is done by adjusting the asymmetry amount Δh.
That is, it is calculated by the following formula. hW = hC-Ch + Δh / 2 (1) hD = hC-Ch-Δh / 2 (2) The plate crown amount Ch is defined as follows, as shown in FIG.

Ch = hC- (hW + hD) / 2 (3) The plate thickness hC at the center of the plate width is derived from the following knowledge. That is, when the total rolling load P is 3000 tons and parallel reduction is performed (condition 1), the reduction position on the work side is set to 1
When a rolling load difference was caused by lowering by 00 μm (condition 2), the exit side plate thickness hC at the plate width center and the plate crown amount Ch were obtained. The results are shown in Table 1.

[0015]

[Table 1]

According to the "Table 1", the variation of the sheet thickness at the center of the sheet width under the conditions 1 and 2 is about 9 μm, which has sufficient accuracy and the sheet crown amount does not change. found. That is, it has been found that when the total rolling load P is constant, the plate thickness hC at the center of the plate width and the plate crown amount Ch are constant regardless of the rolling load difference. Based on the above knowledge, the plate thickness hC at the center of the plate width is expressed by a relational expression (YRR = f ₁ (P, P, ……), YHW
= F ₂ (P, ...), YHD = f ₃ (P, ...)), and the amount of change ΔCR of each roll diameter at the center position of the work roll and backup roll cylinders, and the plate thickness at both ends of the plate width Is calculated from the correction amounts OfW and OfD.

That is, the plate thickness hC at the center of the plate width is expressed by the following equation. hC = (SW + SD) / 2 + 2YRR + (YHW + YHD) / 2 + ΔCR + (OfW + OfD) / 2 (4) The offset amounts OfW and OfD are backlash of the housing and the like. Further, it is considered that the asymmetric amount Δh between the work side and the drive side is caused by the difference in rolling position between the work side and the drive side (SW-SD) and the difference in housing extension between the work side and the drive side (YHW-YHD). And, regarding the plate thickness difference caused by the reduction position difference, the reduction position difference (plate width B) / (distance between chocks L)
Calculated by That is, the plate thickness difference Δh can be expressed by the following equation. Δh = B (SW-SD + YHW-YHD + OfW-OfD) / L (5) Regarding the housing differential expansion (YHW-YHD),
By formulating the elongation difference with respect to the total load P in advance,
It can be calculated.

From the above, the gauge meter plate thickness model using the total rolling load P can be formulated as the above formulas (4) and (5), and the plate thickness at the plate end can be calculated from the above (1) (2). ), It is possible to further improve the plate thickness control accuracy by comparing the gauge thickness with the measured plate thickness. However, the following equation is calculated from the equations (4) and (5). SW = hC + Δh · L / 2B-α-β · L / 2B (6) SD = hC-Δh · L / 2B-α + β · L / 2B (7) where α = 2YRR + (YHW + YHD) / 2 + ΔCR + (O
fW + OfD) / 2 β = (YHW−YHD + OfW−OfD) · B / L The rolling positions of the work side and the drive side of the rolling mill are independently set by the formulas (6) and (7).

The above is the description regarding the derivation of the gauge meter plate thickness model used in the first aspect of the present invention.
The plate thickness control method of the present invention will be described with reference to the flowchart shown in FIG. A target plate thickness hC at the center of the plate width in the pass determined based on the pass schedule of the rolled material,
A predicted total rolling load P determined based on the target plate thickness hC and the target crown amount Ch, and a target plate thickness difference Δh derived from a plate thickness difference between the work side and the drive side before the pass, a camber shape, and the like. By substituting into the above equations (6) and (7), the work-side and drive-side rolling-down positions SW,
SD is calculated.

Next, the second and third inventions will be described. In the present invention, using the rolling load, which is the sum of the rolling reaction forces on the work side and drive side, the deformation amount at the center of the work roll cylinder YRR = f ₁ (P, ...), the deformation amount on the work side and drive side housings. YHW, YHD and
The plate crown amount Ch is calculated. First, regarding the deformation amount YRR at the center of the work roll cylinder and the plate crown amount Ch,
Under the constant rolling load, which is the sum of the rolling reaction forces on the work side and drive side, only the load difference was changed, and the degree of influence of the load difference was analyzed.

As an example of the result, as shown in Table 2, it was found that the change amount of the plate thickness at the center of the plate width was as small as about 9 μm and the plate crown amount did not change.

[0022]

[Table 2]

That is, it has been found that, under a constant rolling load, the deformation amount YRR at the center of the work roll cylinder and the plate crown amount Ch are constant regardless of the rolling load difference. As a result, the work roll body center deformation amount YRR and the plate crown amount Ch
Is the formulation YRR = f ₁ (P, ...) for the rolling load, which is the sum of the rolling reaction forces on the work side and drive side.
,), And Ch = f ₄ (P, ...), it can be calculated. Then, the relational expression of the amount of deformation of the work side and drive side housings with respect to the rolling load, which is the sum of the rolling reaction forces on the work side and drive side, YHW = f ₂
......), and YHD = f ₃ (P, ...) Can be easily derived by performing a conventional roll tightening experiment.

Further, the asymmetric amount Δh between the work side and the drive side is defined by the difference in the rolling position between the work side and the drive side {(SW-S0W)-(SD-S0D)}, and the difference in the expansion between the work side and the drive side housing ( YHW
-YHD). Then, regarding the plate thickness difference caused by the reduction position difference, {(plate width B)-(distance b between the work side and the drive side end part plate thickness defining point and the plate width end part)} / ( It is calculated by the distance L) between the work side and drive side rolling positions. Based on these findings, the plate thickness hC at the plate width center position, the plate thickness difference Δh between the work side and the drive side end, the work side,
The plate thicknesses hW and hD at the drive side end are the deformation amount YRR at the center of the work roll cylinder, the work side and drive side housing deformation amounts YHW and YHD, and the plate crown amount Ch with respect to the sum of the rolling loads on the work side and the drive side. Each relational expression {YRR = f ₁ (P, ...), YHW = f
₂ (P, ...), YHD = f ₃ (P, ...), Ch = f ₄ (P, ...)
…)}, And the amount of change ΔCR of each roll diameter at the center position of the work roll and the backup roll, the correction amount Of1 for the plate pressure at the center of the plate width, and the correction for the plate thickness difference at the work side and drive side ends. Amount Of2, correction amount O for plate pressure at the work side and drive side ends
FW, OfD, work side, drive side roll-down positions SW, SD, work-side and drive side roll-down positions S0W, S0D at which the roll gap at the center position of the work roll before the start of rolling becomes 0, and the plate width B of the plate material , The distance b between the plate thickness defining points at the work side and drive side ends and the plate width end, and the distance L between the work side and drive side rolling positions.

From the above, the gauge meter formula using the sum of rolling loads on the work side and drive side is as follows (8)
Formula (9) or formula (10) and (11) can be formulated, and in addition, the gauge meter can be learned by comparing the calculated plate thickness by the gauge meter with the actually measured plate thickness. It is possible to improve the accuracy of. hC = {(SW-S0W) + (SD-S0D)} / 2 + YRR + (YHW + YHD) / 2 + ΔCR + Of1 (8) Δh = {(B-2b) / L} · {(SW-S0W)-(SD- S0D) + (YH W-YHD)} + Of2 (9) hC = {(SW-S0W) + (SD-S0D)} / 2 + YRR + (YHW + YHD) / 2 + ΔCR ... (10) Δh = {(B- 2b) / L} · {(SW-S0W)-(SD-S0D) + (YH W-YHD)} (11) Then, the equations (8) and (9) or (10) and (11) are obtained. ) Formula work-side and drive-side roll-down position S
By solving the simultaneous linear equations of W and SD, the rolling positions on the work side and drive side of the rolling mill can be obtained.

The above is a description regarding the derivation of the gauge meter plate thickness model used in the present invention, and the plate thickness control method will be described below with reference to the flow charts shown in FIGS. 3 and 4. Fig. 3 shows the work thickness and the work side at the center position of the work width, and the work side so as to keep the work thickness difference at the drive side end.
This is a case where the rolling position on the drive side is set, and the work is determined based on the target plate thickness hC at the plate width center position and the target plate crown amount Ch in the pass determined based on the pass schedule of the rolled material. The predicted value P of the sum of rolling loads on the drive side and the drive side, and the target plate thickness difference Δh derived from the plate thickness difference between the work side and the drive side before the pass, the camber shape, etc. are given in the above (8).
By substituting into the equation (9), the work side and drive side rolling-down positions SW and SD are derived.

FIG. 4 shows a case where the work side and drive side rolling positions are set so that the work side of the plate material and the plate thickness at the drive side end are protected, and the rolling positions are determined based on the pass schedule of the rolled material. In the path,
Predicted value P of the sum of the target plate thickness hD of the drive side end and the target plate crown amount Ch, the work side and the rolling load of the drive side, and the plate thickness of the work side and the drive side before the pass. The target plate thickness hW of the work side end derived from the difference, the camber shape, etc.
By substituting into the equations (10) and (11), the work side and drive side rolling-down positions SW and SD are derived.

[0028]

[Examples] Targeting 130 rolled materials (4) (5)
The accuracy of the gauge meter formula shown in the formula was verified. The defined point of the plate thickness was a point 100 mm inside from the plate ends of the drive side and the work side, and the plate thickness at that point was actually measured by a γ-ray plate thickness gauge to learn the plate thickness. The amount of work-side and drive-side housing deformation with respect to the total rolling load was the result of measurement just before the roll chance (shown in FIG. 5). As a result, as shown in FIGS. 6 and 7, the accuracy of the gauge meter system was good in both the plate thickness hD on the drive side and the plate thickness difference Δh, and therefore highly accurate plate thickness control was possible.

Incidentally, in FIG. 6, "gauge meter accuracy"
Is (gauge meter accuracy) = (predicted plate thickness hD by the gauge meter formula on the drive side) − (measured plate thickness on the drive side), and in FIG. 7, (gauge meter accuracy) = (drive Predicted plate thickness difference between zide and work side)-(measured plate thickness difference between drive side and work side). Further, X is an average value and σ is a standard deviation. In addition, for 130 rolled materials, the above (8)
The accuracy of the gauge meter formula (9) was verified. The definition point of the target plate thickness is the center part of the plate width, and the target plate thickness difference between the drive side and the work side is the plate thickness difference within 100 mm from each plate edge. Further, the learning of the gauge meter was carried out by using the plate thickness actually measured by the γ-ray plate thickness meter. Also,
The amount of work side and drive side housing deformation with respect to the sum of the work side and drive side rolling loads is
Results of actual measurement just before the roll chance (shown in FIG. 5)
Was used.

As a result, the accuracy of the gauge meter system is shown in Table 3.
As shown in, the plate thickness and the plate thickness difference at the center portion of the plate width are good, and therefore the plate thickness can be controlled with high accuracy.

[0031]

[Table 3]

The definition point of the target plate thickness is the central part of the plate width, and the target plate thickness difference between the drive side and the work side is the above (8) when the plate thickness difference is 150 mm inside from each plate end. Table 4 shows the accuracy verification result of the gauge meter formula (9). The number of target rolled materials is 100. As shown in Table 4, the accuracy of the gauge meter system was good in both the plate thickness and the plate thickness difference in the plate width central portion, and therefore, highly accurate plate thickness control was possible.

[0033]

[Table 4]

The definition point of the target plate thickness is the central part of the plate width, and the target plate thickness difference between the drive side and the work side is the above (8) when the plate thickness difference is 50 mm inside from each plate end. Table 5 shows the accuracy verification result of the gauge meter formula (9). The number of target rolled materials is 100. As shown in Table 5, the accuracy of the gauge meter system was good in both the plate thickness and the plate thickness difference in the plate width central portion, and therefore, highly accurate plate thickness control was possible.

[0035]

[Table 5]

For 150 rolled materials, the above (1
0) The accuracy of the gauge meter formula shown in the formula (11) was verified. The definition point of the target plate thickness is a point 100 mm inside from the plate end of each of the drive side and the work side. Further, the learning of the gauge meter was carried out by using the plate thickness actually measured by the γ-ray plate thickness meter. The amount of deformation of the housings on the work side and the drive side with respect to the sum of the rolling loads on the work side and the drive side was the result of measurement (shown in FIG. 5) immediately before the roll chance. As a result, as shown in Table 6, the accuracy of the gauge meter system is good, and the plate pressures on the work side and the drive side are both good, so that the plate thickness can be controlled with high accuracy.

[0037]

[Table 6]

When the definition point of the target plate thickness is a point 150 mm inside from the plate ends of the drive side and the work side,
Table 7 shows the accuracy verification results of the gauge meter formulas (10) and (11). The number of target rolled materials is 111. As shown in Table 7, the gauge meter accuracy has good work-side and drive-side plate thickness.
Highly accurate thickness control was possible.

[0039]

[Table 7]

Table 8 shows the accuracy verification results of the gauge meter formulas (10) and (11) when the defined point of the target plate thickness is set to the point 50 mm inside from the plate edge on the drive side and the work side. . The number of target rolled materials is 131. As for the accuracy of the gauge meter system, as shown in Table 8, the work side and drive side plate thicknesses were good, and therefore highly accurate plate thickness control was possible.

[0041]

[Table 8]

The present invention is not limited to the above-mentioned embodiments and examples.

[0043]

According to the present invention, the rolling position is determined by using the total rolling load or the sum of the rolling loads on the work side and the drive side, instead of using the rolling load difference which is likely to cause an error in the estimated value as in the prior art. Since it is determined, highly accurate plate thickness control becomes possible.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a plate thickness profile in a plate width direction and an average plate thickness of a conventionally used rolled material.

FIG. 2 is an explanatory diagram of the definition of the plate crown amount used in the present invention.

FIG. 3 is a flow chart showing the method of the present invention.

FIG. 4 is a flow chart showing the method of the present invention.

FIG. 5 is a graph showing the deformation characteristics of the housing.

FIG. 6 is a graph showing the gauge meter accuracy of the plate thickness of the plate end portion on the work side.

FIG. 7 is a graph showing the gauge meter accuracy of the plate thickness difference Δh.

─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Shintaro Shimada 1 Kanazawa-machi, Kakogawa City, Hyogo Prefecture Kobe Steel Works, Ltd. Inside the Kakogawa Steel Works (72) Inventor Dan Jiji Kanazawa-cho, Kakogawa City, Hyogo Prefecture Kobe Steel Co., Ltd. In the Kakogawa Steel Works (72) Inventor Masaki Sudo 1 Kanazawa-cho, Kakogawa City, Hyogo Prefecture Kobe Steel Co., Ltd. Inside the Kakogawa Steel Works (56) Reference JP-A-6-182418 (JP, A) JP-A-55-141307 ( JP, A) JP 62-89511 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B21B 37/00-37/78

Claims (7)

(57) [Claims] 1. When the rolling positions of the work side and the drive side of the rolling mill are set independently of each other so that the plate thicknesses of both ends of the plate material in the plate width direction satisfy a preset target value, the total rolling load is set. Relative to the work-side and drive-side housing deformations, work roll center position deformation amount and plate crown amount, change amount of each roll diameter at the work roll and backup roll center position, and plate width both ends Using the gauge meter plate thickness model of the plate thickness profile in the plate width direction composed of the correction amount for the plate thickness of Control method. 2. The strip thickness control method in a rolling mill according to claim 1, wherein the gauge meter strip thickness model is represented by the following equation. hC = (Sw + SD) / 2 + 2YRR + (YHW + YH
D) / 2 + ΔCR + (OfW + OfD) / 2 hW = hC-Ch + Δh / 2 hD = hC-Ch-Δh / 2 Δh = B (SW-SD + YHW-YHD + OfW-Of
D) / L However, hC, hW, hD: Plate width center, work side, plate thickness SW at the plate thickness defining point on the drive side, SD: Work side, drive side rolling position YRR: Work roll center position Amount of deformation, YRR =
f ₁ (P, ...), P is the total rolling load YHW, YHD: Deformation amount of the housing on the work side and drive side, YHW = f ₂ (P, ...), YHD = f ₃ (P,
......) ΔCR: Change amount OfW of each roll diameter at the center position of the work roll and the backup roll, OfD, OfD: Amount of correction for the plate thickness at the work side and drive side ends Ch: Plate crown, Ch = hC- (hW + hD ) / 2 Δh: Target plate thickness difference between work side and drive side B: Plate width L: Distance between chocks 3. The strip thickness control method for a rolling mill according to claim 2, wherein the rolling position is obtained by the following equation. SW = hC + Δh · L / 2B−α−β · L / 2B SD = hC−Δh · L / 2B−α + β · L / 2B where α = 2YRR + (YHW + YHD) / 2 + ΔCR + (O
fw + OfD) / 2 β = (YHW−YHD + OfW−OfD) · B / L 4. The rolling load is defined as the sum of rolling reaction forces generated in the housings on the work side and the drive side during rolling of the plate material, and the deformation amount of the housings on the work side and the drive side with respect to this rolling load and the center of the cylinder of the work roll. Each relational expression of the amount of deformation, the work side and drive side reduction positions where the roll gap at the center position of the work roll before the start of rolling is 0, and the roll diameters at the center position of the work roll and backup roll that occur after the start of rolling Of the plate width at the center of the plate width and the correction amount for the plate thickness difference at both ends of the plate width using a gauge meter formula It is special to set the work-side and drive-side roll-down positions so as to protect the difference between the work thickness and the work side and drive side end. A method for controlling the thickness of rolling mills. 5. The strip thickness control method for a rolling mill according to claim 4, wherein the gauge meter equation is represented by the following equation. hC = {(SW-S0W) + (SD-S0D)} / 2+
YRR + (YHW + YHD) / 2 + ΔCR + Of1 Δh = {(B-2b) / L} · {(SW-S0W)-
(SD-S0D) + (YHW-YHD)} + Of2 where, hC: thickness of plate width central part, Δh: difference of plate thickness between work side and drive side end, SW, SD: reduction of work side, drive side Position, S0W, S0D: Work-side and drive-side rolling position where the roll gap at the center of the work roll cylinder before rolling is 0, YRR: Deformation amount of the work roll cylinder center with respect to rolling load, YRR = f ₁ ( P, ……), P is the sum of rolling reaction forces generated on the workside and driveside housings, YHW, YHD: Deformation of the workside and driveside housings against rolling load, YHW = f ₂ (P, ……)
, YHD = f ₃ (P, ...) ΔCR: Changes in roll diameters at the center positions of the work roll and backup roll after the start of rolling, Of1: correction amount for the plate thickness at the center of plate width, Of2: work Amount of correction for plate thickness difference between side and drive side ends, B: plate width of plate material, b: work side, distance between plate thickness defining point of drive side end and plate width end, L: work side, drive Distance between rolling positions on the side 6. A rolling load is the sum of rolling reaction forces generated in the housings of the work side and the drive side during rolling of the plate material, and the amount of deformation of the housings of the work side and the drive side with respect to this rolling load, and the amount of deformation of the center of the cylinder of the work roll. , And the relations of the plate crown amount, the work side and drive side reduction positions where the roll gap at the center position of the roll cylinder before the start of rolling is 0, and the rolls at the center position of the work roll and backup roll that occur after the start of rolling Use the gauge meter formula that consists of the amount of change in diameter and the amount of correction for the work-side and drive-side end thicknesses to protect the work-side and drive-side end thicknesses of a given plate material. A strip thickness control method for a rolling mill, characterized in that the rolling positions of the work side and the drive side are set in the. 7. The gauge meter formula is represented by the following formula, wherein the method for controlling the strip thickness of a rolling mill is hW = hC-Ch-Δh / 2 + OfWhD = hC-Ch + Δh / 2 + OfD. However, hC = {(SW-S0W) + (SD-S0D)} / 2+
YRR + (YHW + YHD) / 2 + ΔCR Δh = {(B-2b) / L} · {(SW-S0W)-
(SD-S0D) + (YHW-YHD)} hW, hD: work side, plate thickness at the drive side end, SW, SD: work side, drive side rolling position, S0W, S0D: work roll before rolling start Of the work side where the roll gap at the center of the cylinder is 0, the rolling position of the drive side, YRR: Deformation amount of the center of the work roll cylinder against the rolling load, YRR = f ₁ (P, ...), P is the work side and the drive Sum of rolling reaction forces generated on the side housing, YHW, YHD: Deformation of the work side and drive side housings against rolling load, YHW = f ₂ (P, ...)
, YHD = f ₃ (P, ...) Ch: Amount of strip crown with respect to rolling load, Ch = f ₄ (P, ...)
...) ΔCR: Change in roll diameter at the center position of the work roll and the backup roll after the start of rolling, OfW, OfD: Amount of correction for the plate thickness at the work side and drive side ends B: Plate width of plate material, b : Distance between plate thickness definition points at work side and drive side ends and plate width end, L: Distance between work side and drive side rolling positions