JP5895758B2 - Rolling mill and rolling mill control method - Google Patents

Description

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

  Conventionally, the rolling amount control of the rolling mill has been set based on the lower limit tolerance of the thickness of the steel sheet while taking into account the control accuracy of the rolling mill. That is, when delivering the steel plate as a product, the delivery was performed so as to ensure that the minimum thickness of the steel plate does not fall below the lower limit tolerance.

  On the other hand, there is a product that not only ensures that the minimum value of the plate thickness of the steel plate does not fall below the lower limit tolerance, but also ensures that the average value of the plate thickness of the steel plate does not fall below the nominal thickness. In that case, in the rolling amount control in the conventional rolling mill, by setting the rolling amount so that the minimum value of the steel plate thickness does not fall below the nominal thickness, the average value of the steel plate thickness does not fall below the nominal thickness. I was doing.

JP 2001-347309 A

  However, when the amount of reduction is set so that the minimum value of the steel plate thickness does not fall below the nominal thickness as in the prior art, the average value of the steel plate thickness is excessively greater than the nominal thickness. In other words, in steel plates manufactured so that the average thickness of steel plates does not fall below the nominal thickness as in the prior art, the steel plate materials required for manufacturing are consumed more than necessary, and the weight of the manufactured steel plates is required. There was a problem that it became heavier than that. When the weight of the manufactured steel sheet is heavier than necessary, it is a big problem that affects the weight of the final product manufactured using the steel sheet.

  For example, as in the technique described in Patent Document 1, a method of improving the average thickness deviation in a rolling process by a rolling mill is also known, but this method is for eliminating the offset component in the average thickness deviation. It is a method and cannot correct | amend an average board thickness dynamically during rolling of a steel plate. That is, the technique described in Patent Document 1 cannot reflect the measured value measured during rolling in the average plate thickness, and is insufficient for the purpose of minimizing the material of the steel plate required for manufacturing.

  Therefore, a technique for dynamically correcting the average plate thickness after rolling during rolling of the steel plate has been desired.

  The present invention has been made in view of the above, and the object thereof is to minimize the material of the steel sheet required for manufacturing while keeping the average thickness of the steel sheet below the nominal thickness. It is providing the rolling mill and the control method of a rolling mill.

  In order to solve the above-described problems and achieve the object, the rolling mill of the present invention includes a sheet thickness meter for measuring the sheet thickness of a steel sheet after rolling by a work roll of the rolling mill, and a feeding amount of the steel sheet. Calculate a thickness control target based on inputs from the tachometer to measure, an opening meter to measure the roll gap and the rolling load of the work roll, the thickness meter, the tachometer and the opening meter, And a control unit that controls a reduction cylinder of the rolling mill based on the plate thickness control target.

  In order to solve the above-described problems and achieve the object, a control method for a rolling mill according to the present invention includes a plate thickness meter provided at a subsequent stage of the rolling mill, a tachometer and an opening meter provided at a work roll. In the rolling mill provided with a section, the thickness gauge measures the sheet thickness of the steel sheet after rolling by the work roll of the rolling mill, and the tachometer measures the feed amount of the steel sheet. A feed amount measurement step, a step in which the opening meter measures a roll gap and a rolling load of the work roll, and the control unit inputs from the plate thickness meter, the tachometer, and the opening meter. And a control step of controlling a reduction cylinder of the rolling mill based on the plate thickness control target.

  The rolling mill and the control method of the rolling mill according to the present invention have an effect of minimizing the material of the steel plate required for manufacturing while keeping the average value of the steel plate thickness below the nominal thickness.

FIG. 1 is a cross-sectional view showing an example of a rolling mill according to an embodiment of the present invention. FIG. 2 is a configuration diagram of a rolling mill control system according to the embodiment of the present invention. FIG. 3 is a functional block diagram showing functions of the control unit. FIG. 4 is a flowchart showing a control method according to the embodiment of the present invention. FIG. 5 is a view showing a comparison of sheet thicknesses of steel plates after rolling by the conventional rolling method and the rolling method of the present invention.

  Below, the rolling mill concerning the embodiment of the present invention and the control method of a rolling mill are explained in detail based on a drawing. Note that the present invention is not limited to the embodiments described below.

[Rolling mill]
FIG. 1 is a cross-sectional view showing an example of a rolling mill according to an embodiment of the present invention. As shown in FIG. 1, a steel sheet rolling mill 1 according to an embodiment of the present invention has a structure in which a pair of work rolls 2 a and 2 b are provided on both upper and lower sides across a pass line of a steel sheet S. The upper work roll 2a is applied with a rolling force downward by a backup roll 3a disposed above the work roll 2a. On the other hand, the lower work roll 2b is applied with a rolling force upward by a backup roll 3b disposed below the work roll 2b. As described above, the pair of work rolls 2a and 2b are configured to apply a rolling force to the steel sheet S from above and below.

  The work rolls 2a and 2b are fixed to the housing 5 of the rolling mill 1 via work roll chock 4a and 4b, respectively. The work roll chock 4a, 4b is a mechanism that rotatably holds the shafts of the work rolls 2a, 2b, and is a unit in which the bearings of the work rolls 2a, 2b and their peripheral mechanisms are integrated. The work roll chocks 4a and 4b and the housing 5 of the rolling mill 1 are coupled via a cylinder 6 so that the work rolls 2a and 2b can be driven up and down.

  Similarly, the backup rolls 3a and 3b are fixed to the housing 5 of the rolling mill 1 through backup roll chock 7a and 7b, respectively. The backup roll chock 7a, 7b is a mechanism that rotatably holds the shafts of the backup rolls 3a, 3b, and is a unit in which the bearings of the backup rolls 3a, 3b and their peripheral mechanisms are integrated.

  The upper backup roll chock 7a and the housing 5 of the rolling mill 1 are connected to each other via a reduction cylinder 8. The reduction cylinder 8 has a function of adjusting the reduction force with which the rolling mill 1 rolls the steel sheet S. . On the other hand, the lower backup roll chock 7b and the housing 5 of the rolling mill 1 are coupled via a pass line adjusting mechanism 9, and the pass line adjusting mechanism 9 adjusts the vertical position of the work roll 2b. Thus, the pass line of the steel sheet S is adjusted.

〔System configuration〕
FIG. 2 is a configuration diagram of a rolling mill control system according to the embodiment of the present invention. As shown in FIG. 2, the rolling mill control system according to the embodiment of the present invention includes a rolling mill 1, a thickness gauge 10 that measures the thickness of a steel sheet S rolled by the rolling mill 1, and a rolling mill. A tachometer 11 for measuring the number of revolutions of one work roll 2a, an opening meter 12 for measuring the roll gap and the rolling load of the work rolls 2a, 2b, a thickness gauge 10, a tachometer 11, and an opening meter 12. And a control unit 13 for controlling the rolling load of the rolling cylinder 8 and the roll gap of the work rolls 2a and 2b based on the input from. Each component illustrated in FIG. 2 is conceptually described and does not necessarily match the actual shape and arrangement. For example, the roll gap and the rolling load of the work rolls 2a and 2b may be configured to be measured by different sensors. However, in the embodiment of the present invention, the measurement target is more essential than the individual sensors. The description will be made without distinguishing each sensor.

Parameters L ₁ , L ₂ , L ₃ , h ₁ , h ₂ described in FIG. 2 are parameters for the control unit 13 to calculate the control amount of the rolling mill 1. The parameter L ₁ is the length of the portion of the steel sheet S for which the thickness measurement of the steel sheet S has been completed by the plate thickness meter 10, and this length is based on the number of revolutions of the work roll 2 a measured by the tachometer 11. This is a calculated parameter. Parameter L ₂ is the length between the thickness gauge 10 and the rolling mill 1, the length is facility parameters determined by determining where to place a thickness gauge 10.

Parameter L ₃ is the length after rolling portion of the steel sheet S which rolling is not completed. Incidentally, the parameter L ₃ is the drawing has a actual length of the steel sheet S which is not rolling is completed, the case of not changing the rolling conditions, part of the steel plate S which rolling is not finished by rolling It means the predicted value of the length after being stretched. The predicted value is a parameter calculated using a rolling model from the length of the already rolled steel sheet S measured by the tachometer 11 and the roll gap and the rolling load measured by the opening meter 12. is there.

The parameter h ₁ is an average plate thickness of the portion of the steel sheet S for which the measurement of the plate thickness of the steel sheet S is completed by the plate thickness meter 10, and this average plate thickness is acquired from an actual measurement value by the plate thickness meter 10. The The parameter h ₂ is an average plate thickness of the steel sheet S between the plate thickness meter 10 and the rolling mill 1, and this average plate thickness is calculated from the value of the opening meter 12. Alternatively, for the sake of convenience, it is possible to assume that the rolling condition is not significantly changed, and the parameter h ₂ is the same value as the average thickness obtained from the actual measurement value by the thickness gauge 10.

  FIG. 3 is a functional block diagram showing the functions of the control unit 13. As shown in FIG. 3, the control unit 13 is a control unit that controls a reduction amount of the reduction cylinder 8 based on inputs from the thickness gauge 10, the tachometer 11, and the opening degree meter 12.

As shown in FIG. 3, the control unit 13 includes an h ₁ acquisition unit 13a, an h ₂ acquisition unit 13b, an L ₁ acquisition unit 13c, an L ₂ acquisition unit 13d, an L ₃ acquisition unit 13e, and a plate thickness. Control target calculation means 13f and rolling model data 13g are provided. Each means in the control unit 13 can be configured as hardware or software. For example, the control unit 13 can be configured by a PLC (programmable logic controller).

The h ₁ acquisition unit 13a is a calculation unit that calculates the average plate thickness of the portion of the steel sheet S where the measurement of the plate thickness is completed from the plate thickness of the steel plate S measured by the plate thickness meter 10. The h ₂ acquisition means 13b refers to the rolling model data 13g of the steel sheet S, and determines the thickness between the thickness gauge 10 and the rolling mill 1 from the roll gap and the rolling load of the work rolls 2a and 2b measured by the thickness gauge 10. It is a calculation means which calculates the average board thickness of the steel plate S in between. Here, the rolling model of the steel sheet S is after rolling in the case of rolling with a given roll gap and rolling load in consideration of the plastic characteristics of the steel sheet S being rolled and the rigidity characteristics of the work rolls 2a and 2b. This is a model for estimating the plate thickness. Various rolling models of the steel sheet S are known, but an appropriate model can be selected according to the steel sheet S and the rolling mill 1 to be used in the practice of the present invention.

L ₁ obtaining unit 13c is a rotational speed of the measured work roll 2a by the rotation meter 11 of the rolling mill 1, to calculate the length of the steel sheet S which steel sheet S is sent out after reaching a thickness gauge 10, This is a calculating means for calculating the length of the portion of the steel sheet S for which the measurement of the thickness of the steel sheet S has been completed by the plate thickness meter 10. L ₂ obtaining means 13d is means for obtaining a length between the thickness gauge 10 and the rolling mill 1. Since this length is an equipment parameter determined by determining the position where the thickness gauge 10 is disposed, for example, a value set by an operator using an external input means may be used.

L ₃ acquiring unit 13e, based on the length and the roll gap and rolling load measured by the degree of opening gauge 12 is already rolled measured by the rotation meter 11 steel sheet S, the rolling is not completed steel S It is a calculation means which calculates the length after rolling of this part. As described above, the length of the portion of the steel sheet S that has not been rolled here is the length after rolling, and when the rolling conditions are not changed, the portion of the steel sheet S that has not been rolled is stretched by rolling. It means the predicted value of the length after being applied.

The plate thickness control target calculation means 13f includes the parameter L ₁ acquired by the h ₁ acquisition means 13a, the h ₂ acquisition means 13b, the L ₁ acquisition means 13c, the L ₂ acquisition means 13d, and the L ₃ acquisition means 13e. , L ₂ , L ₃ , h ₁ , h ₂ , a calculation means for calculating the opening setting ΔS of the rolling mill 1 such that the average thickness of the rolled steel sheet S becomes a predetermined value. The following formula is used for this calculation.
ΔS = {h _ave · (L ₁ + L ₂ + L ₃ ) − (h ₁ · L ₁ + h ₂ · L ₂ )} / L ₃
However, h _ave is the target average thickness of the steel sheet S, and a thickness obtained by adding a margin value considering the thickness control accuracy to the average thickness of the required specifications is used. That is, h _ave is a manufacturing parameter of the steel sheet S, and is a value input by the operator using the input unit 14, for example.

Furthermore, the plate thickness control target calculation means 13f calculates the control amount of the rolling mill 1 that realizes the opening setting ΔS after calculating the opening setting ΔS. That is, the opening degree setting ΔS, since an amount corresponding to the thickness of the steel sheet S corresponding to the parameter L _3, the plate thickness of the steel sheet S to calculate the work rolls 2a, roll gap and rolling loads 2b such that ΔS . Also in this calculation, the plate thickness control target calculation means 13f can calculate a specific control amount by referring to the rolling model data 13g.

  Thereafter, the sheet thickness control target calculating means 13f transmits control signals for the roll gaps and the rolling load of the work rolls 2a and 2b to the rolling cylinder 8, whereby the rolling conditions of the rolling mill 1 are changed, and the average sheet thickness of the steel sheet S is changed. The rolling mill 1 is controlled so that becomes a predetermined value.

[Control method]
Next, a rolling mill control method according to an embodiment of the present invention will be described with reference to FIG. Hereinafter, the control method of the rolling mill according to the embodiment of the present invention will be described with reference to the control system configuration diagram of the rolling mill according to the embodiment of the present invention and the functional block diagram of the control unit 13. The implementation of the rolling mill control method according to the embodiment is not limited to the configuration shown in these drawings.

  FIG. 4 is a flowchart showing a control method of the rolling mill according to the embodiment of the present invention. As shown in FIG. 4, the rolling mill control method according to the embodiment of the present invention is implemented as a loop that continues during rolling of the steel sheet S.

  In the control method of the rolling mill according to the embodiment of the present invention, the thickness gauge 10 measures the actual thickness of the rolled steel sheet S in a loop that is continued during the rolling of the steel sheet S (step S1). Further, the feed amount of the steel sheet S is measured by the tachometer 11 (step S2), and the opening meter 12 measures the roll gap and the rolling load of the work rolls 2a and 2b (step S3).

  Thereafter, the control unit 13 calculates a plate thickness control target based on the inputs from the plate thickness meter 10, the tachometer 11, and the opening meter 12 (step S4). Then, the control unit 13 calculates the reduction load of the reduction cylinder 8 and the roll gap of the work rolls 2a and 2b that realize the calculated plate thickness control target, and reduces the control signal applied to the calculated reduction load and the roll gap. The data is transmitted to the cylinder 8 (step S5).

  The control method for the rolling mill according to the embodiment of the present invention is performed in real time after the thickness of the steel sheet S is measured by the thickness gauge 10 by continuously performing the above steps S1 to S5 during rolling. Furthermore, the rolling load of the rolling cylinder 8 of the rolling mill 1 and the roll gap of the work rolls 2a and 2b can be controlled. In the rolling mill control method according to the embodiment of the present invention, the measurement results of the plate thickness are accumulated as the rolling of the steel plate S progresses, and the measurement accuracy of the average plate thickness in the measured range of the plate thickness is also improved. Therefore, this is a particularly effective method when the length of the steel sheet S is longer than the distance between the rolling mill 1 and the thickness gauge 10.

〔effect〕
Finally, effects of the rolling mill and the rolling mill control method according to the embodiment of the present invention will be described. FIG. 5 is a view showing a comparison of sheet thicknesses of steel plates after rolling by the rolling method of the conventional rolling mill and the rolling method of the rolling mill of the present invention. Fig.5 (a) is the plate | board thickness of the steel plate after the rolling by the rolling method of the conventional rolling mill, FIG.5 (b) is the steel plate after the rolling by the rolling method of the rolling mill concerning embodiment of this invention. Real thickness.

  In the rolling method of the conventional rolling mill, only the minimum value of the thickness of the steel sheet after rolling can be controlled. Therefore, in the rolling method of the conventional rolling mill, as shown in FIG. 5 (a), it can only be controlled so that the minimum value of the thickness of the steel sheet after rolling is equal to or greater than the lower limit of the average thickness. It was. That is, originally, even if the minimum value of the plate thickness is less than or equal to the lower limit of the average plate thickness, the material is excessively consumed as long as the average value of the plate thickness is not less than the lower limit of the average plate thickness. I was supposed to.

  On the other hand, in the rolling method of the rolling mill according to the embodiment of the present invention, control is performed so that the average plate thickness is not the minimum value of the plate thickness, but the lower limit of the average plate thickness. Therefore, in the rolling method of the rolling mill according to the embodiment of the present invention, material consumption can be suppressed as compared with the rolling method of the conventional rolling mill.

  From the above, the rolling mill according to the embodiment of the present invention measures the sheet thickness meter 10 that measures the actual thickness of the steel sheet S after rolling by the work rolls 2a and 2b of the rolling mill 1, and the feed amount of the steel sheet S. A thickness control target based on inputs from the rotation meter 11, the opening gauge 12 that measures the roll gap and the rolling load of the work rolls 2 a and 2 b, the thickness gauge 10, the rotation meter 11, and the opening gauge 12. And a control unit 13 that controls the reduction cylinder 8 of the rolling mill 1 based on the plate thickness control target, so that the average value of the plate thickness of the steel plate does not fall below the nominal thickness. The required steel sheet material can be minimized.

In particular, the control unit 13 of the rolling mill according to the embodiment of the present invention calculates the average plate thickness of the portion of the steel plate S where the measurement of the plate thickness is completed from the plate thickness of the steel plate S measured by the plate thickness meter 10. and h ₁ obtaining unit 13a, the work rolls 2a measured by the thickness gauge 10, the roll gap and rolling loads 2b, h for calculating the average thickness of the steel sheet S between the thickness gauge 10 and the rolling mill 1 _The L ₁ acquisition means 13c for calculating the length of the steel sheet portion for which the measurement of the plate thickness of the steel sheet S is completed by the plate thickness meter 10 from the ₂ acquisition means 13b and the feed amount of the steel sheet S measured by the tachometer 11. If was measured and L ₂ obtaining means 13d for obtaining a length between the thickness gauge 10 and the rolling mill 1 as a facility parameters, the feed amount and the opening degree meter 12 measured by the rotation meter 11 steel S Work roll 2a, 2b roll Based on the cap and the rolling load, the L ₃ acquisition means 13e for calculating the length after rolling of the portion of the steel sheet S that has not been rolled, the h ₁ acquisition means 13a, the h ₂ acquisition means 13b and L ₁ because on the basis of the output of the acquisition unit 13c and L ₂ acquisition means 13d and L ₃ acquisition unit 13e and a thickness control target calculating means 13f for calculating a sheet thickness control target, the average after rolling in the rolling of the steel sheet S The plate thickness can be corrected dynamically.

Since the plate thickness control target calculation means 13f of the control unit 13 of the rolling mill according to the embodiment of the present invention calculates the plate thickness control target based on the following equation, the average plate thickness after rolling is controlled during the rolling of the steel plate S. A control amount can be calculated as a target.
ΔS = {h _ave · (L ₁ + L ₂ + L ₃ ) − (h ₁ · L ₁ + h ₂ · L ₂ )} / L ₃
However, h _ave is the average thickness of the target steel sheet S, L ₁ is the output of the L ₁ acquisition means 13c, L ₂ is the output of the L ₂ acquisition means 13d, and L ₃ is the L ₃ acquisition means. 13e is the output of, _{h 1} is the output of _{h 1} acquisition unit 13a, _{h 2} is the output of _{h 2} acquisition unit 13b.

DESCRIPTION OF SYMBOLS 1 Rolling machine 2a, 2b Work roll 3a, 3b Backup roll 4a, 4b Work roll chock 5 Housing 6 Cylinder 7a, 7b Backup roll chock 8 Reduction cylinder 9 Pass line adjustment mechanism 10 Plate thickness meter 11 Tachometer 12 Opening meter 13 Control part 13a h ₁ acquisition means 13b h ₂ acquisition means 13c L ₁ acquisition means 13d L ₂ acquisition means 13e L ₃ acquisition means 13f Plate thickness control target calculation means 13g Rolling model data 14 Input means

Claims (3)

Thickness gauge that measures the actual thickness of the steel sheet after rolling by the work roll of the rolling mill,
A tachometer for measuring the feed amount of the steel sheet;
An opening meter for measuring a roll gap and a rolling load of the work roll;
A control unit that calculates a plate thickness control target based on inputs from the plate thickness meter, the tachometer, and the opening meter, and controls the rolling cylinder of the rolling mill based on the plate thickness control target;
Equipped with a,
The controller is
From the plate thickness of the steel plate measured by the plate thickness meter, first average plate thickness acquisition means for calculating the average plate thickness of the portion of the steel plate for which the measurement of the plate thickness has been completed,
A second average plate thickness obtaining means for calculating an average plate thickness of the steel plate between the plate thickness meter and the rolling mill from the roll gap and the rolling load of the work roll measured by the opening meter;
A first length acquisition means for calculating a length of a portion of the steel sheet in which the measurement of the thickness of the steel sheet is completed with the plate thickness meter, from the feed amount of the steel sheet measured by the tachometer;
Second length acquisition means for acquiring a length between the plate thickness meter and the rolling mill as an equipment parameter;
Based on the feed amount of the steel sheet measured by the tachometer and the roll gap and the rolling load of the work roll measured by the opening meter, the length after rolling of the part of the steel sheet that has not been rolled. A third length acquisition means for calculating
For output of the first average plate thickness acquisition unit, the second average plate thickness acquisition unit, the first length acquisition unit, the second length acquisition unit, and the third length acquisition unit. A plate thickness control target calculating means for calculating the plate thickness control target based on:
Rolling mill, characterized in that it comprises a. The thickness control target calculating means, the rolling mill according to claim 1, characterized in that to calculate the thickness control target based on the following equation.
ΔS = {h _ave · (L ₁ + L ₂ + L ₃ ) − (h ₁ · L ₁ + h ₂ · L ₂ )} / L ₃
Where h _ave is the average thickness of the target steel sheet S, L ₁ is the output of the first length acquisition means, L ₂ is the output of the second length acquisition means, and L ₃ is the output of the third length acquisition means, h ₁ is the output of the first average plate thickness acquisition means, and h ₂ is the output of the second average plate thickness acquisition means. In a rolling mill provided with a thickness meter provided at the rear stage of the rolling mill and a tachometer and an opening meter provided in the work roll, and a control unit,
The plate thickness meter measures the plate thickness of the steel plate after rolling by a work roll of a rolling mill, and a plate thickness measuring step,
A feed amount measuring step in which the tachometer measures a feed amount of the steel sheet;
The opening meter measures a roll gap and a rolling load of the work roll;
The control unit calculates a plate thickness control target based on inputs from the plate thickness meter, the tachometer, and the opening meter, and controls a reduction cylinder of the rolling mill based on the plate thickness control target. Control steps;
Including
The control step includes
The first average plate thickness acquisition means of the control unit calculates the average plate thickness of the portion of the steel plate where the measurement of the plate thickness is completed from the plate thickness of the steel plate measured by the plate thickness meter;
From the roll gap and the rolling load of the work roll measured by the opening meter, the second average plate thickness acquisition means of the control unit determines the average plate thickness of the steel plate between the plate thickness meter and the rolling mill. Calculating steps,
The first length acquisition means of the control unit calculates the length of the portion of the steel plate for which the measurement of the plate thickness of the steel plate has been completed by the plate thickness meter from the feed amount of the steel plate measured by the tachometer. Steps,
The second length acquisition means of the control unit acquires the length between the plate thickness meter and the rolling mill as an equipment parameter;
The third length acquisition means of the control unit completes rolling based on the feed amount of the steel sheet measured by the tachometer and the roll gap and the rolling load of the work roll measured by the opening meter. Calculating the length after rolling of the portion of the steel sheet that has not been done;
The plate thickness control target calculation means of the control unit includes the first average plate thickness acquisition means, the second average plate thickness acquisition means, the first length acquisition means, and the second length acquisition means. Calculating the plate thickness control target based on an output with the third length acquisition means;
A control method for a rolling mill , comprising :

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