JP3770266B2 - Determining device for set value of plate crown and shape in rolling mill - Google Patents

Description

  The present invention controls the shape of the rolled material in the properties of the steel plate in hot rolling, and in particular, in continuous rolling and multi-pass rolling, determines the plate crown shape operation amount of each stand in a well-balanced manner. The present invention relates to an apparatus and a method for determining a set value of a plate crown / shape operation amount for achieving the above.

  In recent years, rolling mills equipped with various sheet crown and shape control devices have been put into practical use, and accurate physical models that express rolling phenomena have been developed. However, in continuous rolling and multi-pass rolling, it is difficult to determine the target value of the plate crown of each stand or each pass, and not only the capacity of the rolling mill can be fully utilized, but also an accurate model cannot be utilized.

  In general, in the control of the plate crown and shape in hot rolling, the schedule for achieving the target plate crown of the final stand within the upper and lower limits of the operation amount of the plate crown and shape control actuator and the allowable range of the shape. It is important to determine the operation amount of the actuator.

  At this time, with respect to the shape of the stand on the way, for example, as disclosed in Patent Document 1 and Patent Document 2, a method for obtaining a flat shape by rolling in a state as close to a constant plate crown ratio as possible. There is. At this time, when determining the target plate crown of each stand, conventionally, only the shape disturbance due to the change in the plate crown ratio is considered, and the upper and lower limit values of the operation amount of the actuator are taken into consideration, as described in Patent Document 1. There wasn't.

  That is, in Patent Document 1, the maximum / minimum plate crown ratio of each stand that can be achieved based on each stand shape allowable range and plate crown shape control operation amount allowable range is calculated, and based on this, the target product plate crown ratio is calculated. On the other hand, the target crown ratio of each stand is determined so that the change in the plate crown ratio between the stands in the downstream stand is small (that is, the flatness between the stands is small in the downstream stand), Based on this, the plate crown shape control operation amount of each stand was determined.

  As a method that considers the upper and lower limits of the operation amount of the actuator, for example, Patent Literature 3 and Patent Literature 4 propose a method using linear programming.

  In addition, in order to make the inter-stand shape as desired, the intermediate stand plate shape that cannot be recognized by the control model is input by the operator from the operator interface as the upper and lower limit values of the shape correction operation amount by visual judgment by the operator, There is Patent Document 5 as a method of determining the operation amount of the actuator.

  As another example, there is Patent Document 6 (unknown at the time of the first application). This is the same as the method of Patent Document 1 until the maximum / minimum plate crown ratio of each stand is calculated, but in determining the target plate crown ratio of each stand, the balance of all the stands is taken into consideration. There are improvements.

Japanese Patent Publication No. 3-33041 Japanese Patent Publication No. 3-72364 JP-A-1-181911 JP-A-1-254305 JP-A-1-245907 JP-A-6-134508

  However, in order to make the inter-stand shape as good as possible, in the conventional method of rolling so that the plate crown ratio is as constant as possible, the shape does not actually become flat even if the plate crown ratio is fixed. There was a problem that there were many cases. Furthermore, since the extension shape of the ear can be more stably passed through the operation, aiming at a flat shape is also a problem.

  Further, in the method of determining and inputting the upper and lower limit values of the inter-stand shape by visual observation by the operator, there are individual differences among operators and the load on the operator becomes a problem.

  In addition, after calculating the maximum / minimum plate crown ratio of each stand, when determining the target plate crown of each stand, the method of determining by focusing only on the shape without considering the upper and lower limit values of the operation amount of the actuator However, there is a case where a target plate crown that cannot be realized is determined due to the capability of the actuator, and as a result, the target plate crown and shape may not be obtained.

  Moreover, when calculating the target plate crown ratio of each stand, the shape target for each stand cannot be realized because the allowable range of each stand shape is not taken into consideration. For example, there is a problem that it is not possible to realize a rolling method of a form that is usually performed, such as rolling on the upstream side on the side of the belly wave and rolling on the downstream side on the side of the ear wave.

  Furthermore, in the method using linear programming in consideration of the upper and lower limit values of the actuator, matrix calculation is necessary and complicated due to the nature of linear programming.

  The present invention has been made to solve the above-mentioned conventional problems, and provides an apparatus and a method for determining a set value of a set value of a plate crown and shape in a rolling mill that can obtain a desired plate crown and shape. Objective.

The present invention relates to a device for determining a set value of a crown / shape operation amount in a rolling mill, in which the crown and shape of the sheet material are controlled by a rolling mill having a plate crown / shape control actuator. Rolling condition input means for inputting rolling conditions such as, maximum / minimum sheet crown ratio calculating means for calculating a maximum sheet crown ratio and a minimum sheet crown ratio in response to an output from the rolling condition input means, and the maximum / minimum A target plate crown ratio determining means for determining a target plate crown ratio for each stand or each pass in response to an output from the plate crown ratio calculating means, and an output from the target plate crown ratio determining means for receiving each stand or each pass. a strip crown and shape manipulated variable determining means for determining the strip crown and shape operation amount, material information and allowable steepness and actuator of each stand The maximum / minimum plate crown ratio range of each stand is determined by substituting the value of the table capacity into the relational expression of the plate crown between adjacent stands, and then within the determined maximum / minimum plate crown ratio range. In addition, by sequentially determining the target plate crown of each stand while going back from the last stand to the upstream stand based on the relational expression of the plate crown between adjacent stands so as to be within the range of the actuator operation amount , The object has been achieved.

In addition, the present invention achieves the same object by providing means for determining the allowable steepness upper and lower limit values and the target shape of each stand by a model formula obtained from actual data of actual operating conditions. It is what.

The present invention also relates to a method for determining a set value of a crown / shape operation amount in a rolling mill, in which the crown and shape of the sheet material are controlled by a rolling mill having a plate crown / shape control actuator . Substituting the values of allowable steepness and actuator capacity into the relational expression of the plate crown between adjacent stands to calculate the maximum plate crown ratio and minimum plate crown ratio of each stand, and the calculated maximum plate crown ratio and minimum from sheet crown ratio, within the maximum and minimum strip crown ratio range of each stand, and so as to be within the range of the actuator operation amount, based on the relation of strip crown between adjacent stands, final stand or al Sequentially toward the upstream stand, determine the target plate crown ratio of each stand or each pass, and determine the determined target plate From down ratio, so as to determine the strip crown and shape the operation amount of each stand or each path is obtained by achieving the above object.

  According to the present invention, the maximum and minimum plate crown ratios of each stand are obtained from material information such as a plate thickness given in advance, a rolling load prediction value, and an allowable steepness upper and lower limit value of each stand.

  After this, the target plate crown of each stand is determined from the target plate crown of the last stand to the upstream stand in order within the maximum and minimum plate crown ratio range of each stand and the range of the actuator operation amount. Therefore, the feasible plate crown target value of each stand can be obtained.

  Further, according to the present invention, when the actual operation data is substituted into the shape control model, the allowable steepness upper and lower limit values of each stand are obtained, and the target shape of each stand is determined, the operator The shape between the stands when the plate crown / shape control actuator is manually set and passed through can be reproduced, and a shape suitable for actual operation can be realized.

  According to the present invention, the target shape is obtained by statistically processing the shape calculated by inputting the actual operation data to the shape control model, and the plate crown target of each stand is set from the target shape and the hardware capability of the actuator. It has the excellent effect that the shape of the plate crown can be achieved while obtaining a shape suitable for actual operation.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic configuration diagram of a device for determining a setting value of a plate crown / shape operation amount of a rolling mill having seven stands according to the present embodiment.

  In FIG. 1, 2 is an F1 stand, 4 is an F7 stand, 6 is a vendor, 8 is a load detection device, 10 is an allowable steepness determination device, and 12 is an operation amount determination device.

In the present embodiment, the plate crown / shape control actuator is a cross between a vendor and a work roll, and FIG. 2 is a side view showing a roll cross. FIG. 3 is a plan view showing the roll cloth, and θ represents the cross angle. As shown in FIG. 2, the roll cross system of each stand includes a pair of an upper backup roll (BUR) and an upper work roll (WR) arranged in parallel, and a lower backup roll (BUR) and a lower work roll (WR) in parallel. As shown in FIG. 3, the pair arranged in parallel is crossed at a required angle θ _i with respect to a horizontal line perpendicular to the rolling direction.

  FIG. 4 is a flowchart showing the operation of this embodiment. The operation of this embodiment will be described below based on this. In step 100 of FIG. 4, the influence coefficient is calculated, and in step 102, the allowable steepness is determined. This is executed in the allowable steepness determination device 10 of FIG.

The allowable steepness determination device 10 first determines each stand (from the material information such as the plate thickness and the plate width, the plate crown / shape control actuator actual value obtained from the vendor 6, the load actual value obtained from the load detection device 8, etc. The influence coefficients Ai, Bi, Ci, offset Di, transfer rate α _i , genetic coefficient β _i , and shape change coefficient ξ _i of the stand No. i = 1 to 7) are obtained in advance.

  Next, the shape (steepness) of each stand (i = 1 to 7) is obtained by the following equations (1) to (4).

Cri ^* = Ai · Pi + Bi · P _Bi + Ci · θ _i ² + Di (1)
Cri = α _i · C _ri ^* + β _i · C _ri-1 (2)
Δε _i = ξ _i (C _ri / hi-C _ri-1 / h _i-1 ) (3)
λ _i = sign (Δε _i ) · 2 / π√ | Δε _i | (4)

Here, Cri ^* is a mechanical crown, Pi is a rolling load, P _Bi is a vendor load, θ _i is a cross angle of the work roll, C _ri is a plate crown, hi is a plate thickness, Δε _i is an elongation difference, λ _i is Steepness. Further, in particular C _r0 as sheet bar crown, h ₀ is given as a sheet bar thickness. Note that the sign (Δε _i ) indicates that the sign is + when Δε _i is positive and − when Δε _i is negative.

  FIG. 5 shows a shape obtained by inputting actual operation data to the shape control model. In FIG. 5, the position of each alphabet character represents the actual data position. This is an example of a steepness target indicating the degree of extension of the plate on the outlet side of the F4 stand and the degree of stretch of the belly. Here, a general material of 900 <plate width ≦ 1200 mm is handled. The horizontal axis represents the product thickness, and the vertical axis represents the shape (steepness) obtained by inputting the actual operation data to the shape control model. In this example, the thinner the material, the longer the ear extension side in the control model. It is better to roll with a steepness (positive side). The allowable steepness (upper limit and lower limit) is determined from the graph shown in FIG.

  Next, at step 104 in FIG. 4, the plate crown ratio variable region is determined. When determining the maximum and minimum plate crown ratio of each stand, two broken lines indicating the upper limit and the lower limit of the graph of FIG. 5 are used as the shape tolerance. Then, a plate crown ratio variable region is determined as a region between a curve indicating the maximum plate crown ratio and a curve indicating the minimum plate crown ratio as shown in the graph of FIG. This region is obtained in consideration of the allowable steepness and the capability of the actuator (vendor, work roll cross).

  Next, in step 106 in FIG. 4, when the target plate crown is outside the plate crown ratio variable region obtained above, the target plate crown is corrected.

  Next, at step 108, the target plate crown of each stand is determined while moving from the target plate crown of the final stand to the upstream stand.

  FIG. 6 is a graph comparing the conventional method and the method according to the present embodiment when determining the target plate crown of the upstream stand from the target plate crown of the final stand. Here, for easy comparison, the target shape of each stand is set to be steepness 0 in both cases.

  In the example shown in FIG. 6, in the conventional method (the rear plate crown ratio is constant), the F6 stand is still good when rolling from the target plate crown in the final F7 stand, but when determining the target plate crown of the F5 stand, A target plate crown that is outside the allowable range of the operation amount and cannot be realized due to the capacity of the actuator has been set.

  In contrast, in the method of the present embodiment, a target plate crown that can be realized can be set by considering both the allowable steepness and the capability of the actuator. Therefore, the accuracy of the plate crown is better than that of the conventional method.

  Finally, in step 110 of FIG. 4, the actuator set value is determined. The operations from step 104 to step 110 are all performed by the operation amount determination device 12 of FIG. The set value of the cross between the vendor and the work roll is finally determined by the operation amount determination device 12, and plate crown / shape control is performed in which the value is set for the vendor and cross of each stand.

Explanatory drawing which shows schematic structure of the determination apparatus of the plate crown and shape operation amount set value of the rolling mill which consists of 7 stands by 1st Example. Side view showing work roll cloth A plan view showing the work roll cloth Flow chart showing the operation of the first embodiment Diagram showing allowable steepness Diagram showing how to set the target plate crown for each stand

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 ... F1 stand 4 ... F7 stand 6 ... Vendor 8 ... Load detection apparatus 10 ... Allowable steepness degree determination apparatus 12 ... Operation amount determination apparatus

Claims (3)

In the apparatus for determining the setting value of the plate crown and shape in the rolling mill, which controls the crown and shape of the plate material by the rolling mill having the actuator for controlling the plate crown and shape,
Rolling condition input means for inputting rolling conditions such as sheet thickness, sheet width and rolling load;
Maximum / minimum sheet crown ratio calculation means for receiving the output from the rolling condition input means and calculating the maximum sheet crown ratio and the minimum sheet crown ratio;
Target plate crown ratio determining means for receiving an output from the maximum / minimum plate crown ratio calculating means and determining a target plate crown ratio of each stand or each pass;
A plate crown / shape operation amount determining means for receiving the output of the target plate crown ratio determining means and determining the plate crown / shape operation amount of each stand or each pass;
Substituting the material information, the allowable steepness of each stand and the value of the actuator capacity into the relational expression of the plate crown between adjacent stands, and determining the maximum / minimum plate crown ratio range of each stand, and then the determination Based on the relational expression of the plate crown between adjacent stands so that it is within the specified maximum / minimum plate crown ratio range and within the range of actuator operation amount, A device for determining a set value of a plate crown and shape in a rolling mill, wherein a target plate crown is sequentially determined. 2. The sheet crown in a rolling mill according to claim 1, further comprising means for determining the allowable steepness upper and lower limit values and the target shape of each stand by a model formula obtained from actual data of actual operating conditions.・ Determining device for shape manipulated variable set value. In the method for determining the set value of the plate crown and shape in the rolling mill, which controls the crown and shape of the plate material by a rolling mill having a plate crown and shape control actuator,
Substituting the material information, the allowable steepness of each stand and the value of the actuator capacity into the relational expression of the plate crown between adjacent stands , and calculating the maximum plate crown ratio and the minimum plate crown ratio of each stand ,
From the calculated maximum plate crown ratio and minimum plate crown ratio, the relational expression of the plate crown between adjacent stands so that it is within the range of maximum / minimum plate crown ratio of each stand and within the range of actuator operation amount. based on, towards the final stand or al sequentially upstream stand, determines a target strip crown ratio for each stand or each path,
A method for determining a plate crown / shape operation amount set value in a rolling mill, wherein the plate crown / shape operation amount of each stand or each pass is determined from the determined target plate crown ratio.

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