JP4683376B2 - Reverse rolling mill - Google Patents

Description

  The present invention relates to a reverse rolling mill that performs rolling by passing a material to be rolled through upper and lower work rolls a plurality of times, and more specifically, wear distribution of upper and lower work rolls can be performed without adversely affecting the cross-sectional shape of the material to be rolled. In addition, the present invention relates to a reverse rolling mill that can achieve the target flatness.

  There are Patent Documents 1 to 3 as technologies related to the present invention. Each patent document will be described in turn.

  Patent Document 1 describes a method of controlling the cross-sectional shape of a material to be rolled in a reverse rolling mill. According to Patent Document 1, in a reverse rolling mill that rolls a material to be rolled a plurality of times through a work roll, for example, a target outlet thickness, a target outlet crown, a target flatness, and a target rolling load are given as conditions. The rolling reduction and the crown operation amount are obtained for each rolling of the material to be rolled, and rolling is performed based on the obtained rolling reduction and the crown operation amount so as to obtain good flatness of the material to be rolled.

  Patent Document 2 describes a rolling mill that can increase the sheet crown control effect even with a medium-width and narrow-width material to be rolled, and can produce a gentle plate with a plate thickness distribution in the width direction even with a wide plate. In this rolling mill, a large crown control is achieved by using a work roll having a novel shape and using a roll shift and a roll bend in combination.

In addition, the function of shifting the upper and lower work rolls in the axial direction is originally for controlling the cross-sectional shape of the material to be rolled, but if this shift function is used to disperse the work roll wear, The shape of the material cannot be controlled. In order to solve this problem, in Patent Document 3, the work roll of the upstream rolling mill is shifted by a certain amount in the axial direction to disperse the wear of the roll surface, and at the same time, the downstream side paired with the upstream side The work roll of the rolling mill is shifted by the same distance in the opposite direction, thereby negating the change in the plate cross-sectional shape due to the shift for wear dispersion.
Japanese Patent Laid-Open No. 5-200418 “Thick Plate Rolling Method” JP-A-8-24919 “Rolling method and rolling machine using both roll shift and roll bend” JP 10-328707 A "Hot tandem rolling mill"

  However, even if a rolling schedule is established in advance as in Patent Document 1, usually, the cross-sectional shape and plate flatness of the material to be rolled cannot be obtained as intended due to various factors. In particular, since the flatness of the final product is important, it is necessary to eliminate the deviation from the target value.

  Moreover, in patent document 2, although the roll shift and roll bend are used together and the control effect of the cross-sectional shape of a to-be-rolled material is enlarged, the countermeasure for disperse | distributing the wear of a work roll is not taken.

  In Patent Document 3, the work roll is subjected to wear dispersion so as not to affect the cross-sectional shape of the material to be rolled, but this wear dispersion method can be applied only to a tandem rolling mill.

  Therefore, a first object of the present invention is to suppress as much as possible the deviation of the flatness or cross-sectional shape of the material to be rolled after the final rolling from the target value in the reverse rolling mill.

  The second object of the present invention is to prevent the plate shape after the final rolling from being affected even if roll shift is continuously performed for wear dispersion in a reverse rolling mill that is not a tandem type. .

  According to the present invention, in order to achieve the first object, a reverse rolling mill that performs rolling a plurality of times by reciprocating a material to be rolled a plurality of times, and vertically rolling the material while sandwiching the rolled material. A work roll, a support roll that supports the upper and lower work rolls in contact with the outer peripheral surface, a plate shape adjusting means that acts on the upper and lower work rolls to control the cross-sectional shape of the material to be rolled, and a target flatness A control unit that controls the plate shape adjusting means during each rolling according to a predetermined plate shape control amount during each rolling based on a target plate shape consisting of at least one of a degree and a target cross-sectional shape; Based on the plate shape of the material to be rolled before the subsequent final rolling, the correction value of the predetermined plate shape control amount at the time of the final rolling is calculated and output to the control unit so that the target plate shape is obtained. Calculation unit , And the control unit controls the plate shape adjusting means at the time of final rolling based on the correction value calculated by the calculation unit (Claim 1). .

  In this reverse rolling mill, a plate shape control amount at each rolling is determined in advance based on a target plate shape comprising at least one of a target flatness and a target cross-sectional shape, and rolling control is performed at each rolling according to the determined plate shape control amount. To do. In particular, the actual plate shape before the final rolling after the second half of the multiple rolling is obtained, the calculation unit calculates a correction value of the plate shape control amount at the time of final rolling based on this plate shape, the control unit is Based on this correction value, the plate shape adjusting means is controlled at the time of final rolling. Thereby, the shift | offset | difference from the target value of the plate | board flatness or cross-sectional shape of the to-be-rolled material after final rolling can be suppressed.

  According to a preferred embodiment of the present invention, the plate shape adjusting means includes: a roll shift device that shifts the upper and lower work rolls in opposite axial directions; a roll bend device that applies bending force to the work roll; It includes at least one reduction device that applies a reduction force to the rolled material via the support roll, and the plate shape control amount includes a roll shift operation amount of the roll shift device and a roll bend operation amount of the roll bend device. And at least one of the reduction operation amounts of the reduction device, the control unit, in an initial stage from the start of rolling until the value obtained by dividing the sheet width of the material to be rolled by the sheet thickness reaches a predetermined value, The wear of the upper and lower work rolls is dispersed by controlling the roll shift device so that the shift positions of the upper and lower work rolls are different every time the material to be rolled is rolled. After the initial stage, the plate shape adjusting means is controlled so as to adjust the cross-sectional shape of the material to be rolled, and the predetermined value is the value of the material to be rolled after the work roll shift in the initial stage after final rolling. It is determined within a range in which the influence on the plate shape can be suppressed (claim 2).

  As a result, even if the wear dispersion roll shift is continuously performed in the initial stage, the final plate shape is not adversely affected.

  The plate shape considered when the calculation unit calculates the correction value is the plate shape of the material to be rolled immediately before final rolling (Claim 3).

  Thereby, the shift | offset | difference from the target value of the plate | board flatness or cross-sectional shape of the to-be-rolled material after final rolling can further be suppressed.

  The plate shape is flatness, and further comprises an input device that can be input by an operator by dividing the flatness of the material to be rolled into a plurality of levels, and the input device is configured so that the level of flatness is input by the operator. The level is output to the calculation unit, and the calculation unit calculates the correction value based on the level.

  By providing an input device that can be input in a plurality of levels, the flatness can be easily input by an operator.

  It comprises a measuring instrument that measures the plate shape of the material to be rolled before the final rolling after the second half of the multiple rolling and outputs it to the calculation unit, and the calculation unit corrects the correction based on the measured plate shape. The value is calculated (claim 5).

  By providing a measuring instrument that measures the plate shape and outputs it to the calculation unit, the plate shape can be automatically input to the calculation unit.

  Further, according to the present invention, in order to achieve the second object, a reverse rolling mill that performs rolling a plurality of times by reciprocating a material to be rolled a plurality of times, and sandwiching the rolled material to perform rolling Upper and lower work rolls, a support roll that supports the upper and lower work rolls in contact with the outer peripheral surface thereof, plate shape adjusting means that acts on the upper and lower work rolls to control the cross-sectional shape of the material to be rolled, A control unit for controlling the plate shape adjusting means at each rolling according to a plate shape control amount at the time of each rolling determined in advance based on a target plate shape comprising at least one of a target flatness and a target cross-sectional shape, The plate shape adjusting means includes a roll shift device that shifts the upper and lower work rolls in opposite axial directions, a roll bend device that applies bending force to the work roll, and a reduction to the material to be rolled. The plate shape control amount includes a roll shift operation amount of the roll shift device, a roll bend operation amount of the roll bend device, and the reduction device. The control unit includes at least one rolling operation amount at an initial stage from the start of rolling until the value obtained by dividing the plate width of the rolled material by the plate thickness reaches a predetermined value. The roll shift device is controlled to vary the shift positions of the upper and lower work rolls to disperse the wear of the upper and lower work rolls, and after the initial stage, the cross-sectional shape of the material to be rolled is adjusted. Controlling the plate shape adjusting means, and the predetermined value is within a range in which the shift of the work roll in the initial stage can suppress the influence on the plate shape of the material to be rolled after the final rolling. Reverse rolling mill is provided which is characterized in that which is defined (claim 6).

  As a result, even if the wear dispersion roll shift is continuously performed in the initial stage, the final plate shape is not adversely affected.

  As described above, in the present invention, the actual plate shape is obtained before final rolling after the latter half of rolling, and the calculation unit calculates a correction value of the plate shape control amount at the time of final rolling based on this plate shape. The control unit controls the plate shape adjusting means at the time of final rolling based on the correction value. Thereby, the shift | offset | difference from the target value of the plate | board flatness or cross-sectional shape of the to-be-rolled material after final rolling can be suppressed. In addition, since roll shift is performed to disperse the work roll wear at an initial stage that does not adversely affect the plate shape obtained after the final rolling, the wear dispersion is performed without adversely affecting the finally obtained plate shape. be able to.

  A preferred embodiment of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the common part in each figure, and the overlapping description is abbreviate | omitted.

  FIG. 1 is a configuration diagram of a reverse rolling mill according to an embodiment of the present invention. As shown in FIG. 1, the reverse rolling mill has a pair of upper and lower work rolls 2, a roll shift device 3 that shifts the upper and lower work rolls 2 in opposite axial directions, and a bending force on the upper and lower work rolls 2. A roll bend device 4 to be applied. In addition, as shown in FIG. 2, it is preferable that each work roll 2 has an uneven | corrugated outline once or more so that the cross-sectional shape control effect of the to-be-rolled material 1 can be exhibited largely. 2, the roll shift device 3 shifts the work roll 2 in the direction of arrow A, and the roll bend device 4 applies a bending force to the work roll 2 in the direction of arrow B. In FIG. 1, the work roll 2 is supported by the backup roll 7, but an intermediate roll may be provided between the backup roll 7 and the work roll 2. The backup roll 7 or the intermediate roll that contacts the outer peripheral surfaces of the upper and lower work rolls 2 and supports the work roll 2 constitutes a support roll.

  According to the embodiment of the present invention, rolling is performed according to the flowchart shown in FIG. Hereinafter, the operation of the reverse rolling mill will be described with reference to FIG.

  First, step S1 in FIG. 3 will be described. In the reverse rolling mill, the material 1 to be rolled is reciprocated a plurality of times through the upper and lower work rolls 2 and rolled a plurality of times. However, according to the embodiment of the present invention, in step S1 of FIG. Based on the target plate flatness of the material 1 to be rolled, the roll shift operation amount, the roll bend operation amount, and the reduction operation amount are determined in advance for each of the multiple rolling operations. In step 2 and subsequent steps, the control unit 8 provided in the reverse rolling mill is provided in the roll shift device 3, the roll bend device 4, and the backup roll 7 during each rolling of the material 1 to be rolled according to these operation amounts. The reduction device 5 such as a hydraulic cylinder is controlled.

  Step S2 will be described. The value obtained by dividing the sheet width of the material 1 to be rolled by the sheet thickness (sheet width W / sheet thickness H) increases as the number of rolling of the material 1 to the work roll 2 increases. The influence of the roll shift at the initial stage where the value of the thickness H is small on the cross-sectional shape and flatness of the material 1 to be rolled obtained after the final rolling is small. Therefore, according to the embodiment of the present invention, in step S2, the control unit 8 sets the shift position of the work roll 2 for each rolling in the initial stage until the value of the plate width W / the plate thickness H reaches a predetermined value. The roll shift device 3 is controlled to change. This prevents the wear of the work roll 2 from being dispersed and prevents the cross-sectional shape and flatness obtained after the final rolling from being adversely affected. When the value of the plate width W / plate thickness H reaches a predetermined value, the wear dispersion by the roll shift is finished (YES in step S3). The wear dispersion control in step S2 is performed by the control unit 8 controlling the roll shift device 3 based on the roll shift operation amount predetermined for each rolling in step S1.

  An alternative timing for finishing the roll shift wear dispersion in step S2 will be described.

First, the flatness of the material 1 to be rolled will be briefly described. As shown in FIG. 4, the rolled material 1 generally changes its shape in the conveying direction so as to wave up and down with an amplitude l _h for each predetermined pitch l _{p in the} conveying direction, and the flatness λ is , Λ = l _h / l _p .

  Further, to briefly describe the plate crown, the plate crown is the difference between the thickness of the end portion in the width direction of the material 1 to be rolled and the thickness of the center portion. Is the amount by which the plate crown changes by being rolled once.

ここで、Ｈは、被圧延材の板厚であり、ａ，ｂは、板幅を板厚で除算した値（板幅W／板厚H）の変化に伴い変化する値である。 There is the following [Equation 1] relationship between the plate flatness λ and the plate crown change ΔCr.

Here, H is the plate thickness of the material to be rolled, and a and b are values that change as the value obtained by dividing the plate width by the plate thickness (plate width W / plate thickness H).

  In [Equation 1], within the range of ΔCr / H <b, even if the plate crown Cr is changed, the plate flatness λ does not change. Perform a roll shift. As a result, it is possible to disperse wear by roll shifting without affecting the flatness of the plate.

  For example, when the value of b decreases every time the work roll 2 rolls the work roll 2, even if the value of ΔCr / H fluctuates depending on the number of rolling, the value is a fluctuation around 2%. If there is, if the value of b becomes 2% or less, the wear dispersion by the roll shift may be finished. The number of rollings that does not satisfy ΔCr / H <b can be estimated from actual operation data. Whether the value of b increases or decreases each time the number of rolling increases is determined by conditions such as the type and temperature of the material 1 to be rolled, so that the value of b decreases as the number of rolling increases, This method can be applied.

  In the above description, the value b is used as a reference, but the value of the plate width W / the plate thickness H can be used instead. That is, when the value b decreases as the number of rolling increases, the value of the sheet width W / sheet thickness H increases as the number of rolling increases, so that the sheet width when ΔCr / H <b is not satisfied. The value of W / sheet thickness H is estimated from actual operation data, and when the sheet width W / sheet thickness H reaches this estimated value, the wear dispersion due to roll shift may be finished.

  When the wear dispersion by the roll shift is finished (YES in step S3), the process proceeds to step S4 in FIG. In this cross-sectional shape control, the control unit 8 controls the roll shift device 3, the roll bend device 4, and the reduction device 5 based on the roll shift operation amount, the roll bend operation amount, and the reduction operation amount that are predetermined for each rolling in step S1. This is done by controlling at least one of the following. Preferably, in order to enhance the shape control effect, the cross-sectional shape control is performed by using the roll shift device 3 and the roll bend device 4 together.

  Thus, the target flatness of the material 1 to be rolled is finally obtained by controlling according to the predetermined roll shift operation amount, roll bend operation amount, and reduction operation amount. However, even if rolling is performed according to a predetermined amount of operation, the flatness finally obtained actually deviates from the target flatness due to various factors.

  Therefore, according to the embodiment of the present invention, the actual flatness of the material 1 to be rolled is obtained in step S5 of FIG. The obtained flatness is input to the calculation unit 9. Subsequently, based on the input flatness, the calculation unit 9 can obtain at least one of the roll shift operation amount, the roll bend operation amount, and the reduction operation amount at the time of final rolling so that the target flatness can be actually obtained. The correction value is calculated and output to the control unit 8. The control unit 8 controls at least one of the roll bend device 4, the roll shift device 3, and the reduction device 5 during the final rolling of the material 1 to be rolled according to the correction value. Thereby, the deviation from the target flatness of the flatness actually obtained by the final rolling can be suppressed.

  This flatness input will be described. For example, the flatness is divided into five levels of 0 to 1%, 1 to 2%, 2 to 3%, 3 to 4%, and 4 to 5%. Thus, the operator can determine the level, and the operator can input the flatness level using the input device. In addition, since the flatness defect of a certain level may be intentionally taken out before final rolling, in this case, the input flatness level is a difference between the actual flatness and the target flatness during the rolling. This input device outputs the inputted flatness level to the calculation unit 9. Instead of the operator's eye measurement, a measuring instrument for measuring the flatness may be provided, and the measuring instrument may output the measurement result of the flatness to the calculation unit 9. As the flatness measuring instrument, an appropriate instrument such as an optical measuring instrument can be used.

  In step S6 of FIG. 3, the calculation unit 9 calculates the correction value described above based on the input flatness level or measured flatness. The inputted flatness is preferably the flatness of the material 1 to be rolled when it is close to the final rolling, and more preferably the flatness of the material 1 to be rolled immediately before the final rolling. Thereby, since the immediately preceding flatness is taken into account, the actual deviation from the target flatness can be further suppressed.

ここで、α_Ｆはワークロールベンディング力影響係数であり、ｈ_Ｎ−１はＮ−１回目の圧延で得られる被圧延材１の板厚であり、λ_Ｎ−１はＮ−１回目の圧延で得られる平坦度であり、ΔＣ_ｒｍλは、λ_Ｎ−１に対応するメカニカルクラウン変化を表し、β_Ｎ−１はＮ−１回目の圧延時の転写率である。 Next, an example of a method for calculating the correction value will be described. When correct only roll bending operation amount at the time of final rolling, the final rolling is a rolling N th can be this correction value [Delta] F _N in the following expression (2).

Here, α _F is a work roll bending force influence coefficient, h _N-1 is a plate thickness of the material 1 to be rolled obtained by the N-1th rolling, and λN _-1 is the N-1th rolling. ΔC _rmλ represents a mechanical crown change corresponding to λ _N-1 , and β _N-1 is a transfer rate at the _{N- 1th} rolling.

ここで、α_Ｓはロールシフト影響係数である。 Roll bend operation amount at the time of final rolling predetermined in step S1 of FIG. 3 as F _N, F _{N +} ΔF _N is not within the acceptable range of roll bending, instead of correcting the bending amount F _N, step S1 It is possible to correct the roll shift operation amount S _N at the time of final rolling determined in (1). The correction amount of the roll shift operation amount [Delta] S _N can be represented by the following Formula 3.

Here, α _S is a roll shift influence coefficient.

  According to the present invention, the method by which the calculation unit 9 calculates the correction value in step S6 is not limited to this example, and the correction value can be calculated by another appropriate method.

  When the calculation of the correction value in step S6 ends, the process proceeds to step S7, and the control unit 8 switches at least one of the roll shift device 3, the roll bend device 4 and the reduction device 5 based on the correction value at the time of final rolling. Rolling is performed under control.

  As described above, according to the embodiment of the present invention, based on the target flatness, the roll shift operation amount, the roll bend operation amount, and the rolling operation amount at the time of each rolling are determined in advance as a rolling schedule, and the control unit 8 The roll shift device 3, the roll bend device 4, and the reduction device 5 are controlled at the time of each rolling in accordance with the determined operation amount. In the above-described embodiment, the rolling schedule performs wear dispersion roll shift until the value obtained by dividing the plate width by the plate thickness from the first rolling reaches a predetermined value, and then performs the cross-sectional shape control of the material 1 to be rolled. Standing like that. The method of determining the roll shift operation amount, roll bend operation amount, and reduction operation amount at the time of each rolling can be calculated using a known appropriate method. For example, as described in Patent Document 1, the amount of roll shift operation and roll bend during each rolling in the order from the final rolling to the first rolling on condition of the target flatness and target plate thickness after the final rolling. The operation amount and the reduction operation amount may be calculated.

  Thus, according to the embodiment of the present invention, rolling is performed according to a predetermined roll shift operation amount, roll bend operation amount, and reduction operation amount during each rolling, but the roll shift operation is finally obtained. In an initial stage that does not adversely affect the cross-sectional shape and flatness of the material 1, roll shift wear dispersion is performed, and then the cross-sectional shape control of the material 1 to be rolled is performed. Therefore, it is possible to disperse the wear of the work roll 2 without adversely affecting the cross-sectional shape and flatness of the material 1 to be finally obtained.

  Furthermore, according to the embodiment of the present invention, based on the actual flatness of the material 1 to be rolled immediately before the final rolling, the operation amount correction value is calculated so as to obtain the target flatness, and based on this correction value. The final rolling is controlled. Thereby, the deviation of the actually obtained flatness from the target flatness can be sufficiently suppressed, and a highly accurate flatness can be realized.

  In addition, this invention is not limited to embodiment mentioned above, Of course, a various change can be added in the range which does not deviate from the summary of this invention. For example, in the above-described embodiment, at least one correction value of the roll shift operation amount, the roll bend operation amount, and the reduction operation amount only at the time of final rolling is calculated, and rolling control is performed based on this correction value at the time of final rolling. However, the amount of roll shift operation and the amount of roll bend operation at the time of the 2nd or more rolling retroactive from the time of the final rolling which is the Nth rolling, for example, each of the N-2th, N-3th and Nth rolling. Further, at least one correction value of the reduction operation amount may be calculated, and rolling control may be performed based on the correction value at the N-2th, N-3th, and Nth rolling. In this case, it is preferable to input the flatness of the material to be rolled 1 to the calculation unit 9 immediately after the N-4th rolling.

  Further, the plate shape adjusting means is constituted by at least one of the above-described roll shift device 3, roll bend device 4 and reduction device 5, but the plate shape adjusting means is not limited to this and is constituted by other appropriate ones. Also good.

  In the above-described embodiment, the roll shift operation amount, the roll bend operation amount, and the reduction operation amount are predetermined for each rolling based on the target flatness, but the present invention is not limited to this, and instead of the target flatness. Based on the target cross-sectional shape of the material 1 to be rolled, the roll shift operation amount, the roll bend operation amount, and the reduction operation amount may be determined in advance in step S1 of FIG. In this case, a cross-sectional shape is obtained by measuring the measuring instrument or the operator in step S5, and a correction value for these manipulated variables is calculated based on this cross-sectional shape in step S6. Other processes and operations are the same as those in the above-described embodiment. Thereby, the shift | offset | difference of the cross-sectional shape of the to-be-rolled material 1 obtained after final rolling and target cross-sectional shape can be suppressed.

  Furthermore, the process of step S1 may be performed based on both the target flatness and the target cross-sectional shape. In this case, in step S5, the flatness and cross-sectional shape of the material to be rolled 1 are obtained by measuring the measuring instrument or the operator, and in step S6, the roll shift operation amount and roll bend are based on the flatness and cross-sectional shape. At least one correction value of the operation amount and the reduction operation amount is calculated. Other processes and operations are the same as those in the above-described embodiment. Thereby, the shift | offset | difference with the flatness and cross-sectional shape of the to-be-rolled material 1 obtained after final rolling, and target flatness and target cross-sectional shape can be suppressed. In this case, the flatness and the cross-sectional shape data may be input to the calculation unit 9 by the operator's measurement in step S6.

  Moreover, it is preferable to apply the shape of patent document 2 which can heighten the plate crown control effect to the work roll 2. FIG. According to Patent Document 2, as shown in FIG. 5, the curve shape of the bus bar of the work roll 2 is a first region in which the roll diameter changes from one axial direction to the other in the axial central portion of the roll. 21, the second region 22 outside the first region 21 where the change of the roll diameter is reversed, and the outer side of the second region 22 where the roll diameter is opposite to the change direction of the roll diameter of the first region 21. The third region 23 having a portion that changes in the direction and the gradient of the roll diameter change is steeper than the gradient of the roll diameter change in the first region 21, and the change in the roll diameter outside the third region 23. Is the same as the change direction of the third region 23, and the change gradient of the fourth region 24 is looser than that of the third region 23, and there is almost no change in the roll diameter outside the fourth region 24. The shape is almost cylindrical or roll diameter Change the fifth region 25 having the same changing direction as the first region 21 is reversed again, it consists. Further, according to Patent Document 2, the position of the inflection point of the work roll 2 is shifted to the center so as to enhance the plate crown control effect on the medium width plate due to roll shift. Even in rolling, the contour shape of the work roll 2 and the roll bending displacement due to the roll bend are superimposed, and the width-direction displacement of the roll on the side where the outer surface of the work roll 2 is in contact with the material to be rolled is a gently changing shape. Thus, a combination of roll shift amount and roll bend force can be commanded according to the sheet width of the material to be rolled (refer to Patent Document 2 for details).

It is a block diagram of the reverse rolling mill by embodiment of this invention. It is explanatory drawing of the roll shift and roll bend by the roll shift apparatus and roll bend apparatus of FIG. It is a flowchart which shows the operation | movement by the reverse rolling mill of FIG. It is explanatory drawing of the flatness of a to-be-rolled material. It is a figure which shows the work roll shape of patent document 2. FIG.

Explanation of symbols

1 Roll material 2 Upper and lower work rolls 3 Roll shift device 4 Roll bend device 5 Reduction device
7 Backup roll 8 Control unit 9 Calculation unit 21 First region 22 Second region 23 Third region 24 Fourth region 25 Fifth region

Claims (5)

A reverse rolling mill that performs rolling a plurality of times by reciprocating a material to be rolled a plurality of times,
In the range of rolling the material to be rolled, the upper and lower work rolls having a contour of irregularities, and sandwiching and rolling the rolled material,
A support roll for supporting the upper and lower work rolls in contact with the outer peripheral surface thereof;
A plate-shaped adjusting means acting on the upper and lower work rolls to control the cross-sectional shape of the material to be rolled,
A control unit for controlling the plate shape adjusting means at each rolling according to a plate shape control amount at the time of each rolling determined in advance based on a target plate shape comprising at least one of a target flatness and a target cross-sectional shape;
Based on the plate shape of the material to be rolled before the final rolling after the second half of the multiple rolling, the correction value of the predetermined plate shape control amount at the time of the final rolling is calculated so as to obtain the target plate shape. And a calculation unit that outputs to the control unit,
The control unit controls the plate shape adjusting means at the time of final rolling based on the correction value calculated by the calculation unit,
The plate-shaped adjustment means, a roll shifting device for shifting in the axial direction opposite said upper and lower work rolls each other, the roll bend device for imparting bending force to the work roll, and said rolling force of the the material to be rolled Including at least one rolling device applied via a support roll;
The plate shape control amount includes at least one of a roll shift operation amount of the roll shift device, a roll bend operation amount of the roll bend device, and a reduction operation amount of the reduction device,
The control unit may shift the work roll can be suppressed the influence of a plate shape of the rolled material after the final rolling, at the initial stage of the plurality of times of rolling, wherein each rolling material to be rolled The wear of the upper and lower work rolls is dispersed by controlling the roll shift device so that the shift positions of the upper and lower work rolls are different, and after the initial stage, the cross-sectional shape of the material to be rolled is adjusted. Controlling the plate shape adjusting means ;
The initial stage is a stage from the start of rolling until the value obtained by dividing the sheet width of the material to be rolled by the sheet thickness reaches a predetermined value,
The reverse rolling machine according to claim 1, wherein the predetermined value is set within a range in which the influence of the work roll shift in the initial stage on the plate shape of the material to be rolled after final rolling can be suppressed .   2. The reverse rolling mill according to claim 1, wherein the plate shape considered when the calculation unit calculates the correction value is a plate shape of the material to be rolled immediately before final rolling. The plate shape is flatness,
The flatness of the material to be rolled before the final rolling after the latter half of the multiple rolling is further provided with an input device that can be input by an operator in a plurality of levels, and the input device has a level of flatness by the operator. The reverse rolling mill according to claim 1 or 2, wherein when the is input, the level is output to the calculation unit, and the calculation unit calculates the correction value based on the level.   It comprises a measuring instrument that measures the plate shape of the material to be rolled before the final rolling after the second half of the multiple rolling and outputs it to the calculation unit, and the calculation unit corrects the correction based on the measured plate shape. The reverse rolling mill according to claim 1, 2 or 3, wherein a value is calculated. A reverse rolling mill that performs rolling a plurality of times by reciprocating a material to be rolled a plurality of times,
In the range of rolling the material to be rolled, the upper and lower work rolls having a contour of irregularities, and sandwiching and rolling the rolled material,
A support roll for supporting the upper and lower work rolls in contact with the outer peripheral surface thereof;
A plate-shaped adjusting means acting on the upper and lower work rolls to control the cross-sectional shape of the material to be rolled,
A control unit for controlling the plate shape adjusting means at each rolling according to a plate shape control amount at the time of each rolling determined in advance based on a target plate shape comprising at least one of a target flatness and a target cross-sectional shape,
The plate-shaped adjustment means, a roll shifting device for shifting in the axial direction opposite said upper and lower work rolls each other, the roll bend device for imparting bending force to the work roll, and said rolling force of the the material to be rolled Including at least one rolling device applied via a support roll;
The plate shape control amount includes at least one of a roll shift operation amount of the roll shift device, a roll bend operation amount of the roll bend device, and a reduction operation amount of the reduction device,
The control unit may shift the work roll can be suppressed the influence of a plate shape of the rolled material after the final rolling, at the initial stage of the plurality of times of rolling, wherein each rolling material to be rolled The wear of the upper and lower work rolls is dispersed by controlling the roll shift device so that the shift positions of the upper and lower work rolls are different, and after the initial stage, the cross-sectional shape of the material to be rolled is adjusted. Controlling the plate shape adjusting means ;
The initial stage is a stage from the start of rolling until the value obtained by dividing the sheet width of the material to be rolled by the sheet thickness reaches a predetermined value,
The reverse rolling machine according to claim 1, wherein the predetermined value is set within a range in which the influence of the work roll shift in the initial stage on the plate shape of the material to be rolled after final rolling can be suppressed .

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