WO2020152868A1

WO2020152868A1 - Rolling equipment and rolling method

Info

Publication number: WO2020152868A1
Application number: PCT/JP2019/002557
Authority: WO
Inventors: Akihiro Omura; Akira Sako; Tadashi Hiura; Toru Takeguchi; Ryohei Kinose; Hideaki Furumoto; Shinya Kanemori
Original assignee: Primetals Technologies Japan, Ltd.; Tata Steel Ijmuiden B.V.
Priority date: 2019-01-25
Filing date: 2019-01-25
Publication date: 2020-07-30
Also published as: EP3914402A1; CN113056337A; JP2022510464A; EP3914402A4; CN113056337B; JP7091560B2

Abstract

Rolling equipment includes a strip wedge controller that obtains the distribution in the strip width direction of a strip load applied to a rolled material 5 from a work side load P_W and a drive side load P_D, that calculates the strip wedge after the rolling based on the distribution in the strip width direction of the strip load obtained and the position in the strip width direction of the rolled material 5 set by a rolled material position setting device, that computes a working roll gap difference between the work side and the drive side of a vertical pair of an upper working roll 21 and a lower working roll 31 for making the strip wedge after the rolling calculated a predetermined value, and that controls the drive side hydraulic cylinder 11D and the work side hydraulic cylinder 11W such that the working roll gap difference computed is attained.

Description

ROLLING EQUIPMENT AND ROLLING METHOD

The present invention relates to rolling equipment and a rolling method.

As an example of a method of simultaneously controlling camber and wedge of a rolled material during hot rolling, Patent Document 1 discloses a method in which a rolled material width-rolled in a vertical mill is constrained by an input side guide and guided to a horizontal mill, which undergoes one-side rolling reduction adjustment to correct the wedge of the rolled material. At the same time, the camber of the rolled material is corrected by an output side guide, whereby it is possible to control the camber and the wedge simultaneously.

Patent Document 2 aims to quickly and accurately calculate a mill stretch amount, which is an element used in computing a gage meter strip thickness by a function of which high responsiveness is required such as automatic strip thickness control in hot rolling. To achieve that, Patent Document 2 describes as follows: an influence coefficient consisting of a mill stretch parameter for estimating a mill stretch matched with the material condition of each rolled material is accurately computed from a dynamics model beforehand by a different function in a device different from an AGC before the operation start of the AGC, for example, earlier by a fixed time at which the rolled material is engaged in the rolling mill. Then, at an appropriate timing, the mill stretch parameter is delivered to an AGC controller via a transmission circuit. After the rolled material has reached the rolling mill, the mill stretch amount is estimated for each control cycle by the AGC. At this time, the mill stretch parameter is used to estimate the mill stretch quickly and accurately from an actual rolling load and an actual bender pressure with using a primary formula.

Japanese Patent No. 3241566

Japanese Patent No. 2878060

The technique disclosed in Patent Document 1 is stated that it can simultaneously control the strip camber and the wedge. However, it is necessary to extract a differential load due to the strip wedge by removing a differential load due to a temperature factor from a differential load measurement value of a rolling roll section. That is, the separation of the differential load due to the strip wedge and the temperature difference is necessary. For that purpose, an apparatus for temperature measurement is required. Further, the technique is greatly affected by the accuracy in the temperature measurement. Due to these factors, there is difficulty in correcting a working roll gap difference in a highly accurate manner.

The technique disclosed in Patent Document 2 can control the strip thickness. There is, however, no description on the details of the distribution of the strip load in the strip width direction or side guides on the input and output sides. Further, the influence of the mill constant difference between the work side and the drive side is not taken into consideration. Further, the thickness of the strip is calculated at its middle portion, and there is no concept of separately calculating the strip thickness on the work side and the drive side, making it disadvantageously impossible to easily calculate the strip wedge after the rolling.

The present invention has been made in view of the above problems. It is an object of the present invention to provide rolling equipment and a rolling method making it possible to control the strip wedge in simple structure.

The present invention includes a plurality of means for solving the above problem, an example of which is rolling equipment including: a drive side hydraulic cylinder; a work side hydraulic cylinder; a vertical pair of working rolls rolling a rolled material by a rolling reduction force imparted by the drive side hydraulic cylinder and the work side hydraulic cylinder; a drive side load sensor detecting a rolling reduction force due to the drive side hydraulic cylinder; a work side load sensor detecting a rolling reduction force due to the work side hydraulic cylinder; a rolled material position setting device setting a position in a strip width direction of the rolled material introduced to the vertical pair of working rolls; and a strip wedge controller configured to adjust a strip wedge of the rolled material after rolling. The strip wedge controller includes: a strip wedge computation section configured to obtain a distribution in the strip width direction of a strip load applied to the rolled material from a load of a drive side support portion and a load of a work side support portion of the working rolls detected by the drive side load sensor and the work side load sensor and to calculate a strip wedge after rolling based on the distribution in the strip width direction of the strip load obtained and the position in the strip width direction of the rolled material set by the rolled material position setting device; a gap difference computation section configured to compute a working roll gap difference, between a drive side and a work side of the vertical pair of working rolls, for making the strip wedge after rolling calculated by the strip wedge computation section a predetermined value; and a gap difference control section configured to controll the drive side hydraulic cylinder and the work side hydraulic cylinder in such a manner that the working roll gap difference computed by the gap difference computation section is attained.

In accordance with the present invention, it is possible to control the strip wedge in simple structure. Other objects, structure, and effects will be apparent from the following description of examples.

Fig. 1 is a diagram illustrating an example of the structure of a hot finish tandem rolling mill. Fig. 2 is a diagram illustrating an example of the structure of a rough rolling mill and a thick strip mill. Fig. 3 is a top view illustrating the structure of a strip wedge controller according to example 1 of the present invention. Fig. 4 is a side view illustrating the structure of the strip wedge controller according to example 1. Fig. 5 is a diagram illustrating the distribution in the width direction of the rolling load and the post-rolling strip wedge calculating method by the strip wedge controller of example 1. Fig. 6 is a block diagram illustrating the strip wedge controller according to example 1. Fig. 7 is a diagram illustrating the relationship between the working roll gap difference and the differential load in the case where the disturbance is the strip wedge before rolling under the condition shown in Table 1 of example 1. Fig. 8 is a diagram illustrating the relationship between the working roll gap difference and the strip wedge after rolling in the case where the disturbance is the strip wedge before rolling under the condition shown in Table 1 of example 1. Fig. 9 is a diagram illustrating the relationship between the working roll gap difference and the differential load in the case where the disturbance is the temperature difference in the strip width direction under the condition shown in Table 1 of example 1. Fig. 10 is a diagram illustrating the relationship between the working roll gap difference and the strip wedge after rolling in the case where the disturbance is the temperature difference in the strip width direction under the condition shown in Table 1 of example 1. Fig. 11 is a diagram illustrating the relationship between the differential load and the roll gap difference correction amount between the work side and the drive side necessary for making the strip wedge after the rolling zero under the condition shown in Table 1 of example 1. Fig. 12 is a diagram illustrating the strip wedge control result in a test machine according to example 1, illustrating the relationship between the rolling distance from the control start and the differential load measurement value. Fig. 13 is a diagram illustrating the strip wedge control result in the test machine according to example 1, illustrating the relationship between the rolling distance from the control start and the working roll gap difference correction amount. Fig. 14 is a diagram illustrating the strip wedge control result in a test machine according to example 1, illustrating the relationship between the rolling distance from the control start and the target value and the measurement value of the strip wedge after the rolling. Fig. 15 is a diagram illustrating the relationship between the calculated value and the measurement value of the strip wedge after the rolling in the test machine of example 1. Fig. 16 is a flowchart illustrating the strip wedge control flow in example 1. Fig. 17 is a top view illustrating the structure of a strip wedge controller according to example 2 of the present invention. Fig. 18 is a side view illustrating the structure of the strip wedge controller of example 2. Fig. 19 is a diagram illustrating the structure for calculating the mill constant on the work side and the drive side of a rolling mill according to example 2. Fig. 20 is a diagram illustrating a mill constant calculation method according to example 2. Fig. 21 is a flowchart illustrating the strip wedge control flow in example 2. Fig. 22 is a top view of the structure of a strip wedge controller according to example 3 of the present invention. Fig. 23 is a side view of the structure of the strip wedge controller of example 3. Fig. 24 is a flowchart illustrating the strip wedge control flow in example 3. Fig. 25 is a top view of the structure of a strip wedge controller according to example 4 of the present invention. Fig. 26 is a side view of the structure of the strip wedge controller of example 4. Fig. 27 is a block diagram illustrating the strip wedge controller of example 4. Fig. 28 is a flowchart illustrating the strip wedge control flow in example 4. Fig. 29 is a top view illustrating the structure of a side guide static control by a strip wedge controller according to example 5 of the present invention. Fig. 30 is a top view of strip wedge control structure in a strip wedge controller according to example 6 of the present invention. Fig. 31 is a side view of the structure of the strip wedge controller of example 6. Fig. 32 is a diagram illustrating the distribution in the width direction of the rolling load and the post-rolling strip wedge calculating method by the strip wedge controller of example 6. Fig. 33 is a flowchart illustrating the strip wedge control flow in example 6. Fig. 34 is a top view of structure for controlling the rolled material in the strip width direction, which is a modification of the strip wedge controller of example 6.

Description of Examples

In the following, examples of the rolling equipment and the rolling method of the present invention will be described with reference to the drawings.

Example 1

Example 1 of the rolling equipment and the rolling method of the present invention will be described with reference to Figs. 1 through 16.

First, the outline of rolling equipment to which the present invention is suitably applicable will be described with reference to Figs. 1 and 2. Fig. 1 is a diagram illustrating an example of the structure of a general hot finish tandem rolling mill, and Fig. 2 is a diagram illustrating an example of the structure of a general rough rolling mill and a general thick strip mill.

The rolling equipment shown in Fig. 1 is a rolling mill generally referred to as a hot finish tandem rolling mill, which includes at least two or more horizontal mills 1 for rolling a rolled material 5, an input side guide 2 arranged on the input side of the first horizontal mill 1 and configured to set the position in the strip width direction of the rolled material 5 introduced into the horizontal mill 1, hydraulic cylinders 6 controlling the position in the strip width direction of the input side guide 2 by a constant pressure, a strip wedge controller 40 controlling the amount of a hydraulic fluid supplied to a hydraulic cylinder 11 in the first horizontal mill 1, a controller (not shown) controlling the operation of various apparatuses of the entire rolling equipment, for example, the amount of the hydraulic fluid supplied to the hydraulic cylinders 6, etc.

The rolling equipment shown in Fig. 2 is a rolling mill generally referred to as a rough rolling mill or a thick strip mill, and includes a horizontal mill 1 for rolling the rolled material 5, an input side guide 2 arranged on the input side of the horizontal mill 1 and an output side guide 3 arranged on the output side in order to set the position in the strip width direction of the rolled material 5 introduced to the horizontal mill 1, hydraulic cylinders 6A controlling the position in the strip width direction of the input side guide 2 by a constant pressure, hydraulic cylinders 6B controlling the position in the strip width direction of the output side guide 3 by a constant pressure, a strip wedge controller 41 controlling the amount of the hydraulic fluid supplied to the hydraulic cylinder 11 inside the horizontal mill 1, a control system (not shown) controlling the operation of various apparatuses of the entire rolling equipment, for example, the amount of the hydraulic fluid supplied to the

hydraulic cylinders

6A, 6B.

Next, the strip wedge controller with which the rolling equipment of the present example will be described in detail with reference to Figs. 3 through 6. Fig. 3 is a top view illustrating the structure of a strip wedge controller according to example 1 of the present invention, and Fig. 4 is a side view illustrating the structure of the strip wedge controller according to example 1.

While the rolling equipment having a strip wedge controller is described below for a case where the rolling equipment has a plurality of horizontal mills 1 as shown in Fig. 1, nothing in particular is changed in the case where the present invention is applied to the rolling equipment as shown in Fig. 2.

The strip wedge controller 40 of the present example shown in Figs. 1 and 3 is a device that adjusts the strip wedge of the rolled material 5 after the rolling by the most upstream horizontal mill 1 on the upstream side of which the input side guide 2 is installed and on the downstream side of which the horizontal mill 1 is installed, and, and further, that adjusts the strip wedge of the rolled material 5 having passed through the rolling equipment shown in Fig. 1.

As shown in Fig. 4, the horizontal mill 1 controlled by the strip wedge controller 40 of the present example includes a drive side hydraulic cylinder 11D, a work side hydraulic cylinder 11W, a vertical pair of an upper working roll 21 and a lower working roll 31 rolling the rolled material 5 by the rolling reduction force imparted by the drive side hydraulic cylinder 11D and the work side hydraulic cylinder 11W, an upper backup roll 22 and a lower backup roll 32 respectively supporting the upper working roll 21 and the lower working roll 31, a drive side load sensor 10D detecting the rolling reduction force due to the drive side hydraulic cylinder 11D, and a work side load sensor 10W detecting the rolling reduction force due to the work side hydraulic cylinder 11W.

Each of the drive side hydraulic cylinder 11D and the work side hydraulic cylinder 11W includes therein a displacement gage such that it is possible to measure the cylinder fluid column position.

The drive side load sensor 10D and the work side load sensor 10W are preferably load cells. It is possible, however, to apply a well-known apparatus capable of detecting load. The measurement results of the drive side load P_D by the drive side load sensor 10D and the work side load P_W by the work side load sensor 10W are output to a strip wedge computation section 7 of the strip wedge controller 40.

As shown in Figs. 3 and 4, the strip wedge controller 40 includes the strip wedge computation section 7, a working roll gap difference computation section 8, and a working roll gap difference control section 9.

The strip wedge computation section 7 obtains the distribution in the strip width direction of the strip load applied to the rolled material 5 from the drive side load P_D detected by the drive side load sensor 10D and the work side load P_W detected by the work side load sensor 10W.

The strip wedge computation section 7 calculates the post-rolling strip wedge based on the distribution in the strip width direction of the strip load obtained and the strip width direction position of the rolled material 5 set by the rolled material position setting device.

In the present example, the rolled material position setting device setting the position in the strip width direction of the rolled material 5 introduced to the vertical pair of upper working roll 21 and lower working roll 31 is the input side guide 2 installed on the input side of the upper working roll 21 and the lower working roll 31. In the case of the rolling equipment shown in Fig. 1, the rolled material 5 is constrained by from the second stand onward, so that it may be determined that the rolled material 5 basically does not meander. Thus, in the present example, the post-rolling strip wedge is calculated, assuming that the center in the strip width direction of the rolled material 5 and the centers in a width directions of the upper working roll 21 and the lower working roll 31 coincide with each other due to the input side guide 2 and from the second stand onward.

In the case of the rolling equipment shown in Fig. 2, the rolled material position setting device consists of the input side guide 2 and the output side guide 3 installed on the input side and the output side, respectively, of the horizontal mill 1.

In the following, the post-rolling strip wedge calculating method for the rolled material 5 by the strip wedge computation section 7 will be described in detail with reference to Fig. 5. Fig. 5 is a diagram illustrating the distribution in the width direction of the rolling load and the post-rolling strip wedge calculating method by the strip wedge controller of example 1.

First, the strip wedge computation section 7 receives the input of the drive side load P_D at the drive side support portion from the drive side load sensor 10D, and receives the input of the work side load P_W at the work side support portion from the work side load sensor 10W, obtaining the distribution in the strip width direction of the strip load applied to the rolled material 5 as shown in Fig. 5 from the drive side load P_Dand the work side load P_W.

Here, the balance in force in the vertical direction of the rolled material 5 is in the relationship to be expressed by equation (1).

Math 1

In equation (1), P_Dis the drive side load detection value (kN), P_Wis the work side load detection value (kN), W is the strip width (mm) of the rolled material 5, p_dis the rolling load (kN/mm) per unit width at the drive side strip end portion, and p_wis the rolling load (kN/mm) per unit width at the work side strip end portion.

The moment equilibrium of point A, which is the center in the width direction of the rolling mill shown in Fig. 5, is in the relationship to be expressed by the following equation (2).

Math 2

In equation (2), p(x) is the distribution of the rolling load in the strip width direction per unit width (kN/mm), L is the distance (mm) between the cylinders on the work side and the drive side, and x is the position (mm) in the strip width direction of the rolled material 5.

Here, the rolling load formula (linear distribution) per unit width of the rolled material 5 is in the relationship to be expressed by the following equation (3), and the restriction range of x is in the relationship to be expressed by the following formula (4).

Math 3

Math 4

From equation (2) in which the relationships of equations (3) and (4) are substituted and from equation (1), the rolling load p_dper unit width at the drive side strip end portion is expressed by the following equation (5), and the rolling load p_wper unit width at the work side strip end portion is expressed by the following equation (6).

Math 5

Math 6

From equations (5) and (6), the distribution in the strip width direction of the strip load can be obtained.

Next, the strip wedge computation section 7 imparts the strip width direction distribution of the strip load obtained to perform roll portion elastic deformation analysis and to calculate the strip wedge after the rolling.

In this roll portion elastic deformation analysis, the post-rolling strip wedge is calculated taking into consideration the bending, shear deformation, and flattening deformation of WR (the upper working roll 21 and the lower working roll 31) and BUR (the upper backup roll 22 and the lower backup roll 32), and the rigid-body displacement of the shaft end portions of WR and BUR.

In this process, the unknowns (f(x, i), y₁, y₂) shown in Fig. 5 are calculated by using formula (7) which is a matrix computation formula composed of (1) the vertical direction force equilibrium formula of WR and BUR, (2) the moment equilibrium formula of WR and BUR), (3) the displacement continuity of the contact portions of WR and BUR.

Math 7

Here, in Fig. 5 and formula (7), f(i, 1) is the inter-roll load distribution, and y₁and y₂are vertical displacement at both roll shaft ends, and are given as y₁(1), y₂(1), y₁(2), and y₂(2). Sign y1 indicates the working roll, sign y2 indicates the backup roll, sign (1) indicates the work side, and sign (2) indicates the drive side. Signs a(i, j), c(1, i), c(2, i), c(3, i), c(4, i), b₁(i), and b₂(i) indicate the influence coefficients.

From the roll change amount including the shaft deflection amount and flattening amount of the upper and lower working rolls and the upper and lower backup rolls calculated by using the above formula (7), there is calculated the surface profile between the rolled material 5, the upper working roll 21, and the lower working roll 31.

From the surface profile thus obtained, there is obtained a post-rolling strip wedge Δh (= drive side strip thickness h_d- work side strip thickness h_w). In this process, the evaluation position of the strip thickness of the rolled material 5 can be arbitrarily determined. Usually, it is desirable for the position to be 25 mm from the strip end.

Referring back to Figs. 3 and 4, the working roll gap difference computation section 8 computes the gap difference between the upper working roll 21 and the lower working roll 31 on the work side and the drive side necessary for setting the post-rolling strip wedge calculated by the strip wedge computation section 7 to a predetermined value.

A working roll gap difference control section 9 controls a drive side hydraulic cylinder 11D and a work side hydraulic cylinder 11W such that the working roll gap difference computed by the working roll gap difference computation section 8 is attained.

In the following, the method of computing the working roll gap difference by the working roll gap difference computation section 8 and the control of the drive side hydraulic cylinder 11D and the work side hydraulic cylinder 11W by the working roll gap difference control section 9 will be described in detail with reference to Fig. 6. Fig. 6 is a block diagram illustrating the strip wedge controller according to embodiment 1.

In the working roll gap difference computation section 8, an influence coefficient Ks including the strip wedge transfer ratio, etc. is multiplied by the deviation between the working roll output side strip wedge Δh (= drive side strip thickness h_d- work side strip thickness h_w) calculated by the strip wedge computation section 7 and the desired strip wedge (output side strip wedge target value Δh_ref). Further, ordinary PID (proportional-integral-differential) control is applied to obtain the working roll gap difference correction amount (the stroke difference at the hydraulic cylinder positions on the work side and the drive side). After this, the working roll gap difference computation section 8 outputs the obtained working roll gap difference correction amount to the working roll gap difference control section 9.

Here, the influence coefficient Ks is a coefficient for conversion from the strip wedge correction amount to the working roll gap difference correction amount. It is given by the following equation (8).

Math 8

Here, in equation (8), ζ is the strip wedge transfer ratio (-) at the strip end position, L is, as in equation (2), the distance (mm) between the work side and drive side cylinders, and W is the strip width (mm).

As the desired strip wedge (output side strip wedge target value Δh_ref), there is employed a value input from the host controller of the

strip wedge controller

40, 41, or there is employed a value input by the operator via the input device (not shown) of the

strip wedge controller

40, 41. In this way, it is to be set in various ways.

The working roll gap difference control section 9 controls the fluid column position of the drive side hydraulic cylinder 11D and the work side hydraulic cylinder 11W such that the working roll gap difference correction amount computed by the working roll gap difference computation section 8 is attained. For example, the computed working roll gap difference correction amount is set to 1/2, and then, at the drive side

hydraulic cylinder

11D, 1/2 working roll gap difference correction amount is subtracted, and, at the work side

hydraulic cylinder

11W, 1/2 working roll gap difference correction amount is added.

As described below, the control of the present example described above is performed based on the following findings first clarified by the present inventors: even if there is a strip wedge before the rolling of the rolled material 5 or even if there is a difference in temperature in the strip width direction, the differential load is measured independently of such disturbance, whereby the working roll gap difference correction amount for setting the strip wedge to a predetermined amount is determined.

In the following, it will be described, with reference to Figs. 7 through 15, how the control of the

strip wedge controller

40, 41 of the present invention has come to be derived (the derivation of the working roll gap difference correction amount by the strip wedge computation section 7 and the working roll gap difference computation section 8).

Fig. 7 is a diagram illustrating the relationship between the working roll gap difference and the differential load in the case where the disturbance is the strip wedge before rolling under the condition shown in Table 1 of example 1, and Fig. 8 is a diagram illustrating the relationship between the working roll gap difference and the strip wedge after rolling in the case where the disturbance is the strip wedge before rolling under the condition shown in Table 1 of example 1. Fig. 9 is a diagram illustrating the relationship between the working roll gap difference and the differential load in the case where the disturbance is the temperature difference in the strip width direction under the condition shown in Table 1 of example 1, and Fig. 10 is a diagram illustrating the relationship between the working roll gap difference and the strip wedge after rolling. Fig. 11 is a diagram illustrating the relationship between the differential load and the roll gap difference correction amount between the work side and the drive side necessary for making the strip wedge after the rolling zero under the condition shown in Table 1 of example 1.

First, under the condition as shown in Table 1, i.e., a strip width of 1750 mm, an input side strip thickness of 30 mm, a rolling reduction ratio of 40%, a working roll diameter of 835 mm × a barrel length of 2180 mm, a backup roll diameter of 1550 mm × a barrel length of 2160 mm, and a mill constant (sum total of the work side and the drive side) of 5880 kN/mm, the present inventors obtained the relationship of the differential load (work side - drive side) (kN) with respect to the working roll gap difference (mm) on the work side and the drive side (drive side: rolling reduction), and the relationship of the post-rolling strip wedge (work side strip thickness large: positive) (mm) with respect to the working roll gap difference (mm) on the work side and the drive side (drive side rolling reduction: positive) when the strip wedge ratio (= (drive side strip thickness - work side strip thickness)/central strip thickness × 100) was varied as follows: 0%, 1% (drive side: thick), and 2% (drive side: thick). Fig. 7 shows the relationship of the differential load with respect to the working roll gap difference, and Fig. 8 shows the relationship of the post-rolling strip wedge with respect to the working roll gap difference.

As a result, as shown in Fig. 7, independently of the strip wedge ratio, as the working roll gap difference increases, the load on the drive side increases, and the differential load increases. As the strip wedge ratio increases, however, the differential load increases if the working roll gap difference is the same.

Further, as shown in Fig. 8, it has become clear that, independently of the strip wedge ratio, the larger the working roll gap difference, the further the post-rolling strip wedge increases such that the strip thickness on the work side increases. Further, it has been clarified that, in order to reduce the post-rolling strip wedge to zero when the strip wedge ratio is 0%, the working roll gap difference is to be set to 0 mm. When the strip wedge ratio is 1%, the working roll gap difference is to be set to approximately 0.9 mm, and when the strip wedge ratio is 2%, the working roll gap difference is to be set to approximately 1.7 to 1.8 mm.

Next, on the assumption that there is a temperature difference in the strip width direction under the condition shown in Table 1, the present inventors obtained the relationship of the differential load (work side - drive side) (kN) with respect to the working roll gap difference (mm) on the work side and the drive side (drive side rolling reduction: positive), and the relationship of the post-rolling strip wedge (work side strip thickness large: positive) (mm) with respect to the working roll gap difference (mm) on the work side and the drive side (drive side rolling reduction: positive) when the deformation resistance ratio (= (drive side deformation resistance - work side deformation resistance)/central deformation resistance + 1.0) was varied as follows: 1.0, 1.3 (drive side: large), and 1.5 (drive side: large). Fig. 9 shows the relationship of the differential load with respect to the working roll gap difference, and Fig. 10 shows the relationship of the post-rolling strip wedge with respect to the working roll gap difference.

As a result, as shown in Fig. 9, as in the case where the strip wedge ratio is varied, independently of the deformation resistance ratio, the load on the drive side increases as the working roll gap difference increases and the differential load increases, and as the deformation resistance ratio increases, the differential load increases even where the working roll gap difference is the same.

Further, as shown in Fig. 10, it has become clear that independently of the deformation resistance ratio, as the working roll gap difference increases, the post-rolling strip wedge increases such that the strip thickness on the work side increases. Further, it has become clear that to reduce the post-rolling strip wedge to zero when the deformation resistance ratio is 1.0, the working roll gap difference is to be set to 0 mm. When the deformation resistance ratio is 1.3, the working roll gap difference is to be set to approximately 0.5 mm, and when the deformation resistance ratio is 1.5, the working roll gap difference is to be set to approximately 0.9 to 1.0 mm.

The relationships of Figs. 7 through 10 have been summed up. Fig. 11 shows the relationship of the pre-rolling strip wedge and the strip width direction temperature difference (deformation resistance difference) with respect to the working roll gap difference correction amount (mm) on the work side and the drive side (drive side rolling reduction: positive) with respect to the differential load detection value (work side - drive side) (kN).

As a result, as shown in Fig. 11, it has become clear that independently of the difference in the pre-rolling strip wedge and the width direction temperature difference (deformation resistance difference), the correction amount of the working roll gap difference can be obtained with respect to the differential load detection value.

In view of this, in a rolling test machine the structure of which shown in Fig. 6 is partially deformed, under the condition shown in Table 2, a control experiment was actually performed in which the strip wedge was calculated from the differential load measurement value after the start of the rolling control and in which the working roll gap difference correction amount was output such that the calculated strip wedge attained a target value. The results are shown in Figs. 12 through 15.

Fig. 12 is a diagram illustrating the strip wedge control result in a test machine under the condition of Table 2, illustrating the relationship between the rolling distance (mm) from the control start and the differential load measurement value (drive side - work side) (kN), Fig. 13 is a diagram illustrating the relationship between the rolling distance (mm) from the control start and the working roll gap difference correction measurement value (drive side rolling reduction: positive) (mm) of the working rolls on the work side and the drive side, and Fig. 14 is a diagram illustrating the measurement value and the target value of the post-rolling strip wedge (drive side strip thickness large: positive) (mm) with respect to the rolling distance (mm) from the control start. Fig. 15 is a diagram illustrating the relationship between the post-rolling strip wedge calculated value (drive side: thick) (mm) and the post-rolling strip wedge measurement value (drive side strip thickness large: positive) (mm) in the test machine.

From the measurement value of the differential load shown in Fig. 12, the post-rolling strip wedge calculated value was calculated by using the method as shown in Fig. 5, and the working roll gap difference correction amount was output to perform rolling in the working roll gap correction amount shown in Fig. 13, with the result that, as shown in Fig. 14, from 500 mm onward from the control start, the target value and the measurement value of the strip wedge coincided with each other at high level.

Further, the relationship between the measurement value shown in Fig. 14 and the calculation result of the post-rolling strip wedge calculated value from the measurement value of the differential load shown in Fig. 12 was evaluated, with the result that, as shown in Fig. 15, it has become clear that the post-rolling measurement strip wedge and the strip wedge calculated value are similar to each other.

From the findings of Figs. 11 and 15, it has become clear that independently of the various parameters such as the pre-rolling strip wedge and the width direction temperature difference (deformation resistance difference), it is possible to obtain the correction amount of the working roll gap difference for setting the strip wedge to a predetermined amount from the differential load detection value.

Next, the rolling method according to the present example will be described with reference to Fig. 16. Fig. 16 is a flowchart illustrating the strip wedge control flow in example 1.

The rolling method described below is executed by rolling equipment as shown in Figs. 1 and 2.

First, as shown in Fig. 16, the

strip wedge controller

40, 41 receives the input of the operating condition. At the same time, it receives the input of the drive side load P_D measured by the drive side load sensor 10D, and the input of the work side load P_W detected by the work side load sensor 10W (step S11).

Next, the strip wedge computation section 7 of the

strip wedge controller

40, 41 computes the width direction distribution of the rolling load from the drive side load P_D and the work side load P_W measured in step S11 (step S12).

After this, the strip wedge computation section 7 computes the post-rolling strip wedge by using the width direction distribution of the rolling load computed in step S12 (step S13). These steps S12 and S13 constitute the strip wedge computation process.

Next, the working roll gap difference computation section 8 of the

strip wedge controller

40, 41 computes the working roll gap difference between the work side and the drive side (the working roll gap difference correction amount) from the post-rolling strip wedge computed by the strip wedge computation section 7 in step S13 (step S14). This step S14 is the working roll gap difference computation process.

Next, the working roll gap difference control section 9 of the

strip wedge controller

40, 41 controls the working roll gap difference between the work side and the drive side such that the working roll gap difference computed by the working roll gap difference computation section 8 in step S14 is attained (step S15). This step S15 constitutes the working roll gap difference control process.

Next, the effect of the present example will be described.

The above-described rolling equipment of example 1 of the present invention includes a drive side hydraulic cylinder 11D, a work side hydraulic cylinder 11W, a vertical pair of an upper working roll 21 and a lower working roll 31 rolling the rolled material 5 by the rolling reduction force imparted from the drive side hydraulic cylinder 11D and the work side hydraulic cylinder 11W, a drive side load sensor 10D detecting the rolling reduction force due to the drive side hydraulic cylinder 11D, a work side load sensor 10W detecting the rolling reduction force due to the work side hydraulic cylinder 11W, a rolled material position setting device setting the strip width direction position of the rolled material 5 introduced to the vertical pair of upper working roll 21 and lower working roll 31, and a

strip wedge controller

40, 41 adjusting the strip wedge of the post-rolling rolled material 5.

Of these, the

strip wedge controller

40, 41 includes a strip wedge computation section 7 which obtains the strip width direction distribution of the strip load applied to the rolled material 5 from the drive side load P_D detected by the drive side load sensor 10D and the work side load P_W detected by the work side load sensor 10W and which calculates the post-rolling strip wedge based on the strip width direction distribution of the strip load obtained and the strip width direction position of the rolled material 5 set by the rolled material position setting device, a working roll gap difference computation section 8 which computes the working roll gap difference between the work side and the drive side of the vertical pair of upper working roll 21 and the lower working roll 31 for making the post-rolling strip wedge calculated by the strip wedge computation section 7 a predetermined value, and a working roll gap difference control section 9 controlling the drive side hydraulic cylinder 11D and the work side hydraulic cylinder 11W such that the working roll gap difference computed by the working roll gap difference computation section 8 is attained.

As a result, while it is unnecessary to perform temperature measurement as in Patent Document 1, it is possible to easily calculate the post-rolling strip wedge, so that it is possible to obtain the working roll gap difference correction amount necessary for setting the post-rolling strip wedge to a predetermined amount from the load on the drive side and the work side. That is, according to the present invention, it is possible to control the strip wedge to a predetermined amount in simple structure.

In the above-described case, the post-rolling strip wedge is calculated on the assumption that the center in the strip width direction of the rolled material 5 and the center in the width direction of the upper working roll 21 and the lower working roll 31 coincide with each other due to the input side guide 2 and from the second stand onward. However, it is not always necessary for the center in the strip width direction of the rolled material 5 and the center in the width direction of the upper working roll 21 and of the lower working roll 31 to coincide with each other. In the case where the center in the strip width direction of the rolled material 5 and the center in the width direction of the upper working roll 21 and of the lower working roll 31 do not coincide with each other, the post-rolling strip wedge can be calculated based on formulas (9) through (18) described in connection with example 6 described below (the strip meandering amount Y_c is not zero, and is regarded as a fixed value).

Example 2

The rolling equipment and the rolling method of example 2 of the present invention will be described with reference to Figs. 17 through 21. The components that are the same as those of example 1 are indicated by the same reference characters, and a description thereof will be left out. This also applies to the other examples described below.

Fig. 17 is a top view illustrating the structure of a strip wedge controller according to example 2 of the present invention, and Fig. 18 is a side view illustrating the structure of the strip wedge controller of example 2.
Fig. 19 is a diagram illustrating the structure for calculating the mill constant on the work side and the drive side of a rolling mill according to example 2. Fig. 20 is a diagram illustrating a mill constant calculation method according to example 2. Fig. 21 is a flowchart illustrating the strip wedge control flow in example 2.

As shown in Figs. 17 and 18, in the present example, previously before the rolling, the displacement amount of the drive side hydraulic cylinder 11D is measured by the displacement gage, and the displacement amount of the work side hydraulic cylinder 11W is measured by the displacement gage.

Then, the mill constants on the work side and the drive side are obtained based on the measured displacement amount of the drive side hydraulic cylinder 11D and the work side hydraulic cylinder 11W by a strip wedge computation section 7A provided instead of the strip wedge computation section 7 of example 1, and the post-rolling strip wedge is calculated by also using the difference in mill constant between the work side and the drive side.

When the mill constant on the work side is different from that on the drive side, the working roll gap difference correction amount is changed when the rolling load is changed due to its influence. In view of this, it is desirable to separately measure the cylinder displacements and the loads of the work side hydraulic cylinder and the drive side hydraulic cylinder, calculating the mill constants on the work side and the drive side from the gradient thereof, and to calculate the post-rolling strip wedge by incorporating the difference in spring constant between the work side and the drive side supporting the upper backup roll 22 and the difference in spring constant between the work side and the drive side supporting the lower backup roll 32.

In the following, the mill constant calculation method will be described with reference to Figs. 19 and 20.

As shown in Fig. 19, the work side and drive side spring constants supporting the upper backup roll 22 will be respectively referred to as K_tw and K_td, and the work side and drive side spring constants supporting the lower backup roll 32 will be respectively referred to as K_bw and K_bd.

On the above assumption, first, in the state in which the upper working roll 21 and the lower working roll 31 kiss each other, the relationship between the cylinder displacement amounts measured by the work side hydraulic cylinder 11W and the drive side hydraulic cylinder 11D and the loads measured by the work side load sensor 10W and the drive side load sensor 10D is organized, and, as shown in Fig. 20, the mill constants K on the work side and the drive side are calculated from the gradient thereof.

After this, with respect to the mill constants K on the work side and the drive side, it is assumed that the upper and lower backup roll support springs and the upper and lower backup roll rigidity and the upper and lower working roll rigidity are series springs, and taking into account the ratio of the upper and lower spring constants obtained through separate analysis with considering the presence of the housing or the like, the spring constants K_tw, K_td, K_bw, and K_bd on the work side and the drive side, which are the unknowns, are obtained. At this time, the calculation is performed by strictly taking into account the working roll shaft deflection deformation, the backup roll shaft deflection deformation due to the load from the working roll to the backup roll, the deformation due to the contact load between the upper and lower working rolls, the flattening deformation between the working rolls and the backup rolls, etc.

Otherwise, the present example is substantially of the same structure and operation as the rolling equipment and rolling method of example 1 described above, and a detailed description thereof will be left out.

Next, the rolling method according to the present example will be described with reference to Fig. 21.

First, as shown in Fig. 21, before the rolling, the

strip wedge controller

40, 41 receives the input of the displacement amount of the drive side hydraulic cylinder 11D and the displacement amount of the work side hydraulic cylinder 11W measured by the displacement gages (step S21).

Next, the strip wedge computation section 7A of the

strip wedge controller

40, 41 obtains the mill constants on the work side and the drive side by using the displacement amount of the drive side hydraulic cylinder 11D and the displacement amount of the work side hydraulic cylinder 11W measured in step S21, and, further, determines the ratio of the upper and lower spring constants, computing the spring constants K_tw, K_td, K_bw, and K_bd on the work side and the drive side from the mill constants obtained (step S22).

Further, as shown in Fig. 21, at the time of rolling, the

strip wedge controller

40, 41 receives the input of the operating condition and, at the same time, receives the input of the drive side load P_D measured by the drive side load sensor 10D and the input of the work side load P_W measured by the work side load sensor 10W (step S23).

Next, the strip wedge computation section 7A of the

strip wedge controller

40, 41 computes the width direction distribution of the rolling load by using the drive side load P_D and the work side load P_W measured in step S23 (step S24).

After this, the strip wedge computation section 7A computes the post-rolling strip wedge by using the width direction distribution of the rolling load computed in step S24 and the spring constants K_tw, K_td, K_bw, and K_bd computed in step S22 (step S25).

Next, the working roll gap difference computation section 8 of the

strip wedge controller

40, 41 computes the working roll gap difference between the work side and the drive side from the post-rolling strip wedge computed by the strip wedge computation section 7A in step S25 (step S26).

Subsequently, the working roll gap difference control section 9 of the

strip wedge controller

40, 41 controls the working roll gap difference between the work side and the drive side such that the working roll gap difference computed by the working roll gap difference computation section 8 in step S26 is attained (step S27).

Also in the rolling equipment and the rolling method of example 2 of the present invention, it is possible to attain substantially the same result as that of the rolling equipment and the rolling method of example 1 described above.

The strip wedge computation section 7A obtains the mill constants on the drive side and the work side based on the displacement amounts of the drive side hydraulic cylinder 11D and the work side hydraulic cylinder 11W measured by the displacement gages detecting the displacement amounts of the drive side hydraulic cylinder 11D and the work side hydraulic cylinder 11W, and calculates the post-rolling strip wedge by also using the difference between the mill constants on the work side and the drive side. When there is a difference in rigidity between the work side and the drive side, a strip wedge is disadvantageously generated under its influence when the rolling load is changed. However, as in the present example, by obtaining beforehand the rigidity on the work side and the drive side, it is possible to eliminate the influence of the rigidity at the time of the calculation of the strip wedge, making it possible to control the post-rolling strip wedge to a predetermined amount with higher accuracy.

Example 3

The rolling equipment and rolling method of example 3 of the present invention will be described with reference to Figs. 22 through 24.

Fig. 22 is a top view of the structure of a strip wedge controller according to example 3 of the present invention, and Fig. 23 is a side view of the structure of the strip wedge controller of example 3. Fig. 24 is a flowchart illustrating the strip wedge control flow in example 3.

As shown in Figs. 22 and 23, in the present example, the detection values of the drive side load sensor 10D and of the work side load sensor 10W are filtered by a filter computation section 12, and the detection values after the filtering are input to the strip wedge computation section 7B.

The filter computation section 12 is, for example, a first-order lag filter.

The strip wedge computation section 7B obtains the strip width direction distribution of the strip load applied to the rolled material 5 by using the detection values after the filtering, and calculates the post-rolling strip wedge based on the obtained strip width direction distribution of the strip load and the strip width direction position of the rolled material 5 set by the rolled material position setting device.

Otherwise, the present example is substantially of the same structure and operation as those of the rolling equipment and rolling method of example 1 described above, and a detailed description thereof will be left out.

Next, the rolling method according to the present example will be described with reference to Fig. 24.

First, as shown in Fig. 24, the

strip wedge controller

40, 41 receives the input of the operating condition, and receives the input of the drive side load P_D measured by the drive side load sensor 10D and the work side load P_W detected by the work side load sensor 10W (step S31).

Next, the filter computation section 12 of the

strip wedge controller

40, 41 filters the drive side load P_D and the work side load P_W measured in step S31 (step S32).

Subsequently, the strip wedge computation section 7B of the

strip wedge controller

40, 41 computes the width direction distribution of the rolling load from the drive side load P_D and the work side load P_W filtered in step S32 (step S33).

After this, the strip wedge computation section 7B computes the post-rolling strip wedge by using the width direction distribution of the rolling load computed in step S33 (step S34).

Next, the working roll gap difference computation section 8 of the

strip wedge controller

40, 41 computes the roll gap difference between the work side and the drive side from the post-rolling strip wedge calculated by the strip wedge computation section 7B in step S34 (step S35).

Next, the working roll gap difference control section 9 of the

strip wedge controller

40, 41 controls the roll gap difference between the work side and the drive side such that the roll gap difference computed by the working roll gap difference computation section 8 in step S35 is attained (step S36).

Also in the rolling equipment and rolling method of example 3 of the present invention, it is possible to attain substantially the same effect as that of the rolling equipment and rolling method of example 1 described above.

In the case where the strip wedge control is not performed with high responsiveness, there is further provided the filter computation section 12 filtering the detection values of the drive side load sensor 10D and the work side load sensor 10W as in the present example, whereby it is possible to make the detection values stable values (free from noise), to prevent an abrupt change in the working roll gap difference operation amount, and to realize a stable strip wedge control.

While in the case described above the filter computation section 12 is a first-order lag filter, this should not be construed restrictively. It is possible to employ a computation section endowed with various filter functions.

Further, also in the present example, it is possible to calculate the post-rolling strip wedge by using the difference in mill constant between the work side and the drive side as in example 2.

Example 4

The rolling equipment and rolling method of example 4 of the present invention will be described with reference to Figs. 25 through 28.

Fig. 25 is a top view of the structure of a strip wedge controller according to example 4 of the present invention, and Fig. 26 is a side view of the structure of the strip wedge controller of example 4. Fig. 27 is a block diagram illustrating the strip wedge controller of example 4. Fig. 28 is a flowchart illustrating the strip wedge control flow in example 4.

As shown in Figs. 25 and 26, the strip wedge controller of the present example further includes a dead band computation section 13 which, when the difference between the post-rolling strip wedge calculated value Δh calculated by the strip wedge computation section 7 and the target strip wedge Δh_ref is equal to or less than a predetermined value, diminishes the absolute value of the difference. This dead band computation section 13 is provided within the working roll gap difference computation section 8C.

In example 1, etc., with respect to a small error in which the strip wedge deviation is equal to or less than a permissible value, control is effected to set it to a predetermined value, so that errors are integrated, and the working roll gap difference correction amount continues to increase. In view of this, as shown in Fig. 27, when the difference between the predetermined target strip wedge value Δh_ref and the strip wedge calculated value Δhis equal to or less than a predetermined value, it is passed through the dead band computation section 13 endowed with a dead band (dead zone) function by which it outputs 0 as the differential value. In this way, it is preferable that no working roll gap difference correction is made for a difference of a minute amount.

Next, the rolling method according to the present example will be described with reference to Fig. 28.

First, as shown in Fig. 28, the

strip wedge controller

40, 41 receives the input of the operating condition, and receives the input of the drive side load P_D measured by the drive side load sensor 10D and the work side load P_W detected by the work side load sensor 10W (step S41).

Next, the strip wedge computation section 7 of the

strip wedge controller

40, 41 computes the width direction distribution of the rolling load from the drive side load P_D and the work side load P_W measured in step S41 (step S42).

After this, the strip wedge computation section 7 computes the post-rolling strip wedge by using the width direction distribution of the rolling load computed in step S42 (step S43).

Next, the dead band computation section 13 in the working roll gap difference computation section 8C of the

strip wedge controller

40, 41 performs dead band computation with respect to the difference between the post-rolling strip wedge calculated value Δh computed by the strip wedge computation section 7 in step S13 and the strip wedge target value Δh_ref (step S44).

Next, the working roll gap difference computation section 8C of the

strip wedge controller

40, 41 computes the working roll gap difference between the work side and the drive side from the post-rolling strip wedge obtained as the result of the dead band computation in step S44 (step S45).

Next, the working roll gap difference control section 9 of the

strip wedge controller

40, 41 controls the working roll gap difference between the work side and the drive side such that the working roll gap difference computed by the working roll gap difference computation section 8C in step S14 is attained (step S46).

Also in the rolling equipment and rolling method of example 4 of the present invention, it is possible to attain substantially the same effect as that of the rolling equipment and rolling method of example 1 described above.

Further, there is provided the dead band computation section 13 which, when the difference between the calculated value Δh of the post-rolling strip wedge calculated by the strip wedge computation section 7 and the target strip wedge Δh_ref is equal to or less than a predetermined value, diminishes the absolute value of the difference, whereby it is possible to prevent the working roll gap difference correction through integration of errors with respect to a small error in which the strip wedge deviation is equal to or less than a permissible value, making it possible to control the post-rolling strip wedge to a more stable value.

The dead band computation section 13 is not restricted to one which, when the difference between the calculated value of the post-rolling strip wedge calculated by the strip wedge computation section 7 and the target strip wedge is equal to or less than a predetermined value, outputs 0 as the difference. Any other type of dead band computation section will do so long as it diminishes the difference through multiplication of a predetermined coefficient the absolute value of which is less than 1.

Further, the dead band computation section is not restricted to one which, when the difference between the calculated value of the post-rolling strip wedge calculated by the strip wedge computation section 7 and the target strip wedge is equal to or less than a predetermined value, diminishes the absolute value of the difference. It may be one which, when the absolute value of the difference between the roll gap difference computed by the gap difference computation section and the current roll gap difference is equal to or less than a predetermined value, diminishes the absolute value of the gap difference output by the gap difference computation section, or one which, when the control value of the roll gap difference between the work side and the drive side output by the gap difference control section is equal to or less than a predetermined value, diminishes the absolute value of the control value.

Further, also in the present example, it is possible to calculate the post-rolling strip wedge by using the difference in mill constant between the work side support portion and the drive side support portion as in example 2, and to perform filtering as in example 3 individually or in combination.

Example 5

The rolling equipment and rolling method of example 5 of the present invention will be described with reference to Fig. 29.

Fig. 29 is a top view illustrating the structure of a side guide static control by a strip wedge controller according to example 5 of the present invention.

As shown in Fig. 29, the strip wedge controller of the present example further includes a position control section 20 which, instead of performing constant pressure control on the input side guide 2, receives, during the rolling of the rolled material 5, the input of the fluid column position of the hydraulic cylinder 6 determining the strip width direction position of the input side guide 2, and controls the fluid column position of the hydraulic cylinder 6 such that the strip width direction position of the input side guide 2 maintains a predetermined position.

Also in the rolling equipment and rolling method of example 5 of the present invention, it is possible to attain substantially the same effect of the rolling equipment and rolling method of example 1 described above.

Further, there is further provided the position control section 20 controlling the strip width direction position of the side guide to a predetermined position, whereby it is possible to perform static control on the side guide. Thus, as compared with example 1, in which constant pressure control is performed on the side guide, it is possible to more reliably suppress generation of off-center in which the center in the strip width direction of the rolled material 5 having passed the rolling mill, and generation of camber, which is a bending phenomenon in the rolled material 5.

Further, also in the present example, calculation of the post-rolling strip wedge by using the difference in mill constant between the work side support portion and the drive side support portion as in example 2, filtering as in example 3, and dead band computation as in example 4 can be performed individually or in combination.

Example 6

The rolling equipment and rolling method of example 6 of the present invention will be described with reference to Figs. 30 through 34.

Fig. 30 is a top view of strip wedge control structure in a strip wedge controller according to example 6 of the present invention, and Fig. 31 is a side view of the structure of the strip wedge controller of example 6. Fig. 32 is a diagram illustrating the distribution in the width direction of the rolling load and the post-rolling strip wedge calculating method by the strip wedge controller of example 6. Fig. 33 is a flowchart illustrating the strip wedge control flow in example 6. Fig. 34 is a top view of structure for controlling the rolled material in the strip width direction, which is a modification of the strip wedge controller of example 6.

As shown in Figs. 30 and 31, in the rolling equipment of the present example, no side guide is arranged on the input side of the rolling mill. Instead, there is provided a centerline deviation sensor 14 detecting the strip width direction position of the rolled material 5 and installed on the output side of the horizontal mill 1.

In the present example, the rolled material position setting device is the centerline deviation sensor 14. The centerline deviation sensor 14 is not always installed on the output side of the upper working roll 21 and the lower working roll 31. It may be set solely on the input side, or on the input side and the output side.

The centerline deviation sensor 14 is formed, for example, by a CCD camera and a processing system for processing the image taken. The end portion of the rolled material 5 is detected from the taken image of the CCD camera by various well-known methods, whereby the strip width direction position of the rolled material 5 is detected. Naturally, this should not be construed restrictively. Any other structure will do so long as it is possible to detect the strip width direction position of the rolled material 5.

A strip wedge computation section 7E calculates the post-rolling strip wedge by also using the detection value of the strip width direction position of the rolled material 5 detected by the centerline deviation sensor 14.

In the following, referring to Fig. 32, a method of calculating the width direction distribution of the rolling load and the post-rolling strip wedge in the strip wedge computation section 7E in the present example, which is not restricted to the case where the center line (equipment center) is not equal to the strip center will be described.

First, the strip wedge computation section 7E receives the input of the drive side load P_D of the drive side support portion from the drive side load sensor 10D, and receives the input of the work side load P_W of the work side support portion from the work side load sensor 10W, obtaining the strip width direction distribution of the strip load applied to the rolled material 5 shown in Fig. 32 from the drive side load P_D and the work side load P_W.

Here, the force equilibrium in the vertical direction in the rolled material 5 is in the relationship to be expressed by equation (9).

Math 9

Equation (9) is the same as equation (1) described above. P_D is the drive side load detection value (kN), P_W is the work side load detection value (kN), W is the strip width (mm) of the rolled material 5, p_d is the rolling load per unit width (kN/mm) at the drive side strip end portion, and p_w is the rolling load per unit width (kN/mm) at the work side strip end portion.

The moment equilibrium of point A, which is at the center in the width direction of the rolling mill in Fig. 32, is in the relationship to be expressed by the following equation (10).

Math 10

In equation (10), p(x) is the strip width direction distribution of the rolling load per unit width (kN/mm), L is the inter-cylinder distance (mm) between the work side and the drive side, Y_C is the strip meandering amount (mm), and x is the strip width direction position (mm) of the rolled material 5.

Here, the rolling load formula per unit width (linear distribution) of the rolled material 5 is in the relationship to be expressed by equation (11), and the restriction range of x is in the relationship to be expressed by the following formula (12).

Math 11

Math 12

From formula (10) computed through the substitution of the relationships of formulas (11) and (12) and the above formula (9), the rolling load p_d per unit width at the drive side strip end portion is to be expressed by equation (13), and the rolling load p_w per unit width at the work side strip end portion is to be expressed by equation (14). It is to be assumed that A and B in equation (17) and equation (18) are defined by equations (15) and (16). Further, it is to be assumed that C and D in equation (13) and equation (14) are defined by equations (17) and (18).

Math 13

Math 14

Math 15

Math 16

Math 17

Math 18

The strip width direction distribution of the strip load can be obtained from equations (13) and (14).

Next, the strip wedge computation section 7E imparts the strip width direction distribution of the strip load obtained, and perform roll portion elastic deformation analysis, calculating the post-rolling strip wedge. The method of calculating the post-rolling strip wedge is the same as that of example 1.

Next, the rolling method according to the present example will be described with reference to Fig. 33.

First, as shown in Fig. 33, the

strip wedge controller

40, 41 receives the input of the operating condition, and receives the input of the drive side load P_D measured by the drive side load sensor 10D and the work side load P_W detected by the work side load sensor 10W. Further, the strip width direction position of the rolled material 5 is detected by the centerline deviation sensor 14 (step S51).

Next, the strip wedge computation section 7E of the

strip wedge controller

40, 41 computes the width direction distribution of the rolling load from the drive side load P_D, the work side load P_W, and the strip width direction position of the rolled material 5 measured in step S51 (step S52).

After this, the strip wedge computation section 7E computes the post-rolling strip wedge by using the width direction distribution of the rolling load computed in step S52 (step S53).

Next, the working roll gap difference computation section 8 of the

strip wedge controller

40, 41 computes the roll gap difference between the work side and the drive side from the post-rolling strip wedge computed by the strip wedge computation section 7E in step S53 (step S54).

Next, the working roll gap difference control section 9 of the

strip wedge controller

40, 41 controls the roll gap difference between the work side and the drive side such that the roll gap difference computed by the working roll gap difference computation section 8 in step S54 is attained (step S55).

Also in the rolling equipment and rolling method of example 6 of the present invention, in which there is provided, as the rolled material position setting device, the centerline deviation sensor 14 detecting the strip width direction position of the rolled material 5 installed on the input side or the output side of at least the upper working roll 21 and the lower working roll 31, and in which the strip wedge computation section 7E calculates the post-rolling strip wedge by also using the detection value of the strip width direction position of the rolled material 5 detected by the centerline deviation sensor 14, it is possible to attain substantially the same effect as that of the rolling equipment and rolling method of example 1 described above.

Further, in the present example, the side guide is not indispensable, so that it is possible to simplify the equipment and to achieve a reduction in cost.

The present example described above uses no side guide. However, also in the present example, it is possible to provide the input side guide 2 as shown in Fig. 34 to mitigate the meandering of the rolled material 5, and then to detect the strip width direction position by the centerline deviation sensor 14 to calculate the post-rolling strip wedge. Alternatively, it is also possible to provide side guides on both the input side and the output side. This form helps to attain a particularly remarkable effect, for example, in the case where the strip meandering cannot be set to zero by the side guide or in the case where a gap exists between the side guide and the rolled material 5.

Further, also in the present example, calculation of the post-rolling strip wedge by using the difference in mill constant between the work side support portion and the drive side support portion as in example 2, filtering as in example 3, and dead band computation as in example 4 can be performed individually or in combination. Further, in the case where a side guide is employed, it is possible to perform static control on the side guide as in example 5. In this case as well, examples 2-4 can be combined as appropriate.

Others

The present invention is not restricted to the above examples but includes various modifications. The above examples, which have been described in detail in order to facilitate the understanding of the present invention, are not always restricted to one including all the components described above. Further, a part of the structure of a certain example can be replaced by the structure of another example. Further, it is also possible to add the structure of another example to the structure of a certain example. Further, with respect to a part of the structure of each example, it is possible to add, delete, or replace another structure.

1: Hydraulic cylinder
2: Input side guide
3: Output side guide
5: Rolled material
6, 6A, 6B: Hydraulic cylinder
7, 7A, 7B, 7E: Strip wedge computation section
8, 8C: Working roll gap difference computation section
9: Working roll gap difference control section
10D: Drive side load sensor
10W: Work side load sensor
11D: Drive side hydraulic cylinder
11W: Work side hydraulic cylinder
12: Filter computation section
13: Dead band computation section
14: Centerline deviation sensor
20: Position control section
21: Upper working roll
22: Upper backup roll
31: Lower working roll
32: Lower backup roll
40, 41: Strip wedge controller

Claims

Rolling equipment comprising:
a drive side hydraulic cylinder;
a work side hydraulic cylinder;
a vertical pair of working rolls rolling a rolled material by a rolling reduction force imparted by the drive side hydraulic cylinder and the work side hydraulic cylinder;
a drive side load sensor detecting a rolling reduction force due to the drive side hydraulic cylinder;
a work side load sensor detecting a rolling reduction force due to the work side hydraulic cylinder;
a rolled material position setting device setting a position in a strip width direction of the rolled material introduced to the vertical pair of working rolls; and
a strip wedge controller configured to adjust a strip wedge of the rolled material after rolling, wherein
the strip wedge controller includes:
a strip wedge computation section configured to obtain a distribution in the strip width direction of a strip load applied to the rolled material from a load of a drive side support portion and a load of a work side support portion of the working rolls detected by the drive side load sensor and the work side load sensor and to calculate a strip wedge after rolling based on the distribution in the strip width direction of the strip load obtained and the position in the strip width direction of the rolled material set by the rolled material position setting device;
a gap difference computation section configured to compute a working roll gap difference, between a drive side and a work side of the vertical pair of working rolls, for making the strip wedge after rolling calculated by the strip wedge computation section a predetermined value; and
a gap difference control section configured to control the drive side hydraulic cylinder and the work side hydraulic cylinder in such a manner that the working roll gap difference computed by the gap difference computation section is attained.
The rolling equipment according to claim 1, wherein:
the rolled material position setting device is a side guide installed on an input side or installed on the input side and an output side of the working rolls; and
the strip wedge computation section configured to calculate the strip wedge after rolling based on the fact that, due to the side guides, a center of the rolled material in the width direction coincides with a center of working rolls in the width direction.
The rolling equipment according to claim 2, wherein
the strip wedge computation section configured to obtain mill constants on the drive side and the work side based on displacement amounts of the drive side hydraulic cylinder and the work side hydraulic cylinder measured by displacement gages detecting the displacement amounts of the drive side hydraulic cylinder and the work side hydraulic cylinder, and calculates the strip wedge after rolling by also using a difference in mill constant between the drive side and the work side.
The rolling equipment according to claim 2, further comprising a filter computation section configured to filter detection values of the drive side load sensor and the work side load sensor.
The rolling equipment according to claim 2, further comprising a dead band computation section configured to diminish an absolute value of a difference between the strip wedge after rolling calculated by the strip wedge computation section and a target strip wedge when the difference is equal to or less than a predetermined value.
The rolling equipment according to claim 2, further comprising a position control section configured to control a position in the strip width direction of the side guide to a predetermined position.
The rolling equipment according to claim 1, wherein:
the rolled material position setting device is a centerline deviation sensor installed at least on an input side or an output side of the working rolls and configured to detect a position in the strip width direction of the rolled material; and
the strip wedge computation section configured to calculate the strip wedge after rolling by also using a detection value of the position in the strip width direction of the rolled material detected by the centerline deviation sensor.
A rolling method for a rolled material using rolling equipment including: a drive side hydraulic cylinder; a work side hydraulic cylinder; a vertical pair of working rolls rolling a rolled material by a rolling reduction force imparted by the drive side hydraulic cylinder and the work side hydraulic cylinder; a drive side load sensor detecting a rolling reduction force due to the drive side hydraulic cylinder; a work side load sensor detecting a rolling reduction force due to the work side hydraulic cylinder; a rolled material position setting device setting a position in a strip width direction of the rolled material introduced to the vertical pair of working rolls; and a strip wedge controller adjusting a strip wedge of the rolled material after rolling, the rolling method comprising:
a) obtaining a distribution in the strip width direction of a strip load applied to the rolled material from a load of a drive side support portion and a load of a work side support portion detected by the drive side load sensor and the work side load sensor and calculating a strip wedge after rolling based on the distribution in the strip width direction of the strip load obtained and the position in the strip width direction of the rolled material set by the rolled material position setting device;
b) computing a working roll gap difference, between a drive side and a work side of the vertical pair of working rolls, for making the strip wedge after rolling calculated by step a) a predetermined value; and
c) controlling the drive side hydraulic cylinder and the work side hydraulic cylinder such that the working roll gap difference computed in step b) is attained.
The rolling method according to claim 8, wherein
the rolled material position setting device is a side guide installed on an input side or installed on the input side and an output side of the working rolls; and
in step a), the strip wedge after rolling is calculated based on the fact that, due to the side guides, a center of the rolled material in the width direction coincides with a center of working rolls in the width direction.
The rolling method according to claim 9, wherein
in step a), there are obtained mill constants on the drive side and the work side based on displacement amounts of the drive side hydraulic cylinder and the work side hydraulic cylinder measured by displacement gages detecting the displacement amounts of the drive side hydraulic cylinder and the work side hydraulic cylinder, and there is calculated the strip wedge after rolling by also using a difference in mill constant between the drive side and the work side.
The rolling method according to claim 9, further comprising
d) filtering detection values of the drive side load sensor and the work side load sensor.
The rolling method according to claim 9, further comprising
e) diminishing an absolute value of a difference between the strip wedge after rolling calculated by the strip wedge computation section and a target strip wedge when the difference is equal to or less than a predetermined value.
The rolling method according to claim 9, further comprising
f) controlling a position in the strip width direction of the side guide to a predetermined position.
The rolling method according to claim 8, wherein:
the rolled material position setting device is a centerline deviation sensor installed at least on an input side or an output side of the working rolls and configured to detect a position in the strip width direction of the rolled material; and
in step a), there is calculated the strip wedge after rolling by also using a detection value of the position in the strip width direction of the rolled material detected by the centerline deviation sensor.