JP2889524B2 - Setting method of shape target value in cold rolling - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of setting a shape target value in cold rolling to obtain an optimum product profile.

[0002]

[Related Background Art] Conventionally, using a multi-high rolling mill or the like, the shape in the width direction of a cold-rolled rolled sheet has been detected,
There are known various cold rolling methods for controlling the shape or state of a surface of a rolling roll based on a detected shape value and a shape target value to control the shape of a rolled sheet material. For example,
The method of controlling the shape of a rolled material described in Japanese Patent Application Publication No. 2-258106 will be described with reference to FIGS. 1 to 3. A multi-high rolling mill 10 includes upper and lower work rolls (rolling rolls) for rolling a plate material 12 to be rolled. ), An intermediate roll 16 and a backup roll 18.
From the work roll 14 and wound up by the winder 22.

The rolling mill 10 is further arranged side by side in the barrel axis direction of the work roll 14 and has a plurality of spray nozzles 24 for spraying a cooling liquid to the work roll 14 to control the shape or state of the surface of the work roll 14. And a shape detector 26 for detecting the shape of the plate 12 in the width direction. The amount of coolant injected by the injection nozzle 24 is adjusted by opening and closing the valve device 34, and the valve device 34 is controlled to open and close by a control command from a valve command device 36.

[0004] The shape detector 26 supplies an output signal corresponding to the detected shape to an elongation difference rate calculating circuit 38, which expands the output signal (shape signal) of the shape detector. Is converted into a difference ratio ε (i). Here, (i)
Is an index indicating the position of the rolling roll 14 in the axial direction corresponding to each injection valve 24, and the difference in elongation will be described later.
The cooling medium output calculation circuit 40 determines each injection nozzle based on a deviation value (also referred to as a shape deviation) between the output signal ε (i) of the elongation difference rate calculation circuit 38 and the target shape value from the target shape value setting circuit 39. 24, and sends a cooling medium output signal s (i) to the valve command device 36. The injection amount of each nozzle 24 is determined, for example, from each of the differential expansion rates ε (i), a differential expansion rate difference, which is a difference value from a target differential expansion rate, a time change rate of the differential expansion rate, and a differential expansion rate. It is performed by fuzzy inference from three evaluation values of the local change rate.

FIG. 2 shows a target shape value (indicated by a target elongation difference) and an actual shape value (actual elongation difference ratio) of a rolled sheet by a solid line and an alternate long and short dash line, respectively. The difference ratio εr (i) and the actual elongation difference ratio ε (i) are discretized for each division width of the shape detector. As described above, in the cold rolling of the sheet material, the surface shape or state of the work roll (rolling roll) is adjusted based on the deviation between the actual shape value (measured value) and the shape target value of the rolled sheet material, and the product sheet material is thereby adjusted. The shape of the rolled sheet is controlled so as to obtain the required quality such as flatness.

Here, the above-mentioned difference in elongation ε is shown in FIG.
Elongation ΔL = L−p Steepness λ = h / p Elongation difference rate ε = ΔL / p ≒ 2.47λ ² Here, as shown in FIG. 4, L is the length of one pitch along the rolling direction wave of the rolled sheet, p
Is defined as the pitch of the wave, and h is defined as the height of the arc of the wave. The value obtained by multiplying the value of the difference in elongation by 10 ⁵ is expressed in units of I-un
It is converted to it. As described above, the unit of the elongation rate deviation (= target elongation difference rate−measured elongation rate value) is a unit of this I
-unit is used.

[0007]

Incidentally, as an evaluation index indicating the quality of the product rolled sheet material, there is a sheet profile other than the one related to the sheet shape such as the flatness (flatness) of the sheet described above. . Flatness refers to flatness in the width direction of the sheet during rolling. If the elongation differs in the length direction in the direction of the sheet width during rolling, this affects the flatness in the direction of the sheet width. The plate profile refers to the shape of a cross section of the rolled plate in the plate width direction (a cross section orthogonal to the rolling direction), and the evaluation index indicating the quality of the plate profile includes a middle thickness ratio and an ear height ratio. As shown in FIG. 5, the middle thickness ratio and the ear height ratio are, as shown in FIG. 5, the thickness Tc of the center 12 c of the cross section, the thickness Tw of the right end 12 ws, and the right end of the right end 12 w Thickness Twmin near the part, left end 12d
The thickness Td of s and the minimum thickness Tdmin near the left end are defined by the following equations.

[0008]

(Equation 1)

[0009] A user of a rolled plate material may require not only the flatness (flatness) of the product but also the quality of the plate profile, and particularly severe requirements may be made on the ear height. . If the profile of the product sheet material is ideally rectangular in cross section, during rolling by the user, along the longitudinal direction at the center in the width direction of the rolled sheet material, so-called "medium elongation" waving, width direction There is almost no possibility that a problem such as so-called "ear extension" occurs at the end portion along the longitudinal direction, but a so-called drum-shaped profile having a large middle thickness ratio has a "medium" shape. Growth "
The so-called drum-shaped profile, in which the phenomenon is likely to occur and the ear ratio is large, is likely to cause the "ear extension" phenomenon, which may have a significant effect on the quality of the final product.

FIG. 9 shows a plate profile required by the user in order to suppress the above-mentioned "middle elongation" and "ear elongation" within an allowable range in the relationship between the allowable middle thickness ratio and the ear height ratio. The allowable ear height ratio for the middle thickness ratio can be obtained from the ear height allowable curve. Note that the above-described ear height factor allowable curve is set according to the product use and the like. In the conventional cold rolling, priority is given to controlling the shape of a rolled sheet material, and control of the cross-sectional shape of a product sheet material, that is, profile control is not actively performed. The profile of the rolled sheet material (final product) is greatly affected by the profile of the cold-rolled material, that is, the profile of the hot-rolled sheet, and if the profile during hot rolling is out of the allowable range, the cold rolling is completed. It has been found that later profiles also often fall out of tolerance and become defective. Therefore, conventionally, when the profile of a product is strictly required, the quality of the sheet profile is maintained by performing cold rolling using only the material whose hot-rolled material profile is within a predetermined acceptance range. Like that.

As described above, when setting the shape target value at the time of cold rolling, conventionally, the profile of the cold-rolled material has not been properly considered, and how the profile of the rolled material has been considered. It was not known whether to set the shape target value. For this reason, in the conventional cold-rolled sheet material, the shape quality such as flatness can be controlled and managed within a target allowable value range, but the profile cannot be sufficiently controlled, and the quality cannot be controlled. Was difficult to manage. The quality related to the profile of the product sheet material is greatly affected by how the above-mentioned shape target value is set. Conventionally, the shape target value is often set by trial and error according to the material characteristics and equipment characteristics of the rolled material so that the required quality such as flatness falls within an allowable value range based on experience and intuition.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and it is an object of the present invention to provide a method for setting a shape target value for controlling a product plate profile after cold rolling to a target profile allowable range. With the goal.

[0013]

In order to achieve the above-mentioned object, a method of setting a shape target value in cold rolling according to the present invention comprises detecting a widthwise shape of a cold-rolled rolled sheet material,
A method for adjusting the shape or state of the surface of the rolling roll based on the detected shape value and the shape target value g to control the shape of the rolled sheet material, in the method of setting the shape target value in cold rolling, The thickness distribution in the width direction of the rolled material is measured, the profile index is calculated from the measured thickness distribution of the rolled material, the shape target correction value f is calculated based on the profile index, and the product rolled sheet material after rolling. The correction coefficient value α is set in accordance with the sheet width and the sheet thickness of the sheet, and the shape target value g is corrected based on the shape target correction value f and the correction coefficient value α.

The shape target correction value is calculated based on the profile index of the rolled material. By controlling the shape using such a shape target correction value, both the flatness and the profile of the product sheet are within an allowable range. If, for example, it is desired to prioritize the correction of the ear height ratio over the correction of the medium thickness ratio of the product rolled sheet material, by setting a shape target correction value that reduces the ear height ratio, Product profile.

The target shape value g used for this shape control
May be set based on at least one characteristic of the deformation resistance of the rolled material, the material, the thickness of the product rolled sheet material, and the number of rolling passes.
The invention according to claim 3 is characterized in that the profile index includes a middle thickness index and an ear height index, and a shape target correction value is calculated using the middle thickness index and the ear height index. You.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. In addition, as a shape control method at the time of cold rolling performed using the shape target value set by the method of the present invention, various conventionally known methods described in, for example, JP-A-2-258106 are applied. It is possible to control the shape of the rolled sheet material by injecting a cooling medium to the rolling rolls and adjusting the thermal crown of the rolling rolls, or to control the bending of the rolling rolls, etc., and to control the left and right ends of the rolls. The shape control may be performed by leveler control or the like for adjusting the amount of reduction of the part.

Therefore, the cold rolling mill and its control device for implementing the method of the present invention may be the conventional cold rolling mill and its control device shown in FIG. In the following, an example in which the method of the present invention is applied will be described. The difference of the configuration is that the method of setting the shape target value in the shape target value setting circuit 39 of FIG. 1 is different from that of the conventional method. Since the rolling may be performed based on the target value, the method of setting the shape target value according to the present invention will be described in detail, and the remaining description is described in detail in the above-mentioned Japanese Patent Application Laid-Open No. 2-258106. The description is omitted.

The functional configuration circuit of the shape target value setting circuit 39 for carrying out the method of the present invention can be represented as an equivalent functional block diagram shown in FIG. 6, and the method of the present invention will be described with reference to this block diagram. The shape target value F (I-unit) set by the method of the present invention is calculated by the following equation (M1). F = g (k, t, e, z) + f (p, q) × α (M1) Here, the f value and the correction coefficient α of the second term are characteristic parts of the present invention, First, the second section will be described. p
Is an evaluation index determined from the middle thickness rate, and q is an evaluation index determined from the ear height rate. The f-value is calculated as a function of the middle thickness rate evaluation index p and the ear height evaluation index q as follows. Is done.

First, the medium thickness ratio calculating circuit 39a and the ear height calculating circuit 39b in FIG. 6 calculate the medium thickness ratio and the ear height ratio of the rolled material, respectively. The middle thickness ratio is calculated by the formula (A1).
The ear height ratio is calculated by the above equation (A2) or (A3). Here, as the ear height ratio, the larger one of the ear height ratios calculated by the equations (A2) and (A3) is adopted. In these operations,
The thickness Tc of the rolled material (the thickness after hot rolling or on the cold rolling mill entry side) is measured by an X-ray thickness gauge or the like, and the data is set to a target shape value via a keyboard (not shown). The signal is supplied to a circuit 39. Calculated middle thickness ratio x and ear height ratio y
Are supplied to a middle-thickness index calculating circuit 39c for calculating the middle-thickness rate evaluation index p and an ear-height index calculating circuit 39d for calculating the ear-height evaluation index q, respectively. In these circuits, the respective indices p and q are obtained by, for example, fuzzy inference. The following equation shows a membership function for obtaining the medium thickness rate evaluation index p.

Phn (x) = ahnx + bhn where 0 ≦ phn (x) ≦ 1 (M2) pmn (x) = amnx + bmn where 0 ≦ pmn (x) ≦ 1 (M3) pln (x) = alnx + bln 0 ≦ pln (x) ≦ 1 (M4) The following equation shows a membership function for obtaining the ear height factor evaluation index q. qhn (y) = chny + dhn where 0 ≦ qhn (y) ≦ 1 (M5) qmn (y) = cmny + dmn where 0 ≦ qmn (y) ≦ 1 (M6) qln (y) = clny + dln where 0 ≦ qln (Y) ≦ 1 (M7) Here, the above formulas (M2) to (M7) are prepared in the required number n sets according to the material of the rolled material, the product use, etc., and the evaluation index p, In calculating q, a set of calculation formulas (indicated by the suffix n) corresponding to the material of the rolled material, the product use, and the like is used. The coefficients ah to al and bh to bl are determined for each range of the medium thickness ratio x. FIG. 7 exemplifies these membership functions. The medium thickness rate x and the medium thickness rate evaluation index (membership function value) pn (x), pmn (x),
The relationship of pln (x) is shown.

Similarly, the coefficients ch to cl and dh to dl are determined for each range of the ear height ratio y, and the ear height ratio y and the ear height ratio evaluation index (membership function value) qhn (y), qmn
The relationship between (y) and qln (y) is obtained from a function similar to the relationship shown in FIG. From the evaluation index values phn, pmn, pln, qhn, qmn, qln thus obtained, a shape target correction value f is calculated by the following equation (M8) (FIG. 6).
Calculation circuit 39e).

[0022]

(Equation 2)

Here, Ki (i = 1 to 9) is a weight coefficient, and this weight coefficient is also set in advance according to the material of the rolled material, the product use, and the like. Mi is obtained by the following equations (M9) to (M17). M1 = min (phn (x), qhn (y)) (M9) M2 = min (phn (x), qmn (y)) (M10) M3 = min (phn (x), qln ( y)) ... (M11) M4 = min (pmn (x), qhn (y)) ... (M12) M5 = min (pmn (x), qmn (y)) ... (M13) M6 = min ( pmn (x), qln (y)) (M14) M7 = min (pln (x), qhn (y)) (M15) M8 = min (pln (x), qmn (y)) (M16) M9 = min (pln (x), qln (y)) (M17) As described above, the shape target correction value f is calculated using a fuzzy rule according to the material of the rolled material, the product use, and the like. Since the calculation is performed according to the thickness ratio and the ear height ratio, for example, when the ear height ratio is required to be extremely small near 0 depending on the product use,
By using the fuzzy rule that gives priority to the correction of the ear height ratio over the middle thickness ratio, it is possible to meet such product requirements.

The method of calculating the shape target correction value f by fuzzy inference is not limited to the above-described calculation method.
Various deformation methods are applicable. Next, the calculation procedure of the correction coefficient α will be described. First, the sheet thickness t and the sheet width of the product are input from a data input device (not shown) to the sheet thickness / sheet width input circuit 39g in FIG. From the plate width, a correction coefficient value α is obtained in a correction coefficient calculation circuit 39h.
The coefficient value α is obtained as a function of (sheet thickness / sheet width), and FIG. 8 illustrates the relationship between the coefficient value α and (sheet thickness / sheet width).

The calculated correction coefficient value α is multiplied by a multiplication circuit 39f.
Is multiplied by the above-described shape target correction value f, and the multiplied value is supplied to the addition circuit 39n. The multiplication circuit 39
The multiplied value of f is supplied to a limiter circuit 39j as necessary, and the multiplied value is compared with the upper and lower limit values in the same circuit 39j.
If these upper and lower limits are exceeded, the upper and lower limits may be limited.

The first term value (reference value) g of the equation (M1) is a value corresponding to the shape target value set by the conventional method. In the method of the present invention, the following material characteristic values k, t, and The calculation is performed using e and z as variables. k is the deformation resistance of the rolled material, t
Is the thickness after cold rolling, e is the number of passes, and z is the material of the material. These material property values are input to the material property input circuit 39k of FIG. 6 via a data input device such as a keyboard (not shown), and are supplied to the first term value calculation circuit 39m. Among these material characteristic values, deformation resistance value k, material z
May be stored in the material characteristic input circuit 39k as a constant in advance.

The calculation circuit 39m calculates a reference value g based on the input material property values. The reference value g is obtained experimentally using a rolled material having a rectangular cross section in the plate width direction and using these material characteristics k, t, e, and z as variables. A reference value g experimentally obtained in advance is stored in the calculation circuit 39m using the material characteristics k, t, e, and z as variables, and a value corresponding to the material characteristic value is read out. 39n, and is added to the second term value of equation (M1).

The result of the operation in the adder circuit 39n may be immediately supplied to the storage circuit 39q. However, if necessary, the limiter circuit 39p compares the result with the upper and lower limit values. You may make it restrict | limit to a lower limit. Thus, the shape target value F is stored in the storage circuit 39q, and is used for the shape control during the cold rolling described above.

[0029]

[Example] JIS having a thickness of 4.0 mm and a width of 1080 mm
1100 series pure aluminum was hot-rolled to prepare three types of hot-rolled materials whose medium thickness ratio and ear height ratio were as shown in Table 1. In the example of the present invention, a shape target correction value is set according to a hot-rolled material profile, and a reference value is corrected by the correction value to set a shape target value. On the other hand, in the comparative example, a shape target value according to the conventional method, which is not corrected by the shape target correction value, is set. Then, the rolled material prepared as described above is each set to a thickness of 0.3 according to the set shape target value.
The product was cold-rolled to 5 mm and a width of 1080 mm, and both ears were cut to obtain a product having a width of 1000 mm. And the profile of the product thus cold-rolled was measured. The shape reference value is +15 I-Unit. Further, if the shape target value is set to an extreme value, stable rolling work cannot be performed, so the upper limit of the shape target value is set to ± 50 I-Unit.

[0030]

[Table 1]

As is clear from Table 1, in Invention Example 1 in which the ear height ratio and the median thickness ratio of the rolled material were originally within the allowable range shown in FIG. 9, the median thickness ratio was not affected by the ear height ratio. Could be improved. Invention example 2 in which ear ratio of rolled material is large
In 3, the correction of the shape target value by the shape target correction value results in that the correction of the ear height ratio is prioritized and the middle thickness ratio is somewhat sacrificed, but both the middle thickness ratio and the ear height ratio are shown in FIG. Improved to within acceptable limits.

On the other hand, in the comparative examples, the middle thickness ratio is reduced in each case because the correction is not performed by the shape target correction value as in the present invention, but the ear height ratio is deteriorated. ,
The ear height ratio deteriorates significantly and exceeds the allowable value shown in FIG.

[0033]

As is apparent from the above description, according to the method of setting the shape target value in the cold rolling of the present invention, the profile index is calculated from the thickness distribution of the rolling material, and the shape target is calculated based on the profile index. A correction value f is calculated, a correction coefficient value α is set according to the width and thickness of the product rolled sheet material, and the shape target value g is corrected based on the shape target correction value f and the correction coefficient value α. As a result, both the flatness and the profile of the product plate can be controlled within the required value range, and the quality of the plate shape can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a shape control device of a multi-high rolling mill.

FIG. 2 is a graph illustrating a shape target value (elongation difference ratio) and a shape value of a rolled material.

FIG. 3 is a graph plotted in a sheet width direction and showing a shape target value (target elongation difference) actually set and a shape value of a rolled material actually measured.

FIG. 4 is a diagram for explaining shape parameters used when calculating an index representing flatness of a rolled material.

FIG. 5 is a diagram for explaining shape parameters used when calculating an index indicating a profile of a rolled material.

FIG. 6 is an equivalent functional block diagram of a shape target value setting circuit 39 of FIG. 1 that implements the method of the present invention, and shows a procedure for setting a shape target value.

FIG. 7 is a graph showing a membership function for obtaining an ear height factor evaluation index according to a medium thickness ratio x.

FIG. 8 is a graph illustrating a relationship between a product thickness / width and a correction coefficient value α set according to the value.

FIG. 9 is a graph showing a required profile of a product plate in a relationship between an allowable middle thickness ratio and an ear height ratio.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Multi-high rolling mill 14 Work roll 24 Coolant injection nozzle 26 Shape detector 36 Valve command device 38 Elongation difference rate calculation circuit 39 Shape target value setting circuit 40 Cooling medium output calculation circuit

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁶ Identification symbol FI B21B 37/00 116Z (56) References JP-A-60-187413 (JP, A) JP-A-61-286011 (JP, A) JP-A-4-187312 (JP, A) JP-A-6-304630 (JP, A) JP-A-7-60324 (JP, A) JP-A-7-303910 (JP, A) JP-A-8-257612 (JP, A) JP-A-10-29010 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B21B 37/00

Claims (3)

(57) [Claims] 1. A shape of a cold rolled rolled sheet material in a width direction is detected, and a shape or a state of a surface of a rolling roll is adjusted based on the detected shape value and a shape target value g to form the rolled sheet material. Controlling the shape target value in the cold rolling, measuring a thickness distribution in the width direction of the rolled material to be inserted into the rolling roll, and calculating a profile index from the measured thickness distribution of the rolled material. Then, a shape target correction value f is calculated based on the profile index, and a correction coefficient value α is set in accordance with the sheet width and the sheet thickness of the product rolled sheet material after rolling, and the shape target correction value f and the correction coefficient value α are calculated. A method of setting a shape target value in cold rolling, wherein the shape target value g is corrected based on the following. 2. The corrected shape target value g is set based on at least one characteristic of deformation resistance of a rolling material, material, thickness of a product rolled sheet material, and number of rolling passes. The method of setting a shape target value in cold rolling according to claim 1. 3. The profile index according to claim 1, wherein the profile index includes a middle thickness index and an ear height index.
The setting method of the shape target value in the cold rolling described.