JP7255531B2 - Winding method of steel strip coil - Google Patents

Description

In the present invention, when a steel strip is wound into a coil (meaning a steel strip coil; the same shall apply hereinafter) with a tension reel in a steel strip manufacturing line, the coil periodically rolls during the winding process. It is also called rolling or lateral runout. Regarding how to take.

In a steel strip processing line, when the steel strip is wound on a steel strip coil (hereinafter also simply referred to as a coil) with a tension reel, if the coil periodically rolls, the following problems arise. be done.
(1) The steel strip meanders at the time of delivery in the next process after winding.
(2) The winding shape shifts in the width direction. (commonly known as Telescope)
If the next process is the shipping destination (customer's side), the product is shipped after being rewound at a low speed in the finishing line of the shipping source, resulting in an extra passing process.
(3) The steel strips rub against each other to form a type of scratch called a crimp flaw, which lowers the yield.

In order to prevent the above problems, it is necessary to quantitatively grasp the rolling, and as part of QA (quality assurance) and QC (quality control), pass/fail judgment and implementation of preventive measures at the time of winding respectively.

The following patent documents can be cited as technologies related to detection of defects during winding of a steel strip, acceptance/rejection determination of winding, and countermeasures for reducing defects.

In Patent Document 1, when winding a thin sheet metal strip, a laser rangefinder is used to detect the winding diameter for each of the driving side (synonymous with drive side) and the work side (synonymous with work side or operator side). , a method for winding a thin sheet metal strip is disclosed, which includes a roundness detecting step of detecting a phase difference between a waveform of a deflection amount on the driving side and a waveform of a deflection amount on the working side.

In Patent Document 2, a plurality of rangefinders capable of measuring distances at different positions in the width direction of a steel strip coil or a steel strip immediately before winding are provided, and a difference in distance measurement values between these rangefinders is provided. is calculated, and a determination is made as to whether the steel strip is rolled in the thickness direction based on the difference between the measured distance values.

Patent document 3 is characterized by measuring the amount of lateral deflection of the coil when winding or paying out the metal strip coil, and controlling the tension of the metal strip during winding or delivery according to the amount of lateral deflection. A method for winding or dispensing a metal strip coil is disclosed.

Further, in Patent Document 4, in a winding method for winding a metal strip into a coil with a winding device for a metal strip, the difference in tension between the winding tension on the working side and the winding tension on the driving side is used to determine whether the winding is successful or not. and a method for winding a metal strip, in which the winding speed of the metal strip is reduced when the differential tension exceeds a predetermined threshold value and the winding is determined to be unsatisfactory.

Japanese Patent Application Laid-Open No. 2004-130362 JP 2015-182084 A JP-A-10-323714 JP 2016-132020 A

In Patent Documents 1 to 3, when the steel strip coil is wound, the difference between the distance measurement values at each position on the width direction drive side and the work side of the coil or the phase difference between the distance measurement values at each position is calculated. It is used as an index of rolling of the coil at the time of picking.

However, using the difference in distance measurements or the phase difference as an index of rolling of the coil during winding has the following problems.
1. Problems when using the difference in distance measurement 1.1 Change in the relative position of the steel strip between the working side and the driving side The same applies hereinafter), so as the winding weight increases during winding, the position of the steel strip on the working side becomes slightly lower than that on the driving side, so the apparent distance The difference in measured values becomes slightly larger.
1.2 Error in Origin Position of Rangefinder If there is an error in the origin position of the rangefinder between the working side and the drive side, this error will be included in the difference between the distance measurement values.
1.3 Correspondence discrepancies between the degree of rolling and the degree of rolling In actual rolling, the degree of rolling gradually worsens as the diameter of the coil increases during winding, but the difference in the distance measurement value increases monotonically as the winding increases. Instead, the amplitude increases as a whole while increasing and decreasing. For example, FIGS. 3 and 4 are diagrams showing the relationship between the difference in distance measurement values and the number of reel rotations (hereinafter also simply referred to as the number of rotations). In FIG. 3, the amount of meandering at the shipping destination deviated from the allowable range, so the steel strip coil was judged to have rolled significantly during winding at the shipping source (hereinafter, sometimes referred to as a rolling NG coil. ) as a function of the rpm of the distance measurement difference (in this example working side-drive side). In Fig. 4, the amount of meandering at the shipping destination was within the allowable range, so it was determined that the degree of rolling at the shipping source was small during winding (hereinafter, sometimes referred to as a rolling OK coil). ), the difference in distance measurements (in this example, working side - drive side) versus the number of revolutions. Both coils have the same nominal thickness and width. In both FIGS. 3 and 4, the difference in the distance measurement value does not monotonically increase as the number of revolutions of the tension reel increases, but increases and decreases. It can be seen that the amplitude of the difference in the distance measurements is greater in FIG. 3 (rolling NG coil), but it is difficult to determine at what extent this amplitude would worsen the rolling.

That is, the magnitude of the difference in the distance measurement values and the magnitude of the rolling do not necessarily correspond one-to-one. Therefore, it can be determined that the difference in distance measurement values is not sufficient as a quantitative index representing rolling. In addition, we tried a method of setting a threshold for the difference in distance measurement values at the end of winding and judging whether the winding result passed or failed based on the magnitude relationship with the threshold. Meandering at the time of dispensing occurred quite frequently. In addition, if the difference in distance measurement values is used, the value does not monotonically increase, so it is difficult to treat it as a predictive index. We are not doing enough to take preventive measures before it gets worse.
2. Problems when phase difference is used Phase difference alone does not provide a sufficient evaluation index for rolling, since the magnitude (amplitude) of rolling cannot be determined.

Further, in Patent Document 4, the differential tension between the winding tensions on the driving side and the working side is used as a judgment index to determine whether the winding is successful or not and to reduce the winding speed. However, the differential tension is not a factor of rolling. Even if there is, it is not a quantitative index of the rolling phenomenon itself. Other rolling factors include the thickness profile, variations in the mechanical properties (hardness, YP) of the steel sheet within the steel strip, surface roughness, and the like. Therefore, if the differential tension is used as a judgment index, the degree of rolling cannot be accurately grasped.

In view of the problems of the prior art described above, the present invention adopts a new index different from the difference in distance measurement values and the phase difference as an index for capturing the rolling phenomenon during winding of the steel strip coil, and thereby, the degree of rolling It is an object of the present invention to provide a method for winding a steel strip coil as a solution to the problem of making it possible to accurately determine the size of the .

The inventors of the present invention have made intensive studies to solve the above problems, and as a result, found that the difference in distance measurement values between the drive side rangefinder and the work side rangefinder during steel strip coil winding is determined by measuring the difference in the distance measurement values between the drive side rangefinder and the work side rangefinder when the tension reel rotates at a constant rotation. It has been shown that if the difference between the maximum value and the minimum value within each value is calculated, and the calculated result is used as an index for rolling, the occurrence of troubles due to rolling during winding of steel strip coils can be effectively reduced. The present invention was made by discovering and further studying.

That is, the present invention is as follows.
(1) In the winding process of forming a steel strip coil with a tension reel, the first and second distances are obtained by using one point at each end in the width direction of the outer peripheral surface of the steel strip coil at the time of winding as the distance measurement target point. A method of winding a steel strip coil comprising:
obtaining the maximum and minimum values of the difference between the two distance measurement values for each constant rotation of the tension reel, and calculating the difference R between the maximum and minimum values. winding method.
(2) The steel strip coil winding method according to (1), wherein whether or not to rewind the steel strip coil after completion of winding is determined based on the change in R.
(3) The steel strip coil winding method according to (1) or (2), characterized in that transition of the R for each constant rotation is predicted during the winding step until the winding is completed.
(4) The steel strip coil according to (3), wherein it is determined whether or not to change the winding conditions during the winding process based on the predicted result of the transition of R. winding method.
(5) The steel strip coil winding method according to (4), wherein the change in the winding condition is a change in winding tension.
(6) The steel strip coil winding method according to (4) or (5), wherein the change in the winding condition is a change in line speed.

According to the present invention, the degree of rolling up to the completion of winding can be accurately and quantitatively grasped, so that the success rate of the steel strip coil after winding is improved and the reliability of acceptance/rejection determination is improved. In addition, since it becomes possible to predict the degree of deterioration of rolling during the initial stage of winding, it is possible to implement preventive measures such as increasing the winding tension or reducing the line speed. Furthermore, since deterioration of the degree of rolling can be prevented, rewinding in the finishing line becomes unnecessary, and the occurrence of crimping defects can be prevented, contributing to an improvement in yield.

FIG. 10 is an explanatory diagram of a process of calculating a difference R between the maximum value and the minimum value of the difference in distance measurement values for each constant rotation; It is a schematic diagram showing an installation form of a rangefinder used in the present invention. Regarding rolling NG coils (steel strip coils that were determined to have rolled excessively at the time of winding at the shipping site because the meandering amount at the shipping destination exceeded the allowable range), the work side during winding before shipping 3 is a graph showing an example of transition of a difference (working side-drive side) in distance measurement values of rangefinders on the driving side and the driving side. Regarding rolling OK coils (steel strip coils that were judged to have a small degree of rolling at the time of winding at the shipping destination because the amount of meandering was within the allowable range at the time of delivery at the shipping destination) Work during winding before shipping FIG. 10 is a graph showing an example of the transition of the difference (working side-drive side) in the distance measurement values of the side and drive side rangefinders; FIG. FIG. 4 is a graph showing changes in R for the example (rolling NG coil) of FIG. 3; FIG. FIG. 5 is a graph showing changes in R for the example (rolling OK coil) of FIG. 4; FIG. FIG. 10 is a schematic diagram showing an example of an embodiment of a method for judging whether a result of winding is acceptable. FIG. 4 is a block and flow diagram illustrating an example method for predicting the transition of R; FIG. 10 is a flow chart showing an example of an embodiment in which it is determined whether or not to change the winding condition during the winding process based on the prediction result of the transition of R; 4 is a graph showing a comparison of meandering occurrence rates at the time of coil delivery from a finishing line for steel strip coils of an example of the present invention and a comparative example. It is a schematic diagram which shows the calculation method of Rr(x). FIG. 10 is a schematic diagram showing a transition state of R when the line speed is decreased and the winding tension is increased in the flow of FIG. 9; FIG. 10 is a schematic diagram showing a transition state of R when only increasing the winding tension is executed in the flow of FIG. 9; FIG. 10 is a schematic diagram showing a transition state of R when the line speed is not decreased and the winding tension is not increased in the flow of FIG. 9;

Embodiments of the present invention will be described below. The present invention is based on the premise that, as shown in FIG. 2, a steel strip S is wound by a tension reel TR (also abbreviated as reel TR) to form a steel strip coil SC (also abbreviated as coil SC). In the winding process, first and second rangefinders 1 and 2 (hereinafter simply referred to as ) are provided, and the difference between the two distance measurement values is continuously calculated from the start of winding to the end of winding. The premise steps are disclosed in Patent Documents 1 to 3.

A steel strip having a YP of 200 to 700 MPa, a thickness of 0.14 to 0.67 mm, and a width of 600 to 1100 mm is preferable as an object to which the present invention is applied.

As shown in FIG. 2, the rangefinders 1 and 2 are preferably laser rangefinders, one mounted on the driving or working side and the other on the opposite side. However, the coil radial distances of both installation positions from the tension reel TR axis do not necessarily have to be exactly the same. The results of FIGS. 1, 3 and 4 are obtained when rangefinder 1 is installed on the working side and rangefinder 2 is installed on the drive side.

Here, the preferred range of the positions of the distance measurement target points of the rangefinders 1 and 2 will be described. Assuming that the position of the distance measurement target point is a position that is a distance ΔW inside from each of the width direction end points of the design winding area with the nominal width W, and is represented by ΔW / W, ΔW / W is If ΔW/W is too small, the distance measurement target point may deviate from the outer peripheral surface of the coil SC depending on the degree of rolling. Also in the case of , it may be difficult to correctly grasp the degree of rolling. To avoid this difficulty, ΔW/W is preferably 0.05 to 0.20.

Under the above premise, the present invention, as shown in FIG. and calculating the difference R=ΔLmax−ΔLmin. Note that FIG. 1 illustrates a case where the rotation speed of the constant rotation is set to 1, and R is calculated from a certain rotation speed N for each rotation.

By using the R, it is possible to more accurately grasp the degree of rolling compared to the case of using the difference in distance measurement values.

Incidentally, in FIGS. 5 and 6, the constant rotation is calculated as one rotation from the transition of the difference (working side - driving side) of the distance measurement value in FIG. 3 (rolling NG coil) and FIG. 4 (rolling OK coil). It shows the transition of R after Here, "transition" means a change accompanying an increase in the number of rotations (meaning the number of rotations of the reel; the same shall apply hereinafter). Further, R for each constant rotation is made to correspond to the representative rotation number on a one-to-one basis, with any one number of rotations in each constant rotation being taken as a representative rotation number. Any single number of rotations within each constant number of rotations may be used as the representative number of rotations. In FIGS. 5 and 6, the rotation speeds Ns+1, Ns+2, Ns+3, . Here, Ns is the rotation speed at the start of winding. For example, if the constant number of revolutions is every 10 revolutions, the representative number of revolutions may be the number of revolutions Ns+10, Ns+20, Ns+30, . Alternatively, the rotation speeds Ns, Ns+10, Ns+20, .

From FIG. 5, in the rolling NG coil, R changes in an oscillating waveform state as the rotation speed of the reel increases, the central value of the amplitude of R increases almost monotonously, and when the rotation speed reaches about 1600 to 2000 times, R amplitude tends to increase. On the other hand, from FIG. 6, in the rolling OK coil, R changes in the vibration waveform state as the rotation speed increases, which is the same as in the rolling NG coil, but the center value of the amplitude of R slightly increases monotonically. Although there is a tendency to increase, the increasing tendency is much smaller than that in FIG. .

The tendencies seen in the transition of R illustrated in FIGS. 5 and 6 are in agreement with the phenomenon that the degree of actual rolling gradually worsens as the coil diameter increases during winding. Therefore, in the present invention, whether or not to rewind the steel strip coil after completion of winding is determined based on the transition of R, and if not, it is determined to be acceptable, and otherwise to be rejected.

Assuming that the rotation speed of the constant rotation is M, M does not have to be a natural number. M=1 to 50 times, for example, from the viewpoint that it becomes difficult to accurately grasp the degree of rolling in any case.

Next, an embodiment in which pass/fail determination of the result of winding is performed will be described with reference to FIG. In FIG. 7, x is the number of rotations of the reel (the same applies to other figures). FIG. 7 schematically shows the transition of R with respect to x for a rolling NG coil.

The point x=x0 at the start of winding and the point x=xE at the end of winding on the x-axis correspond to the number of revolutions of coil TOP and coil END, respectively. In addition, the rotation speed x is converted to the ratio u = (x - x0) / (xE - x0) x 100 (%) to the total rotation speed calculated from the coil TOP, and the winding end stage on the u axis Then, two points u=u1 and u2 are taken, and the area between the two points u1 and u2 is defined as the vicinity of the coil END. u1 and u2 are respectively referred to as the lower and upper values of u near coil END.

In the embodiment of FIG. 7, a threshold value that distinguishes the magnitude of R at the end of winding is prepared as a pass/fail reference value Rz, and the average value Rav of R near the coil END is compared with Rz to determine whether Rav exceeds Rz. If so, it is judged to be unacceptable, and otherwise judged to be acceptable.

The acceptance/rejection reference value Rz is determined using a large amount of actual data on changes in R for rolling NG coils and rolling OK coils.

According to the above-described embodiment, it is possible to prevent an increase in the frequency of rewinding in the finishing line due to erroneously determining that a passing coil that should be a rolling OK coil is rejected, thereby reducing the workload of the finishing line. In addition, the present inventors have found that it is possible to prevent the occurrence of troubles at the shipping destination due to erroneously judging a failed coil, which should be a rolling NG coil, as an acceptable coil and shipping the coil.

The pass/fail criterion value Rz is determined based on the result of calculating R at the end of winding from the data of the difference in distance measurement values for past rolling NG coils and rolling OK coils, but if Rz is too small, it passes. There is a risk that the frequency of erroneously determining a failure may increase, and if it is too large, the frequency of erroneously determining a failure as a pass may increase. 2.00 mm.

Also, if the upper limit value u2 of u near the coil END is too large, Rav may become abnormally high due to the influence of the unsteady portion at the end of winding. For example, u2=95±3% from the viewpoint that the data may be ignored. Also, if the lower limit value u1 of u near the coil END is too small, the proportion of R(x) data used for calculating Rav is too large, and the pass/fail judgment accuracy may decrease. If it is too large, the number of R(x) data used to calculate Rav may be insufficient, so u1=80±3%, for example. x=x(u1) and x(u2) corresponding to u1 and u2 are, for example, when x0=0 times and xE=2800 times, x(u1)=2240±84 times and x(u2)=2660 times. ±84 times.

Furthermore, in the present invention, as a preferred embodiment, the transition of the R for each constant rotation until the completion of winding is predicted during the winding process, and further, based on the predicted result of the transition of the R and determining whether or not to change the winding conditions during the winding process.
The winding conditions include winding tension and line speed.

According to the findings of the present inventors, the increase in the winding tension during the winding process slows down the increasing tendency of R with respect to x, and the winding in synchronism with the decrease in the line speed during the winding process. It was found that a decrease in take-up speed (reel rotation speed) also slowed down the increasing trend of R with respect to x.

According to the above-described preferred embodiment, it is predicted whether or not R will eventually exceed the allowable range during the winding process, and if it is predicted that it will exceed, the winding conditions are immediately changed and rolling NG is detected. Coil generation can be prevented.

FIG. 8 is a block and flow diagram illustrating an example method for predicting the transition of R. FIG. In addition, in FIG. 8, the same or corresponding members as those in FIG. In this example, a computing unit 10 receives each distance measurement from rangefinders 1 and 2, while receiving tension reel PLG signals, line speed and shearcut signals from PLC (Programmable Logic Controller) 11. , and using these, the calculations in steps 101 to 103 are performed.

The tension reel PLG signal is an output signal of the tension reel rotation speed from a PLG (pulse generator, not shown) for measuring the rotation speed of the tension reel TR. The line speed is the running speed of the steel strip S before or after winding the coil SC. The shear cut signal is a signal that tells when the leading edge of the steel strip S before winding has been shear cut by a shear (not shown) on the upstream side of the tension reel TR.

The computing device 10 calculates R in step 101 . That is, the maximum value and the minimum value of the difference between the distance measurements of the rangefinders 1 and 2 are obtained for each constant rotation of the reel TR, and the difference R is calculated. The tension reel PLG signal, the line speed, and the shear cut signal are used to specify each section of the constant number of rotations for which each R is calculated. That is, when the time (=distance from the shear to the tension reel TR/line speed) elapses from when the shear cut signal is received until the tip of the steel strip S winds around the tension reel TR, the number of rotations x of the reel is set to the initial value. (for example, x=x0), while receiving the distance measurement values of rangefinders 1 and 2, the difference between the two distance measurement values is calculated for each constant rotation and accumulated as distance difference data, and the maximum of the accumulated distance difference data is calculated. A value and a minimum value are extracted, and the difference (=maximum value-minimum value) is calculated as R. On the other hand, as x that corresponds to the calculated R one-to-one, the representative number of revolutions of each constant rotation section for which each R is calculated is employed. Thus, a one-to-one correspondence between the representative number of rotations per fixed rotation and R is obtained.

Next, in step 102 (FIG. 8), as shown in FIG. 11, from the transition of R up to the middle of the winding process (for example, point x=xc), the transition of R thereafter is predicted. An approximate linear expression Rr(x) is calculated by the method of least squares. The number of R data used to calculate this approximate linear expression is [(xc−x0)/number of rotations of constant rotation] (rounded down to the nearest decimal point).

Here, as the value of u=uc corresponding to the point x=xc in the middle of the winding, if it is too small, the approximation deteriorates, and if it is too large, the calculation time of the approximate linear formula Rr(x) will be insufficient and the winding conditions will not be satisfied. uc=20 to 30% is exemplified from the point of view that there is a possibility that the change execution timing will be delayed.

Next, in step 103 (FIG. 8), the formula value Rr(e) of Rr(x) is calculated as the predicted value of R at the point x=e in the vicinity of the coil END in FIG.

After executing step 103, the process proceeds to step 201 in FIG.

FIG. 9 is a flow chart showing an example of an embodiment for determining whether or not to change the winding condition during the winding process based on the prediction result of the R transition. In this example, two thresholds R1 and R2 were set as follows. That is, R1>R2, R1 is a threshold value for determining whether to change the line speed, and R2 is a threshold value for determining whether to change the winding tension and whether the winding result is acceptable. value (=pass/fail reference value Rz in FIG. 7).

At step 201, it is judged whether or not Rr(e) exceeds the threshold value R1, and if Yes, at step 202, the line speed is changed. Specifically, a signal is sent to the line speed control means (not shown) to prompt a line speed change. In this example, the change in line speed is a change to the low speed side. Then go to step 203 . If No, proceed to step 203 without doing anything. Here, if the threshold value R1 is excessively large, the judgment in step 201 will always be No, and there is a risk that there will be no room for executing step 202 (line speed change). Twice or less. Also, if the line speeds before and after the change in the line speed in step 202 are V1 and V2 (<V1), respectively, and ΔV=V1−V2, then if ΔV is too small, the effect of reducing rolling is poor, and it is too large. From the viewpoint that there is a possibility that the production efficiency will decrease if the ΔV is increased, for example, the ratio of ΔV to V1 [(ΔV/V1)×100%] is 30 to 40%.

Next, at step 203, it is judged whether or not Rr(e) exceeds the threshold value R2, and if Yes, at step 204, the winding tension is changed. Specifically, a signal is sent to the winding tension control means (not shown) to prompt the winding tension to be changed. In this example, the change in winding tension is a change to the high tension side. Then go to step 205 . If No, proceed to step 205 without doing anything. The winding tensions before and after the winding tension is changed in step 204 are T1 and T2 (>T1), respectively, and ΔT=T2−T1. From the viewpoint that there is a risk of damaging the steel strip, ΔT is, for example, a ratio to T1 [(ΔT/T1)×100%], which is 10 to 40%.

Next, in step 205, the average value Rav of R near the coil END is calculated. The transition state of R for calculating the average value Rav is divided according to the three cases shown in FIGS. 12 to 14. FIG.

FIG. 12 shows the case where both the line speed change and the winding tension change (steps 202 and 204) are executed because Rr(e)>R1>R2. In this case, as x increases, R tends to increase almost overlapping with Rr(x) before changing the line speed, then the increasing trend slows down after changing the line speed, and then after increasing the winding tension. , the increasing trend becomes even more gradual.

FIG. 13 shows the case where only the winding tension change (step 204) is executed because R1>Rr(e)>R2. In this case, as x increases, R has a tendency to increase almost overlapping with Rr(x) before changing the winding tension, and then the increasing tendency slows down after changing the winding tension.

In FIG. 14, R1>R2>Rr(e) holds, so neither line speed change nor winding tension change (steps 202 and 204) are performed. In this case, as x increases, R tends to increase from coil TOP to coil END while being substantially overlapped with Rr(x).

Finally, in step 206, it is determined whether or not Rav exceeds a threshold value R2 (=Rz). subject to If No, step 208 passes (rolling OK coil). FIG. 12 illustrates the case of Rav>R2 (failed), and FIGS. 13 and 14 illustrate the case of Rav≦R2 (passed).

In the example of FIG. 9, the line speed is changed first, and the winding tension is changed later. As a flow in that case, in FIG. 9, descriptions of R1 . A flow in which steps 202 and 204 are interchanged with a threshold value (=pass/fail reference value Rz in FIG. 7) that determines whether the line speed is to be changed and whether the winding result is pass/fail is used.

The present invention was applied to the operation of winding a steel strip plated with tin in a tin plating line (ETL) with a tension reel, and was used as an example. In the examples, the steel strip has three thicknesses (nominal) of 0.15 mm, 0.17 mm and 0.19 mm, and a width (nominal) W of 997 mm. The distance measurement target points of rangefinders 1 and 2 were set at positions (ΔW/W=150/997=0.15) at a distance of ΔW=150 mm inside from both end points in the width direction of the design winding area. R was calculated every 20 rotations of the reel, and the representative number of rotations corresponding to R one-to-one was the number of rotations at the completion of each 20 rotations for which each R was calculated.

(Example 1)
As Example 1, whether or not to rewind the steel strip coil after the completion of winding was determined by the following determination methods for each of the inventive example and the comparative example. The result of winding was determined to be unacceptable in some cases, and the results were compared. In the example of the present invention, based on the calculated R, the transition of R is obtained, and as shown in FIG. If it is less than the value Rz, it is accepted, and if it exceeds it, it is rejected. Note that u1=80%, u2=95%, and Rz=1.70 mm. On the other hand, in the comparative example, R was not calculated, and the difference ΔL between the distance measurement values of the rangefinders 1 and 2 was averaged in the vicinity of the coil END, and the average value was provided for the difference in the distance measurement values. If it is below a predetermined threshold (5.0 mm) or less, it is judged to be acceptable, and if it exceeds it, it is judged to be unsatisfactory.
When comparing the acceptance number rate for 20 coils each in the example of the present invention and the comparative example, it was 70% in the comparative example, and 95% in the example of the present invention, compared to the comparative example. Improved.

These acceptable coils of the present invention example and the comparative example were paid out by a pay-off reel (not shown) in the finishing line of the next process, and the presence or absence of meandering was examined. In this investigation, at a point 5 m downstream from the payoff point (payoff reel installation point), one side edge in the width direction of the steel strip was detected by a light emitting/receiving type strip width end position sensor (not shown. For example, EPC). Equivalent to the detection part of [Edge position control, registered trademark]), measure the width direction variation amount of the detection point, and if the measured value is within ± 0.50 mm, there is no meandering , and meandering occurred in other cases, and the meandering occurrence number rate of the examples of the present invention and the comparative example was obtained.

The results are shown in FIG. As can be seen from FIG. 10, in the example of the present invention, the frequency of occurrence of meandering at the time of delivery of acceptable coils to the next process (finishing line) is much lower than that in the comparative example. That is, it can be seen that the acceptance/rejection determination method of the winding result based on the transition of R according to the present invention is a much more accurate method than the conventional method.

(Example 2)
In the second embodiment, as an example of the present invention, the transition of R is predicted by the method illustrated in FIGS. The pass/fail judgment of the winding result was performed based on the R of the above.

At this time, in step 102, R from the coil TOP (u=0) to u=uc (=20%) is used as data for calculating the approximate linear expression Rr(x). Threshold values R1 and R2 in FIG. 9 were set to R1=1.5×R2 and R2 (=Rz)=1.70 mm. The lower limit value u1 and the upper limit value u2 near the coil END are the same as in Example 1, and the value of x that satisfies u=90% was adopted as e corresponding to Rr(e).

In step 202 of changing line speed, the ratio of ΔV to V1 was set to 40%, and in step 204 of changing winding tension, the ratio of ΔT to T1 was set to 40%.

As a result, the acceptance number rate for 200 coils of the invention example in Example 2 reached 99%, which was improved compared to the acceptance number rate of the invention example in Example 1.

1 first rangefinder 2 second rangefinder 10 computing device 11 PLC (programmable logic controller)
101-103, 201-208 Step S Steel strip SC Steel strip coil (coil for short)
TR tension reel (reel for short)

Claims (6)

Both of the first and second rangefinders, in the process of winding the steel strip coil into a steel strip coil with a tension reel, each having one point at each end in the width direction of the outer peripheral surface of the steel strip coil at the time of winding as a distance measurement target point. is provided, and the difference between the two distance measurements is calculated continuously from the start of winding to the end of winding, comprising:
determining the maximum and minimum values of the difference between the two distance measurement values for each constant rotation of the tension reel, and calculating the difference R between the maximum and minimum values;
obtaining a transition of the difference R with the number of rotations of the tension reel;
a step of determining the magnitude of the degree of rolling according to the magnitude of the increasing trend of the difference R in the transition;
A method for winding a steel strip coil, comprising: 2. The steel strip coil winding method according to claim 1, wherein it is determined whether or not to rewind the steel strip coil after winding is completed based on the transition of said R. 3. The method of winding a steel strip coil according to claim 1, wherein transition of said R for each constant rotation until completion of winding is predicted in the course of said winding step. 4. The steel strip coil winding method according to claim 3, wherein it is determined whether or not to change the winding condition during the winding step based on the predicted result of the transition of R. . 5. The steel strip coil winding method according to claim 4, wherein the change in the winding condition is a change in winding tension. 6. The steel strip coil winding method according to claim 4 or 5, wherein the change in the winding condition is a change in line speed.

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