JPH1071425A - Coiling method of metal strip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress variance in flatness of edge wave, etc., of the inner peripheral side of a coil in coiling by deciding a coiling tension based on the thickness/ width of a metal strip, the outer diameter of a coil and the degree of a projecting shape in the cross section of a metal strip. SOLUTION: At the beginning, the number of coiling is set at 1, next, by taking a plate crown, plate shape and coiled shape into account, distribution in the width direction of coiling force is calculated. Next, for discriminating formation of clearance, presence/absence of existence of the region, where tension is turned to negative, is investigated. By confirming that a negative region do not exist, a coil part and coiling core part are regarded as an integrated body, the external pressure distribution acted on a cylinder is calculated. Further, by converting the toughness of the coiling core to a cylinder of thickness τ, the deformation of the cylinder integrating the coil part and coiling core part is analyzed. After analysis, the stress and strain distribution in a coil are calculated. Thus, by discriminating the number (n) of the coiling is smaller than a total number N of the coiling calculation process is repeated until (n) is equal to N.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of winding a metal band, and more particularly, to setting of a winding tension when winding a metal band while applying a winding tension to the metal band by a tension reel and an upper limit of a coil outer diameter. The present invention relates to a method of winding a metal strip having a characteristic value.

[0002]

2. Description of the Related Art Conventionally, there has been a method of winding a metal strip with a tension reel. In this case, the winding tension is usually determined from the plate thickness and the plate width. The reason why the winding tension is determined based on the plate thickness and the plate width is to cope with the following phenomena. First, when the winding tension is insufficient and the coil is loosely wound, the coil winding shape such as telescoping occurs, the coil is removed, the inner circumferential deformation of the coil occurs due to its own weight at the time of standing, or the winding is performed. This is because buckling deformation (especially when the plate thickness is small) of the inner circumference of the coil due to the force, slip flaws due to tightening of the coil in the uncoiler on the entrance side of the next process line, and the like occur. Second, if the winding tension is excessive, deformation of the mandrel and spool, or occurrence of medium elongation due to the plate crown, etc., will occur.

Further, as described above, the inner peripheral portion is kept low for the purpose of suppressing deformation of the inner peripheral portion of the coil such as buckling or crushing without uniquely determining the winding tension simply by the thickness and width of the plate. A method of winding under tension (JP-A-6-71337) has been proposed. In addition, in order to suppress deformation of the inner peripheral portion of the coil and to secure the load resistance of the coil, a method of determining the winding tension from the inner and outer diameters of the coil in addition to the thickness and width of the coil (Japanese Unexamined Patent Application Publication No.
-2777753).

[0004]

In recent years, thin plate users have come to demand particularly strict flatness depending on applications such as panels. Prior to shipment, flatness correction by leveler correction or the like is performed on materials for such uses. However, if the user unfolds the coil, the flatness of the material that has been strictly flattened by the correction is often deteriorated (ear waves on the inner circumferential side of the coil).
In a remarkable case, there has been a problem that it has to be diverted to another use or scrap down.

[0005] The above-described method of setting the winding tension in the prior art is aimed at suppressing deformation of the inner peripheral portion of the coil or securing the coil withstand load, and is not necessarily effective in suppressing flatness change during winding. This is not a typical setting method.
Further, it is considered that it is necessary to reduce the winding tension in order to suppress the occurrence of middle elongation due to the sheet crown. However, if the winding tension is lowered unnecessarily, there is a risk of causing deformation of the inner peripheral portion such as the elliptical shape of the coil inner diameter,
The idea of proper tension setting was not fully established.

It has been assumed that such a change in flatness is caused by a change in flatness on the inner circumferential side of the coil due to some factor that cannot be interpreted according to conventional wisdom when the metal strip is wound.

Therefore, the first present invention provides a method of winding a metal strip which can suppress a change in flatness such as an ear wave on the inner circumferential side of the coil at the time of winding which cannot be dealt with by the prior art. The purpose is to:

When winding a metal strip with low tension,
In addition to the elliptical deformation of the inner diameter part pointed out in the prior art, in actual operation, an oil agent such as rust-preventive oil is applied on the plate surface, which may make it slippery. In this case, a slip may occur in the coil during winding, or an axial displacement may occur during the axial swing of the coil performed for the purpose of positioning the coil end. Therefore,
Normally, the winding tension required for stable operation depends on the material thickness,
It is determined according to the plate width and the application status of the oil agent. Therefore, when the winding tension in the actual operation exceeds an appropriate winding tension for preventing the elliptical deformation of the inner diameter portion, a flatness change necessarily occurs in the inner peripheral portion. was there.

Accordingly, a second object of the present invention is to provide a method for winding a metal strip which does not cause a change in flatness on the inner peripheral side of the coil while securing the winding tension necessary for stable operation. I do.

[0010]

Means for Solving the Problems The inventors of the present invention repeated the simulation calculation using the model and the actual machine test, and found that the profile shape of the metal strip showed a flatness change such as an ear wave or middle elongation on the inner circumferential side of the coil. The present invention has been completed based on the finding that it is important for suppression. First,
Regarding the phenomenon of ear waves and middle elongation, in the inner peripheral part of the coil, the center part of the sheet width shrinks in the longitudinal direction due to the drum-shaped compression deformation, so that the flatness changes like an ear wave, while the sheet width of the winding tension After the directional distribution became constant, it was found that the tension acts on the central part of the plate width in a non-uniform manner, so that a medium-elongated flatness change appears. Then, they discovered that factors that most influence such a change in flatness are the degree of convexity of the cross section of the metal strip and the winding tension, and completed the first invention.

That is, according to the first aspect of the present invention, the invention is directed to a metal strip using a tension reel, which winds up a coil while applying a predetermined winding tension to the metal strip. In the winding method, the winding tension is determined from a thickness of the metal strip, a width of the metal strip, an outer diameter of the coil, and a degree of a convex shape of a cross section of the metal strip. It is characterized by. According to a second aspect of the present invention, there is provided a method for winding a metal strip using a tension reel that winds the metal strip while applying a predetermined winding tension to the metal strip, thereby forming a coil. Focusing on the degree of the convex shape of the cross section, the winding tension is reduced as the shape becomes gradually closer from the trapezoid where only the portions near both ends become thinner to the mountain shape which gradually becomes thinner from the center of the plate width to both ends. .

According to the first or second aspect, the winding tension can be appropriately set by focusing on the convex shape (profile shape) of the cross section of the metal strip. As a result, deformation of the inner peripheral portion such as an elliptical shape caused by too small winding tension does not occur. In addition, an ear wave is not generated on the inner peripheral portion of the coil due to an excessively large winding tension. This makes it possible to suppress a change in flatness of the metal strip.

According to a third aspect of the present invention, there is provided a method for winding a metal strip using a tension reel, which winds the metal strip while applying a predetermined winding tension to the metal strip to form a coil. Determining the width distribution of the winding tension in consideration of the convex shape of the cross section of the metal strip, determining the external pressure distribution acting on the wound coil portion, and measuring the circumferential stress or circumferential strain in the coil. Seeking the
The winding tension is determined so that the circumferential stress or the circumferential distortion is equal to or less than a predetermined value that does not cause ear waves, and further determined such that the winding tension is equal to or less than a predetermined value that does not cause middle elongation. And a step of performing the operation. Here, the external pressure acting on the wound coil portion refers to an external pressure that the winding tension of the metal strip wound around the coil exerts substantially uniformly from the outer periphery of the coil portion.

According to such a simulation method, a phenomenon corresponding to the actual machine can be predicted by calculation.
It is possible to calculate an appropriate winding tension corresponding to a predetermined profile shape.

According to a fourth aspect of the present invention, in the configuration of the first, second, or third aspect, the convex shape has a crown index representing a degree of inclination of the convex portion in a width direction or a correlation with the crown index. It is characterized in that evaluation is performed using a coefficient that has. According to a fifth aspect of the present invention, in the configuration of the fourth aspect, the convex shape and the crown index have the following relational expression. t (z) = t ₀ [1−α (| z | / h) ⁿ ] Here, 2h is the plate width, z is the distance from the plate width center, t ₀ is the plate thickness at the plate width center, and α is the crown. The ratio, n, is the crown index.

The convex shape (profile shape) of the cross section of the metal strip
The crown index or an index having a correlation with the crown index is used to evaluate. Therefore, the evaluation of the profile shape of the metal strip can be reliably performed.

The inventors have further advanced the knowledge that the factors that most influence the change in flatness are the degree of convexity of the cross section of the metal strip and the winding tension, and based on the results of experiments and analysis. The second invention has been completed by obtaining a method of defining the conditions for generating flatness and determining the upper limit of the coil size.

That is, the invention according to claim 6 of the second invention is a method of winding a metal strip using a tension reel that forms a winding coil while applying a predetermined winding tension to the metal strip. In the winding method, the upper limit of the coil outer diameter is defined from the winding tension and the degree of the convex shape of the cross section of the metal strip, and the coil outer diameter when winding the metal strip is set to the upper limit. It is characterized by being smaller than the value. According to a seventh aspect of the present invention, in the sixth aspect, the degree of the convex shape of the cross section of the metal band plate is changed from a trapezoid in which only portions near both ends are thin to a mountain shape in which the thickness gradually decreases from the center of the plate width to both ends. The closer the value is, the lower the upper limit is. According to an eighth aspect of the present invention, in the sixth or seventh aspect, the degree of the convex shape is evaluated by a crown index representing a degree of inclination of the convex portion in a width direction.

Thus, the upper limit of the coil outer diameter is defined based on the winding tension and the convex shape (profile shape) of the cross section of the metal strip, and the winding is stopped at a coil outer diameter smaller than the upper limit. Even when a necessary winding tension is set, flatness does not change in the inner peripheral portion of the coil.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention for defining a winding tension will be described with reference to the drawings. FIG. 1 is a diagram showing an algorithm of winding process analysis, FIG. 2 is a diagram showing an example of measurement of a profile shape, and FIG. 3 is a diagram showing a relationship between a crown index and a profile shape. Hereinafter, the procedure for analyzing the flatness at the time of winding the metal strip will be described with reference to FIG.

First, the algorithm for calculating the stress / strain distribution in the coil and the digitization of the profile shape of the metal strip will be described. FIG. 1 is a diagram showing an algorithm of the winding process analysis. For analysis of the winding process,
A winding model capable of calculating stress and strain generated when winding the metal strip is used. This winding model was created by the present inventors, and when calculating stress and strain, the profile shape of the plate, the rigidity of the tension reel, the distribution of the winding tension in the width direction of the plate, the distance between the plates in the coil The resulting gap is taken into account.

In the procedure for analyzing the winding process, first, the number of windings is set to 1 at the beginning of the flow (S1). Next, the width direction distribution of the winding tension is calculated in consideration of the sheet crown such as the crown index n and the crown ratio α, the sheet shape, and the winding shape (S2). Then, to determine the formation of the gap,
It is checked whether there is a region where the tension becomes negative (S3). If a negative area exists (S3, YES), the winding tension distribution is corrected (S4), and the process returns to step S2. When it is confirmed that no negative area exists (S3, NO),
The wound coil portion and the winding core portion (mandrel + rubber sleeve) are regarded as an integral cylinder, and the distribution of external pressure acting on the cylinder is calculated (S5). The calculation formula is as shown in the figure. Then, the rigidity of the core is converted into a cylinder having a thickness τ, and the deformation of the cylinder including the coil and the core is analyzed (S
6). After analyzing the axisymmetric deformation of the cylinder, the stress and
The distortion distribution is calculated (S7). Then, it is determined whether the number of turns n of the coil is smaller than the total number of turns N (S8). If n is smaller than N (S8, YES), the number of turns n is increased by one (S9), and the calculation procedure of S2 to S7 is repeated. n is N
(S8, N0), the flow ends.

Next, as shown in FIG. 2, the profile shape of the metal strip was actually measured. Then, the profile shape of the metal strip is convex, and the present inventors have
This profile shape having a convex shape was expressed by the following exponential equation. t (z) = t ₀ [1−α (| z | / h) ⁿ ] Here, 2h is the plate width, z is the distance from the plate width center, t ₀ is the plate thickness at the plate width center, and α is the crown. The ratio, n, is the crown index.

FIG. 3 shows the relationship between the value of the crown index n and the profile shape using the above-mentioned exponential equation with the crown ratio α being 1%. When the crown index is reduced by changing the profile shape, only the plate thickness at both ends is gradually reduced. That is, when the crown index n decreases, the profile shape changes from a trapezoidal shape to a mountain shape with the top at the center of the plate width.

Next, the results calculated by the simulation of FIG. 1 using the above-described profile index will be described with reference to FIGS. FIG. 4 is a diagram showing the width distribution of the winding tension, FIG. 5 is a diagram showing the width distribution of the circumferential distortion of the innermost circumference of the coil, and FIG. 6 is a relationship between the winding radius and the winding tension. FIG. The conditions used for the calculation are as shown in Table 1.

[0026]

[Table 1]

As shown in FIG. 4, the winding tension is largest near the center of the sheet width, and gradually decreases toward both ends of the sheet width, and becomes zero at both ends of the sheet width. Become. Thus, it is understood that the winding tension acts on the plate in the vicinity of the central portion of the plate width.

As shown in FIG. 5, the circumferential distortion at the innermost periphery of the coil is the largest in the vicinity of the center of the sheet width, as shown in FIG. Gradually decreases and becomes zero at both ends of the sheet width. Thereby, it turns out that an inner peripheral part of a coil undergoes compression deformation in the circumferential direction. Also, since the compression deformation is large near the center of the plate width, it can be seen that the inner periphery of the coil deforms like a drum.

As shown in FIG. 6, the relationship between the winding radius and the winding tension is such that in the case of a material having a normal crown ratio (at most about 1%), the winding radius is small (the winding length is short). At this stage, the tension acting on the plate edge becomes zero,
A gap is formed between the plates in the coil.

From the above analysis results, the mechanism of occurrence of the change in flatness during winding is presumed as follows. That is, as shown in FIG. 22, in the inner peripheral portion of the coil, the central portion of the plate width shrinks in the longitudinal direction due to a drum-shaped compression deformation,
An undulating flatness change appears. On the other hand, after the distribution of the winding tension in the plate width direction becomes constant, the tension acts on the central portion of the plate width in a non-uniform manner, so that a middle-extended flatness change appears.

Next, with reference to FIGS. 7 to 9, factors affecting the flatness change of the metal strip will be described using the above-described winding model. FIG. 7 is a diagram showing the effect of the winding tension, FIG. 8 is a diagram showing the effect of the crown ratio, and FIG.
FIG. 3 is a diagram showing the influence of a crown index. In addition, in the figure, the figure a located on the left side shows the width direction distribution of the strain in the circumferential direction of the spool, and the figure b located on the right side shows the width direction distribution of the winding tension.

When the winding tension is changed, FIG.
As shown in a, the unevenness in the width direction of the distortion in the circumferential direction of the spool becomes remarkable near the center of the plate width as the winding tension increases, and this portion undergoes strong compressive deformation. As shown in FIG. 7b, the change in the tension acting on the plate becomes more pronounced near the center of the plate width as the winding tension is increased, as is the case with the unevenness in the circumferential direction of the spool in the width direction. Thereby, as the winding tension increases, the winding tension acting near the center of the plate width increases, and the drum-shaped deformation of the inner peripheral portion of the coil becomes more remarkable.

In the case where the crown ratio is changed, FIG.
8A and 8B, no influence of the crown ratio on the width direction distribution of the spool circumferential distortion and the width direction distribution of the winding tension is observed. Thus, it can be understood that the magnitude of the crown ratio hardly affects the bias of the winding tension and the deformation of the inner peripheral portion of the coil.

When the crown index is changed, FIG.
As shown in a, the area where the strain in the circumferential direction of the spool is concentrated moves from near the center of the sheet width to the center of the sheet width as the crown index decreases. As shown in FIG. 9b, the region where the tension acting on the plate concentrates moves from near the center of the plate width to the center of the plate width as the crown index decreases as in the case of the change in the spool circumferential distortion. Along with this, as the crown index is smaller, the bias of the winding tension toward the center of the plate width becomes remarkable, and the compressive strain generated near the center of the plate width on the inner periphery of the coil also increases.

From FIGS. 7 to 9, it is considered that factors affecting the flatness change are the winding tension and the crown index. Thus, the magnitude of the winding tension is determined by the determination of the crown index.

For the purpose of verifying the mechanism of the change in flatness found by the numerical analysis using the above winding model and quantifying the conditions for generating flatness, the winding tension was measured using the actual machine under the conditions shown in Table 2. The relationship between the occurrence of the change in flatness and the flatness was investigated. The other conditions were the same as those shown in Table 1.

[0037]

[Table 2]

As a result, the winding tension was set to 8 kgf / mm ² , 4
When kgf / mm ² , flatness change of the ear wave appeared at the innermost periphery of the coil, and when winding tension was 2 kgf / mm ² , flatness change did not appear at the innermost periphery. When the winding tension was 4 kgf / mm ² , a slight change in flatness of the middle elongation was observed over almost the entire length of the coil excluding the innermost peripheral portion. Ona, the winding tension when the ^{8kgf / mm 2, 2kgf / mm} 2 , the flatness change of the medium elongation was observed.
From this, it was confirmed that under a specific winding tension condition, the flatness change of the ear wave appeared on the inner circumference of the coil, and the flatness change of the middle elongation appeared almost over the entire length of the coil excluding the inner circumference. The model was validated.

Therefore, based on the present analysis model, the conditions under which the change in the flatness of the ear wave and the middle elongation were quantitatively estimated. The results are shown in FIGS. FIG. 10 is a diagram showing the radial distribution of circumferential strain and the position where ear waves are generated at the center of the plate width, and FIG. 11 is a diagram showing the winding tension and the position where middle elongation occurs at the center of the plate width.

As shown in FIG. 10, what is shown by the dotted line and the solid line is the result of the radial distribution of the circumferential strain calculated by the winding model at the changing winding tension. The thick dotted line indicates that the winding tension is 8 kgf.
/ Mm ² , the thin dotted line indicates the winding tension of 4 kgf / m
m ² and the solid line show the results when the winding tension was 2 kgf / mm ² . The ear wave height measured by the actual winder is indicated by x, Δ, and ○, and the x mark is the ear wave height of 3
mm or more, the mark Δ indicates an ear wave height of 3 mm or less, and the mark ○ indicates that no ear wave was generated.

From FIG. 10, it can be seen from FIG. 10 that the size of the compressive strain ε _s (ear strain generated) where the ear wave starts to be generated (the tension is positive and the compression is negative) and the size of the compressive strain ε _c leading to the poor ear wave. (Ear deficiency distortion) is obtained as follows. ε _s = 300 × 10 ⁻⁶ ε _c = 700 × 10 ⁻⁶ Then, the magnitude ε of the circumferential compressive strain is such that ε <ε _s is a safe area, ε _s <ε <ε _c is an ear wave generating area, ε> ε _c can be regarded as the ear wave failure area.

As shown in FIG. 11, similarly to FIG.
The dotted line and solid line show the magnitude of the winding tension.
You. The mark “△” indicates middle elongation of ear wave height of 1 to 2 mm.
○ indicates that no middle elongation occurred. From the figure,
Tension σ_s(Tension that can generate medium elongation)
Value. σ_s= 6kgf / mm^Two Then, the winding tension σ acting on the central portion of the sheet thickness becomes σ <
σ_sIs the safety margin, σ> σ _sIs the area where medium elongation can occur
Can be.

[0043]

【Example】

[First Embodiment] Hereinafter, as a first embodiment of the present invention,
A method of determining the winding tension from the profile shape of the plate and the outer diameter of the coil will be described. When the above-described winding model is used, when a crown ratio α, a crown index n, a coil outer diameter R, and a winding tension σ _T are given, a circumferential strain ε _max at a central portion of a plate width at the innermost circumference of the coil is obtained. Winding tension σ acting on the center of the sheet width after the gap begins to form
_max can be calculated.

Graphs obtained by such calculations are shown in FIG. 12 and FIG. FIG. 12 is a diagram showing the relationship between the winding tension and the circumferential strain at the center of the plate width, FIG. 13 is a diagram showing the relationship between the winding tension and the tension at the center of the plate width, and FIG. It is a figure which shows the relationship between a crown index and the winding tension of the winding width center part.

The circumferential strain at the center of the plate width calculated using the crown index n as a parameter is as shown in FIG.
It is shown with the change of the crown index n. The circumferential strain at the center of the plate width is proportional to the magnitude of the winding tension. In addition, the smaller the crown index n, the greater the circumferential distortion corresponding to the winding tension. Therefore, at a certain winding tension, the smaller the crown index n, the greater the circumferential distortion at the center of the plate width. The dotted line indicates the ear wave poor distortion ε _C (700 × 1
It represents 0 ^-6), thereby to generate Mimiha the plate becomes more than this value.

As in the case of the circumferential distortion at the center of the sheet width, FIG.
As shown in the above, the tension at the center of the plate width calculated using the crown index n as a parameter is proportional to the magnitude of the winding tension. Also, as the crown index n decreases,
The tension at the center of the plate width corresponding to the winding tension increases. For this reason, at a certain winding tension, the smaller the crown index n, the greater the tension acting on the central portion of the plate width. The dotted line indicates the tension σ _S (6 kgf / mm ² ) at which the medium elongation can be generated. If the tension exceeds this value, the medium elongation occurs at the center.

From the crown index n, the distortion of the ear wave and the tension at which the middle elongation can be generated, a winding tension (ear wave poor tension) σ _T1 for generating the ear wave failure and a winding tension (medium extension generating tension) for generating the middle elongation. ) Σ _T2 is determined. When the crown index of the metal strip is determined, as shown in FIG. 14, an ear wave fault tension σ _T1 for generating an ear wave fault and a medium elongation generating tension σ _T2 for generating a middle elongation are determined. At this time, the ear wave poor tension σ
_T1 takes into account the coil weight. The ear-wave poor tension σ _T1 and the medium elongation generation tension σ _T2 decrease as the crown index n decreases. Thereby, when the crown index n is small, the winding tension is set to be small. Specifically, if only the occurrence of an ear wave defect is to be suppressed, the winding tension is equal to the ear wave defect tension σ.
_In order to suppress the generation of the middle elongation to be equal to or less than _{T1, the} tension is set to be equal to or less than the middle elongation generating tension σ _T2 . In addition, if both the occurrence of the eaves defect and the occurrence of the elongation are suppressed, the eaves defect tension σ _T1 and the elongation occurrence tension σ
_The winding tension is set so as to be less than _T2 . In addition, ○, □, and △ marks indicate coil weights of 5, 10, and 15, respectively.
The bad ear wave tension σ _T1 at the time of ton is shown, and the mark ▲ shows the middle elongation generating tension σ _T2 .

Next, a specific procedure for determining the winding tension will be described. When the profile shape as shown in FIG. 2 is given, the winding tension can be determined using FIG. First, a profile index n is obtained from the profile shape. Then, for the determined n, the winding tension is set to σ _T2 or less for a user who does not like the occurrence of medium elongation,
Winding tension σ for users who do not like poor ear waves
_For users who do not like both the occurrence of middle elongation and poor ear wave, the value is set to a value smaller than the smaller of the winding tensions σ _T1 and σ _T2 .

[Second Embodiment] Next, a method for determining the winding tension from the thickness measurement at three points of the width of the plate will be described. FIG.
FIG. 4 is a diagram showing the relationship between CC75 / TC25 and ear wave poor tension and medium elongation generation tension. The thickness of the metal strip in the hot rolling step is usually controlled at three points: a central portion of the plate width, and 25 mm and 75 mm from the central portion of the plate width. The winding tension is set using the three points for managing the plate thickness. That is, with respect to the plate width central portion t ₀ of metal strip, it is defined from the sheet width central portion t ₀ 25 mm, the difference between the respective plate width position 75mm respectively TC25, CC75. When these TC25 and CC75 are represented by exponential expressions formed by the present inventors, they have the following relational expression with the crown index. CC75 / TC25 = [(h−75) / (h−25)] ⁿ Expression 2h is a plate width, and n is a crown index. Thus, when CC75 / TC25 is obtained, it is the same as when the crown index is obtained. First, the plate thickness is measured from three points of the plate width. After that, CC75 / TC2
Find 5 As the value of CC75 / TC25 increases, the crown index increases. Using the equation, CC75 and T
CC75 / TC25 of the ratio of C25 and bad ear tension σ _T1 ,
FIG. 15 shows the result of _obtaining the relationship of the medium elongation generation tension σ _T2 . When CC75 and TC25 are given, using FIG. 15, the winding tension is set to σ _T2 or less for a user who does not like the occurrence of medium elongation, and the winding tension σ is set for a user who does not like the poor ear wave. _For users who do not like both the occurrence of middle elongation and poor ear wave, the value is set to a value smaller than the smaller of the winding tensions σ _T1 and σ _T2 .

[0050]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a second embodiment of the present invention which defines the coil outer diameter will be described in the order of theoretical analysis results, flatness change generation mechanism, actual machine experimental results, and flatness change generation conditions. This will be described together with an example. First, coil deformation was examined by theoretical analysis, and the mechanism of occurrence of flatness change was estimated (FIG. 16).
reference). Next, a coil winding experiment was performed using an actual recoiler line to verify the estimated mechanism of the flatness change, and to confirm the validity of the analysis model (see FIG. 17).

FIG. 16 shows a calculation result of a distribution in the thickness direction of the circumferential strain generated in the inner peripheral portion of the coil when a plate having a crown is wound by a tension reel. The stress / strain is indicated as positive for tension and negative for compression. As shown in the figure, the inner circumferential portion of the coil undergoes compressive deformation in the circumferential direction. The compressive strain increases in the central portion of the sheet with a large thickness, and the compressive strain increases as the winding tension increases. From this, it is presumed that when the coil becomes large, plastic strain is caused, and as a result, an ear wave-like flatness change appears.

In order to confirm this, a coil winding experiment was carried out using an actual recoiler line. FIG.
Shows the measurement results of the distortion of the inner peripheral portion of the coil. It can be seen that the inner circumferential portion of the coil exhibits the same deformation as expected from the analysis results, and the magnitude of the generated compressive strain can be well estimated from the analysis.

FIG. 18 shows the measured results of the relationship between the winding tension and the wave height of the ear wave generated on the inner peripheral portion of the coil.
Shows the actual measurement result of the relationship between the winding tension and the length of the occurrence of the ear wave failure (measured from the innermost circumference of the coil). From these figures, it can be seen that the greater the winding tension, the greater the degree of the ear wave and the longer the length at which the ear wave is generated.

The results of plotting the ear wave generation positions in the experiment on the calculation results of the radial distribution of the circumferential strain at the center of the plate width are shown in FIG. 10 described above. From FIG. 10, it can be seen that when the compressive strain in the circumferential direction exceeds 700 × 10 ⁻⁶ , an ear wave failure occurs. Therefore, in coil winding, the compression distortion of the inner peripheral portion is 700 × 1
It is necessary to not exceed 0 ^-6.

FIG. 20 shows the relationship between the outer radius of the coil and the circumferential distortion at the center of the plate width at the innermost periphery of the coil when the crown shape and the winding tension are fixed, using the developed analysis method. The calculated results are shown. As shown in the figure, when the outer radius of the coil increases, the compressive strain in the circumferential direction increases, exceeding the ear wave generation limit of 700 × 10 ⁻⁶ . That is, for each profile shape and winding tension,
The outer radius of the coil at which ear waves start to be generated (the upper limit of the outer radius of the coil) can be determined.

[0056]

Hereinafter, as a second embodiment of the present invention, a specific method for determining the upper limit of the coil size based on the profile of the plate and the winding tension required for stable operation will be described.

FIG. 21 shows that the winding tension was 4, 5, 6 kgf /
The result of obtaining the relationship between the crown index and the upper limit of the coil outer radius when mm ² is set is shown. By referring to the figure, the upper limit value of the outer radius of the coil for avoiding generation of ear waves can be obtained, and by setting the outer radius of the coil within the upper limit value, a coil having no flatness change during winding can be used by the user. Can be provided.

[0058]

As described above, according to the first, second and third aspects of the present invention, the winding tension can be appropriately set by focusing on the profile shape of the metal strip. As a result, deformation of the inner peripheral portion such as an elliptical shape caused by too small winding tension does not occur. In addition, an ear wave is not generated on the inner peripheral portion of the coil due to an excessively large winding tension. This makes it possible to suppress a change in flatness of the metal strip.

According to the fourth and fifth aspects of the present invention, in addition to the effect of the first aspect, a crown index or an index having a correlation with the crown index is used for evaluating the profile shape of the metal strip. Therefore, the evaluation of the profile shape of the metal strip can be reliably performed.

As described above, according to the sixth to eighth aspects of the present invention, the upper limit value of the coil size is determined from the winding tension and the degree of the convex shape of the cross section of the metal strip, thereby ensuring stable operation. While ensuring the necessary winding tension for
At the same time, it is possible to provide a coil in which the flatness of the inner peripheral portion does not change.

[Brief description of the drawings]

FIG. 1 is a diagram showing an algorithm for winding process analysis.

FIG. 2 is a diagram showing a measurement example of a profile shape.

FIG. 3 is a diagram showing a relationship between a crown index and a profile shape.

FIG. 4 is a diagram showing a change in winding tension.

FIG. 5 is a diagram showing circumferential distortion of the innermost circumference of the coil.

FIG. 6 is a diagram illustrating a relationship between a winding radius and a winding tension.

FIG. 7 is a diagram showing the effect of winding tension.

FIG. 8 is a diagram showing the influence of the crown ratio.

FIG. 9 is a diagram showing the influence of a crown index.

FIG. 10 is a diagram illustrating a radial distribution of circumferential distortion and a position where an ear wave is generated at a central portion of a plate width.

FIG. 11 is a diagram showing a winding tension and a middle elongation occurrence position in a central portion of a plate width.

FIG. 12 is a diagram illustrating a relationship between a winding tension and a circumferential distortion at a central portion of a plate width.

FIG. 13 is a diagram showing the relationship between the winding tension and the tension at the center of the plate width.

FIG. 14 is a diagram showing a relationship between a crown index, an ear wave defective tension, and a medium elongation generating tension.

FIG. 15 is a diagram showing the relationship between CC75 / TC25, ear wave poor tension, and medium elongation generation tension.

FIG. 16 is a diagram illustrating a calculation result of a distribution in a thickness direction of a circumferential strain generated in an inner circumferential portion of a coil.

FIG. 17 is a diagram showing an actual measurement result of a distribution in a thickness direction of a circumferential strain generated in an inner circumferential portion of a coil.

FIG. 18 is a diagram illustrating a relationship between a winding tension and a crest height of an ear wave generated in an inner peripheral portion of a coil.

FIG. 19 is a diagram showing a measurement result of a relationship between a winding tension and a length at which an ear wave defect occurs.

FIG. 20 is a diagram showing a relationship between an outer radius of a coil and a circumferential distortion at a central portion of a plate width at an innermost circumference of the coil.

FIG. 21 is a diagram illustrating a relationship between a crown index and an upper limit of a coil outer radius at each winding tension.

FIG. 22 is a diagram showing a mechanism for generating a change in flatness.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Haruhiro Inaba 1 Kanazawacho, Kakogawa City, Hyogo Prefecture Inside the Kobe Steel Works Kakogawa Works (72) Inventor Yoshiaki Kigawa 1 Kanazawacho, Kakogawa City, Hyogo Prefecture God Co., Ltd. Inside Koto Steel Works Kakogawa Works (72) Inventor Yuichiro Sugimoto 1 Kanazawacho, Kakogawa City, Hyogo Prefecture Kobe Steel Works Kakogawa Works 1 (72) Inventor Mamoru Sawada 1 Kanazawacho, Kakogawa City, Hyogo Prefecture Kobe Corporation Inside the steel mill Kakogawa Works

Claims (8)

[Claims] 1. A winding method for a metal strip using a tension reel that turns a coil while applying a predetermined winding tension to the metal strip, wherein the winding tension is controlled by the metal strip. A method of winding a metal strip, which is determined from a thickness of a sheet, a width of the metal strip, an outer diameter of the coil, and a degree of a convex shape of a cross section of the metal strip. 2. A method for winding a metal strip using a tension reel that turns a winding coil while applying a predetermined winding tension to the metal strip, the cross section of the metal strip being convex. A winding method of a metal band, wherein the winding tension is reduced as the shape becomes closer to a mountain shape gradually thinning from a trapezoid in which only portions near both ends become thinner from the center of the plate width to both end portions. 3. A method for winding a metal strip using a tension reel that turns a winding coil while applying a predetermined winding tension to the metal strip, wherein the convex shape of the cross section of the metal strip is determined. Determining a width distribution of the winding tension in consideration of the above; obtaining an external pressure distribution acting on the wound coil portion; obtaining a circumferential stress or circumferential strain distribution in the coil; Determining the winding tension such that the stress or circumferential distortion is not more than a predetermined value that does not cause ear waves, and further determining that this winding tension is not more than a predetermined value that does not cause medium elongation. A method for winding a metal band, comprising: 4. The winding of a metal strip according to claim 1, wherein the convex shape is evaluated by a crown index indicating a degree of inclination of the convex portion in a width direction or a coefficient having a correlation with the crown index. Method. 5. The method according to claim 4, wherein the convex shape and the crown index have the following relational expression. t (z) = t ₀ [1−α (| z | / h) ⁿ ] Here, 2h is the plate width, z is the distance from the plate width center, t ₀ is the plate thickness at the plate width center, and α is the crown. The ratio, n, is the crown index. 6. A winding method of a metal strip using a tension reel that turns a winding coil while applying a predetermined winding tension to the metal strip, wherein the winding tension and the metal strip are provided. The upper limit of the coil outer diameter is defined from the cross-sectional shape including the degree of the convex shape of the cross section of the cross section, and the coil outer diameter when winding the metal strip is made smaller than the upper limit. How to wind the board. 7. The upper limit value decreases as the degree of the convex shape of the cross section of the metal strip decreases from a trapezoid where only portions near both ends become thinner to a mountain shape which becomes thinner gradually from the center of the plate width to both ends. 6. The method for winding a metal band according to item 6. 8. The method according to claim 6, wherein the degree of the convex shape is evaluated by a crown index indicating a degree of inclination of the convex portion in a width direction.