Field
[0001] The present invention relates to a meandering control method, a meandering control
apparatus, and a manufacturing method for a steel sheet.
Background
[0002] In general, a large number of deflector rolls are installed in a continuous steel
sheet manufacturing device for the purpose of changing a traveling direction of a
steel sheet. By installing the deflector roll, the continuous steel sheet manufacturing
device is formed compactly, thereby reducing construction costs. On the other hand,
an adverse effect caused by installing the deflector roll is that meandering of the
steel sheet occurs due to frictional force of the deflector roll. Therefore, a center
position control (CPC) meandering control device is generally used to suppress the
meandering of the steel sheet due to the frictional force of the deflector roll. However,
the CPC meandering control device may not be usable due to restriction on costs and
installation places. For example, in a horizontal looper device, it is difficult to
install the CPC meandering control device on the deflector roll on a moving looper
car due to restriction on costs and electronic components. Therefore, a deflector
crown roll having a convex roll profile is used for the deflector roll in which the
CPC meandering control device cannot be installed. By forming the roll profile as
a convex shape, frictional force becomes centering force, and meandering of the steel
sheet can be suppressed to some extent although not as much as the CPC meandering
control device. In addition, since only the roll profile is processed into the convex
shape, there are almost no restrictions on costs and installation places, and the
roll profile can be frequently used.
[0003] In recent years, with an increase in high-tensile steel sheet or the like, a shape
defect is likely to occur at a tip end portion or a tail end portion of a coil of
a hot-rolled steel sheet manufactured in a hot-rolling step as an upstream step, and
a situation in which meandering of the steel sheet cannot be suppressed at a joint
portion between the steel sheets having such a shape defect has frequently occurred.
If the meandering of the steel sheet cannot be suppressed, the steel sheet is rolled
out and comes into contact with a peripheral frame, which causes a serious trouble
such as breakage and results in incapacity of operation. Therefore, it is difficult
to newly install the CPC meandering control device in an existing facility, and thus,
meandering countermeasures by a crown roll such as adjusting the convex shape of the
crown roll are taken. However, if the convex shape of the crown roll is too high,
the steel sheet and the roll surface cannot be brought into contact with each other
on the entire surface, and as a result, a contact defect or the like may occur, so
that an effect of suppressing meandering by the crown roll is limited. In addition,
since it is known that the shape defect at the tip end portion or the tail end portion
of the coil causes meandering, the portions are usually removed, but costs increase
due to the addition of a removal step, and removal of the tip end portion and the
tail end portion are directly linked to reduction in the yield. Therefore, to reduce
CO
2, it is needless to say that it is better not to perform the removal step as possible.
In addition, a method of suppressing the meandering of the steel sheet by a guide
roll in contact with an end portion of the steel sheet in the width direction has
also been proposed, but in such method, large collision force that suppresses the
meandering of the steel sheet is generated in the guide roll, and defects such as
chipping of the end portion of the steel sheet in the width direction may occur by
the collision force.
[0004] From such a background, Patent Literature 1 proposes a meandering control method
of suppressing meandering of a steel strip by predicting a meandering amount of the
steel strip from a real-time simulation of the meandering amount of the steel strip
on the upstream side of a steering device and movement of the steel sheet and controlling
the steering device based on the predicted meandering amount.
Citation List
Patent Literature
Summary
Technical Problem
[0006] However, in the meandering control method described in Patent Literature 1, the meandering
amount on the upstream side of the steering device used for predicting the meandering
amount of the steel strip is a part of shape information of the steel strip, and is
insufficient as information for suppressing the meandering of the steel strip. In
addition, in the meandering control method described in Patent Literature 1, the lack
of information is to be complemented by real-time simulation, but there is no description
on a simulation method, and the meandering control method has not been put to practical
use.
[0007] The present invention has been made in view of the above problems, and an object
thereof is to provide a meandering control method and a meandering control apparatus
for a steel sheet capable of suppressing meandering of a steel sheet having a shape
defect. Another object of the present invention is to provide a manufacturing method
for a steel sheet capable of manufacturing a steel sheet having a good yield by suppressing
meandering of a steel sheet having a shape defect.
Solution to Problem
[0008] To solve the problem and achieve the object, a meandering control method for a steel
sheet according to the present invention includes: a measurement step of measuring
an out-of-plane deformation amount of the steel sheet on an upstream side of a steering
device that changes a conveyance direction of the steel sheet; a calculation step
of calculating an average curvature of the steel sheet using the out-of-plane deformation
amount of the steel sheet measured in the measurement step; and a control step of
calculating an off-center amount of the steel sheet in the steering device using the
average curvature of the steel sheet calculated in the calculation step, and controlling
a winding position of the steel sheet relative to the steering device based on the
calculated off-center amount.
[0009] Moreover, the measurement step may include a step of measuring the out-of-plane deformation
amount of the steel sheet on a delivery side of a cutting device installed on the
upstream side of the steering device, the cutting device being configured to cut an
end portion of the steel sheet in a width direction.
[0010] Moreover, a meandering control apparatus for a steel sheet according to the present
invention includes: a steering device that changes a conveyance direction of the steel
sheet; a measurement device that measures an out-of-plane deformation amount of the
steel sheet on an upstream side of the steering device; a position adjustment device
that adjusts a winding position of the steel sheet relative to the steering device;
and a control device that controls the position adjustment device, wherein the control
device calculates an average curvature of the steel sheet using the out-of-plane deformation
amount of the steel sheet that is measured by the measurement device, calculates an
off-center amount of the steel sheet in the steering device using the calculated average
curvature of the steel sheet, and controls the position adjustment device based on
the calculated off-center amount.
[0011] Moreover, the measurement device may be installed on a delivery side of a cutting
device installed on the upstream side of the steering device, the cutting device being
configured to cut an end portion of the steel sheet in a width direction.
[0012] Moreover, a manufacturing method for a steel sheet according to a first mode of the
present invention includes: a storage step of storing the steel sheet in a looper
device while suppressing the meandering of the steel sheet using the method of controlling
the meandering of the steel sheet according to the present invention; and a cold rolling
step of cold-rolling the steel sheet stored in the looper device.
[0013] Moreover, a manufacturing method for a steel sheet according to a second mode of
the present invention includes: a storage step of storing the steel sheet in a looper
device while suppressing the meandering of the steel sheet using the method of controlling
the meandering of the steel sheet according to the present invention; and an annealing
step of annealing the steel sheet stored in the looper device.
Advantageous Effects of Invention
[0014] A meandering control method and a meandering control apparatus for a steel sheet
according to the present invention can suppress meandering of a steel sheet having
a shape defect. Further, according to a manufacturing method for a steel sheet of
the present invention, it is possible to manufacture a steel sheet having a good yield
by suppressing meandering of a steel sheet having a shape defect.
Brief Description of Drawings
[0015]
FIG. 1 is a block diagram illustrating a configuration of a manufacturing line of
a steel sheet to which a meandering control method and a meandering control apparatus
for a steel sheet according to an embodiment of the present invention are applied.
FIG. 2 is a schematic diagram illustrating a configuration of a looper device illustrated
in FIG. 1.
FIG. 3 is a diagram illustrating an example of shape data of the steel sheet measured
by a measurement device.
FIG. 4 is a diagram illustrating an example of a relationship between a maximum bending
of a joint portion of the steel sheet and an occurrence state of a defect.
FIG. 5 is a diagram illustrating an example of a method of measuring an out-of-plane
deformation amount. Description of Embodiments
[0016] Hereinafter, a meandering control method, a meandering control apparatus, and a manufacturing
method for a steel sheet according to an embodiment of the present invention will
be described with reference to the drawings.
[Concept]
[0017] First, a concept of the present invention will be described.
[0018] A shape defect of a steel sheet occurs mainly due to widthwise nonuniformity of elongation
in the longitudinal direction in a rolling process. The shape defect of the steel
sheet is superposition such as bending (one-side elongation) and edge wave/center
buckle, and the shape defect that most greatly affects the meandering of the steel
sheet is bending. In particular, in the case of a thin plate, out-of-plane deformation
derived from bending disappears when the thin plate is formed into a cut plate, and
it becomes difficult to measure bending. On the other hand, the edge wave/center buckle
can be measured because the out-of-plane deformation remains even in the cut plate.
[0019] If the shape of the steel sheet is a curved surface shape in which the cross section
in the width direction is a straight line, geometric definition of a curvature κ of
the bending is described as in the following Mathematical Formula (1). In Mathematical
Formula (1), x represents a longitudinal position of the steel sheet, v represents
displacement of the steel sheet in the width direction from the center position of
the steel sheet in the width direction, w represents displacement of the steel sheet
in the vertical direction from the center position of the steel sheet in the width
direction, and ω represents a twist angle of the steel sheet.

[0020] Since it is difficult to observe the curvature κ shown in Mathematical Formula (1),
the bending of the steel sheet in the longitudinal direction is considered as an average
value (average bending), and an average curvature K is defined as in Mathematical
Formula (2) shown below. In Mathematical Formula (2), L represents a length of the
steel sheet for averaging.

[0021] Accordingly, by substituting Mathematical Formula (1) into Mathematical Formula (2),
the average curvature K is expressed as the following Mathematical Formula (3). The
first term on the right side of Mathematical Formula (3) is an amount observed as
meandering or skewing of the steel sheet, and the second term on the right side is
an amount observed as out-of-plane deformation of the steel sheet. From Mathematical
Formula (3), it can be seen that, even if only the meandering of the steel sheet is
observed, the bending (average curvature K) of the steel sheet deeply related to the
meandering of the steel sheet is not found. On the other hand, if meandering of the
steel sheet does not occur, a value of the first term on the right side becomes zero,
so that the average curvature K can be obtained from an observation amount of the
out-of-plane deformation (second term on the right side). In a thin plate, when meandering
occurs, the out-of-plane deformation of the thin plate is often accompanied.

[0022] When the twist angle ω of the steel sheet is small, Mathematical Formula (3) can
be approximated as the following Mathematical Formula (4), and Mathematical Formula
(4) can be transformed as the following Mathematical Formula (5).


[0023] When the twist angle ω of the steel sheet is small, the deflection W of the steel
sheet can be expressed by the following Mathematical Formula (6). In Mathematical
Formula (6), y represents the position of the steel sheet in the width direction.

[0024] Further, a length 1(x, y) of the steel sheet along the bent curved surface can be
expressed by the following Mathematical Formula (7).

[0025] Further, an elongation difference rate Δε
1(x, y) of the steel sheet can be defined as the following Mathematical Formula (8).

[0026] In Mathematical Formula (8), l
0(x) represents the average length of the steel sheet in the width direction, and is
expressed as the following Mathematical Formula (9). In Mathematical Formula (9),
b represents the sheet width of the steel sheet.

[0027] Therefore, by substituting Mathematical Formula (6) and Mathematical Formula (7)
into Mathematical Formula (9), Mathematical Formula (10) shown below is obtained.

[0028] When the deflection W and the twist angle ω of the steel sheet are small, Mathematical
Formula (10) can be approximated as Mathematical Formula (11) shown below, and Mathematical
Formula (12) shown below is obtained by deforming Mathematical Formula (11).


[0029] When Mathematical Formula (6), Mathematical Formula (7), and Mathematical Formula
(12) are substituted into Mathematical Formula (8), the elongation difference rate
Δε
1(x, y) of the steel sheet is expressed by the following Mathematical Formula (13).

[0030] The curvature K
1 of the average bending converted from the elongation difference rate Δε
1(x, y) of the steel sheet is defined by the following Mathematical Formula (14) .

[0031] By substituting Mathematical Formula (13) into Mathematical Formula (14), the following
Mathematical Formula (15) is obtained.

[0032] Therefore, since Mathematical Formula (15) corresponds to the second term on the
right side of Mathematical Formula (5), Mathematical Formula (5) can be modified as
Mathematical Formula (16) shown below.

[0033] According to the above description, when the meandering of the steel sheet does not
occur and the first term on the right side of Mathematical Formula (16) becomes zero,
it can be seen that the average curvature K of the average bending can be obtained
from the curvature K
1. The curvature K
1 can be calculated by substituting measured values of the out-of-plane deformation
amount of the steel sheet and the gradient thereof into Mathematical Formula (14).
Therefore, in the present invention, the out-of-plane deformation amount of the steel
sheet and the gradient thereof are measured at a position at which the meandering
of the steel sheet does not occur, the average curvature K of the steel sheet is calculated
from the measured value, the off-center amount of the steel sheet in the steering
device (the positional deviation direction and positional deviation amount of the
center position in width direction of the steel sheet relative to the center position
in the width direction of the steering device when the steel sheet reaches the steering
device) is calculated from the calculated average curvature K, and the winding position
of the steel sheet relative to the steering device is controlled based on the calculated
off-center amount. The same control may be performed by measuring the meandering amount
and the out-of-plane deformation amount of the steel sheet at a position at which
the meandering of the steel sheet occurs, and calculating the average curvature K
of the steel sheet using the measured meandering amount and out-of-plane deformation
amount of the steel sheet. Accordingly, it is possible to suppress meandering of a
steel sheet having a shape defect. In addition, by manufacturing the steel sheet using
such meandering control method, it is possible to suppress the meandering of the steel
sheet having the shape defect and to manufacture a steel sheet having a good yield.
[0034] Hereinafter, a description will be given as to a meandering control method, a meandering
control apparatus, and a manufacturing method for a steel sheet according to an embodiment
of the present invention, which is conceived based on the above concept. Note that
the out-of-plane deformation amount is one of indices indicating bending and one-side
elongation of a steel sheet S. As a method of measuring the out-of-plane deformation
amount, methods illustrated in FIGS. 5(a) and 5(b) can be considered. The method illustrated
in FIG. 5(a) is a method of winding the steel sheet S around a roll 20 or pressing
the steel sheet S to apply normal force to the steel sheet S to elongate a wrinkle,
and measuring bending (one-side elongation) of the steel sheet S in which the wrinkle
is elongated. On the other hand, the method illustrated in FIG. 5(b) is a method of
straightening the steel sheet S in the longitudinal direction (not meandering) and
converting the bending (one-side elongation) of the steel sheet S from a height of
the wrinkle of the steel sheet S. In the method illustrated in FIG. 5(a), when the
length of the steel sheet S in which the wrinkle is elongated in the longitudinal
direction is short, it is difficult to measure the out-of-plane deformation amount.
Therefore, it is desirable to employ the method illustrated in FIG. 5(b), and in the
present embodiment, the out-of-plane deformation amount is measured (converted) using
the method illustrated in FIG. 5(b).
[Configuration of Manufacturing Line]
[0035] First, with reference to FIGS. 1 and 2, a description will be given as to a configuration
of a manufacturing line of the steel sheet to which the meandering control method
and the meandering control apparatus for the steel sheet according to the embodiment
of the present invention are applied.
[0036] FIGS. 1(a) and 1(b) are block diagrams illustrating a configuration of a manufacturing
line of the steel sheet to which the meandering control method and the meandering
control apparatus for the steel sheet according to the embodiment of the present invention
are applied. As illustrated in FIG. 1(a), the manufacturing line of the steel sheet
to which the meandering control method and the meandering control apparatus for the
steel sheet according to the embodiment of the present invention are applied includes
a cutting device 1 that cuts an end portion of the steel sheet in the width direction,
a looper device 2 that stores the steel sheet having the end portion in the width
direction cut by the cutting device 1, and a cold rolling mill 3 that cold-rolls the
steel sheet stored in the looper device 2. As illustrated in FIG. 1(b), an annealing
furnace 4 for annealing the steel sheet stored in the looper device 2 may be disposed
instead of the cold rolling mill 3.
[0037] FIG. 2 is a schematic diagram illustrating a configuration of the looper device 2
illustrated in FIGS. 1(a) and 1(b). As illustrated in FIG. 2, in the present embodiment,
the looper device 2 includes a horizontal looper including a deflector roll. A free
looper FL is disposed at the most upstream portion of the looper device 2, the cutting
device 1 (not illustrated) is disposed downstream of the free looper FL, a bridle
roll BR is disposed downstream of the cutting device 1, and a first deflector roll
#1DEF is disposed downstream of the bridle roll BR. A first steering roll #1STR also
having a deflector function is disposed downstream of the deflector roll #1DEF. The
steering roll #1STR includes a CPC meandering control device. On the downstream side
of the steering roll #1STR, a looper car #1LP car including a second deflector roll
is disposed. The looper car #1LP car adjusts the length of the steel sheet S between
the rolls by moving in the left-right direction of the drawing.
[0038] A second steering roll #2STR also having a deflector function is disposed on the
downstream side of the looper car #1LP car. The steering roll #2STR includes the CPC
meandering control device. On the downstream side of the steering roll #2STR, a looper
car #2LP car including a third deflector roll is disposed. The looper car #2LP car
adjusts the length of the steel sheet S between the rolls by moving in the left-right
direction of the drawing. A third steering roll #3STR also having a deflector function
is disposed on the downstream side of the looper car #2LP car. The steering roll #3STR
includes the CPC meandering control device.
[0039] Between the deflector roll #1DEF and the looper car #1LP car and between the steering
roll #2STR and the looper car #2LP car, support rolls that support the weight of the
steel sheet S are disposed at a pitch of 2.5 m. Between the looper car #1LP car and
the steering roll #2STR and between the looper car #2LP car and the steering roll
#3STR, separator rolls having a function of supporting the weight of the steel sheet
S and opening and closing when the steel sheet S passes through the looper car are
installed at a pitch of 15 m. Although not illustrated, a guide vertical roll is installed
at a predetermined pitch in the vicinity of the support roll for suppressing meandering.
[Configuration of Meandering control apparatus for Steel Sheet]
[0040] Next, a configuration of the meandering control apparatus for the steel sheet according
to the embodiment of the present invention will be described with reference to FIG.
1.
[0041] As illustrated in FIGS. 1(a) and 1(b), the meandering control apparatus for the steel
sheet according to the embodiment of the present invention includes a measurement
device 11, a position adjustment device 12, and a control device 13.
[0042] The measurement device 11 is configured with a profilometer such as a three-dimensional
laser scanner, and is disposed on the upstream side of a steering device that changes
a conveyance direction of the steel sheet. Specifically, in the present embodiment,
the measurement device 11 is disposed on the downstream side of the cutting device
1 and on the upstream side of the looper device 2 (steering roll). The measurement
device 11 measures shape data of the steel sheet including the out-of-plane deformation
amount of the steel sheet, and outputs an electric signal indicating the measured
shape data to the control device 13. The location of the measurement device 11 is
not limited to the position on the downstream side of the cutting device 1 and on
the upstream side of the looper device 2, and may be disposed at any position as long
as the steel sheet does not meander or the meandering amount of the steel sheet can
be regarded as zero. For example, the measurement device 11 may be disposed at a position
at which the meandering amount of the steel sheet has a size that does not affect
the measurement of the shape data of the steel sheet (for example, the meandering
amount of the steel sheet in the width direction is within ±20 mm). Further, when
the cutting device 1 is not disposed, the measurement device 11 may be disposed on
the upstream side of the looper device 2.
[0043] The position adjustment device 12 adjusts the winding position of the steel sheet
relative to the steering roll in the looper device 2 according to a control signal
output from the control device 13. An operator may manually adjust the winding position
of the steel sheet relative to the steering roll.
[0044] The control device 13 is configured by an information processing device such as a
computer, and controls the entire operation of the meandering control apparatus for
the steel sheet by executing a computer program stored in advance. In the present
embodiment, the control device 13 calculates an average curvature of the steel sheet
using the out-of-plane deformation amount of the steel sheet measured by the measurement
device 11, calculates an off-center amount of the steel sheet in the steering roll
using the calculated average curvature of the steel sheet, and controls the position
adjustment device 12 based on the calculated off-center amount. FIG. 3 is a diagram
illustrating an example of the shape data of the steel sheet measured every 0.1 seconds
by the measurement device 11. Since the shape data illustrated in FIG. 3 includes
an error, the measurement device 11 may smooth the shape data to calculate a mathematical
formula representing the curved surface of the steel sheet, and calculate the average
curvature of the steel sheet using the calculated mathematical formula.
[0045] As is apparent from the above description, the meandering control apparatus for the
steel sheet according to the embodiment of the present invention measures the out-of-plane
deformation amount of the steel sheet on the upstream side of the steering device
that changes the conveyance direction of the steel sheet, calculates the average curvature
of the steel sheet using the measured out-of-plane deformation amount of the steel
sheet, calculates the off-center amount of the steel sheet in the steering device
using the calculated average curvature of the steel sheet, and controls the winding
position of the steel sheet relative to the steering device based on the calculated
off-center amount. Accordingly, it is possible to suppress meandering of a steel sheet
having a shape defect. In addition, by manufacturing the steel sheet using such meandering
control method, it is possible to suppress the meandering of the steel sheet having
the shape defect and to manufacture a steel sheet having a good yield.
[First Example]
[0046] In the present example, whether there is a defect in a steel sheet was evaluated
when meandering control according to the present invention was performed (example)
and when the meandering control according to the present invention was not performed
(comparative example and reference example) on a plurality of steel sheets having
different shapes. The evaluation results are shown in Table 1 below. In the example,
the winding position of the steel sheet relative to the steering roll #1STR illustrated
in FIG. 2 was controlled. As shown in Table 1, it was confirmed that occurrence of
defects in the steel sheet due to the meandering of the steel sheet can be suppressed
by executing the meandering control of the present invention. In addition, it was
confirmed that, when there is no bending in the steel sheet, the steel sheet does
not meander even if meandering control is not performed, and therefore no defect occurs
in the steel sheet (reference example). Additionally, it was confirmed that, even
when there is bending in the steel sheet, if a difference between a sheet width and
a line width of the steel sheet is 0.4 m or more, the steel sheet does not collide
with a guide vertical roll even if the steel sheet meanders, and therefore no defect
occurs in the steel sheet (reference example).
Table 1
Sheet width (m) |
Line width (m) |
Bending (1/m) |
Edge wave/center buckle (elongation difference rate) |
Meandering amount (m) |
Off-center amount (m) |
Whether there is defect |
Remarks |
1.0 |
1.65 |
0 |
0 |
0 |
0 |
No |
Reference example |
1.3 |
1.65 |
0 |
0 |
0 |
0 |
No |
Reference example |
1.0 |
1.65 |
0.005 |
0 |
0 |
0 |
No |
Reference example |
1.1 |
1.65 |
0.005 |
0 |
0 |
0 |
No |
Reference example |
1.2 |
1.65 |
0.005 |
0 |
0 |
0 |
No |
Reference example |
1.3 |
1.65 |
0.005 |
0 |
0 |
0 |
Yes |
Comparative example |
1.3 |
1.65 |
0.005 |
0 |
0 |
-0.05 |
No |
Example |
1.3 |
1.65 |
-0.005 |
0 |
0 |
0 |
Yes |
Comparative example |
1.3 |
1.65 |
-0.005 |
0 |
0 |
0.05 |
No |
Example |
1.3 |
1.65 |
0.005 |
0.002 (edge) |
0 |
0 |
No |
Comparative example |
1.3 |
1.65 |
0.005 |
0.002 (edge) |
0 |
-0.05 |
No |
Example |
1.3 |
1.65 |
0.005 |
-0.002 (center) |
0 |
0 |
Yes |
Comparative example |
1.3 |
1.65 |
0.005 |
-0.002 (center) |
0 |
-0.05 |
No |
Example |
1.0 |
1.45 |
0 |
0 |
0 |
0 |
No |
Reference example |
1.1 |
1.45 |
0 |
0 |
0 |
0 |
No |
Reference example |
1.0 |
1.45 |
0.005 |
0 |
0 |
0 |
No |
Reference example |
1.2 |
1.45 |
0.005 |
0 |
0 |
0 |
Yes |
Comparative example |
1.2 |
1.45 |
0.005 |
0 |
0 |
-0.05 |
No |
Example |
[Second Example]
[0047] In the present example, a relationship between the maximum bending of a joint portion
of the steel sheet and occurrence of defects was evaluated. The evaluation results
are illustrated in FIG. 4. In FIG. 4, a horizontal axis represents a sheet width,
a vertical axis represents the maximum bending of the steel sheet, a white circle
represents a joint portion without defects, and a black circle represents a joint
portion with defects. As illustrated in FIG. 4, it was confirmed that three defects
occur in 52 joint portions, and defects occur when both the sheet width and the bending
are large. In addition, the positive and negative of the bending represented the occurrence
direction of the defect, and the occurrence of the defect and the direction thereof
was able to be predicted by a value of the bending. Therefore, if the bending and
the sheet width are larger than a predetermined value, when the steel sheet is intentionally
off-centered in the direction opposite to the occurrence direction of the defect predicted
from the bending by the downstream steering roll, the occurrence of defects derived
from the bending can be suppressed.
[0048] Although the embodiments to which the invention made by the present inventors is
applied have been described above, the present invention is not limited by the description
and drawings configuring a part of the disclosure of the present invention according
to the present embodiments. That is, other embodiments, examples, operation techniques,
and the like made by those skilled in the art based on the present embodiment are
all included in the scope of the present invention.
Industrial Applicability
[0049] According to the present invention, it is possible to provide a meandering control
method and a meandering control apparatus for a steel sheet capable of suppressing
meandering of the steel sheet having a shape defect. Further, according to the present
invention, it is possible to provide a manufacturing method for the steel sheet capable
of manufacturing the steel sheet having a good yield by suppressing meandering of
the steel sheet having the shape defect.
Reference Signs List
[0050]
- 1
- CUTTING DEVICE
- 2
- LOOPER DEVICE
- 3
- COLD ROLLING MILL
- 4
- ANNEALING FURNACE
- 11
- MEASUREMENT DEVICE
- 12
- POSITION ADJUSTMENT DEVICE
- 13
- CONTROL DEVICE
- S
- STEEL SHEET
1. A meandering control method for a steel sheet, the method comprising:
a measurement step of measuring an out-of-plane deformation amount of the steel sheet
on an upstream side of a steering device that changes a conveyance direction of the
steel sheet;
a calculation step of calculating an average curvature of the steel sheet using the
out-of-plane deformation amount of the steel sheet measured in the measurement step;
and
a control step of calculating an off-center amount of the steel sheet in the steering
device using the average curvature of the steel sheet calculated in the calculation
step, and controlling a winding position of the steel sheet relative to the steering
device based on the calculated off-center amount.
2. The meandering control method for the steel sheet according to claim 1, wherein the
measurement step includes a step of measuring the out-of-plane deformation amount
of the steel sheet on a delivery side of a cutting device installed on the upstream
side of the steering device, the cutting device being configured to cut an end portion
of the steel sheet in a width direction.
3. A meandering control apparatus for a steel sheet, the apparatus comprising:
a steering device that changes a conveyance direction of the steel sheet;
a measurement device that measures an out-of-plane deformation amount of the steel
sheet on an upstream side of the steering device;
a position adjustment device that adjusts a winding position of the steel sheet relative
to the steering device; and
a control device that controls the position adjustment device,
wherein the control device
calculates an average curvature of the steel sheet using the out-of-plane deformation
amount of the steel sheet that is measured by the measurement device,
calculates an off-center amount of the steel sheet in the steering device using the
calculated average curvature of the steel sheet, and
controls the position adjustment device based on the calculated off-center amount.
4. The meandering control apparatus for the steel sheet according to claim 3, wherein
the measurement device is installed on a delivery side of a cutting device installed
on the upstream side of the steering device, the cutting device being configured to
cut an end portion of the steel sheet in a width direction.
5. A manufacturing method for a steel sheet, the method comprising:
a storage step of storing the steel sheet in a looper device while suppressing the
meandering of the steel sheet using the method of controlling the meandering of the
steel sheet according to claim 1 or 2; and
a cold rolling step of cold-rolling the steel sheet stored in the looper device.
6. A manufacturing method for a steel sheet, the method comprising:
a storage step of storing the steel sheet in a looper device while suppressing the
meandering of the steel sheet using the method of controlling the meandering of the
steel sheet according to claim 1 or 2; and
an annealing step of annealing the steel sheet stored in the looper device.