[Title of the Invention] ROLLING APPARATUS AND ROLLING MONITORING
METHOD
[Technical Field]
5 [OOOl]
The present invention relates to a rolling apparatus that executes stable rolling by
monitoring the behavior and tlie like of a steel sheet that is rolled, and a rolling monitoring
method of the steel sheet.
[Background Art]
10 [0002]
In a case of rolling a steel sheet by using rolling stands each having a pair of
rolling mills, the steel sheet may sometimes "meander"; that is, conveying positions of the
steel sheet may vary in the width di~ectiono f the rolling mills. Since side guides that
guide the width-directional position of the steel sheet are disposed on the entering side of
15 each of the rolling stands, a largely meandering steel sheet has contacted with either of the
side guides in some cases.
[0003]
In a case where the steel sheet contacts with either of the side guides, a fractured
piece of the steel sheet may scatter and be pressed into the steel sheet, which may form a
20 defective steel sheet. Further, in a case where the fractured piece pressed into the rolling
mill generates a scratch on the surface of the mill, the scratch on the mill will probably be
transferred on a steel sheet that is rolled. In this case, the rolling mill needs to be replaced
with a new one, failing to execute an efficient rolling process.
[0004]
25 Accordingly, Patent Documents 1 and 2 as tlie related art, for example, propose
methods of measuring and controlling the meandering of the steel sheet. Patent
Document 1 proposes a method of detecting the meandering on the basis of a deviation of a
rolling load in the width direction of the rolling stand so as to adjust the roll gap, for
example. Patent Document 2 proposes a method of measuring the meandering amount of
the steel sheet by imaging, with an imaging unit, a steel sheet that is conveyed between
5 rolling stands in a final rolling apparatus of a hot-rolled steel sheet, the apparatus including
a plurality of rolling stands that are lined up in the rolling direction.
[Prior Art Document(s)]
[Patent Document(s)]
[0005]
10 [Patent Document 11 JP 2000-042615A
[Patent Document 21 JP 2004-141956A
[Summa~yo f the Invention]
[Problem(s) to Be Solved by the Invention]
[0006]
15 In Patent Document 1, unfortunately, it has been impossible to detect the
meandering amount accurately because the meandering amount is calculated on the basis
of the deviation of the rolling load in the width direction of the rolling mill and therefore
the calculation is largely affected by the shape of the rolling mill itself, thickness
distribution in the width direction of the sheet itself, and the like. Further, in Patent
20 Document 2, although it is possible to measure the meandering amount between the rolling
stands because the imaging unit images the steel sheet conveyed between the rolling stands,
it has been impossible to measure the meandering amount of the steel sheet at the position
where the steel sheet enters the rolling stand.
[0007]
25 Furthermore, on the entering side of the rolling stand, the steel sheet does not only
meander in the width direction but also is deformed in some cases by variations in the
thickness direction. The techniques disclosed in Patent Documents 1 and 2 have failed to
examine such deformation of the steel sheet sufficiently. Therefore, it has been difficult
to surely prevent the contact between the steel sheet and the side guide provided on the
rolling stand and to execute stable rolling of the steel sheet.
5 [OOOS]
The present invention has been made in view of the aforementioned
circumstances, and aims to provide a rolling apparatus that enables an operator to
recognize the rolling status such as the behavior of the steel sheet entering the rolling stand
and enables a stable rolling process, and a rolling monitoring method of the steel sheet.
10 [Means for Solving the Problem(s)]
[0009]
In order to solve at least one of the above problems, the rolling apparatus
according to the present invention includes a plurality of rolling stands each including a
pair of rolling mills, and an imaging unit provided between adjacent rolling stands, the
15 imaging unit being configured to image a steel sheet entering the pair of rolling mills of the
rolling stand from an upstream side in a rolling direction of the rolling stand located on a
downstream side in the rolling direction. The imaging unit is disposed so as to satisfy the
following equation (I), on the upstream side in the rolling direction of the rolling stand
located on the downstream side in the rolling direction, in a centsal portion in the width
20 direction of the steel sheet in an area in which t'he steel sheet is able to be conveyed:
2 x L x tan(al2) > W, (1)
wherein L represents a distance in the rolling direction between the rolling stand and the
imaging unit, a represents a horizontal viewing angle of the imaging unit, and W,
represents a maximum width of the steel sheet.
25 [OOlO]
The rolling apparatus having the above configuration includes the imaging unit
--
configured to image the steel sheet entering the pair of rolling mills. From an image
obtained by the imaging unit, the operator can recognize the meandering or deformation of
the steel sheet at the position where the steel sheet enters the rolling stand. In this manner,
it becomes possible to recognize the rolling status such as the behavior of the steel sheet
5 fsom an image. Fusther, on the basis of the recognized rolling status of the steel sheet, for
example, the operator can perform an operation to prevent a touch between the steel sheet
and the side guides provided on the rolling stand. Furthermore, by providing the imaging
unit within the above range, it becomes possible to image, with a single imaging unit, the
steel sheet entering the pair of rolling mills. The use of such a rolling apparatus makes it
10 possible to execute stable contsol of the meandering and shape of the steel sheet and to
manufacture a quality rolled steel sheet.
[OO 111
Here, the imaging unit may be disposed within a range of 0.5 m in the width
direction of the steel sheet fiom the center in the width direction of the steel sheet in the
15 area in which the steel sheet is able to be conveyed. The provision of the imaging unit
within the above range makes it possible to image, with a single imaging unit, the steel
sheet entering the pair of rolling mills. The operator can recognize the behavior of the
steel sheet entering the pair of rolling mills surely fsom an image obtained by the imaging
unit and also can recognize the behavior of the steel sheet intuitively.
20 [0012]
Further, the imaging unit may be disposed at a height to image the steel sheet
entering the pair of rolling mills at a tilt angle 8 with respect to the rolling direction of the
steel sheet, and the tilt angle 8 may be smaller than or equal to 20'. The disposition of the
imaging unit at that position makes it possible to image the steel sheet entering the pair of
25 rolling mills. The operator can recognize the behavior of the steel sheet entering the pair
of rolling mills accurately from an image obtained by the imaging unit.
[00 131
Further, the horizontal viewing angle a of the imaging unit may be smaller than or
equal to 50". The use of such an imaging unit reduces a strain of an obtained image, and
accordingly, it becomes possible to recognize the behavior of the steel sheet entering the
5 pair of rolling mills accurately from the obtained image.
[0014]
A rolling monitoring method of a steel sheet according to the present invention is
a rolling monitoring method of a steel sheet to monitor a rolling status of a steel sheet that
is rolled by a plurality of rolling stands each including a pair of rolling mills, the rolling
10 monitoring method including imaging the steel sheet entering the pair of rolling mills with
an imaging unit disposed between adjacent rolling stands so as to satisfy the following
equation (I), on an upstream side in a rolling direction of the rolling stand located on a
downstream side in the rolling direction, in a central portion in a width direction of the
steel sheet in an area in which the steel sheet is able to be conveyed, and displaying, on a
15 display apparatus, an image of the steel sheet entering the pair of rolling mills, the image
being obtained by the imaging unit:
2 x L x tan(al2) > W,,, (1)
wherein L represents a distance in the rolling direction between the rolling stand and the
imaging unit, a represents a horizontal viewing angle of the imaging unit, and W,,,
20 represents a maximum width of the steel sheet.
[OOlS]
According to the above rolling monitoring method of the steel sheet, the imaging
unit images the steel sheet entering the pair of rolling mills. The operator can recognize
the rolling status of the steel sheet from an image obtained by the imaging unit and adjust
25 rolling conditions in accordance with the lneandering or deformation of the steel sheet,
thereby executing a stable rolling process of the steel sheet.
[00 161
Further, according to the rolling monitoring method, when it is determined that, as
a result of an image analysis of the image of the steel sheet, detection conditions for
detecting a specific rolling status of the steel slieet are satisfied, a warning may be issued.
5 By making it possible to automatically detect tlie specific rolling status of the steel slieet
through image analysis of the obtained image, the nionitoring load on the operator can be
reduced.
[Effect(so) f the Invention]
[0017]
10 According to the present invention, it becomes possible to provide a rolling
apparatus that enables an operator to recognize a rolling status such as the behavior of a
steel sheet entering the rolling stand and enables a stable rolling process, and to provide a
rolling monitoring method of the steel slieet.
[Brief Description of the Drawing(s)]
15 [0018]
[FIG. 11 FIG. 1 is a side view showing a rolling apparatus according to an
embodiment of the present invention.
[FIG. 21 FIG. 2 is a top view showing the rolling apparatus according to the
embodiment.
20 [FIG. 31 FIG. 3 is a scliematic view showing an imaging camera unit included in
the rolling apparatus according to the embodiment.
[FIG. 41 FIG. 4 is a schematic view showing an image obtained by the imaging
camera unit included in the rolling apparatus according to the embodiment.
[FIG. 51 FIG. 5 is a schematic view showing an example of a behavior of a steel
25 sheet that is monitored by use of the image obtained by the imaging camera unit according
to the embodiment, and showing a state in which a bottom portion of the steel sheet is bent.
~-
[FIG. 61 FIG. 6 is a schematic view showing another example of the behavior of
the steel sheet that is monitored by use of the image obtained by the imaging camera unit
according to the embodiment, and showing a state in which the steel sheet contacts with a
side guide.
5 [FIG. 71 FIG. 7 is a schematic view showing an example in which a sharp shape of
the steel sheet is monitored by use of the image obtained by the imaging camera unit
according to the embodiment.
[FIG. 81 FIG. 8 is a schematic view showing an example in which a sign of
opening in the steel sheet is monitored by use of the image obtained by the imaging camera
10 unit according to the embodiment.
[FIG. 91 FIG. 9 is a schematic view showing an example in which water leaked by
a fault in the equipment is monitored by use of the image obtained by the imaging camera
unit according to the embodiment.
[FIG. 101 FIG. 10 is a schematic perspective view of a rolling apparatus showing
15 the state shown in FIG. 9.
[Mode(s) for Carrying out the Invention]
[0019]
The rolling apparatus and the rolling nlonitoring method of the steel sheet each
according to an embodiment of the present invention will be described below with
20 reference to the appended drawings. A rolling apparatus 10 and a rolling monitoring
method of a steel sheet according to this embodiment are used in a final rolling step in a
hot-rolling line of a steel sheet 1.
[0020]
The rolling apparatus 10 includes a plurality of rolling stands 11 arranged in series
25 along a rolling direction Z. FIGS. 1 and 2 show two rolling stands 11A and 11B which
are adjacent to each other from among the plurality of rolling stands 11. Each of the
rolling stands 11 (1 1A and 11B) includes a pair of rolling mills 12 (12A and 12B) disposed
in the vertical direction, and the entering side of each of the rolling stands 11 (11A and
11B) includes side guides 13 (13A and 13B) which guide the width-direction position of
the conveyed steel sheet 1.
5 [0021]
An imaging camera unit 15 is disposed between the two rolling stands IIA and
11B as an imaging unit that images the rolling stand 11B located on the downstream side in
the rolling direction 2. The imaging camera unit 15 is located on the upstream side in the
rolling direction Z of the rolling stand 11B and images the steel sheet 1 entering the pair of
10 rolling mills 12B of the rolling stand 11B.
[0022]
Here, as shown in FIG. 2, the imaging camera unit 15 is provided on the upstream
side in the rolling direction Z of the rolling stand 1lB in a central portion, in the width
direction of the steel sheet in an area P in which the steel sheet 1 is able to be conveyed.
15 Note that the central portion in the width direction of the steel sheet in the area P in which
the steel sheet 1 is able to be conveyed may have a range of 0.5 m in the width direction of
the steel sheet from a center C in the width direction of the steel sheet in the area P in
which the steel sheet 1 is able to be conveyed, for example, as shown in FIG. 2.
[0023]
20 The imaging camera unit 15 is disposed so as to satisfy the following equation (1):
2 x L x tan(al2) > W,,,, (1)
wherein L represents a distance in the rolling direction Z between the imaging camera unit
15 and the rolling stand 11B (the center of the rolling mill 12B), a represents a horizontal
viewing angle of the imaging camera unit 15, and W, is a maximum width of the steel
25 sheet 1.
[0024]
~ -~
The horizontal viewing angle a of the imaging camera unit 15 may be smaller
than or equal to 50°, for example. In this embodiment, the horizontal viewing angle a of
the imaging camera unit 15 is set to 50".
[0025]
5 Further, the imaging camera unit 15 is disposed at a height to image the steel sheet
1 entering the pair of rolling mills 12B at a tilt angle 0 with respect to the rolling direction
Z of the steel sheet 1, as shown in FIG. 1. The tilt angle 0 may be smaller than or equal to
20°, for example. In this embodiment, the rolling direction Z of the steel sheet 1 is the
horizontal direction. Therefore, a height H of the imaging camera unit 15 from the
10 position where the steel sheet 1 is conveyed is represented by the following equation (2).
H = L x tan0 (2)
[0026]
Furthermore, the imaging camera unit 15 is disposed between the two rolling
stands 11A and 11B which are adjacent to each other in the rolling direction Z, as shown in
15 FIG. 1. Here, the distance between the rolling stands 11A and 11B are represented as Lo
and the diameter of the rolling mill 12 is represented as R. In this case, the imaging
camera unit 15 may be disposed at any position between a position away from the center of
the rolling stand 11A on the upstream side in the rolling direction Z by 2R to the
downstream side in the rolling direction Z and a position away from the center of the
20 rolling stand 11A on the upstream side in the rolling direction Z by Ld2 to the downstream
side in the rolling direction Z. If the imaging camera unit 15 is disposed beyond the
above range to be closer to the rolling stand 11A on the upstream side in the rolling
direction Z, it becomes difficult to dispose the imaging camera unit 15 because the imaging
camera unit 15 would contact with the rolling stand 1 IA, for example. In contrast, if the
25 imaging camera unit 15 is disposed beyond the above range to be closer to the rolling stand
11B on the downstream side in the rolling direction Z, it becomes difficult to include a
portion where the steel sheet 1 enters the pair of rolling mills 12B within an imaged range.
[0027]
Accordingly, it is desirable to dispose the imaging camera unit 15 within an
installation area S regulated by the above range, as shown in FIGS. 1 and 2. The
5 disposition of the imaging camera unit 15 within the installation area S makes it possible to
obtain an image in which at least the portion where the steel sheet 1 enters the pair of
rolling mills 12B is included within the imaged range. Further, the imaging camera unit
15 is preferably disposed such that a range ml including the side guides 13B, in addition to
the portion where the steel sheet 1 enters, is included in the image. From the image
10 obtained by the imaging camera unit 15 disposed in this manner, the operator can
recognize a variety of rolling statuses in the rolling apparatus 10, such as the behavior of
the steel sheet 1 at the time of rolling or a fault in equipment of the rolli~lga pparatus 10.
[002S]
Note that the rolling apparatus 10 includes at least one imaging camera unit 15.
15 In this case, the imaging camera unit 15 is preferably provided at a position where the
portion at which the steel sheet 1 enters the pair of rolling mills 12 of the rolling stand 11
can be imaged, the rolling stand 11 being located at the downstream end in the rolling
direction Z fiom among the plurality of rolling stands 11. Further, if the imaging camera
unit 15 is disposed at each space between the plurality of rolling stands 11, images
20 obtained by the respective imaging camera units 15 can be compared or analyzed. This
enables recognition of the rolling statuses in each of the rolling stands 11, changes of the
rolled steel sheet 1, and the like.
[0029]
Next, the imaging camera unit 15 included in the rolling apparatus 10 according to
25 this embodiment will be described with reference to FIG. 3. In the environment of a
hot-rolling line in which the steel sheet 1 is rolled, a large number of fine particles, much
- --
vapor, and the like are generated and heat load is heavy. Accordingly, the imaging
camera unit 15 is required to have a durability to be able to operate even in a harsh
environment.
[0030]
5 The imaging camera unit 15 according to this embodiment includes a case main
part 20, a case lens part 30, a camera main body 16, and an air supply part 18 which
supplies air to the case main pait 20, as shown in FIG. 3.
[003 11
The case main part 20 includes a fixing part 21 which fixes the camera main body
10 16, a camera window part 22 disposed in fiont of the camera main body 16, and an
insertion through hole 23 through which wiring of the camera main body 16 is inserted.
Here, the fixing part 21 is configured to be able to fix the camera main body 16 firmly so
as not to cause a position shift of the camera main body 16 owing to vibration or the l i e .
Further, in terms of improving the durability, the case main part 20 is made of a stainless
15 steel having a thickness of 1 cm or more, for example. Note that in the case main part 20,
in order to prevent a cable inserted through the insertion through hole 23 kom being heated,
one opening may be commonly used as the air supply part 18 and the insertion through
hole 23.
[0032]
20 The case lens part 30 includes a flange part 31 which is connected detachably to
the case main part 20, a lens opening 32 which communicates with the camera window
part 22 of the case main part 20, and a lens 33 disposed in the lens opening 32. Note that
air is also supplied to the case lens part 30.
[0033]
25 The imaging camera unit 15 images the steel sheet 1 entering the rolling stand
11B with the camera main body 16 through the lens 33, the lens opening 32, and the
camera window part 22.
[0034]
The rolling apparatus 10 having the above configuration allows the steel sheet 1 to
be conveyed from the upstream side in the rolling direction Z to the downstream side in the
5 rolling direction Z, and rolls the steel sheet 1 with the plurality of rolling stands 11.
During this process, the imaging camera unit 15 disposed between the adjacent rolling
stands 11, as described above, images the steel sheet 1 entering the pair of rolling mills
12B of the rolling stand 11 on the downstream side in the rolling direction Z. The image
obtained by the imaging camera unit 15 is displayed on a display apparatus (not shown).
10 The operator monitors the behavior of the steel sheet 1 while watching the image displayed
on the display apparatus.
[0035]
FIG. 4 shows an example of the image displayed on the display apparatus. For
example, a past within a display area M in FIG. 4 is displayed on the display apparatus.
15 The image obtained by the imaging camera unit 15 includes the postion at which the
conveyed steel sheet 1 enters the pair of rolling mills 12B, the steel sheet 1 entering the
pair of rolling mills 12B, and side guides on both sides in the width direction of the steel
sheet 1. That is, the imaging camera unit 15 is disposed at a position that enables
obtaining an image by which the position relation between the steel sheet 1 entering the
20 pair of rolling mills 12B and the side guides 13B can be recognized.
100361
The operator recognizes the meandering and defosmation of the steel sheet 1 fsom
the image obtained by the imaging camera unit 15 and adjusts leveling setting of the
rolling stand 11A on the upstream side, setting of a bender, setting of the side guides 13A
25 and 13B, and the like. In this manner, the final rolling of the steel slieet 1 is executed.
[0037]
~-
From the image obtained by the imaging camera unit 15, the operator can
recognize the following beliavior of the steel sheet 1, for example.
[0038]
[Use Example 11
5 In some cases where the steel sheet 1 conveyed through the hot-rolling line
meanders, at a bottom portion of the steel sheet 1, a side edge of the steel sheet 1 contacts
with the side guide 13% and becomes bent, and the steel sheet I enters the rolling mills
12%, having portions locally folded, as shown in FIG 5, for example. This phenomenon
is called "Shibori" in Japanese language. Once such a plienomenon occurs, a scratch is
10 generated on the rolling mill 12%, so that the mill needs to be replaced with new one and
the process is suspended.
[0039]
Conventionally, the state of the steel sheet 1 conveyed fiom the side guides 13% to
the portion where the steel sheet 1 enters the pair of rolling mills 12% cannot be recognized
15 because there is no means for monitoring the state directly. Accordingly, conventionally,
it has been determined whether the steel sheet 1 meanders or not, for example, on the basis
of the deviation of a load in the width direction of the steel sheet with respect to a load cell
provided on a looper or the deviation of a load in the width direction of the steel sheet with
respect to the load cell provided on the rolling stand 11%. Alternatively, it has been
20 determined whether the steel sheet I meanders or not, on the basis of an image obtained by
an imaging unit from a side or a top of the conveyed steel sheet 1.
[0040]
However, the absolute quantity of the meandering of the steel sheet 1 cannot be
obtained from tlie deviation of the load with respect to the load cell of the looper. Fulthel;
25 in a case where the steel sheet 1 is away from the looper, such as in a case where the end of
tlie steel sheet is conveyed, the deviatio~oi f tlie load with respect to the load cell cannot be
-
obtained, and accordingly, the meandering of the steel sheet 1 cannot be determined. On
the other hand, in a case of using the deviation of the load with respect to the load cell of
the rolling stand IIB, it is inlpossible to separate the deviation of the load to one that
attributes to the meandering of the steel sheet 1 and one that attributes to a wedge
5 (difference in thickness across the width direction of the steel sheet).
[0041]
Further, in a case of using the image obtained by imaging the steel sheet 1 from
the side or the top, the range where the steel sheet 1 can be imaged from the top is, for
example, a range where the steel sheet 1 conveyed between the adjacent rolling stands 11A
10 and 11B is imaged, such as a range mO in FIG. 2. In a case where the steel sheet 1 is
imaged from the side, it is difficult to dispose an imaging unit at a position where the
portion of the steel sheet 1 entering the rolling mills 12B can be imaged, and accordingly,
an image of the steel sheet 1 conveyed between the rolling stands I1A and 11B is obtained.
Therefore, the image does not include the portion of the steel sheet I entering the pair of
15 rolling mills 12B. Accordingly, the behavior of the steel sheet 1 entering the pair of
rolling mills 12B is estimated fiom the image, and on the basis of the estimation, it is
determined whether the steel sheet 1 meanders or not. However, the estimated behavior
of the steel sheet 1 may differ from the actual behavior of the steel sheet 1 and the
meandering of the steel sheet I is not always recognized accurately.
20 [0042]
In contrast, by disposing the imaging camera unit 15 as in the rolling apparatus 10
according to this embodiment, the steel sheet 1 entering the pair of rolling mills 12B can be
imaged. Therefore, the obtained image includes the portion of the steel sheet 1 actually
entering the pair of rolling mills 12B, and on the basis of the image, the operator can
25 recognize the behavior of the steel sheet 1 accurately. For example, as shown in FIG. 5, it
is possible to recognize tlie following behaviors of the steel slieet 1: entering the position
where the side guides 13B are installed; buckling owing to contact between a side edge of
the steel sheet and the side guide 13B; and entering the pair of rolling mills 12B while
folding. It is difficult to estimate such behaviors from an image obtained by imaging the
range on the upstream side in the rolling direction Z with respect to the side guides 13B.
5 [0043]
[Use Example 21
When the steel sheet 1 conveyed in the hot-rolling line meanders, a side edge at
any of a top pottion, a middle poition, and a bottom portion of the steel sheet 1 may
contact with either of the side guides 13B, as shown in FIG. 6, for example. The contact
10 between the steel sheet 1 and the side guide 13B generates a fractured piece of the steel
sheet 1 and it scatters. When the scattered piece is rolled by the pair of rolling mills 12B
together with the steel sheet 1, a plunge defect is generated on the steel sheet 1.
[0044]
The touch between the steel sheet I and the side guide 13B has been determined
15 conventionally on the basis of an image obtained by an imaging unit imaging the conveyed
steel sheet 1 from the side or the top. However, the position where the imaging unit can
be disposed is limited to the upstream side in the rolling direction Z with respect to the side
guides 13B between the adjacent rolling stands 11A and 11B. Therefore, the portion
where the steel sheet 1 is conveyed between the side guides 13B is not included in the
20 image. Accordingly, from this image, the behavior of the steel sheet 1 with respect to the
side guides 13B is estimated, and on the basis of this estimation, the degree of contact
between the steel sheet 1 and the side guide 13B is determined. However, the estimated
behavior of the steel sheet 1 may differ from the actual behavior of the steel sheet 1, and
accordingly, the degree of contact between the steel sheet 1 and the side guide 13B may
25 not always be recognized accurately.
[0045]
-
In contrast, by disposing the imaging camera unit 15 as in the rolling apparatus 10
according to this embodiment, the steel sheet 1 conveyed between the side guides 13B can
be imaged. Therefore, the obtained image includes the portion where the steel sheet 1 is
actually conveyed between the side guides 13B, and on the basis of the image, the operator
5 can recognize the behavior of the steel sheet 1 accurately. For example, when the steel
sheet 1 enters the position where the side guides 13B are installed, as shown iit FIG. 6, the
operator can recognize clearly the state where a side edge of the steel sheet touches with
the side guide 13B and fractured pieces are scattered with sparks. It is difficult to
estimate such a behavior from an image obtained by imaging the range on the upstream
10 side in the rolling direction Z with respect to the side guides 13B.
[0046]
Note that the generation of sparks of the steel sheet 1 is desirably recognized
automatically through an image analysis of an image obtained by the imaging camera unit
15. Usually, in the obtained image, portions other than the area where the steel sheet 1 is
15 able to be conveyed are displayed in black because the temperature is low. Accordingly,
when sparks are generated, the sparks appear as red spots in the black portions. These red
spots are detected through an image analysis, and thus the generation of sparks can be
recognized automatically. That is, a red spot in the image is a detection condition for
detecting the generation of sparks of the steel sheet 1.
20 [0047]
The image analysis of the image obtained by the imaging camera unit 15 is
executed by a monitoring apparatus (not shown) that monitors the rolling status of the steel
sheet 1 by analyzing the image, for example. Tlie rolling status of the steel sheet 1,
monitored by the monitoring apparatus, includes a variety of statuses in the rolling
25 apparatus 10, such as the behavior of the steel sheet 1 at the time of rolling arid a fault in
the equipment of the rolling apparatus 10. The monitoring apparatus is achieved by a
computer, for example, and a CPU included therein executes an image analysis program so
that the computer can function as the monitoring apparatus. The image analysis program
may be stored in a storage apparatus included in the computer or a computer-readable
storage medium such as a magnetic disk or an optical disk.
5 [0048]
The monitoring apparatus, for example, analyzes the image obtained by the
imaging camera unit 15, and when the generation of red spots is detected in the image,
issues a warning to the operator. The warning may be issued by a display of the warning
content on a display apparatus or by sound using a sound output apparatus such as a
10 speaker (not shown), for example. Having received the warning from the monitoring
apparatus, the operator checks the rolling status of the steel sheet 1 in the rolling apparatus
10, and may adjust setting or the like as necessary. In this manner, by enabling the image
analysis of the obtained image and automatic detection of a specific behavior of the steel
sheet 1, such as the generation of sparks of the steel sheet 1, the monitoring load on the
15 operator can be reduced.
[0049]
[Use Example 31
When the top portion or the bottom portion of the steel sheet 1 has an abnormal
sharp shape, usually, it becomes difficult to convey the portion having the abnormal sharp
20 shape to the rolling stand 11. In a case of an abnormal sharp shape, depending on the
shape such as a fish tail, a tongue, or a side sharp shape, an appropriate leveling operation
or a bender operation is needed. Therefore, it is required to recognize the sharp shape of
the steel sheet 1 accurately.
[0050]
25 Conventionally, the sharp shape of the steel sheet 1 has been determined on the
basis of an image obtained by an imaging unit imaging the conveyed steel sheet 1 from the
~-
side or the top. However, since the steel sheet 1 is conveyed at a high speed, it is difficult
to recognize the sharp shape of the conveyed steel sheet 1 by seeing the image obtained by
the imaging unit.
[005 11
5 Accordingly, by disposing the imaging camera unit 15 as in the rolling apparatus
10 according to this embodiment, it becomes possible to obtain an image in which the
sharp shape of the steel sheet 1 is easily recognized. That is, the imaging camera unit 15
is disposed at a height to image the steel sheet 1 entering the pair of rolling mills 12B at a
tilt angle 8 with respect to tlie rolling direction Z of the steel sheet 1. The tilt angle 8 is
10 smaller than or equal to 20". For example, in a case where the tilt angle 8 is 20°, the
speed of conveying the steel sheet 1 in the image obtained by the imaging camera unit 15
becomes approximately 0.34 times (i.e., sin20° times) as high as the actual speed of
conveying the steel sheet 1.
[0052]
15 Therefore, as shown in FIG. 7, for example, the steel sheet 1 seems to be conveyed
at a lower speed than the actual speed of conveying the steel sheet 1 for the operator
monitoring the image obtained by imaging the steel sheet 1 from the top obliquely.
Accordingly, it becomes easier to recognize the sharp shape of the steel sheet 1. Thus, the
operator can recognize the sharp shape accurately, and can execute a leveling operation or
20 a bender operation easily at a top portion and a bottom portion of the steel slieet 1.
[0053]
[Use Example 41
An opening in tlie steel sheet 1 being conveyed leads to a serious trouble, such as
incompletion, for example, strip iupture in finishing stands. In order to minimize damage
25 caused by such a trouble, it is required to he able to detect, at an early stage, a postion of
the steel sheet 1 that is likely to open or a portion having an opening.
Since the opening of the steel sheet 1 has a lower temperature than other portions,
the opening is displayed in a different color. Conventionally, by use of this difference in
color, on the basis of an image obtained by an imaging unit imaging the conveyed steel
5 sheet 1 fsom the side or the top, the opening of the steel sheet 1 has been determined.
However, when the opening of the steel sheet 1 is detected on the basis of such
determination, in many cases, it has already become difficult to repair the opening.
[0055]
In contrast, by disposing the imaging camera unit 15 as in the rolling apparatus 10
10 according to this embodiment, the steel sheet 1 entering the pair of rolling mills 12B car1 be
imaged. From an image obtained by the imaging camera unit 15, the present inventors
have found out that water spouts from the portion of the steel sheet 1 entering the pair of
rolling mills 12B before an opening is generated in the steel sheet 1, as shown in FIG. 8,
for example. According to this knowledge, by monitoring the image of the portion of the
15 steel sheet 1 entering the pair of rolling mills 12B and the vicinity thereof carefully, the
operator can detect a sign of opening in the steel sheet 1. When the operator notices a
sign of water spouting from the portion of the steel sheet 1 entering the pair of rolling mills
12B, the operator can execute a leveling operation or a bender operation at an early stage,
thereby preventing the opening in the steel sheet 1.
20 [0056]
Note that the generation of water spouting due to the opening of the steel sheet 1
is desirably recognized automatically through an image analysis of an image obtained by
the imaging camera unit 15. Since the opening of the steel sheet 1 has a lower
temperature than the other portions, by specifying a portion that tul-~lsin to black in the red
25 steel sheet 1 tlxough an image analysis of the image obtained by the imaging camera unit
15, the opening of the steel sheet 1 can be recognized automatically. The image analysis
can be executed by the above described monitoring apparatus (not shown).
The monitoring apparatus analyzes the image obtained by the imaging camera
unit 15, for example, and specifies an area that turns into black fiom a portion in the image
5 showing the steel sheet 1. Then, the monitoring apparatus calculates the size of the black
area per unit size. When the size of the black area per unit size exceeds a predetermined
threshold, the monitoring apparatus determines the generation of water spouting from the
steel sheet 1, and issues a warning to the operator. That is, the ratio of the black area in
the image is a detection condition for detecting the opening of the steel sheet 1. In this
10 manner, by enabling automatic detection of the rolling status of the steel sheet 1 through an
image analysis of the obtained image, such as water spouting due to the opening of the
steel sheet 1, the monitoring load on the operator can be reduced.
[0058]
[Use Example 51
15 In the rolling apparatus 19, water can be leaked by a fault in the equipment, such
as a fault of a pipe in the apparatus. When the leaked water covers the steel sheet 1, as
shown in FIG. 9, for example, the temperature of the steel sheet 1 decreases locally, leading
to a serious trouble. In order to minimize damage caused by such a trouble, it is required
to find the fault in the equipment, such as a water leak, at an early stage.
20 [0059]
Conventionally, the water leak due to a fault in the equipment has been
determined on the basis of the presence or absence of water on the steel sheet 1, which can
be recognized from an image obtained by an imaging unit imaging the conveyed steel sheet
1 from the side or the top. Here, when the water is leaked by a fault in the equipment, the
25 water leaked on the steel sheet 1 flows toward the rolling stand 11B via the looper 17 as a
watershed, as shown in FIG. 10. However, the position where the imaging unit can be
-
disposed is limited to the upstream side in the rolling direction Z with respect to the side
guides 13B between the adjacent rolling stands 11A and IIB. Therefore, unless a large
amount of water is leaked, water leaked on the steel sheet 1 does not appear in the image,
so that it has been difficult to find the water leak due to a fault in the equipment at an early
5 stage.
[0060]
In contrast, by disposing the imaging camera unit 15 as in the rolling apparatus 10
according to this embodiment, the steel sheet 1 entering the pair of rolling mills 12B can be
imaged. Therefore, from the obtained image, as shown in FIG. 9, for example, the state in
10 which water leaked on the steel sheet 1 by a fault in the equipment flows to the portion of
the steel sheet 1 entering the pair of rolling mills 12B can be recognized. While
monitoring the image, by checking carefully whether there is water on the steel sheet 1 at
the portion of the steel sheet 1 entering the pair of rolling mills 12B or the vicinity thereof,
the operator can find a water leak due to a fault in the equipment at an early stage.
15 [0061]
Note that the generation of a water leak due to a fault in the equipment is
desirably recognized automatically through an image analysis of the image obtained by the
imaging camera unit 15. When water leaks onto the steel sheet 1 owing to a fault in the
equipment, a portion on the steel sheet 1 which becomes wet with water has a lower
20 temperature than other portions, and appears as a black area in the image. Accordingly,
the image obtained by the imaging camera unit 15 is subjected to an image analysis, and
the portion that turns into black in the red steel sheet 1 is specified, and thus the water leak
on the steel sheet 1 can be recognized automatically. The image analysis can be executed
by the above described monitoring apparatus (not shown).
25 [0062]
As in the Use Example 4, the nionitoring apparatus analyzes the image and
specifies the black area from a portion in the image showing the steel sheet 1. Then, the
monitoring apparatus calculates the size of the black area per unit size, and when the size
exceeds a predetermined threshold, the monitoring apparatus determines the generation of
a water leak on the steel sheet 1, and issues a warning to the operator. That is, the ratio of
5 the black area in the image is a detection condition for detecting a water leak on the steel
sheet 1. In this manner, by enabling automatic detection of the rolling status of the steel
sheet 1 through an image analysis of the obtained image, such as a water leak on the steel
sheet 1, the monitoring load on the operator can be reduced.
[0063]
10 The configuration of the rolling apparatus 10 and the rolling monitoring method
of the steel sheet according to this embodiment have been described above. The rolling
stand 10 includes the imaging camera unit 15 which images the steel sheet 1 entering the
pair of rolling mills 12B of the rolling stand 11B on the downstream side in the rolling
direction Z. Thus, an image of the steel sheet 1 entering the pair of rolling mills 12B, as
15 shown in FIG. 4, can be obtained, for example. On the basis of this image, the operator
can recognize the behavior of the steel sheet 1 entering the pair of rolling mills 12B.
Considering the behavior of the steel sheet 1, the operator adjusts leveling setting or the
like of the rolling stand 11A on the upstream side, thereby preventing a contact between
the side guide 13B and the steel sheet 1 and executing stable rolling of the steel sheet 1.
20 [0064]
Further, the imaging camera unit 15 is disposed on the upstream side in the rolling
direction Z of the rolling stand 11B, in a central portion in the width direction of the steel
sheet in an area P in which the steel sheet 1 is able to be conveyed, so as to satisfy the
following equation (1). Accordingly, it becomes possible to obtain an image of the steel
25 sheet 1 entering the pair of rolling mills 12B, as shown in FIG. 4, for example, with a
single imaging camera wit 15. On the basis of the image, the operator can recognize the
behavior of the steel sheet 1 accurately.
[0065]
Fu~thennore, in this embodiment, the imaging camera unit 15 is disposed within a
range of 0.5 m in the width direction of the steel sheet from the center C in the width
5 direction of the steel sheet in the area P in which the steel sheet 1 is able to be conveyed, as
shown in FIG. 2. Accordingly, it becomes possible to obtain an image by which the
behavior of the steel sheet 1 can be recognized intuitively with the imaging camera unit 15.
[0066]
Furthermore, in this embodiment, the imaging camera unit 15 is disposed at a
10 height to image the steel sheet 1 entering the pair of rolling mills 12B at the tilt angle 8
with respect to the rolling direction Z of the steel sheet 1, as shown in FIG. I, and the tilt
angle 8 is smaller than or equal to 20'. That is, the imaging camera unit 15 is disposed
such that the height H of the steel sheet 1 from the position where the steel sheet 1 is
conveyed satisfies the following equation (2). Accordi~~glwy,i th the imaging camera unit
15 15, it becomes possible to image the steel sheet 1 entering the pair of rolling mills 12%
surely, and to obtain an image in which the behavior of the steel sheet 1 can be recognized
accurately. Further, even in a case where there is an obstacle above the rolling stand 11B
on the downstream side in the rolling direction Z, the imaging camera unit 15 can image
the steel sheet 1 entering the pair of rolling mills 12% without being prevented from
20 imaging the steel sheet 1 by the obstacle.
[0067]
In addition, the horizontal viewing angle a of the imaging camera unit 15 is
smaller than or equal to 50°, and is set to 50' in this embodiment. Accordingly, it
becomes possible to obtain an image having less strain in which the behavior of the steel
25 sheet 1 entering the pair of rolling mills 12% can be recognized accurately.
[0068]
Further, in this embodiment, the imaging camera unit 15 includes the case main
part 20, the case lens part 30, the camera main body 16, and the air supply part 18 which
supplies air to the case main part 20. The case main part 20 is made of a stainless steel
having a thickness of 1 cm or more, for example. Such a configuration can prevent early
5 degradation of the camera main body 16 due to heat load or the like. Accordingly, the
imaging camera unit 15 can be kept installed all the time between the rolling stands 11 of
the final rolling apparatus in the hot-rolling line of the steel sheet 1, and also the operator
can recognize the behavior of the rolled steel sheet.
[0069]
10 Further, the case lens part 30 is detachably attached to the case main part 20.
Therefore, in a case where the lens 33 becomes dirty, only the case lens part 30 needs to be
replaced with a new one, resulting in highly efficient maintenance. Furthermore, the case
main part 20 and the case lens part 30 are configured to be supplied with air. Therefore, it
becomes possible to prevent early degradation of the camera main body 16 and the lens 33
15 due to head load, fine particles, vapor, and the like.
[0070]
The rolling apparatus and the rolling monitoring method of the steel sheet
according to this embodiment have been described above. However, the present
invention is not limited thereto and can be modified as appropriate without departing from
20 the technical idea of the invention.
[0071]
For example, the configuration of the imaging camera unit is not limited to the
examples shown in this embodiment, and an imaging camera unit having a different
configuration may be used. However, in a case where the imaging camera unit is used in
25 a final rolling apparatus in a hot-rolling line of a steel sheet, for example, the configuration
needs to have durability against heat load, fine particles, vapor, and the like.
Further, configurations of the rolling stand and the side guides are not limited to
the examples shown in this embodiment either, and a rolling stand and side guides having
different configurations may be used.
5 [Reference Signs List]
[0073]
1 steel sheet
10 rolling apparatus
11 rolling stand
12 rolling mill
15 imaging camera unit (imaging unit)
[Natne of Document] CLAIMS .
[Claim 11
A rolling apparatus comprising:
a plurality of rolling stands each includiiig a pair of rolling mills; and
5 an imaging unit provided between adjacent rolling stands, the imaging unit being
configured to image a steel sheet entering the pair of rolling mills of the rolling stand fiom
an upstream side of the rolling stand located on a downstream side in a rolling direction,
wherein tlie imaging unit is disposed so as to satisfy the following equation (I), on
the upstream side in the rolling direction of the rolling stand located on the downstream
10 side in the rolling direction, in a central portion in the width direction of the steel sheet in
an area in which the steel sheet is able to be conveyed:
2 x L x tan(al2) > W, (1)
wherein L represents a distance in the rolling direction between the rolling stand located on
the downstream side in the rolling direction and the imaging unit, a represents a horizontal
15 viewing angle of the imaging unit, and W,,, represents a maximum width of the steel
sheet.
[Claim 21
The rolling apparatus according to claim 1,
wherein the imaging unit is disposed within a range of 0.5 m in the width
20 direction of the steel sheet fiom a center in the width direction of the steel sheet in the area
in which tlie steel sheet is able to be conveyed.
[Claim 31
The rolling apparatus according to claim 1 or claim 2,
wherein the imaging unit is disposed at a height to image the steel sheet entering
25 tlie pair of rolling mills at a tilt angle 0 with respect to the rolling direction of the steel
slieet, the tilt angle 0 being smaller than or equal to 20'.
[Claim 41
. ~-
The rolling apparatus according to any one of claims 1 to 3,
wherein the horizonial viewing angle 0. of the imaging unit is smaller than or
equal to 50".
[Claim 51
5 A rolling monitoring method to monitor a rolling status of a steel sheet that is
rolled by a plurality of rolling stands each including a pair of rolling mills, the rolling
monitoring method comprising:
imaging the steel sheet entering the pair of rolling mills of tlie rolling stand
located on a downstream side in a rolling direction, with an imaging unit disposed between
10 adjacent rolling stands so as to satisfy the following equation (I), on an upstream side in
the rolling direction of the rolling stand located on the downstream side in the rolling
direction, in a central portion in a width direction of the steel sheet in an area in which the
steel sheet is able to be conveyed; and
displaying; on a display apparatus, an image of the steel sheet entering the pair of
15 rolling mills, the image being obtained by tlie imaging unit:
2 x L x tan(w.12) > W,,, . (1)
wherein L represents a distance in the rolling direction between the rolling stand located on
tlie downstream side in the rolling direction and the imaging unit, a represents a horizontal
viewing angle of the imaging unit, and W, represents a maximum width of the steel
20 sheet.
[Claim 61
The rolling monitoring method according to claim 5,
wherein, when it is determined that, as a result of an image analysis of the image
of the steel sheet, detection conditions for detecting a specific rolling~status of the steel
25 sheet are satisfied, a warning is issued.