Technical Field
[0001] The present disclosure relates to a device for assisting in evaluation of a surface state
of a roll that is provided in a hot-dip metal coating bath, a device for removing a foreign
substance on the surface of the roll, and a method of removing a foreign substance on the surface
of the roll.
Background Art
[0002] In a continuous hot-dip coating line in which a steel strip is continuously immersed in
a hot-dip metal coating bath, and coating treatment is performed on a surface of the steel strip,
surface flaws may be caused to occur due to foreign substances (including coarsened
precipitates) that adhere to rolls provided in the bath (hereinafter also referred to as “in-bath
roll(s)”, if appropriate). In order to remove foreign substances that adhere to surfaces of inbath rolls, there is a technique of keeping a surface of a sink roll clean using a wiper device as
described in Japanese Utility Model Application Laid-Open (JP-U) No. S61-164268.
SUMMARY OF INVENTION
Technical Problem
[0003] However, in the wiper device described in JP-U No. S61-164268, a grasp of a state of
removal of a foreign substance on the surface of the in-bath roll is not considered. That is, with
respect to removal operation of a foreign substance that is present on a surface of an in-bath
roll, even in a case in which the wiper device described in JP-U No. S61-164268 is applied to
this operation, there is a problem that a state of removal of a foreign substance from a surface
of a roll that includes completion of the removal cannot be evaluated.
[0004] Therefore, an object of the disclosure is to provide a device for assisting in evaluation
of a surface state of a roll that can grasp a state of removal of a foreign substance from a surface
of a roll provided in a hot-dip metal coating bath, a device for removing a foreign substance
from a surface of a roll, and a method of removing a foreign substance from a surface of a roll.
Solution to Problem
[0005] A device for assisting in evaluation of a surface state of a roll according to a first aspect
of the disclosure includes a vibration detection unit that is configured to detect vibration in a
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scraper unit having a blade configured to abut a surface of a roll provided in a hot-dip metal
coating bath, and a vibrator unit that is configured to generate vibration that has been detected
by the vibration detection unit at a position distanced from the scraper unit, and to enable
evaluation of a state of removal of a foreign substance present on the surface of the roll based
on the vibration that has been generated.
[0006] A device for assisting in evaluation of a surface state of a roll according to a second
aspect of the disclosure is the device for assisting in evaluation of a surface state of a roll
according to the first aspect, and further includes, in a case in which a state of the vibration that
has been detected by the vibration detection unit is defined as a first state, a conversion unit that
is configured to convert the first state into a second state for generation by the vibrator unit.
[0007] A device for removing a foreign substance from a surface of a roll according to a third
aspect of the disclosure includes a scraper unit that has a blade configured to abut a surface of
a roll provided in a hot-dip metal coating bath and to remove a foreign substance from on the
surface of the roll, and the device for assisting in evaluation of a surface state of a roll according
to the first aspect or the second aspect.
[0008] A device for removing a foreign substance from a surface of a roll according to a fourth
aspect of the disclosure includes a scraper unit that has a blade configured to abut a surface of
a roll provided in a hot-dip metal coating bath and to remove a foreign substance from the
surface of the roll, a vibration detection unit that is configured to detect vibration in the scraper
unit, a drive unit that is configured to cause the scraper unit to move along an axial direction of
the roll, and a movement control unit that is configured to control the drive unit such that the
scraper unit is caused to move to a predetermined position in the axial direction of the roll and
remove the foreign substance, based on the vibration that has been detected by the vibration
detection unit.
[0009] A device for removing a foreign substance from a surface of a roll according to a fifth
aspect of the disclosure is the device for removing a foreign substance from a surface of a roll
according to any one of the first to fourth aspects, in which the hot-dip metal coating bath
comprises a hot-dip galvanizing bath.
[0010] A method of removing a foreign substance from a surface of a roll according to a sixth
aspect of the disclosure includes an abutting process of bringing a blade of a scraper unit that
is provided with the blade into abutment with a surface of a roll that is provided in a hot-dip
metal coating bath, a vibration detecting process of detecting vibration that has been generated
in the scraper unit, a state evaluating process of generating the vibration detected in the scraper
unit at a position distanced from the scraper unit and evaluating a state of removal of a foreign
substance that is present on the surface of the roll based on the vibration that has been generated,
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and a removing process of removing a foreign substance using the scraper unit based on the
state of removal of the foreign substance that has been evaluated.
[0011] A method of removing a foreign substance from a surface of a roll according to a
seventh aspect of the disclosure is the method of removing a foreign substance on a surface of
a roll according to the sixth aspect, and further includes, in a case in which a state of the
vibration that has been detected in the vibration detecting process is defined as a first state, a
converting process of converting the first state into a second state to be reproduced in the state
evaluating process.
[0012] A method of removing a foreign substance from a surface of a roll according to an
eighth aspect of the disclosure includes an abutting process of bringing a blade of a scraper unit
that is provided with the blade into abutment with a surface of a roll that is provided in a hotdip metal coating bath, a vibration detecting process of detecting vibration that has been
generated in the scraper unit, a state evaluating process of evaluating a state of removal of a
foreign substance that is present on the surface of the roll, based on the vibration that has been
detected in the vibration detecting process, at a position distanced from the scraper unit, a
position changing process of controlling a position of the scraper unit in an axial direction of
the roll based on the vibration that has been detected, and a removing process of removing a
foreign substance using the scraper unit based on the state of removal of the foreign substance
that has been evaluated.
[0013] A method of removing a foreign substance from a surface of a roll according to a ninth
aspect of the disclosure is the method of removing a foreign substance on a surface of a roll
according to any one of the sixth to eighth aspects, in which the hot-dip metal coating bath
includes a hot-dip galvanizing bath.
Advantageous Effects of Invention
[0014] As described above, in the disclosure, it is possible to provide a device for assisting in
evaluation of a surface state of a roll that can grasp a state of removal of a foreign substance
from a surface of a roll provided in a hot-dip metal coating bath, a device for removing a foreign
substance from a surface of a roll, and a method of removing a foreign substance from a surface
of a roll.
BRIEF DESCRIPTION OF DRAWINGS
[0015] Fig. 1 shows a layout view that illustrates an example of a schematic configuration of
an apparatus for manufacturing a hot-dip metal coated steel strip according to a first
embodiment of the disclosure.
Fig. 2 shows an explanatory view that illustrates a schematic configuration of a device
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for removing a foreign substance from a surface of a roll according to the first embodiment.
Fig. 3 shows an explanatory view that illustrates a schematic configuration of the
device for removing a foreign substance from a surface of a roll according to the first
embodiment.
Fig. 4 shows a diagram that schematically illustrates a result of a spectral analysis on
vibration that has been directly detected in a scraper unit, according to the first embodiment,
before a foreign substance from a surface of a roll is removed.
Fig. 5 shows a diagram that schematically illustrates a result of a spectral analysis on
vibration that has been directly detected in the scraper unit, according to the first embodiment,
after the foreign substance on the surface of the roll has been removed.
Fig. 6 shows a diagram that schematically illustrates a result of a spectral analysis on
vibration that is reproduction of the vibration having been detected in the scraper unit, according
to the first embodiment, before the foreign substance on the surface of the roll is removed.
Fig. 7 shows a diagram that schematically illustrates a result of a spectral analysis on
vibration that is reproduction of the vibration having been detected in the scraper unit, according
to the first embodiment, after the foreign substance on the surface of the roll has been removed.
Fig. 8 shows a flowchart of a method of removing a foreign substance from a surface
of a roll according to the first embodiment.
Fig. 9 shows an explanatory view that illustrates a schematic configuration of a
modification example of the device for removing a foreign substance from a surface of a roll
according to the first embodiment.
Fig. 10 shows an explanatory view that illustrates a schematic configuration of a
modification example of the method of removing a foreign substance from a surface of a roll
according to the first embodiment.
Fig. 11 shows an explanatory view that illustrates a schematic configuration of a device
for removing a foreign substance from a surface of a roll according to a second embodiment.
Fig. 12 shows a flowchart of a method of removing a foreign substance from a surface
of a roll according to the second embodiment.
DESCRIPTION OF EMBODIMENTS
[0016] Hereinafter, preferred embodiments according to the disclosure will be described in
detail with reference to the accompanying drawings. In the present description and the
drawings, constituent elements that have substantially the same functions and structures are
denoted with the same reference signs, and repeated explanation is omitted.
[0017] [First Embodiment]
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Next, a device for assisting in evaluation of a surface state of a roll, a device for
removing a foreign substance from a surface of a roll, and a method of removing a foreign
substance from a surface of a roll, according to a first embodiment of the disclosure will be
described.
[0018]
First, a schematic configuration of an apparatus for manufacturing a hot-dip metal
coated steel strip 10 according to the first embodiment of the disclosure will be described with
reference to Fig. 1. Fig. 1 shows a layout view that illustrates an example of the schematic
configuration of the apparatus for manufacturing a hot-dip metal coated steel strip 10 according
to the present embodiment.
[0019] As shown in Fig. 1, the apparatus for manufacturing a hot-dip metal coated steel strip
10 is an apparatus that is used for manufacturing a hot-dip metal coated steel strip 1A by
continuously immersing a steel strip 1 in a coating bath 11 and performing hot-dip metal coating
treatment to form a coating film on a surface of the steel strip 1.
[0020] The steel strip 1 is an example of a metal strip to be subjected to the coating treatment
with a molten metal M. The type of the steel strip 1 is not particularly limited, and may be, for
example, a mild steel or a high tensile strength steel.
[0021] A coating tank 12 stores the coating bath 11 that contains the molten metal M.
Examples of the molten metal M as a component of the coating bath 11 include an elementary
substance of Zn, Al, Sn, or Pb, and any alloy thereof. Alternatively, the molten metal M may
further contain a non-metal element such as Si or P, a typical metal element such as Ca, Mg, or
Sr, and/or a transition metal element such as Ti, V, Cr, Mn, Fe, Co, Ni, or Cu, in addition to this
metal or alloy. In the following description, an example will be described in which molten zinc
is used as the molten metal M forming the coating bath 11, and in which the hot-dip metal
coated steel strip 1A is manufactured by causing the molten zinc to adhere to the surface of the
steel strip 1.
[0022] As shown in Fig. 1, the apparatus for manufacturing a hot-dip metal coated steel strip
10 according to the present embodiment includes a snout 13, a sink roll 14, support rolls 15A,
15B, gas wiping nozzles 16, an induction heating device 17, and a device for removing a foreign
substance from a surface of a roll 100.
[0023] The snout 13 is a tubular member. The snout 13 has an upper end that is connected to
an exit side of an annealing furnace (not shown), and a lower end that is provided to be inclined
and that is immersed in the coating bath 11. The snout 13 covers the steel strip 1 from the
outside thereof, and the inside of the snout 13 has a non-oxidizing atmosphere. As a result,
6
contact is avoided between the surface of the steel strip 1 and the air, after an annealing process,
thereby suppressing oxidation.
[0024] The sink roll 14 is disposed in a lower portion of the coating bath 11. The sink roll 14
has a diameter that is larger than a diameter of each of the support rolls 15A, 15B. The sink
roll 14 rotates in the clockwise direction in the drawing along with conveyance of the steel strip
1, and changes a conveyance direction of the steel strip 1 that has been introduced obliquely
downward into the coating bath 11 through the snout 13, toward an upper side in a vertical
direction.
[0025] The support rolls 15A, 15B are disposed above the sink roll 14 in the coating bath 11,
and sandwich the steel strip 1 that has been changed in direction by the sink roll 14 and that is
pulled upward in the vertical direction, from both left and right sides. The support rolls 15A,
15B reduce vibration of the steel strip 1 that is pulled up. The support rolls 15A, 15B may be
just a single roll instead of a pair, or may be three or more rolls. Alternatively, arrangement of
the support rolls 15A, 15B may be omitted.
[0026] The gas wiping nozzles 16 eject a gas such as air or the like onto the surface of the
steel strip 1 in order to adjust a coating weight of the molten metal M with respect to the steel
strip 1. A gas that has been compressed by a compressor (not shown) or the like is introduced
into the gas wiping nozzles 16. The gas wiping nozzles 16 are disposed at both sides in a
thickness direction of the steel strip 1, and are arranged at positions that are located on a
downstream side of the support rolls 15A, 15B in the conveyance direction of the steel strip 1
and that have at a predetermined height from the bath surface of the coating bath 11. The gas
that is ejected from the gas wiping nozzles 16 is blown onto both sides of the steel strip 1 that
has been pulled upward in the vertical direction from the coating bath 11, thereby removing an
excess molten metal M. As a result, a coating weight of the molten metal M with respect to the
surface of the steel strip 1 is adjusted to an appropriate amount, thereby adjusting a film
thickness of the molten metal M that adheres to the surface of the steel strip 1.
[0027] The induction heating device 17 is provided on a downstream side of the gas wiping
nozzles 16 in the conveyance direction of the steel strip 1, and performs heat treatment on the
steel strip 1. Specifically, induction heating coils, which are connected to a high-frequency
power supply (not shown), are provided at both sides in the thickness direction of the steel strip
1. By being heated through the induction heating device 17, a temperature near the surface of
the steel strip 1 is raised to about 500°C, thereby causing alloying to occur between the molten
metal M that adheres to the surface of the steel strip 1 and the steel strip 1. As a result, a
galvannealed film is formed on the surface of the steel strip 1.
[0028] Operation of the apparatus for manufacturing a hot-dip metal coated steel strip 10 that
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has the above-described configuration will be described. The apparatus for manufacturing a
hot-dip metal coated steel strip 10 causes the steel strip 1 to move using a drive source (not
shown) and to pass through each component in the apparatus. The steel strip 1 is introduced
obliquely downward into the coating bath 11 through the snout 13, and travels around the sink
roll 14. Then, the conveyance direction of the steel strip 1 is changed to the vertically upward
direction. Next, the steel strip 1 passes between the support rolls 15A, 15B and moves up, and
is pulled up to the outside of the coating bath 11. Thereafter, an excess molten metal M that
adheres to the steel strip 1 is removed by a pressure of the gas that is blown from the gas wiping
nozzles 16, thereby adjusting a coating amount of the molten metal M with respect to the surface
of the steel strip 1 to a predetermined coating weight. Subsequently, alloying between the
molten metal M and the steel strip 1 is promoted by the induction heating device 17, thereby
forming an alloyed coating film on the surface of the steel strip 1. As described above, the
apparatus for manufacturing a hot-dip metal coated steel strip 10 causes the steel strip 1 to be
continuously immersed in the coating bath 11 and to be coated with the molten metal M, thereby
manufacturing the hot-dip metal coated steel strip 1A having a predetermined coating weight.
[0029] Various foreign substances may be present on surfaces of the rolls (hereinafter, in the
description, each of the support rolls 15A, 15B, and the sink roll 14 is also simply referred to
as “roll(s)”) in the coating bath 11. A foreign substance that adheres on the surfaces of the rolls
is, for example, a substance to which a top dross (Fe2Al5Znx), a bottom dross (FeZn3, FeZn7,
Fe5Zn21, or Fe3Zn10), a scum (an oxide of Zn or Al), or impurities in the bath, which is/are
present in the coating bath 11, adhere. Another example of a foreign substance on the surfaces
of the rolls is an alloy constituent in the coating bath 11 that has been precipitated on the surfaces
of the rolls and that has been coarsened. In a case in which such a foreign substance on the
surfaces of the rolls comes into contact with a surface of a steel strip, a surface defect such as a
flaw or the like on the surface of the steel strip may be caused to occur.
[0030] Thus, as shown in Fig. 1, the apparatus for manufacturing a hot-dip metal coated steel
strip 10 includes the device for removing a foreign substance from a surface of a roll 100. The
device for removing a foreign substance from a surface of a roll 100 removes a foreign
substance that is present on the surfaces of the rolls. Specifically, the device for removing a
foreign substance from a surface of a roll 100 scrapes a foreign substance on the surfaces of the
rolls by pressing a scraper unit 110, which is a spatulate member, against the surfaces of the
rolls. Details of the device for removing a foreign substance from a surface of a roll 100 will
be described later.
[0031] Although Fig. 1 shows an example in which the device for removing a foreign
substance from a surface of a roll 100 is provided for the support roll 15B, the device may also
8
be provided for the sink roll 14 and/or the support roll 15A. The schematic configuration of the
apparatus for manufacturing a hot-dip metal coated steel strip 10 according to the present
embodiment has been described above.
[0032]
Next, the device for removing a foreign substance from a surface of a roll 100
according to the present embodiment will be described with reference to Figs. 2 and 3. Fig. 2
shows a view that illustrates a schematic configuration of the device for removing a foreign
substance from a surface of a roll 100 according to the present embodiment. Fig. 3 shows a
view that illustrates a schematic configuration of the device for removing a foreign substance
from a surface of a roll 100 according to the present embodiment, and also shows a crosssectional view that is taken along line A-A’ in Fig. 2. As shown in Fig. 2, the device for
removing a foreign substance from a surface of a roll 100 according to the present embodiment
includes the scraper unit 110, a vibration detection unit 120, and a vibrator unit 160. The
vibration detection unit 120 and the vibrator unit 160 are components of a device for assisting
in evaluation of a state 118 according to the present embodiment. The device for assisting in
evaluation of a state 118 is a device that assists in evaluation of a state of removal of a foreign
substance from a surface of a roll.
[0033] (Scraper Unit)
The scraper unit 110 is a spatulate member that is pressed against a surface of a roll
provided in the coating bath 11. Specifically, the scraper unit 110 includes a blade 111 and a
rod 113. The blade 111 is a metallic flat-plate member, and is to be brought into abutment with
the surface of the roll. Specifically, a tip portion 111A, which is a flat-plate portion of the blade
111, is to be brought into abutment with the surface of the roll. The blade 111 has a width in a
roll axis direction that is shorter than an axial length of the roll. An abutment position of the
blade 111 is not particularly limited as long as the position does not obstruct conveyance of the
steel strip 1. For example, the blade 111 is configured to be brought into abutment with an
upper face or a side face of the roll. The blade 111 is made of, for example, a tool steel such as
SKD11, SKH51, or the like, a stainless steel such as SUS304L, SUS316L, or the like, or a Cobased alloy such as a STELLITE #6, a STELLITE #21, or the like (“STELLITE” is a registered
trademark).
[0034] The rod 113 is a rod-shaped member that extends from a main body unit 130 toward
the roll. The rod 113 has one end 113A that is supported by the main body unit 130, and the
other end 113B on which the blade 111 is supported. A shape or material of the rod 113 is not
particularly limited as long as the shape or material can support the blade 111 in the coating
bath 11.
9
[0035] The scraper unit 110 is movable toward the surface of the roll through an air cylinder
115. Specifically, the air cylinder 115 is connected to the rod 113, and the rod 113 is displaced
by the air cylinder 115, so that the tip portion 111A of the blade abuts on the surface of the roll
or is separated from the surface of the roll.
[0036] (Vibration Detection Unit)
As shown in Figs. 2 and 9, the vibration detection unit 120 detects vibration that is to
be caused to occur in the scraper unit 110. Since such vibration corresponds to a state of
removal of a foreign substance that is present on the surface of the roll, the removal state of the
foreign substance on the surface of the roll is grasped by the vibration detection unit 120
detecting the vibration. Specifically, in a case in which the scraper unit 110 is brought into
abutment with the surface of the roll, friction is caused to occur between the scraper unit 110
and the roll, and vibration is caused to occur in the rod 113 by the friction. Vibration is also
caused to occur in the rod 113 by passing-over of unevenness that is a relatively large foreign
substance. Such vibration varies in accordance with a state of removal of a foreign substance
that is present on the surface of the roll. That is, in a case in which a foreign substance remains
on the surface of the roll, a frictional force that is caused to occur between the scraper unit 110
and the roll, or a height difference of a surface shape is large. Thus, vibration that is caused to
occur in the scraper unit 110 becomes large. In a case in which the foreign substance is
distanced from the surface of the roll, the vibration that is caused to occur in the scraper unit
110 becomes small due to reduction in the frictional force between the scraper unit 110 and the
roll, or reduction in the height difference. That is, a state of removal of a foreign substance on
the surface of the roll is grasped by detecting a variation in intensity of vibration (amplitude or
vibration energy) in the rod 113 of the scraper unit 110.
[0037] Specifically, as shown in Fig. 9, the vibration detection unit 120 is provided in an
intermediate portion 113C of the rod 113. Vibration that is caused to occur in the scraper unit
110 propagates from the other end 113B to the one end 113A of the rod 113. Although an
example in which the vibration detection unit 120 is provided in the rod 113 has been described,
the disclosure is not limited this. For example, the vibration detection unit 120 may be provided
in a connection portion of the rod 113 and the air cylinder 115.
[0038] The vibration detection unit 120 is a uniaxial acceleration sensor, and detects vibration
that is caused to occur in the scraper unit 110 by detecting acceleration that is caused to occur
in the rod 113 in a direction orthogonal or parallel to a longitudinal direction of the rod 113. As
an example, the vibration detection unit 120 is a piezoelectric acceleration sensor.
[0039] (Main Body Unit)
As shown in Fig. 2, the main body unit 130 is a frame part that is provided outside the
10
coating bath 11, and that supports the scraper unit 110 and the like at predetermined positions.
Specifically, the main body unit 130 supports the one end 113A of the rod 113 of the scraper
unit 110. The main body unit 130 is provided with the air cylinder 115, and a drive unit 140,
which will be described later.
[0040] (Drive Unit)
The device for removing a foreign substance from a surface of a roll 100 according to
the present embodiment further includes the drive unit 140. The drive unit 140 causes the
scraper unit 110 to move along the axial direction of the roll. The scraper unit 110 is caused to
move along the axial direction of the roll, whereby a foreign substance on the surface of the roll
can be removed at any position in the axial direction of the roll. Specifically, the drive unit 140
includes a screw feed mechanism 141, a drive source 143, and a guide shaft 145.
[0041] The screw feed mechanism 141 includes a screw shaft 141A whose axial direction is
arranged along the axial direction of the roll, and support portions 141B that rotatably support
both ends of the screw shaft 141A. The screw shaft 141A is a rod-shaped member that has an
outer circumferential surface provided with threads at a predetermined pitch. As shown in Fig.
3, the screw shaft 141A is inserted while being screwed into a bracket 141C to which the air
cylinder 115 of the scraper unit 110 is attached. The drive source 143 is connected to an end
portion of the screw shaft 141A, and the screw shaft 141A is configured to be rotated by the
drive source 143. As a result, the scraper unit 110 is screw-fed by the rotation of the screw shaft
141A, and is caused to move along the axial direction of the roll.
[0042] The guide shaft 145 is a rod-shaped member that is provided along the axial direction
of the roll in parallel with the screw shaft 141A. The guide shaft 145 has both ends that are
supported by the support portions 141B of the screw shaft 141A. As shown in Fig. 3, the guide
shaft 145 supports a bracket 145A to which the one end 113A of the rod 113 of the scraper unit
110 is attached. Press operation of the scraper unit 110 against the roll (see the double-headed
arrow in Fig. 3) is performed by the air cylinder 115 while the scraper unit 110 is stably caused
to move in the roll axis direction by the guide shaft 145.
[0043] (Control Unit)
The device for removing a foreign substance from a surface of a roll 100 according to
the present embodiment includes a control unit 150. The control unit 150 controls operation of
the device for removing a foreign substance from a surface of a roll. Specifically, as shown in
Fig. 2, the control unit 150 obtains a detection result from the vibration detection unit 120, and
controls the drive unit 140 and the air cylinder 115. For example, an operation unit 180 is
connected to the control unit 150, and the control unit 150 controls the drive unit 140 and the
air cylinder 115 based on an input from the operation unit 180 that is operated by an operator.
11
[0044] The control unit 150 outputs the detection result from the vibration detection unit 120
to the vibrator unit 160, which will be described later. The type of the detection result from the
vibration detection unit 120 is not limited, and may be, for example, a variation in intensity of
vibration with respect to time.
[0045] (Vibrator Unit)
The vibrator unit 160 causes vibration that has been detected by the vibration detection
unit 120 to occur at a position distanced from the scraper unit 110 based on a detection result
from the vibration detection unit 120. That is, the vibrator unit 160 causes vibration that is
reproduction of the vibration having been detected by the vibration detection unit 120 to occur
at a position distanced from the scraper unit 110. Specifically, as shown in Fig. 9, the vibrator
unit 160 includes an amplification section 161 and a vibration generation section 163. A
detection result from the vibration detection unit 120 is input to the vibrator unit 160 that is
located at a position distanced from the scraper unit 110 through wired connection such as an
electric cable or the like. The detection result from the vibration detection unit 120 is input to
the vibration generation section 163 after a signal is amplified in the amplification section 161
of the vibrator unit 160. The vibration generation section 163 causes a physical vibration to
occur based on the input signal. In particular, the vibrator unit 160 causes vibration that is
reproduction of a variation in intensity (a variation in amplitude) of vibration having been
detected by the vibration detection unit 120 to occur.
[0046] Hereinafter, variations in vibration, which have been detected by the vibration
detection unit 120, before and after removal of a foreign substance on the surface of the roll
will be described with reference to Figs. 4 to 7. Fig. 4 shows a diagram that schematically
illustrates a result of a spectral analysis on vibration that has been directly detected in the rod
113 of the scraper unit 110 before a foreign substance on the surface of the roll is removed. Fig.
5 shows a diagram that schematically illustrates a result of a spectral analysis on vibration that
has been directly detected in the rod 113 of the scraper unit 110 after the foreign substance on
the surface of the roll has been removed. As shown in Fig. 4, peaks having high intensities are
detected at a wide range of frequencies, and large vibration is caused to occur, before a foreign
substance on the surface of the roll is removed. In contrast, as shown in Fig. 5, the intensities
of the peaks decrease after the foreign substance on the surface of the roll has been removed.
In particular, in a region of low frequencies of 1000 Hz or lower, the intensities of the peaks
greatly decreased. In this manner, in a case in which a foreign substance on the surface of the
roll has been removed, intensity (amplitude) of vibration in the scraper unit 110 decreases.
[0047] Fig. 6 shows a diagram that schematically illustrates a result of a spectral analysis on
vibration that is reproduced by the vibrator unit 160 based on the vibration that has been
12
detected in the rod 113 of the scraper unit 110 before the foreign substance on the surface of the
roll is removed. Fig. 7 shows a diagram that schematically illustrates a result of a spectral
analysis on vibration that is reproduced by the vibrator unit 160 based on the vibration that has
been detected in the rod 113 of the scraper unit 110 after the foreign substance on the surface
of the roll has been removed. As shown in Fig. 6, also in the result of the spectral analysis on
the vibration that is reproduced by the vibrator unit 160, peaks having high intensities are
detected at a wide range of frequencies, and large vibration is caused to occur, before the foreign
substance on the surface of the roll is removed. In contrast, as shown in Fig. 7, intensities of
the peaks decrease, and in particular, the intensities of the peaks greatly decrease in a region of
low frequencies, after the foreign substance on the surface of the roll has been removed.
[0048] As described above, in the vibration that is reproduced by the vibrator unit 160 based
on the vibration that has been detected by the vibration detection unit 120, the same tendency
as the tendency in the vibration that is caused to occur in the rod 113 of the scraper unit 110
was observed. That is, even in the vibration that is reproduced by the vibrator unit 160, the
tendency was observed in which the intensity of the vibration decreases with the removal of the
foreign substance on the surface of the roll. In this manner, the vibrator unit 160 can achieve a
grasp of a state of removal of a foreign substance on the surface of the roll, at a position
distanced from the scraper unit 110.
[0049] An example of the vibrator unit 160 is an electrodynamic shaker. In particular, an
example of the vibrator unit 160 is a vibratory table having a vibratory surface that can be
touched by an operator or the like. The vibrator unit 160 is provided at a position distanced
from the scraper unit 110. For example, the vibrator unit 160 is provided at a periphery of the
coating tank 12, in an operator room of an operation line, or the like.
[0050] Vibration that has been generated in the scraper unit 110 is reproduced by the vibrator
unit 160, whereby a state of removal of a foreign substance on the surface of the roll is grasped.
That is, a variation in intensity of vibration is reproduced by the vibrator unit 160, and thus, in
a state in which vibration of the vibrator unit 160 is large, presence of a foreign substance
remaining on the surface of the roll is grasped. In a state in which the vibration of the vibrator
unit 160 is small, completion of removal of the foreign substance on the surface of the roll is
grasped.
[0051] Vibration is reproduced by the vibrator unit 160, whereby in the device for removing
a foreign substance from a surface of a roll 100, a removal state can be grasped on a basis
similar to a basis in manual removal of a foreign substance. That is, in a case in which an
operator performs operation of removing a foreign substance on the surface of the roll using a
tool such as a scraper or the like, the operator grasps a state of removal of the foreign substance
13
on the surface of the roll by feeling vibration of the scraper. By reproducing vibration through
the vibrator unit 160, an operator or the like can sense and grasp a state of removal of a foreign
substance through the vibration, also in the device for removing a foreign substance from a
surface of a roll 100. The schematic configuration of the device for removing a foreign
substance from a surface of a roll 100 according to the present embodiment has been described
above.
[0052]
Next, a method of removing a foreign substance from a surface of a roll according to
the present embodiment will be described with reference to Fig. 8. Fig. 8 shows a flowchart of
the method of removing a foreign substance from a surface of a roll according to the present
embodiment. As shown in Fig. 8, first, the scraper unit 110 is brought into abutment with a
surface of a roll (S101). Specifically, the blade 111 that is provided in the other end 113B of
the rod 113 of the scraper unit 110 is brought into abutment with the surface of the roll. As a
result, removal of a foreign substance on the surface of the roll performed by the scraper unit
110 is started. In the present embodiment, an operator operates the operation unit 180 to cause
the scraper unit 110 to move.
[0053] During the removal of the foreign substance on the surface of the roll, vibration is
caused to occur in the rod 113 of the scraper unit 110. The vibration in the scraper unit 110 is
detected by the vibration detection unit 120 (S103).
[0054] The vibration in the rod 113 that has been detected in step S103 is reproduced as
vibration, at a position distanced from the scraper unit 110, by the vibrator unit 160 (S105).
[0055] A state of removal of the foreign substance that is present on the surface of the roll is
grasped based on the vibration that has been reproduced by the vibrator unit 160 in step S105
(S107). That is, the removal state of the foreign substance on the surface of the roll is grasped
by the operator that touches the vibrator unit 160. Here, in a case in which the operator feels
the vibration of the vibrator unit 160 and determines that the removal of the foreign substance
on the surface of the roll is not sufficient, the operator does not move a position of the scraper
unit 110 in the roll axis direction (that is, moving operation is not performed), and continues
the removal of the foreign substance using the scraper unit 110 at that position. That is, in a
portion of the surface of the roll in which the scraper unit 110 performs the removal of the
foreign substance, the removal of the foreign substance is continuously performed by the
scraper unit 110 at the same position until the operator determines that the removal of the
foreign substance has been completed, based on the vibration of the vibrator unit 160. In a case
in which the operator determines that the removal of the foreign substance on the surface of the
roll has been completed, the operator operates the operation unit 180 to change the position of
14
the scraper unit 110 in the roll axis direction, and removes a foreign substance that is present
on the surface of the roll at another position in the roll axis direction (S109).
[0056] Specifically, in a case in which the vibration that has been detected in step S103 is
large, the foreign substance remains on the surface of the roll, and the vibration that is
reproduced in the vibrator unit 160 also becomes large. Thus, the operator continues the
removal of the foreign substance using the scraper unit 110 at the position in the roll axis
direction. In a case in which the vibration that has been detected in step S103 is small, the
foreign substance on the surface of the roll has been removed, and the vibration that is
reproduced in the vibrator unit 160 also becomes small. Thus, the operator changes the position
of the scraper unit 110 in the roll axis direction. The method of removing a foreign substance
from a surface of a roll according to the present embodiment has been described above.
[0057] According to the present embodiment, an operator can grasp a state of removal of a
foreign substance from a surface of a roll that is provided in the hot-dip galvanizing bath 11
through vibration of the vibrator unit 160. Thus, it is possible to evaluate a removal state
including completion of removal of a foreign substance, with respect to removal operation of a
foreign substance on the surface of the roll.
[0058] In the device for removing a foreign substance 100 according to the first embodiment,
the vibration that has been detected by the vibration detection unit 120 is transmitted to the
vibrator unit 160 through the control unit 150, whereby the vibration is reproduced. However,
the disclosure is not limited to this configuration. For example, as in a device for removing a
foreign substance 101 according to a modification example that is shown in Fig. 9, the vibration
that has been detected by the vibration detection unit 120 may be transmitted to the vibrator
unit 160 through a conversion unit 170, whereby vibration may be reproduced. Specifically,
the device for removing a foreign substance 101 includes the conversion unit 170, and in a case
in which a state of the vibration that has been detected by the vibration detection unit 120 is
defined as a first state, the conversion unit 170 converts the first state into a second state that is
to be reproduced in the vibrator unit 160. As shown in Fig. 9, the conversion unit 170 is
provided between the vibration detection unit 120 and the vibrator unit 160 on an electric circuit.
The conversion unit 170 electrically converts a detection result from the vibration detection unit
120 and outputs the detection result to the vibrator unit 160. Specifically, the conversion unit
170 converts frequencies as the first state that has been detected by the vibration detection unit
120 into frequencies as the second state that can be reproduced in the vibrator unit 160.
Specifically, the conversion unit 170 converts a signal that relates to frequencies among
detection results from the vibration detection unit 120 into a signal that relates to frequencies
that can be reproduced in the vibrator unit 160, and outputs the signal to the vibrator unit 160.
15
The state of the vibration in the scraper unit 110 is converted into the state of the vibration that
can be reproduced by the vibrator unit 160, by the conversion unit 170, whereby the state
becomes a state of vibration that is optimal for reproduction in the vibrator unit 160. Thus, this
facilitates a grasp of a state of removal of a foreign substance on the surface of the roll.
Examples of the vibration frequencies as the second state that can be reproduced in the vibrator
unit 160 include frequencies in a range within capability of human perception. As a result, in a
case in which the vibrator unit 160 is a shaker, a human can grasp a state of removal of a foreign
substance on the surface of the roll through vibration that is reproduced by the vibrator unit 160.
The conversion unit 170 may have a function as a filter that removes noise from a detection
result from the vibration detection unit 120. As shown in Fig. 10, in the method of removing a
foreign substance in a case in which the device for removing a foreign substance 101 is used, a
first state is converted into a second state that is to be reproduced in step S107 (S113), in a case
in which a state of vibration that has been detected in step S103 is defined as the first state. In
the device for removing a foreign substance 101, the vibration detection unit 120, the vibrator
unit 160, and the conversion unit 170 are components of a device for assisting in evaluation of
a state 119 that assists in evaluation of a state of removal of a foreign substance on the surface
of the roll.
[0059] [Second Embodiment]
Next, a device for removing a foreign substance from a surface of a roll according to
a second embodiment of the disclosure will be described.
As described above, in the second embodiment, constituent elements that have
substantially the same functions and structures as those in the first embodiment are denoted
with the same reference signs, and repeated explanation is omitted.
[0060]
A device for removing a foreign substance 102 according to the present embodiment
is used in the apparatus for manufacturing a hot-dip metal coated steel strip 10, similarly to the
device for removing a foreign substance 100 according to the first embodiment.
[0061] As shown in Fig. 11, in the device for removing a foreign substance 102, a control unit
151 evaluates a surface state of a roll based on a detection result from the vibration detection
unit 120, and causes the scraper unit 110 to move in the roll axis direction in accordance with
the evaluation result. As described above, in the device for removing a foreign substance 102,
the control unit 151 evaluates a state of removal of a foreign substance on the surface of the
roll, and thus the vibrator unit 160 of the device for removing a foreign substance 100 according
to the first embodiment is not provided. As shown in Fig. 11, the device for removing a foreign
substance 102 according to the present embodiment includes the operation unit 180 for manual
16
operation of the scraper unit 110.
[0062] The control unit 151 according to the present embodiment obtains the detection result
from the vibration detection unit 120, and controls the drive unit 140 and the air cylinder 115.
In particular, the control unit 151 functions as a movement control unit that causes the scraper
unit 110 to move to a predetermined position in the roll axis direction by controlling the drive
unit 140 based on vibration that has been detected by the vibration detection unit 120.
[0063] Removal can be performed at a predetermined position in the roll axis direction by
grasping a removal state through the vibration that has been detected by the vibration detection
unit 120. That is, a foreign substance remains on the surface of the roll, at a position in the roll
axis direction in which the vibration is relatively large. The scraper unit 110 is caused to move
in the roll axis direction to the predetermined position and the foreign substance on the surface
of the roll is removed, whereby the foreign substance on the surface of the roll can be effectively
removed. Specifically, the control unit 151 obtains a detection result from the vibration
detection unit 120. In a case in which the detection result exceeds a preset threshold, the control
unit 151 determines that the removal of the foreign substance on the surface of the roll has not
been completed, and continues the removal of the foreign substance on the surface of the roll
at the same position in the roll axis direction without causing the scraper unit 110 to move in
the roll axis direction. In a case in which the detection result from the vibration detection unit
120 is the preset threshold or lower, the control unit 151 determines that the removal of the
foreign substance on the surface of the roll has been completed, and causes the scraper unit 110
to move to another position in the roll axis direction. The threshold is a value in a case in which
it is determined that a foreign substance adheres, in manual removal of the foreign substance.
In the present embodiment, an acceleration sensor is used as the vibration detection unit 120.
Therefore, in a case in which an effective value of acceleration that is detected by the
acceleration sensor exceeds the preset threshold, the control unit 151 determines that a foreign
substance adheres to the surface of the roll. With regard to evaluation of a state of removal of
a foreign substance on the surface of the roll performed by the control unit 151, it may be
determined that the foreign substance adheres, in a case in which a detection result from the
vibration detection unit 120 exceeds the threshold a predetermined number of times within a
predetermined time period.
[0064] The control unit 151 drives the drive source 143 to cause the scraper unit 110 to move
to a predetermined position in the axial direction of the roll through the screw feed mechanism
141. Then, the control unit 151 causes the air cylinder 115 to operate to press the scraper unit
110 against the surface of the roll. As a result, the removal of the foreign substance is performed
at the predetermined position in the axial direction of the roll by the scraper unit 110.
17
[0065]
Next, a method of removing a foreign substance from a surface of a roll according to
the present embodiment will be described with reference to Fig. 12. Fig. 12 shows a flowchart
of the method of removing a foreign substance from a surface of a roll according to the present
embodiment. As shown in Fig. 12, first, the scraper unit 110 is brought into abutment with a
surface of a roll (S121). During removal of a foreign substance on the surface of the roll,
vibration is caused to occur in the rod 113 of the scraper unit 110, and the vibration is detected
by the vibration detection unit 120 (S123).
[0066] In step S125, the control unit 151 compares the detection result that has been detected
in step S123 with the threshold. As a result, a state of removal of the foreign substance that is
present on the surface of the roll is grasped in the control unit 151. Then, it is determined
whether or not the removal of the foreign substance on the surface of the roll has been completed
in the control unit 151 (S127). In a case in which it is not determined that the removal of the
foreign substance has been completed, the processing returns to step S125, and the removal
state of the foreign substance is grasped. In a case in which it is determined that the removal
of the foreign substance on the surface of the roll has been completed in step S127, a position
of the scraper unit 110 in the axial direction of the roll is changed based on the vibration that
has been detected in step S123, and the foreign substance that is present on the surface of the
roll is removed at another position in the roll axis direction (S129).
[0067] Specifically, in a case in which the vibration that has been detected in step S123 is
large, the control unit 151 determines that the foreign substance remains on the surface of the
roll, and continues the removal of the foreign substance using the scraper unit 110 at the position
in the roll axis direction. In a case in which the vibration that has been detected in step S103 is
small, the control unit 151 determines that the foreign substance on the surface of the roll has
been removed, and changes the position of the scraper unit 110 in the roll axis direction. At
this time, the change in the position in the roll axis direction may be performed by causing the
scraper unit 110 to move at a predetermined pitch. The scraper unit 110 may be caused to m
ove to a position in the roll axis direction in which vibration is relatively large, based on a state
of the vibration that has been detected by the vibration detection unit 120. The method of
removing a foreign substance from a surface of a roll according to the present embodiment has
been described above.
[0068] According to the present embodiment, the control unit 151 can grasp a state of removal
of a foreign substance from a surface of a roll that is provided in the hot-dip galvanizing bath
11, from a detection result from the vibration detection unit 120. As a result, it is possible to
18
evaluate a removal state including completion of removal of a foreign substance, with respect
to removal operation of a foreign substance on the surface of the roll.
[0069] Although the preferred embodiments according to the disclosure have been described
above in detail with reference to the accompanying drawings, the disclosure is not limited to
these examples. It is obvious to those having ordinary knowledge in the art to which the
disclosure pertains that various modifications or applications are conceivable within the
technical scope described in the appended claims, and it should be understood that such
modifications or applications are also naturally within the technical scope of the disclosure.
[0070] For example, in the first embodiment, an example has been described in which the
vibrator unit 160 is a vibratory table having a vibratory surface that can be touched by a human,
but the disclosure is not limited to this example. For example, a vibrator may be used which
can be gripped by a human. In particular, the vibrator unit 160 may be configured by a controller,
which serves as the operation unit 180 used in a case in which the scraper unit 110 is caused to
move, having a vibration function.
[0071] In the first embodiment and the second embodiment, an example has been described
in which the vibration detection unit 120 is a piezoelectric acceleration sensor, but the vibration
detection unit 120 is not particularly limited as long as the vibration detection unit 120 can
detect vibration that is caused to occur in the rod 113. For example, a configuration may be
applicable in which an acoustic signal or displacement that is associated with vibration in the
rod 113 is detected by a non-contact type vibration detection unit 120 such as a microphone, a
laser displacement meter, or the like.
[0072] The vibration detection unit 120 may be a sensor that is attached to a robotic arm
capable of coming into contact with the scraper unit 110 and that detects displacement
associated with vibration. This robotic arm may be a slave arm in a master-slave manipulator.
In this case, a configuration may be applicable in which a master arm, in the master-slave
manipulator, to which displacement of the slave arm is transmitted functions as the vibrator unit
160.
[0073] In the device for removing a foreign substance 100 according to the first embodiment,
an operator evaluates a state of removal of a foreign substance from a surface of a roll based on
vibration of the vibrator unit 160. In the device for removing a foreign substance 101 according
to the second embodiment, the control unit 151 evaluates a state of removal of a foreign
substance from a surface of a roll based on a detection result from the vibration detection unit
120. However, the disclosure is not limited to these configurations. For example, in a device
for removing a foreign substance according to another embodiment of the disclosure, a case in
which a control unit evaluates a state of removal of a foreign substance from a surface of a roll
19
may be set as an automatic operation mode, and a case in which an operator evaluates a state
of removal of a foreign substance from a surface of a roll based on vibration of the vibrator unit
160 may be set as a manual operation mode. Then, a configuration may be made such that these
modes can be switched.
[0074] In the embodiment described above, vibration that has been detected by the vibration
detection unit is caused to occur in the vibrator unit (in other words, the vibration is reproduced),
but the disclosure is not limited to this configuration. As long as an operator or the like can
sense a variation in vibration, for example, a vibration reproduction unit may be used instead
of using a vibrator unit. An example of the vibration reproduction unit is a speaker that
reproduces vibration having been detected by the vibration detection unit as sound and that
performs aural representation, a display that visually displays a signal that relates to a variation
in vibration that has been detected by the vibration detection unit, or the like.
[0075] With regard to the above-described embodiments, the following supplementary notes
are further disclosed.
[0076] (Supplementary Note 1)
A device for removing a foreign substance from a surface of a roll in a hot-dip
galvanizing bath, the device including:
a scraper unit that has a blade configured to abut a surface of a roll provided in a hotdip galvanizing bath; and
a vibration detection unit that is configured to detect vibration in the scraper unit.
[0077] (Supplementary Note 2)
The device for removing a foreign substance from a surface of a roll in a hot-dip
galvanizing bath according to supplementary note 1, the device further including a vibration
reproduction unit that is provided at a position distanced from the scraper unit and that is
configured to reproduce the vibration that has been detected by the vibration detection unit.
[0078] (Supplementary Note 3)
The device for removing a foreign substance from a surface of a roll in a hot-dip
galvanizing bath according to supplementary note 2, the device further including, in a case in
which a state of the vibration that has been detected by the vibration detection unit is defined
as a first state, a conversion unit that is configured to convert the first state into a second state
to be reproduced in the vibration reproduction unit.
[0079] (Supplementary Note 4)
The device for removing a foreign substance from a surface of a roll in a hot-dip
galvanizing bath according to any one of supplementary notes 1 to 3, the device further
including:
20
a drive unit that is configured to cause the scraper unit to move along an axial direction
of the roll; and
a movement control unit that is configured to control the drive unit such that the scraper
unit is caused to move to a predetermined position in the axial direction of the roll, based on
the vibration that has been detected by the vibration detection unit.
[0080] (Supplementary Note 5)
A method of removing a foreign substance from a surface of a roll in a hot-dip
galvanizing bath, the method including:
an abutting process of bringing a blade of a scraper unit that is provided with the blade
into abutment with a surface of a roll that is provided in a hot-dip galvanizing bath;
a vibration detecting process of detecting vibration that has been generated in the
scraper unit; and
a state grasping process of grasping a state of removal of a foreign substance that is
present on a surface of a roll, based on the vibration that has been detected in the vibration
detecting process, at a position distanced from the scraper unit.
[0081] (Supplementary Note 6)
The method of removing a foreign substance from a surface of a roll in a hot-dip
galvanizing bath according to supplementary note 5, the method further including a vibration
reproducing process of reproducing the vibration in the scraper unit that has been detected,
in which, in the state grasping process, the removal state is grasped based on the
vibration that has been reproduced in the vibration reproducing process.
[0082] (Supplementary Note 7)
The method of removing a foreign substance from a surface of a roll in a hot-dip
galvanizing bath according to supplementary note 6, the method further including, in a case in
which a state of the vibration that has been detected in the vibration detecting process is defined
as a first state, a converting process of converting the first state into a second state to be
reproduced in the vibration reproducing process.
[0083] (Supplementary Note 8)
The method of removing a foreign substance from a surface of a roll in a hot-dip
galvanizing bath according to any one of supplementary notes 5 to 7, the method further
including a scraper position changing process of controlling a position of the scraper unit in an
axial direction of the roll based on the vibration that has been detected.
[0084] All documents, patent applications, and technical standards described in the
description are incorporated herein by reference to the same extent as that in a case in which
each individual document, patent application, and technical standard are specifically and
21
individually indicated to be incorporated by reference.
Reference Signs List
[0085]
10 apparatus for manufacturing hot-dip metal coated steel strip
100 device for removing foreign substance from surface of roll
101 device for removing foreign substance from surface of roll
102 device for removing foreign substance from surface of roll
110 scraper unit
111 blade
113 rod
113A one end
113B other end
118 device for assisting in evaluation of surface state of roll
119 device for assisting in evaluation of surface state of roll
120 vibration detection unit
130 main body unit
140 drive unit
150 control unit
160 vibrator unit
170 conversion unit

22
CLAIMS
1. A device for assisting in evaluation of a surface state of a roll, the device comprising:
a vibration detection unit that is configured to detect vibration in a scraper unit having
a blade configured to abut a surface of a roll provided in a hot-dip metal coating bath; and
a vibrator unit that is configured to generate vibration that has been detected by the
vibration detection unit at a position distanced from the scraper unit, and to enable evaluation
of a state of removal of a foreign substance present on the surface of the roll based on the
vibration that has been generated.
2. The device for assisting in evaluation of a surface state of a roll according to claim
1, the device further comprising:
in a case in which a state of the vibration that has been detected by the vibration
detection unit is defined as a first state,
a conversion unit that is configured to convert the first state into a second state for
generation by the vibrator unit.
3. A device for removing a foreign substance from a surface of a roll, the device
comprising:
a scraper unit that has a blade configured to abut a surface of a roll provided in a hotdip metal coating bath and to remove a foreign substance from the surface of the roll; and
the device for assisting in evaluation of a surface state of a roll according to claim 1 or
2.
4. A device for removing a foreign substance from a surface of a roll, the device
comprising:
a scraper unit that has a blade configured to abut a surface of a roll provided in a hotdip metal coating bath and to remove a foreign substance from the surface of the roll;
a vibration detection unit that is configured to detect vibration in the scraper unit;
a drive unit that is configured to cause the scraper unit to move along an axial direction
of the roll; and
a movement control unit that is configured to control the drive unit such that the scraper
unit is caused to move to a predetermined position in the axial direction of the roll and remove
the foreign substance, based on the vibration that has been detected by the vibration detection
unit.
23
5. The device for removing a foreign substance from a surface of a roll according to
any one of claims 1 to 4, wherein the hot-dip metal coating bath comprises a hot-dip galvanizing
bath.
6. A method of removing a foreign substance from a surface of a roll, the method
comprising:
an abutting process of bringing a blade of a scraper unit that is provided with the blade
into abutment with a surface of a roll that is provided in a hot-dip metal coating bath;
a vibration detecting process of detecting vibration that has been generated in the
scraper unit;
a state evaluating process of generating the vibration detected in the scraper unit at a
position distanced from the scraper unit and evaluating a state of removal of a foreign substance
that is present on the surface of the roll based on the vibration that has been generated; and
a removing process of removing a foreign substance using the scraper unit based on
the state of removal of the foreign substance that has been evaluated.