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[Document Type] SPECIFICATION
[Title of the Invention] APPARATUS FOR MANUFACTURING GRAINORIENTED
ELECTRICAL STEEL SHEET AND METHOD OF
MANUFACTURING GRAIN-ORIENTED ELECTRICAL STEEL SHEET
[Technical Field]
[0001]
The present invention relates to an apparatus for manufacturing a grainoriented
electrical steel sheet in which a magnetic domain is controlled by irradiation
of a laser beam and a method of manufacturing a grain-oriented electrical steel sheet.
[Background Art]
[0002]
The above-mentioned grain-oriented electrical steel sheet is used as a material
included in the iron core of an electrical device such as a transformer or a rotating
device. In the grain-oriented electrical steel sheet, a reduction in energy loss (iron
loss) during magnetization is required. Iron loss is classified into eddy-current loss
and hysteresis loss. Furthermore, eddy-current loss is classified into classical eddycurrent
loss and anomalous eddy-current loss.
[0003]
Here, in order to improve soft magnetic properties by imparting magnetic
anisotropy to the grain-oriented electrical steel sheet in a rolling direction, a grainoriented
electrical steel sheet having an insulating film formed on the sheet surface to
impart stress to base iron has been provided. As the grain-oriented electrical steel
sheet having the insulating film formed thereon, a grain-oriented electrical steel sheet
in which a glass film is formed on the surface of the steel sheet and the insulating film
is fiirther formed on the glass film, is disclosed. In addition, it is well known that a
reduction in the thickness of the electrical steel sheet is effective to reduce the eddycurrent
loss.
[0004]
In order to suppress the eddy-current loss, particularly, the anomalous eddycurrent
loss, for example, as described in Patent Documents 1 and 2, a laser magnetic
domain control method, in which a laser beam is converged and irradiates an electrical
steel sheet in an almost wfdth direction from above an insulating film to form laser
irradiation lines that extend in the width direction on the surface of the steel sheet such
that a region which periodically has residual strains in a rolling direction in the vicinity
of the surface of the base iron of the electrical steel sheet is provided to subdivide
magnetic domains, is disclosed.
[0005]
In a case where the laser magnetic domain control described above is
performed, there is a need to control an interval PL between the laser irradiation lines
on the surface of the steel sheet in the rolling direction to be constant by repeatedly
scanning the transferred steel sheet in the width direction with the laser beams using a
laser beam irradiation device disposed in a line on which the steel sheet is transferred
in a manufacturing process of the electrical steel sheet. Here, there is a limitation on
the scanning speed of the laser beam by the laser beam irradiation device, and thus in a
case where the steel sheet is transferred at a high speed, there is a case that the interval
PL between the laser irradiation lines in the rolling direction cannot be controlled to be
a predetermined interval with good accuracy.
[0006]
In addition, in a case where the laser magnetic domain control is performed,
when laser irradiation conditions such as laser beam intensity, the scanning speed of
- 2 -
M
the laser beam, the interval PL (pitch) between the laser irradiation lines in the rolling
direction, and a laser spot diameter are changed, the state of strain imparted to the steel
sheet is also changed, and thus the effect of subdividing magnetic domains is
significantly affected. Accordingly, a transfer velocity VL of the steel sheet during
the laser beam irradiation is maintained to be constant, and the laser beam irradiation is
performed by optimizing the laser irradiation conditions.
[0007]
However, in a continuous processing line which is a manufacturing process of
the grain-oriented electrical steel sheet, a preceding coil and a following coil are
connected by welding at the time of switching between the coils of the steel sheet. At
this time, the transfer velocity of the steel sheet at a laser irradiation position is
maintained at a constant level by using a looper facility.
Here, in a case where the transfer velocity of the steel sheet at the laser
irradiation position is increased to improve producibility of the grain-oriented electrical
steel sheet, there is a problem in that the looper facility is increased in size.
[0008]
In addition, in a case where the transfer velocity of the steel sheet at the laser
irradiation position is changed, appropriate laser irradiation conditions are changed,
and thus there is concern that the magnetic domain control may not be accurately
performed.
Here, in Patent Document 3, a technique of changing laser irradiation
conditions according to the transfer velocity is disclosed. However, even in a case
where the laser irradiation conditions are changed, it is difficult to stabilize the effect
of subdividing magnetic domains both in a steady condition in which the transfer
velocity is constant and in an unsteady condition in which the transfer velocity is
changed.
[0009]
From these circumstances, the present invention provides an apparatus for
manufacturing a grain-oriented electrical steel sheet and a method of manufacturing a
grain-oriented electrical steel sheet, which are capable of stably performing the
magnetic domain control with laser beams without changing laser irradiation
conditions even in a case where the transfer velocity of a steel sheet at a laser
irradiation position is changed,.
[Prior Art Document]
[Patent Document]
[0010]
[Patent Document 1] Japanese Examined Patent Application, Second
Publication No. H06-019112
[Patent Document 2] Published Japanese Translation No. 2003-500541 of
the PCX International Publication
[Patent Document 3] Japanese Unexamined Patent Application, First
Publication No. 2005-336529
[Disclosure of the Invention]
[Means for Solving the Problems]
[0011]
According to the present invention, an apparatus for manufacturing a grainoriented
electrical steel sheet in which a magnetic domain is controlled by irradiating a
laser beam, includes: a plurality of laser beam irradiation devices which are arranged in
a transfer direction of a steel sheet; and a transfer-direction movement mechanism
which moves the laser beam irradiation devices in the transfer direction of the steel
4
t
sheet.
[0012]
In this case, by the plurality of laser beam irradiation devices arranged in the
transfer direction, irradiation of the laser beam can be performed at a plurality of points
of the steel sheet in the transfer direction simultaneously. In addition, the interval
between the laser beam irradiation devices in the transfer direction can be adjusted by
the transfer-direction movement mechanism. Accordingly, even in a case where the
transfer velocity of the steel sheet is changed, laser irradiation lines can be formed at a
predetermined pitch.
[0013]
Here, a control unit may further be included which adjusts a movement
velocity of each of the laser beam irradiation devices according to a transfer velocity of
the steel sheet and maintains a relative velocity between the steel sheet and the laser
beam irradiation device at a constant level.
[0014]
In this case, even when the transfer velocity of the steel sheet is changed, the
relative velocity between the steel sheet and the laser beam irradiation device can be
maintained at a constant level by adjusting the movement velocity of the laser beam
irradiation device according to the actual transfer velocity. In addition, by performing
laser irradiation in the state where the relative velocity between the steel sheet and the
laser beam irradiation device is maintained at a constant level, the laser irradiation
lines can be formed without changing the optimum laser irradiation conditions for the
magnetic domain control.
[0015]
In addition, when the transfer velocity of the steel sheet at the time of forming
t
laser irradiation lines using the single laser beam irradiation device is defined as a
reference transfer velocity VLo, in a case where the n laser beam irradiation devices are
used, the control unit may allow irradiation of a laser beam to be performed after
controlling a movement direction and a movement velocity VS of the laser beam
irradiaiipn device so that a relative velocity VA between a transfer velocity VL of the
steel sheet and the movement velocity VS of the laser beam irradiation device in the
transfer direction becomes VA=nxVLo.
[0016]
In this case, the number of laser beam irradiation devices used and the
movement velocity VS of the laser beam irradiation device are set by the control unit
according to the transfer velocity VL of the steel sheet. Accordingly, the relative
velocity VA between the steel sheet and the laser beam irradiation device is obtained
by multiplying the number n of laser beam irradiation devices used and the reference
transfer velocity VLo. Therefore, in each of the laser beam irradiation devices, the
laser beam irradiation can be performed under the optimum laser irradiation conditions
for the magnetic domain control at the reference transfer velocity VLQ.
[0017]
In addition, according to the present invention, there is provided a method of
manufacturing a grain-oriented electrical steel sheet in which a magnetic domain is
controlled by irradiation of a laser beam, wherein a plurality of laser beam irradiation
devices which are arranged in a transfer direction of a steel sheet and are able to move
in the transfer direction of the steel sheet are provided. When a transfer velocity of
the steel sheet at the time of forming laser irradiation lines using the single laser beam
irradiation device is defined as a reference transfer velocity VLo, in a case where the n
laser beam irradiation devices are used, irradiation of a laser beam is performed after
»
controlling a movement direction and a movement velocity VS of the laser beam
irradiation device so that a relative velocity VA between a transfer velocity VL of the
steel sheet and the movement velocity VS of the laser beam irradiation device in the
transfer direction becomes VA=nxVLo.
[0018]
In this case, the relative velocity VA between the steel sheet and the laser
beam irradiation device is obtained by multiplying the number n of laser beam
irradiation devices used and the reference transfer velocity VLQ. Therefore, in each of
the laser beam irradiation devices, irradiation of the laser beam can be performed under
the optimum laser irradiation conditions for the magnetic domain control at the
reference transfer velocity VLQ.
[Effects of the Invention]
[0019]
According to the present invention, even in a case where the transfer velocity
of the steel sheet at the laser irradiation position is changed, irradiation of the laser
beam can be stably performed.
[Brief Description of the Drawings]
[0020]
FIG. 1 is an explanatory top view of an apparatus for manufacturing a grainoriented
electrical steel sheet in an embodiment of the present invention.
FIG. 2 is an explanatory side view of the apparatus for manufacturing a grainoriented
electrical steel sheet in the embodiment of the present invention.
FIG. 3 is an explanatory schematic view of a laser beam irradiation device.
FIG. 4 is a flowchart in a case where a transfer velocity of the steel sheet is
decelerated. ..,
7 -
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FIG 5 is a graph showing changes in the transfer velocity, movement
velocities of the devices, and a relative velocity in the case where the transfer velocity
of the steel sheet is decelerated.
FIG. 6 is a flowchart in a case where the transfer velocity of the steel sheet is
accelerated.
FIG. 7 is a graph showing changes of the transfer velocity, the movement
velocities of the devices, and the relative velocity in the case where the transfer
velocity of the steel sheet is accelerated.
FIG. 8 is an explanatory top view of an apparatus for manufacturing a grainoriented
electrical steel sheet in another embodiment of the present invention.
[Embodiments of the Invention]
[0021]
An apparatus for manufacturing a grain-oriented electrical steel sheet in this
embodiment will be described using FIGS. 1 to 3.
The apparatus 10 for manufacturing the grain-oriented electrical steel sheet
4
irradiates a steel sheet 31 which is transferred in a rolling direction with a laser to
perform magnetic domain control of the steel sheet 31.
[0022]
As shown in FIGS. 1 and 2, the apparatus 10 for manufacturing a grainoriented
electrical steel sheet in this embodiment includes a support roll 11 which
supports the steel sheet 31 being transferred, a laser device 12 which emits a laser
beam, a plurality of (n) laser beam irradiation devices 20 which are arranged in a
transfer direction of the steel sheet 31, a linear motion device 15 which moves the laser
beam irradiation devices 20 in the transfer direction of the steel sheet 31, and a control
unit 18 which controls the operations of the laser beam irradiation devices 20.
•
Here, in this embodiment, as shown in FIGS. 1 and 2, four laser beam
irradiation devices 20a, 20b, 20c, and 20d are arranged in the transfer direction.
[0023]
The laser device 12 emits a laser beam that can be transmitted through fiber.
As the laser beam which can be transmitted through fiber, a YAG laser (a wavelength
of 1.06 jum), a fiber laser (a wavelength of 1.07 to 1.08 p-m), and the like may be
applied.
The laser beam emitted by the laser device 12 is transmitted to the
corresponding laser beam irradiation device 20 via a transmission fiber 13.
[0024]
As shown in FIG. 3, the laser beam irradiation device 20 includes a collimator
21, a polyhedral rotating polygon mirror 22, and an ID lens 23.
The collimator 21 adjusts the diameter of a laser beam LB which is output
from the transmission fiber 13. In addition, the rotating polygon mirror 22 deflects
the laser beam LB and scans the steel sheet 31 at a high speed in the width direction of
the steel sheet 31. The 16 lens 23 converges the laser beam LB scanned by the
rotating polygon mirror 22.
As a scanning method using a beam, there is a method using a galvano mirror.
The fiinctions of the collimator may include both functions of changing the beam
diameter and forming the beam in an elliptical shape.
[0025]
Here, by adjusting the rotational speed of the rotating polygon mirror 22, the
scanning speed of the laser beam LB on the steel sheet 31 can be adjusted.
In addition, the laser beam irradiation device 20 includes a focusing
mechanism (not illustrated) which is disposed between the rotating polygon mirror 22
and the fB lens 23, and a range finder (not illustrated) which measures the distance
between the steel sheet 31 and the fB lens 23. The distance between the fB lens 23
and the steel sheet 31 can be adjusted by the focusing mechanism.
[0026]
The linear motion device 15 includes a guide rail 16 which extends in the
transfer direction of the steel sheet 31 and a driving measure (not illustrated) for
moving the laser beam irradiation device 20 along the guide rail 16. As the driving
measure, for example, a combination of a ball screw and a rotary motor, a linear motor,
or the like may be employed.
[0027]
By the linear motion device 15, the laser beam irradiation device 20 can be
moved to an arbitrary position in the transfer direction of the steel sheet 31.
In addition, in the linear motion device 15, a movement velocity VS of the
laser beam irradiation device 20 in the transfer direction can be adjusted.
[0028]
Here, in a case where the plurality of (n) laser beam irradiation devices 20 are
used, an interval D(m) between an irradiation position of the laser beam irradiation
device 20 positioned at the rearmost side in the transfer direction among the laser beam
irradiation devices 20 used and an irradiation position of the m-th laser beam
irradiation device 20 positioned in front thereof in the transfer direction is adjusted to
satisfy the following relationship.
D(m)=nxh(m)xPL+qxPL...(l)
where m is an integer that satisfies 2 VL=4xVLo
n=4

Laser output P P=Po
Scanning speed VC VC=VCo
Irradiation frequency f f=fo
Converged shape dlxdc dlxdc=DLoxDCo
«
Laser irradiation line pitch PL PL=PLo
[0037]
In addition, during welding at the time of switching between the coils of the
steel sheet 31, irradiation of the laser beam is performed under the following quasisteady
condition.
VL=VLo
n=l

Laser output P P=Po
Scanning speed VC VC=VCo
- 14 -
#
Irradiation frequency f f=fo
Converged shape dlxdc dlxdc=DLoxDCo
Laser irradiation line pitch PL PL=PLo
[0038]
As described above, the transfer velocity VL and the number n of the laser
beam irradiation devices 20 used are different between the steady condition and the
unsteady condition, but the laser irradiation conditions are the same.
[0039]
First, a case where velocity is decelerated from the steady condition to the
quasi-steady condition will be described using the flowchart of FIG. 4 and the graph of
FIG. 5.
In the steady condition, the transfer velocity VL of the steel sheet 31 is
VL=4xVLo, and the laser irradiation lines 32 are formed at a pitch of PL=4 mm by
using the four laser beam irradiation devices 20a, 20b, 20c, and 20d.
[0040]
The transfer velocity VL is decelerated and becomes VL<4xVLo. Here, the
control unit 18 detects the transfer velocity VL, calculates the movement velocity VS
of the laser beam irradiation device 20, and gives the instruction to the linear motion
device 15. According to the instruction from the control unit 18, the linear motion
device 15 moves the four laser beam irradiation devices 20a, 20b, 20c, and 20d used
rearward in the transfer direction at the movement velocity VS. At this time, the laser
beam irradiation devices 20a, 20b, 20c, and 20d are moved while the intervals
therebetween are maintained. Thereby, the relative velocity between the steel sheet
31 and the laser beam irradiation device 20 is set to 4xVLo, and irradiation of the laser
is performed. At this time, the laser irradiation conditions are the same both in the
- 15 -
#
steady condition and the quasi-steady condition.
[0041]
In addition, when the transfer velocity VL becomes VL=3xVLo, the laser
beam irradiation device 20a on the rear side in the transfer direction is paused, and the
laser irradiation lines 32 are formed at an interval of PL=4 mm by using the three laser
beam irradiation devices 20b, 20c, and 20d. In addition, the interval between the
laser beam irradiation devices 20b, 20c, and 20d at this time is set by the above
expression (1). The laser irradiation conditions at this time are the same both in the
steady condition and the quasi-steady condition.
[0042]
Furthermore, the transfer velocity VL is decelerated and becomes VL<3xVLo.
According to the instruction from the control unit 18, the linear motion device 15
moves the three laser beam irradiation devices 20b, 20c, and 20d used rearward in the
transfer direction at the movement velocity VS. At this time, the laser beam
irradiation devices 20b, 20c, and 20d are moved while the intervals therebetween are
f
maintained. Thereby, the relative velocity between the steel sheet 31 and the laser
irradiation device 20 is set to 3xVLo, and irradiation of the laser is performed. At this
time, the laser irradiation conditions are the same both in the steady condition and the
quasi-steady condition.
[0043]
In addition, when the transfer velocity VL becomes VL=2xVLo, the laser
beam irradiation device 20b on the rear side in the transfer direction is paused, and the
laser irradiation lines 32 are formed at an interval of PL-4 mm by using the two laser
beam irradiation devices 20c and 20d. The laser irradiation conditions at this time are
the same both in the steady condition and the quasi-steady condition. . -
- 16 -
#
[0044]
Furthermore, the transfer velocity VL is decelerated and becomes VL<2xVLo.
According to the instruction from the control unit 18, the linear motion device 15
moves the two laser beam irradiation devices 20c and 20d used rearward in the transfer
direction at the movement velocity VS. Thereby, the relative velocity between the
steel sheet 31 and the laser irradiation device 20 is set to 2xVLo, and irradiation of the
laser is performed. At this time, the laser irradiation conditions are the same both in
the steady condition and the quasi-steady condition.
[0045]
In addition, when the transfer velocity VL becomes VL=VLo, the laser beam
irradiation device 20c on the rear side in the transfer direction is paused, the laser
irradiation lines 32 are formed at an interval of PL=4 mm by using the one laser beam
irradiation device 20d.
In this manner, without changing the laser irradiation conditions, the transfer
velocity VL is decelerated from 4xVLo in the steady condition to VLo in the quasii
steady condition.
During the operation under the quasi-steady condition, the operation of
welding the coils of the steel sheet 31 is performed.
[0046]
Next, when welding of the coils of the steel sheet 31 is completed, the transfer
velocity VL is accelerated from the quasi-steady condition to the steady condition. A
case where the velocity is accelerated from the quasi-steady condition to the steady
condition will be described using the flowchart of FIG. 6 and the graph of FIG. 7.
[0047]
The transfer velocity VL is accelerated and becomes VL>VLo. Here, the
- 17 -
control unit 18 detects the transfer velocity VL, calculates the movement velocity VS
of the laser beam irradiation device 20, and gives the mstruction to the linear motion
device 15. According to the instruction from the control unit 18, the linear motion
device 15 moves the laser beam irradiation device 20d used forward in the transfer
direction at the movement velocity VS, and the laser irradiation is performed at a
relative velocity between the steel sheet 31 and the laser irradiation device 20 of VLQ.
At this time, the laser irradiation conditions are the same both in the steady condition
and the quasi-steady condition.
[0048]
In addition, when the transfer velocity VL becomes VL=2xVLo, the next laser
beam irradiation device 20c is started, and the laser irradiation lines 32 are formed at
an interval of PL=4 mm by using the two laser beam irradiation devices 20c and 20d.
In addition, the interval between the laser beam irradiation devices 20c and 20d at this
time is set by the above expression (1). In addition, the laser irradiation conditions
are the same both in the steady condition and the quasi-steady condition.
[0049]
Furthermore, the transfer velocity VL is accelerated and becomes VL>2xVLo.
According to the instruction from the control unit 18, the linear motion device 15
moves the two laser beam irradiation devices 20c and 20d used forward in the transfer
direction at the movement velocity VS. At this time, the laser beam irradiation
devices 20c and 20d are moved while the intervals therebetween are maintained.
Thereby, the relative velocity between the steel sheet 31 and the laser irradiation
devices 20c and 20d is set to 2xVLo, and irradiation of the laser is performed. In
addition, the laser irradiation conditions are the same both in the steady condition and
the quasi-steady condition.
#
[0050]
In addition, when the transfer velocity VL becomes VL=3xVLo, the next laser
beam irradiation device 20b is started, and the laser irradiation lines 32 are formed at
an interval of PL=4 mm by using the three laser beam irradiation devices 20b, 20c, and
20d. The interval between the laser beam irradiation devices 20b, 20c, and 20d at this
time is set by the above expression (1). In addition, the laser irradiation conditions
are the same both in the steady condition and the quasi-steady condition.
[0051]
Furthermore, the transfer velocity VL is accelerated and becomes VL>3xVLo.
The laser beam irradiation devices 20b, 20c, and 20d used are moved forward in the
transfer direction at the movement velocity VS. At this time, the laser beam
irradiation devices 20b, 20c, and 20d are moved while the intervals therebetween are
maintained. Thereby, the relative velocity between the steel sheet 31 and the laser
irradiation devices 20b, 20c, and 20d is set to 3xVLo, and irradiation of the laser is
performed. In addition, the laser irradiation conditions are the same both in the
steady condition and the quasi-steady condition.
[0052]
In addition, when the transfer velocity VL becomes VL=4xVLo, the next laser
beam irradiation device 20a is started, the laser irradiation lines 32 are formed at an
interval of PL=4 mm by using the three laser beam irradiation devices 20a, 20b, 20c,
and 20d.
In this manner, without changing the laser irradiation conditions, the transfer
velocity VL is accelerated from VLo in the quasi-steady condition to 4xVLo in the
steady condition.
[0053]
- 19 -
In the apparatus 10 for manufacturing the grain-oriented electrical steel sheet
having the above configuration in this embodiment, by the plurality of laser beam
irradiation devices 20 arranged in the transfer direction, the laser irradiation lines 32
can be formed by performing irradiation of the laser beams at a plurality of points in
the transfer direction of the steel sheet 31 simultaneously. In addition, since the linear
motion devices 15 which move the laser beam irradiation devices 20 along the transfer
direction is provided, the intervals D(m) between the laser beam irradiation devices 20
in the transfer direction can be adjusted. Accordingly, even in a case where the
transfer velocity VL of the steel sheet 31 is changed, the laser irradiation lines 32 can
be formed at a predetermined pitch PL.
[0054]
In addition, since the apparatus 10 for manufacturing the grain-oriented
electrical steel sheet in this embodiment includes the control unit 18 which adjusts the
movement velocity VS of the laser beam irradiation device 20 according to the transfer
velocity VL of the steel sheet 31 and maintains the relative velocity VA between the
steel sheet 31 and the laser beam irradiation device 20 at a constant level, the laser
irradiation lines 32 can be formed at the predetermined pitch PL by performing laser
irradiation in a state where the laser beam irradiation devices 20 are moved without
changing the optimum laser irradiation conditions.
[0055]
Moreover, in this embodiment, in the case where the n laser beam irradiation
devices 20 are used, irradiation of the laser beam is perfonned after controlling the
movement direction and the movement velocity VS of the laser beam irradiation
device 20 so that the relative velocity VA between the transfer velocity VL of the steel
sheet 31 and the movement velocity VS of the laser beam irradiation device 20 in the
- 20 -
transfer direction becomes VA=nxVLo. Accordingly, even when the transfer velocity
VL of the steel sheet 31 is changed, the laser irradiation lines 32 can be formed at the
predetermined pitch PL without changing the optimum laser irradiation conditions of
each of the laser beam irradiation devices 20.
[0056]
While the embodiments of the present invention have been described above,
the present invention is not limited thereto and can be appropriately modified without
departing from the technical idea of the present invention.
For example, in the description, a laser beam which can be transmitted
through fiber is used. However, the present invention is not limited thereto, and a
carbon dioxide laser or the like may also be used. In this case, the laser device is
disposed in each of the laser beam irradiation devices.
In addition, in the description, the laser beam is transmitted through fiber from
the single laser device to the four laser irradiation devices. However, the present
invention is not limited thereto, and two or more laser devices may be used.
[0057]
In addition, in the description, the laser beam irradiation device is moved in
the transfer direction by using the linear motion device. However, the present
invention is not limited thereto, and the laser beam irradiation device may be moved in
the transfer direction by other movement mechanisms.
Furthermore, in a case where the width of the steel sheet is large, as shown in
FIG. 8, the plurality of laser beam irradiation devices may be arranged in the width
direction.
[Industrial Applicability]
[0058]
- 21 -
i
According to the present invention, it is possible to provide the apparatus for
manufacturing a grain-oriented electrical steel sheet and the method of manufacturing
the same, which are capable of forming the laser irradiation lines at the predetermined
pitch without changing the optimum laser irradiation condition of each of the laser
beam irradiation devices even in the case where the transfer velocity of the steel sheet
is changed,.
[Reference Number]
[0059]
10: METHOD OF MANUFACTURING GRAIN-ORIENTED ELECTRICAL
STEEL SHEET
15: LINEAR MOTION DEVICE (TRANSFER-DIRECTION MOVEMENT
MECHANISM)
18: CONTROL UNIT
20: LASER BEAM IRRADIATION DEVICE
31: STEEL SHEET
32: LASER IRRADIATION LINE
22

ORIGINAL
1 1 NOV 7fm i 96 76^13] Pocument Type] CLAIMS
[Claim 1]
An apparatus for manufacturing a grain-oriented electrical steel sheet in which
a magnetic domain is controlled by irradiating a laser beam, the apparatus comprising:
a plurality of laser beam irradiation devices which are arranged in a transfer
direction of a steel sheet; and
a transfer-direction movement mechanism which moves the laser beam
irradiation devices in the transfer direction of the steel sheet.
[Claim 2]
The apparatus for manufacturing a grain-oriented electrical steel sheet
according to claim 1, further comprising:
a control unit which adjusts a movement velocity of each of the laser beam
irradiation devices according to a transfer velocity of the steel sheet and maintains a
relative velocity between the steel sheet and the laser beam irradiation device at a
constant level.
[Claim 3]
The apparatus for manufacturing a grain-oriented electrical steel sheet
according to claim 2,
wherein, when the transfer velocity of the steel sheet at a time of forming
laser irradiation lines using the single laser beam irradiation device is defined as a
reference transfer velocity VLo,
in a case where the n laser beam irradiation devices are used, the control unit
allows an irradiation of a laser beam to be performed after controlling a movement
direction and a movement velocity VS of the laser beam irradiation device so that a
relative velocity VA between a transfer velocity VL of the steel sheet and the,
- 23 -
ORIGINAL
movement velocity-VS of the laser beam irradiation device in the transfer direction
becomes yA=nxVLo. .. •
ta^-"! 11 NOV 2013
Amethodof manufacturing a grain-oriented electrical steel sheet .in which a '
magnetic domain is controlled by ia'adiating of a laser beam, -.
- wherein a plurahty of laser beam irradiation devices which are arranged in a
" transfer dhectibn of a steel sheet and are able to move in" ttie transfer direction of the
-steel sheet are provided, and"~^'-~^-^-'^"~~""~''''"'^'-'^^^"•^^'' ' '^ " --_-
when a transfer velocity of the steel sheet at the time of forming laser
irradiation lines using the single laser beam irradiation device is defined as a reference
' transfer velocity VLo,
in a case where the n laser beam irradiation devices are used, irradiation of a
laser beam is performed after controlling a movement drrection and a movement
velocity VS of the laser beam irradiation device so that a relative-velocity V i between
a transfer velocity VL of the steel sheet and the movement velocity VS of the laser
beam irradiation device in the transfer direction becomes VA=nxVLo.