CLEAR VERSION
【CLAIMS】
【Claim 1】
A method for refining a magnetic domain of a grain-oriented electrical steel
strip, comprising
5 a steel strip supporting roll position adjusting step of controlling a position of
the steel strip in a vertical direction while supporting the steel strip proceeding along a production line, a laser irradiating step of forming a groove on a surface of the steel strip by irradiating a laser beam onto the surface of the steel strip to melt the steel strip, and a detecting step of detecting a defect in the groove formed on the surface of the 10 steel strip while the steel strip proceeds.
【Claim 2】
The method for refining the magnetic domain of the grain-oriented electrical
steel strip, further comprising
15 a correcting step of adjusting a laser focal point position of the steel strip
according to a result measured in the detecting step.
【Claim 3】
The method for refining the magnetic domain of the grain-oriented electrical 20 steel strip of claim 2, wherein
the correcting step includes a step of setting a depth of the groove of a steady state as a reference value, a calculating step of comparing a detected depth of the groove with the reference value, and a position adjusting step of adjusting a position of the steel strip supporting roll or a position of a condensing mirror in accordance with a depth 25 deviation of the groove detected in the calculating step to adjust a focus position with respect to the steel strip.
【Claim 4】
The method for refining the magnetic domain of the grain-oriented electrical 30 steel strip of claim 3, wherein
the position adjusting step includes a first adjusting step of adjusting the
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position of the steel strip supporting roll or the position of the condensing mirror by a predetermined value in one of up and down directions when a deviation between a depth of an actual groove and the reference value is 2 μm or more, an additional adjusting step of comparing and calculating a depth of the groove detected after the first adjusting and 5 the reference value and then further adjusting the position of the steel strip supporting roll or the position of the condensing mirror by a predetermined value in the same direction as in the first adjusting when the calculated deviation is less than 2 μm and equal to or greater than 1 μm, a reverse adjusting step of adjusting the position of the steel strip supporting roll or the position of the condensing mirror by a predetermined
10 value in a direction that is opposite to the first adjusting when the depth of the groove detected after the first adjusting is compared and calculated with the reference value to determine that the calculated deviation is 2 μm or more, and an additional reverse adjusting step of comparing and calculating the depth of the groove detected after the reverse adjusting and the reference value and then adjusting the position of the steel
15 strip supporting roll or the position of the condensing mirror by a predetermined value in the same direction as in the reverse adjusting when the calculated depth deviation is less than 2 μm and equal to or greater than 1 μm.
[Claim 5]
20 The method for refining the magnetic domain of the grain-oriented electrical steel strip of claim 2, wherein
the correcting step further includes an initial position setting step of setting the positions of the steel strip supporting roll and the condensing mirror in an initial process. 25
[Claim 6]
The method for refining the magnetic domain of the grain-oriented electrical steel strip of claim 5, wherein
the initial position setting step includes a step of changing the position of the
30 steel strip supporting roll according to a set time interval, a step of detecting a depth
change of the groove according to a position change of the steel strip supporting roll, a
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CLEAR VERSION
step of detecting the position of the steel strip supporting roll, a step of calculating the position of the steel strip supporting roll when the depth of the groove is the deepest through the position of the steel strip supporting roll and depth data of the groove corresponding to the position of the steel strip supporting roll, and a step of adjusting 5 the position of the steel strip supporting roll or the condensing mirror irradiating a laser according to the calculated value.
【Claim 7】
The method for refining the magnetic domain of the grain-oriented electrical 10 steel strip of any one of claim 1 to claim 6, wherein
in the detecting step, the groove of the steel strip is measured by a leakage magnetic flux measuring method.
【Claim 8】
15 The method for refining the magnetic domain of the grain-oriented electrical
steel strip of claim 7, wherein
the detecting step includes a step of magnetizing the surface of the steel strip by applying a magnetic force thereto, a step of detecting a leakage magnetic flux formed by the groove, and a step of confirming a defect in the groove by calculating the detected
20 leakage magnetic flux.
【Claim 9】
The method for refining the magnetic domain of the grain-oriented electrical steel strip of claim 7, wherein
25 in the laser irradiating step, regarding the surface of the steel strip that proceeds
while contacting a surface of the steel strip supporting roll in a form of a circular arc, a laser beam is irradiated from a reference point which is a laser beam irradiation position set when an irradiation direction of a laser beam passes a central axis of the steel strip supporting roll to a position spaced apart from a center of the steel strip supporting roll
30 by a predetermined angle along an outer circumferential surface.
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CLEAR VERSION
【Claim 10】
The method for refining the magnetic domain of the grain-oriented electrical steel strip of claim 9, wherein
in the laser irradiating step, the laser beam is irradiated in a range spaced apart 5 from the reference point by 3 to 7 degrees along the outer circumferential surface thereof from the center of the steel strip supporting roll.
【Claim 11】
The method for refining the magnetic domain of the grain-oriented electrical 10 steel strip of claim 7, wherein
the laser irradiating step further includes an angle changing step of changing an angle of an irradiation line of the laser beam irradiated on the surface of the steel strip.
【Claim 12】
15 The method for refining the magnetic domain of the grain-oriented electrical
steel strip of claim 11, wherein
in the angle changing step, the angle of the irradiation line of the laser beam is changed to a range of ±4 degrees with respect to a width direction of the steel strip.
20 【Claim 13】
An apparatus for refining a magnetic domain of a grain-oriented electrical steel strip, comprising
steel strip supporting roll position adjusting equipment that controls a position of a steel strip in up and down directions while supporting the steel strip moving along a
25 production line, laser irradiating equipment that irradiates a laser beam on the steel strip to melt it to form a groove thereon, and a detector that detects whether or not the groove is defective by checking a state of the groove formed on the surface of the steel strip.
【Claim 14】
30 The apparatus for refining the magnetic domain of the grain-oriented electrical
steel strip of claim 13, wherein
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a corrector that adjusts a laser focal point position of the steel strip according to a result measured by the detector is included.
【Claim 15】
5 The apparatus for refining the magnetic domain of the grain-oriented electrical
steel strip of claim 14, wherein
the steel strip supporting roll position adjusting equipment includes a steel strip supporting roll position control system that controls the position of the steel strip supporting roll, which supports the steel strip, according to a laser irradiation position of 10 the laser irradiating equipment, and
the corrector is connected to the steel strip supporting roll position control system and controls the steel strip supporting roll position control system according to a signal of the detector.
15 【Claim 16】
The apparatus for refining the magnetic domain of the grain-oriented electrical steel strip of claim 13, wherein
regarding the surface of the steel strip that proceeds while contacting a surface of the steel strip supporting roll in a form of a circular arc, the laser irradiating
20 equipment irradiates a laser beam from a reference point which is a laser beam irradiation position set when an irradiation structure direction of a laser beam passes a central axis of the steel strip supporting roll, to a position spaced apart from a center of the steel strip supporting roll by a predetermined angle along an outer circumferential surface.
25
【Claim 17】
The apparatus for refining the magnetic domain of the grain-oriented electrical steel strip of claim 13, wherein
an optical system of the laser irradiating equipment has a structure that is 30 rotatable by a driver and rotates with respect to the steel strip to change the angle of the irradiation line of the laser beam with respect to a width direction of the steel strip.
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CLEAR VERSION
【Claim 18】
The apparatus for refining the magnetic domain of the grain-oriented electrical
steel strip of any one of claim 13 to claim 17, wherein
5 the detector includes: a non-conductive roll supporting a moving steel strip;
a leakage flux measurer including a magnetizer that applies a magnetic force to
the surface of the steel strip passing through the non-conductive roll to magnetize the
surface of the steel strip, and a magnetic sensor that is spaced apart from the steel strip
and measures a leakage magnetic field of the groove formed in the steel strip; and
10 a controller that calculates an output signal of the magnetic sensor to check
whether the groove is defective.
【Claim 19】
The apparatus for refining the magnetic domain of the grain-oriented electrical 15 steel strip of claim 18, wherein
the controller includes a signal changer that changes the leakage magnetic field
signal detected by the magnetic sensor to a groove size signal, and a calculator that
compares and calculates a groove size reference value that is preset in a steady state and
an actual groove size value outputted from the signal changer to determine whether the
20 groove is defective.
【Claim 20】
The apparatus for refining the magnetic domain of the grain-oriented electrical
steel strip of claim 19, wherein
25 the calculator compares the preset steady state groove size reference value and
the actual groove size value outputted from the signal changer to determine whether the groove is defective.
【Claim 21】
30 The apparatus for refining the magnetic domain of the grain-oriented electrical
steel strip of claim 19, wherein
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the controller further includes an equipment controller that controls driving of the equipment in accordance with an output signal of the calculator.
【Claim 22】
5 The apparatus for refining the magnetic domain of the grain-oriented electrical
steel strip of claim 18, wherein

the detector further includes a driver that adjusts an interval between the leakage magnetic flux measurer and the steel strip.
10 Dated this day of 28th June 2019
GOPINATH A. S.
INPA-1852
AGENT FOR THE APPLICANT
15
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