KR102427574B1 - Method and apparatus for refining magnetic domains grain-oriented electrical steel - Google Patents

Abstract

By optimizing equipment and processes, this can increase the efficiency of magnetic domain refinement and improve workability to increase processing capacity. A steel plate support roll position adjustment step of controlling the vertical position of the steel plate while supporting the steel plate progressing along the production line, a laser irradiation step of irradiating a laser beam to the surface of the steel plate to melt the steel plate to form a groove on the surface of the steel plate And when the laser beam irradiated in the width direction of the steel sheet in the laser irradiation step is irradiated to the surface of the steel sheet support roll supporting the steel sheet beyond the side end of the steel sheet, a protection step for protecting the surface of the steel sheet support roll from the laser beam grain-oriented electrical steel sheet It provides a magnetic domain refining method of

Description

Magnetic domain refining method of grain-oriented electrical steel sheet and apparatus thereof

It relates to a magnetic domain refining method and apparatus for grain-oriented electrical steel sheet for permanently refining the magnetic domain of the grain-oriented electrical steel sheet by irradiating the laser.

For example, in order to reduce power loss of electric devices such as transformers and improve efficiency, a grain-oriented electrical steel sheet having low iron loss and high magnetic flux density is required.

In order to reduce the iron loss of the grain-oriented electrical steel sheet, a technique for reducing the iron loss by irradiating a mechanical method or a laser beam to the surface of the steel sheet to refine the magnetic domain in the direction perpendicular to the rolling direction is disclosed.

The magnetic domain refining method can be broadly divided into temporary domain refining and permanent domain refining depending on whether the improvement effect of domain refining is maintained after stress relief annealing.

The temporary domain refining method has a disadvantage in that the domain refining effect is lost after stress relief annealing. The temporary domain refining method refines the magnetic domain by forming a local compressive stress portion on the surface of the steel sheet. However, this method requires re-coating because it causes damage to the insulating coating layer on the surface of the steel sheet, and has a disadvantage in that the manufacturing cost is high because domain refining is performed in the intermediate process rather than the final product.

The permanent magnetic domain refining method can maintain the iron loss improvement effect even after heat treatment. For the permanent domain refining treatment, a technique using an etching method, a roll method, or a laser method is mainly used. In the case of the etching method, it is difficult to control the depth or width of the groove formation, it is difficult to guarantee the iron loss characteristics of the final product, and it is not environmentally friendly because it uses an acid solution. In the case of a method using a roll, there are disadvantages in stability, reliability, and process complexity for machining.

In the method of permanent magnetic domain refining of a steel sheet using a laser, a laser beam is irradiated to the surface of the steel sheet in a state in which the steel sheet is supported and the tension is adjusted to form a molten groove in the steel sheet surface to refine the magnetic domain. As such, in refining the magnetic domain using a laser, it is required to improve and optimize a more effective process so that high-speed processing is possible, and the iron loss of the electrical steel sheet can be lowered and the magnetic flux density can be increased.

Provided are a magnetic domain refining method of a grain-oriented electrical steel sheet capable of preventing damage to a steel sheet support roll by a laser beam irradiated outside the steel sheet, and an apparatus therefor.

In addition, by optimizing equipment and processes, thereby improving the magnetic domain refining efficiency and improving workability to increase the processing capacity, it provides a magnetic domain refining method and apparatus for grain-oriented electrical steel sheet.

Provided are a magnetic domain refining method and apparatus for grain-oriented electrical steel sheet that can improve product quality by more effectively removing contaminants such as healing and spatter formed by laser irradiation.

Provided are a magnetic domain refining method and apparatus for grain-oriented electrical steel sheet capable of providing an optimal operating environment required for the process.

The magnetic domain refining method of this embodiment includes a steel plate support roll position adjustment step of controlling the vertical position of the steel plate while supporting the steel plate progressing along a production line, irradiating a laser beam to the surface of the steel plate to melt the steel plate to melt the surface of the steel plate When the laser beam irradiated in the width direction of the steel plate during the laser irradiation step of forming a groove in the A protective step may be included.

The protecting step may include blocking the laser beam irradiated to the surface of the steel sheet support roll exposed under the steel sheet through the blocking plates disposed at both ends of the steel sheet support roll.

The protection step includes the steps of detecting a meandering of the steel sheet progressing along the steel sheet support roll, calculating the moving amount of the blocking plate according to the meandering amount of the steel sheet detected in the meandering detecting step, according to the value calculated in the calculation step The step of moving the blocking plate along the axial direction of the steel plate support roll may include covering the surface of the steel plate support roll exposed from the steel plate with the blocking plate.

The protecting step may include reflecting a laser beam from the surface of the steel sheet support roll.

The protection step may include a reflection step of changing the irradiation angle of the laser beam irradiated to the steel sheet support roll outside the width direction side end of the steel sheet.

The protecting step may further include moving the laser beam reflection position according to the width of the steel sheet.

In the laser irradiation step, the laser beam irradiation position when the irradiation direction of the laser beam passes through the central axis of the steel plate support roll for the surface of the steel plate progressing in contact with the surface of the steel plate support roll in an arc shape as a reference point, the steel plate at the reference point A laser beam may be irradiated to a position spaced apart at an angle along the outer circumferential surface from the center of the support roll.

In the laser irradiation step, the laser beam may be irradiated in a range of 3 to 7° apart along the outer circumferential surface from the center of the steel sheet support roll with respect to the reference point.

The magnetic domain refinement method may further include a setting maintenance step of setting and maintaining an internal operating environment of a laser room in which laser irradiation is performed.

The magnetic domain refining method may further include a tension control step of applying a tension to the steel plate so that the steel plate is maintained in a flat unfolded state.

The magnetic domain refining method may further include a meandering control step of allowing the steel sheet to move without bias from side to side along the center of the production line.

The setting maintenance step may include isolating the inside of the laser room from the outside to block the inflow of external contaminants, and controlling the inside temperature, pressure and humidity of the laser room.

The magnetic domain refining method may further include a post-treatment step for removing the hill-up and spatter formed on the surface of the steel sheet through the laser irradiation step.

The post-treatment step may include a brush step of removing the heel-up and spatter on the surface of the steel sheet with a brush roll.

The post-treatment step includes a cleaning step of further removing heal-up and spatter remaining on the steel sheet surface by electrolytically reacting the steel sheet with an alkali solution, and filtering foreign substances contained in the alkali solution removed from the steel sheet in the cleaning step from the alkali solution It may further include a filtering step for betting.

The meander control step includes a meander amount measurement step of measuring the amount of meander in which the central position of the width of the steel sheet deviates from the center of the production line, and the axis of the steering roll according to the meander amount of the steel sheet measured in the meander amount measurement step. It may include a meandering amount control step of controlling the meandering amount of the steel plate by rotating and moving it to adjust the direction in which the steel plate moves.

The meandering amount control step may control the meandering amount of the steel sheet within ±1mm.

The tension control step includes a steel sheet tension application step of applying tension to the steel sheet by the tension bridle roll, a steel sheet tension measurement step for measuring the tension of the steel sheet subjected to the steel sheet tension application step, and It may include a steel plate tension control step of controlling the steel plate tension by adjusting the speed of the tension bridle roll according to the tension of the steel plate measured in the steel plate tension measurement step.

The steel plate support roll position adjustment step includes a steel plate support step of supporting the steel plate positioned in the laser irradiation step with a steel plate support roll, a luminance measurement step of measuring the brightness of a flame generated when the laser is irradiated to the steel plate in the laser irradiation step, and A steel plate support roll position control step of controlling the position of the steel plate support roll to be located within the depth of focus of the laser by adjusting the position of the steel plate support roll by the steel plate support roll position control system according to the brightness of the flame measured in the luminance measuring step. may include

In the laser irradiation step, the upper width, lower width and depth of the steel sheet are irradiated on the surface of the steel sheet by an optical system receiving the laser beam irradiated from the laser oscillator to form grooves of 70 μm or less, 10 μm or less, and 3 to 30 μm, respectively. At the same time, the laser beam irradiation and energy transfer step of delivering the laser beam energy density within the range of 1.0 to 5.0 J/mm² necessary for melting the steel sheet to the steel sheet so that the re-solidified portion remaining on the inner wall of the groove of the molten portion is generated when irradiating the laser beam to the steel sheet. can

In the laser irradiation step, the laser oscillator controller turns on the laser oscillator that oscillates the laser beam under normal working conditions and controls the laser oscillator to the off state when the meandering amount of the steel sheet is 15 mm or more. It may include a beam oscillation control step.

In the laser irradiation step, the laser oscillator may oscillate a single mode continuous wave laser beam.

In the laser irradiation step, the optical system may control the laser scanning speed to adjust the distance between the laser beam irradiation lines to 2 to 30 mm in the rolling direction.

The laser irradiation step may further include an angle conversion step of converting an irradiation line angle of a laser beam irradiated to the surface of the steel sheet.

The angle conversion step may convert the irradiation angle of the laser beam in the range of ±4° with respect to the width direction of the steel sheet.

The laser irradiation step may further include a dust collecting step of sucking and removing fumes and molten iron generated during laser beam irradiation. The dust collecting step may include a spraying step for removing the molten iron remaining in the groove by spraying compressed dry air into the groove of the steel sheet.

The laser irradiation step may further include a blocking step of blocking the scattered light and heat of the laser beam from flowing into the optical system of the laser irradiation facility.

The magnetic domain refining apparatus of this embodiment includes a steel plate support roll position adjusting device that controls the vertical position of the steel plate while supporting the steel plate moving along the production line, and melts the steel plate by irradiating a laser beam to form a groove on the surface of the steel plate It may include a laser irradiation facility to form, and a protection unit for protecting the surface of the steel plate support roll from the laser beam irradiated to the surface of the steel plate support roll supporting the steel plate out of the side end of the steel plate along the width direction.

The protection unit may include a blocking plate disposed at both ends of the steel plate support roll and blocking the laser beam by covering the surface of the steel plate support roll exposed under the steel plate.

The protection unit includes a steel plate detector for detecting meandering of the steel plate passing through the steel plate support roll, a movement amount calculator for calculating the movement amount of the blocking plate according to the detection signal of the steel plate detector, and the axis of the steel plate support roll according to the output signal of the movement amount calculator It may further include a moving part for moving the blocking plate along the direction.

The protection unit may include a coating layer made of a copper material coated to reflect the laser beam on the surface of the steel sheet support roll.

The protection unit is installed in the lower part of the optical system of the laser irradiation facility at a position corresponding to the surface of the steel plate support roll exposed through both ends in the width direction of the steel plate and reflects the laser beam irradiated from the optical system to the steel plate support roll. It may include a reflecting member. .

The protection part may further include a cover amount adjusting part for moving the reflective member along the axial direction of the steel plate support roll according to the width of the steel plate.

The laser irradiation facility is a reference point to the laser beam irradiation position when the irradiation direction of the laser beam passes through the central axis of the steel plate support roll for the surface of the steel plate progressing in contact with the surface of the steel plate support roll in an arc shape, and the steel plate at the reference point It may have a structure in which a laser beam is irradiated to positions spaced apart at an angle along the outer circumferential surface from the center of the support roll.

The laser irradiation facility may have a structure for irradiating a laser beam in a range spaced apart from the center of the steel plate support roll by 3 to 7° along the outer circumferential surface with respect to the reference point.

It may further include a laser room for accommodating the steel plate support roll position adjusting equipment and the laser irradiation equipment in isolation from the outside and providing an operating environment for laser irradiation.

It may further include a tension control device for imparting tension to the steel plate to be maintained in a flat unfolded state.

It may further include a meandering control device for allowing the steel sheet to move without bias from side to side along the center of the production line.

The laser room forms an inner space to accommodate the laser irradiation equipment and the steel plate support roll position control equipment to isolate it from the outside, and an inlet and an outlet are formed on both sides along the moving direction of the steel plate, and inside the laser room It may include a positive pressure device for increasing the pressure from the outside, an optical system lower frame that separates the upper space where the optical system of the laser irradiation facility is located from the lower space through which the steel plate passes, and a constant temperature and humidity controller for controlling the temperature and humidity inside the laser room.

It may further include a post-treatment facility for removing the hill up (hill up) and spatter (spatter) formed on the surface of the steel sheet.

The post-treatment facility may include a brush roll disposed at the rear end of the laser room to remove heal-up and spatter on the surface of the steel sheet.

The post-treatment facility is disposed at the rear end of the brush roll and electrolytically reacts the steel sheet with an alkali solution to further remove heal-up and spatter remaining on the surface of the steel sheet, and is connected to the clean unit and contained in the alkali solution of the clean unit. It may further include a filtering unit for filtering out foreign substances from the alkaline solution.

The meander control facility includes a steering roll for changing the moving direction of the steel sheet, a meander measuring sensor for measuring the degree (a meandering amount) of the central position of the width of the steel sheet deviating from the center of the production line, and the meander measurement It may include a strip center position control system (Strip Center Position Control System) for adjusting the direction in which the steel plate moves by rotating and moving the shaft of the steering roll according to the output value of the sensor.

The tension control device includes a tension bridle roll for inducing movement while applying tension to the steel plate, a steel plate tension measuring sensor for measuring the tension of the steel plate passing through the tension bridle roll, and the steel plate It may include a strip tension control system for adjusting the speed of the tension bridle roll according to the tension of the steel plate measured by the tension measuring sensor.

The steel plate support roll position adjusting device includes a steel plate support roll for supporting the steel plate at the laser irradiation device position, a luminance measuring sensor for measuring the brightness of a flame generated when laser irradiation is performed on the steel plate in the laser irradiation device, and the luminance measurement It may include a steel plate support roll position control system for controlling the position of the steel plate support roll according to the brightness of the flame measured by the sensor.

The laser irradiation facility includes a laser oscillator for oscillating a continuous wave laser beam, and by irradiating the laser beam oscillated from the laser oscillator on the surface of the steel sheet, the upper width, lower width and depth are respectively within 70 μm, within 10 μm, 3 to An optical system that delivers the laser energy density within the range of 1.0 to 5.0 J/mm² required for melting the steel sheet to the steel sheet so that a 30 μm groove is formed and a re-solidified portion remaining on the inner wall surface of the groove of the molten portion is generated during laser irradiation. can

The laser irradiation equipment may further include a laser oscillator controller that turns on the laser oscillator under normal working conditions and controls the laser oscillator to turn off when the steel sheet meandering amount is 15 mm or more.

The laser oscillator may oscillate a single mode continuous wave laser beam.

The optical system may control the laser scanning speed to adjust the interval of the laser irradiation line to 2 to 30 mm along the rolling direction.

The laser irradiation facility may have a structure in which an optical system for irradiating a laser beam on a steel plate is rotatable by a driving unit, and the optical system rotates with respect to the steel plate to convert the angle of irradiation of the laser beam with respect to the width direction of the steel plate.

The laser irradiation facility may further include a shielding unit for blocking the laser scattered light and heat from flowing into the optical system.

The laser irradiation facility may further include a molten iron removal facility for removing fumes and spatters generated according to laser beam irradiation on the steel sheet.

The molten iron removal equipment may include an air knife for removing the molten iron remaining in the groove by spraying compressed dry air into the groove of the steel sheet, and a dust collection hood for removing the fumes and molten iron by suction.

As described above, according to this embodiment, while the steel sheet is advanced at a high speed of 2 m/sec or more, the magnetic domain refining process by laser is stably performed to improve the iron loss improvement rate before and after heat treatment of the electrical steel sheet by 5% or more, 10%, respectively more can be obtained.

In addition, by preventing the laser beam from being irradiated to the surface of the steel plate support roll regardless of the width of the steel plate or the meandering of the steel plate with respect to the steel plate support roll, damage to the surface of the steel plate support roll by the laser beam can be prevented.

In addition, it is possible to minimize damage during laser beam irradiation by increasing the durability of the steel plate support roll itself to the laser beam.

In addition, it is possible to increase the magnetic domain refining efficiency and improve workability to increase the magnetic domain refining processing capability.

In addition, it is possible to more effectively remove contaminants such as heal-up and spatter formed by laser irradiation, thereby improving product quality.

In addition, by providing an optimal operating environment required for the process, high-quality products can be mass-produced.

1 is a diagram schematically showing the configuration of a magnetic domain refining apparatus of a grain-oriented electrical steel sheet according to the present embodiment.
2 is a schematic view showing a steel sheet subjected to magnetic domain refinement according to the present embodiment.
3 is a schematic diagram showing the configuration of the optical system of the laser irradiation equipment according to the present embodiment.
4 and 5 are schematic views showing a first embodiment of the protection unit according to the present embodiment.
6 is a schematic diagram illustrating a second embodiment of the protection unit according to the present embodiment.
7 is a schematic diagram illustrating a third embodiment of the protection unit according to the present embodiment.

The terminology used below is for the purpose of referring to specific embodiments only, and is not intended to limit the present invention. As used herein, the singular forms also include the plural forms unless the phrases clearly indicate the opposite. The meaning of "comprising," as used herein, specifies a particular characteristic, region, integer, step, operation, element and/or component, and other specific characteristic, region, integer, step, operation, element, component, and/or group. It does not exclude the existence or addition of

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described so that those of ordinary skill in the art can easily carry out the present invention. As can be easily understood by those of ordinary skill in the art to which the present invention pertains, the embodiments described below may be modified in various forms without departing from the concept and scope of the present invention. Accordingly, the present invention may be implemented in various different forms and is not limited to the embodiments described herein.

In the following description, the present embodiment will be described as an example of the equipment for the permanent magnetic domain refinement of the grain-oriented electrical steel sheet used for the iron core material of the transformer.

1 schematically shows a magnetic domain refining apparatus of a grain-oriented electrical steel sheet according to this embodiment, and FIG. 2 shows a magnetic domain refining-treated steel sheet according to this embodiment. In the following description, the rolling direction or the moving direction of the steel sheet means the x-axis direction in FIG. 2, the width direction means the y-axis direction in FIG. 2 in a direction perpendicular to the rolling direction, and the width of the steel sheet with respect to the y-axis direction. means length. In FIG. 2 , reference numeral 31 denotes an irradiation line continuously formed on the surface of the steel sheet 1 by being dug in the form of a groove by a laser beam.

Referring to FIG. 1 , the magnetic domain refining apparatus of the grain-oriented electrical steel sheet according to this embodiment stably performs the permanent domain refining process even if the steel sheet 1 proceeds at a high speed of 2 m/s or more.

The magnetic domain refining apparatus of this embodiment includes a steel plate support roll position adjusting facility that controls the vertical position of the steel plate while supporting the steel plate 1 moving along the production line, and melts the steel plate by irradiating a laser beam to the surface of the steel plate. It may include a laser irradiation device for forming a groove, and a protection unit for protecting the surface of the steel plate support roll from the laser beam irradiated to the surface of the steel plate support roll supporting the steel plate out of the side end of the steel plate along the width direction.

In addition, the magnetic domain refining apparatus may further include a laser room 20 for accommodating the steel plate support roll position adjusting equipment and the laser irradiation equipment in isolation from the outside and providing an operating environment for laser irradiation.

In addition, the magnetic domain refining apparatus may further include a tension control device for applying tension to the steel sheet so that the steel sheet is maintained in a flat unfolded state without being sagging.

In addition, the magnetic domain refining apparatus may further include a meandering control device for allowing the steel sheet to move without bias from side to side along the center of the production line.

In addition, the magnetic domain refining apparatus may further include a post-treatment facility for removing hill-up and spatter formed on the surface of the steel sheet according to laser beam irradiation.

Hill-up refers to a portion formed by irradiating a laser beam on the surface of a steel sheet to form a groove, in which iron molten in the steel sheet is piled up at a predetermined height or more on both sides of the groove portion. Spatter refers to molten iron that is generated during laser beam irradiation and solidified on the surface of the steel sheet.

The meander control facility determines the degree (steering amount) of steering rolls 2A, 2B for changing the moving direction of the steel sheet 1, and the central position of the width of the steel sheet 1 deviating from the center of the production line. The center of the steel plate for adjusting the direction in which the steel plate 1 moves by rotating and moving the axes of the steering rolls 2A and 2B by calculating the meander measuring sensor 4 for measuring and the detection signal of the meandering measuring sensor 4 It may include a strip center position control system (3).

The meandering measuring sensor 4 is disposed at the rear end of the steering roll 2B to detect the actual meandering amount of the steel sheet passing through the steering roll in real time.

By the meander control facility, the steel sheet is moved straight along the center of the production line without bias, so that a groove can be formed on the surface of the steel sheet over the entire width of the steel sheet.

The meandering control equipment measures the amount of meandering of the steel sheet by the meandering sensor 4 in the pre-process of forming grooves on the surface of the steel sheet by laser irradiation. The value measured by the meander measurement sensor 4 is output to the steel plate central position control system, and the steel plate central position control system calculates the output value of the meander measurement sensor and rotates the axes of the steering rolls 2A, 2B according to the calculated meandering degree. will be moved In this way, when the steering rolls 2A and 2B are rotated and moved, the moving direction of the steel sheet wound around the steering roll and moved is adjusted. Accordingly, the meandering amount of the steel sheet is controlled, so that the meandering amount of the steel sheet 1 can be controlled within ±1mm.

The tension control facility is a tension bridle roll (TBR) (5A, 5B) for inducing movement while applying a tension of a certain size to the steel plate 1, the steel plate passing through the tension bridle roll ( 1) Adjust the speed of the tension bridle rolls 5A and 5B according to the tension of the steel plate 1 measured by the steel plate tension measuring sensor 7, and the steel plate tension measuring sensor 7 for measuring the tension of 1) It may include a strip tension control system 6 for

The steel sheet tension measuring sensor 7 is disposed at the rear end of the tension bridle roll 5B to measure the actual tension of the steel sheet to which the tension is applied through the tension bridle roll 5B in real time.

In this embodiment, the tension of the steel sheet can be set so that the steel sheet does not break due to excessive tension while making the surface shape of the steel sheet flat at the laser irradiation position of the laser irradiation equipment.

The tension control facility is a tension bridle roll by a strip tension control system 6 according to the tension of the steel sheet measured by the steel sheet tension measuring sensor 7 in order to operate with a steel sheet tension within a set range. Adjust the speed of TBR) (5A, 5B). Accordingly, the tension control facility controls the tension error of the steel sheet 1 to be within the set range to apply tension to the steel sheet.

The steel sheet passing through the tension control facility is introduced into the laser room 20, goes through the steel sheet support roll position adjustment facility and the laser irradiation facility, is subjected to magnetic domain refinement processing, and then exits to the outside of the laser room 20. The laser room will be described later.

In this embodiment, inside the laser room 20, a steel plate support roll 9 is disposed just below the laser irradiation equipment, and deflector rolls 8A and 8B are disposed on both sides with the steel plate support roll interposed therebetween. are placed

The moving direction of the steel sheet 1 is switched toward the steel sheet support roll 9 by the deflector rolls 8A and 8B. As the steel plate 1 passes through the deflector roll 8A, the direction of movement is switched toward the steel plate support roll 9, and the steel plate 1 comes into contact with the steel plate support roll 9, and then the direction is changed again toward the deflector roll 8B, so that the deflector roll 8B. is moved past

The steel plate 1 is wound in an arc shape along the steel plate support roll 9 by the deflector roll and passes while being in surface contact with the steel plate support roll. In order to minimize the fluctuation of the laser beam focal length due to vibration and wave of the steel plate when irradiating the laser beam, the steel plate must be sufficiently in surface contact with the steel plate support roll to pass, and in this state, the laser beam is applied to the steel plate moving along the steel plate support roll. should be investigated In this embodiment, as the steel sheet is in surface contact with the steel sheet support roll as described above, the laser beam can be accurately irradiated to the steel sheet.

The steel plate support roll position adjustment facility includes a steel plate support roll 9 that supports the steel plate 1 to the laser irradiation position of the laser irradiation facility, and the brightness of a flame generated when the laser irradiation equipment is irradiated with a laser beam to the steel sheet 1 in the laser irradiation facility a luminance measuring sensor 10 for measuring ) may be included.

The steel plate support roll position adjustment facility supports the steel plate 1 at the position of the laser irradiation part by the steel plate support roll 9, and places the steel plate within a depth of focus with high laser steel plate irradiation efficiency. The position of the steel plate support roll 9 is adjusted up and down as a whole so that the brightness of the flame generated during laser irradiation is the best. In addition, the brightness of the flame generated when the laser is irradiated to the steel plate is measured using the luminance measuring sensor (10).

In this embodiment, the steel plate support roll position adjusting equipment may further include a distance measuring sensor 11 for measuring the actual distance between the surface of the steel plate from the optical system of the laser irradiation equipment. The steel plate support roll position control system 12 calculates the distance between the optical system and the steel plate surface actually measured by the brightness of the flame detected by the luminance measuring sensor 10 and the distance measuring sensor 11 to position the steel plate support roll 9 . control more precisely.

The meander control equipment, tension control equipment, and steel plate support roll position adjusting equipment serve to create conditions for the steel plate at the laser irradiation position so that a laser groove can be precisely formed in the steel plate by the laser irradiation equipment. For the steel plate at the laser irradiation position, the center position of the steel plate should be at the center position of the production line, and the distance from the optical system should be maintained at the set value.

The laser irradiation equipment may include a laser oscillator controller 13 , a laser oscillator 14 for oscillating a continuous wave laser beam 16 , and an optical system 15 .

3 shows the optical system of the laser irradiation facility according to the present embodiment.

As shown in FIG. 3 , the optical system 15 is rotatably installed to provide a module plate 37 that provides an angle of laser beam irradiation with respect to the width direction of the steel plate, and a driving unit for rotating the module plate 37 . (36), the header 39 installed on the module plate 37 and emitting the laser beam applied from the laser oscillator 14 into the optical system 15, rotatably installed on the module plate 37, the header ( 39), a polygon mirror 32 that reflects the laser beam emitted from it, a rotation motor 33 that rotates the polygon mirror 32, is installed on the module plate 37 and is reflected from the polygon mirror 32 A condensing mirror 35 that reflects the laser beam 16 toward the steel sheet and condensing it on the steel sheet, and a driving motor 34 connected to the condensing mirror 35 to move the condensing mirror 35 to adjust the focal length of the laser beam. , may include a shutter 38 installed on the module plate 37 to selectively block the module plate 37 depending on whether the laser beam is irradiated.

In the optical system 15, a header 39, a polygon mirror 32, a condensing mirror 35, and a shirt are arranged in a module plate 37 constituting an optical box to form a single body. The laser oscillator 14 and the header 39 are connected by, for example, an optical cable 41 . Accordingly, the laser emitted from the laser oscillator 14 is sent to the header 39 via the optical cable 41 . Inside the module plate 37 constituting the optical box, the header 39, the polygon mirror 32, and the condensing mirror 35 are arranged in a fixed position to reflect the laser beam 16 to a desired position. As shown in FIG. 3 , for example, the header 39 may be disposed on both sides with a polygon mirror 32 interposed therebetween to respectively emit a laser beam toward the polygon mirror 32 . Two condensing mirrors 35 are arranged in accordance with each laser beam reflected from the polygon mirror 32 . The laser beam emitted from the header 39 is reflected from the polygon mirror 32 rotating according to the driving of the rotation motor 33 and sent to the condensing mirror 35 . The laser beam 16 reflected by the condensing mirror 35 is reflected from the condensing mirror 35 toward the steel sheet through the shutter 38 and is condensed on the surface of the steel sheet 1 . Accordingly, a laser beam is periodically irradiated to the surface of the steel sheet to form continuous grooves in the width direction.

The overall focal length of the laser beam 16 by the optical system 15 is adjusted by the vertical movement of the steel plate support roll 9, and if the left and right focal lengths do not match, the driving motor 34 connected to the condensing mirror 35 is installed. ) is adjusted by

The shutter 38 is installed under the module plate 37 to open and close the module plate 37 . The shutter 38 is opened when the laser beam is irradiated downward from the condensing mirror 35 to prevent interference with the laser beam, and is closed when the laser beam is not irradiated, so that external fumes or foreign substances are trapped inside the optical system 15 . to block entry into

If the amount of meandering of the steel sheet is excessive, the steel sheet is deviated from the laser irradiation position, and damage occurs while the laser is irradiated to the steel sheet support roll 9 . Accordingly, in order to prevent damage to the steel plate support roll, the laser oscillator controller 13 turns on the laser oscillator under normal working conditions and controls the laser oscillator to be off when the steel plate meandering amount is 15 mm or more. do.

The laser oscillator 14 may oscillate a single mode continuous wave laser beam and transmit it to the optical system 15 . The optical system 15 irradiates the transmitted laser beam 16 to the surface of the steel sheet.

The laser oscillator 14 and the optical system 15 irradiate a laser beam on the surface of the steel sheet to form grooves having an upper width, a lower width and a depth of less than 70 μm, less than 10 μm, and 3 to 30 μm, respectively, while simultaneously forming a laser beam. The laser energy density within the range of 1.0 to 5.0 J/mm 2 necessary for melting the steel sheet may be delivered to the steel sheet so that the re-solidified portion remaining on the inner wall of the groove of the molten portion is generated during irradiation.

The optical system 15 has a function of controlling the laser scanning speed, so that the interval between the laser irradiation lines (31 in FIG. 2 ) can be adjusted to 2 to 30 mm in the rolling direction. Accordingly, it is possible to improve the iron loss of the steel sheet by minimizing the effect of the heat affected zone (HAZ, Heat Affected Zone) by the laser beam.

In addition, the laser irradiation equipment may have a structure that converts the irradiation angle of the laser beam irradiated to the surface of the steel plate with respect to the width direction of the steel plate. In this embodiment, the laser irradiation equipment may convert the irradiation angle of the laser beam in the range of ±4° with respect to the width direction of the steel sheet.

To this end, the laser irradiation facility has a structure in which the optical system 15 for irradiating a laser beam on the steel sheet is rotatable by the driving unit 36, and the angle of the irradiation line of the laser beam formed on the surface of the steel sheet is converted with respect to the width direction of the steel sheet. It may be a structure that As described above, the angle of the irradiation line of the laser beam by the optical system is changed, so that the irradiation line 31 by the laser beam is inclined in the range of ±4° in the direction perpendicular to the rolling direction of the steel sheet. Accordingly, it is possible to minimize the decrease in magnetic flux density due to the formation of the groove by the laser.

In addition, in this embodiment, the laser irradiation facility controls the irradiation position of the laser beam on the steel plate 1, and the laser beam irradiated to the steel plate is reflected from the steel plate to prevent the back reflection phenomenon entering the optical system or laser oscillator. is structured.

To this end, as shown in FIG. 3 , the laser irradiation facility supports the steel sheet in the direction of irradiation of the laser beam irradiated from the optical system 15 with respect to the surface of the steel sheet advancing in contact with the surface of the steel sheet support roll 9 in an arc shape. Using the laser beam irradiation position when passing through the central axis of the roll 9 as the reference point P, the angle from the reference point P along the outer circumferential surface from the center of the steel sheet support roll 9 (the separation angle for convenience of explanation below) R)) and may have a structure in which a laser beam is irradiated to a spaced position.

The reference point P is a point where the line passing through the central axis of the steel plate support roll 9 and the steel plate meet in FIG. 3 . When the irradiation direction of the laser beam passes through the central axis of the steel sheet support roll 9, the focus of the laser beam is set to the reference point P. In this case, as the irradiation direction of the laser beam is perpendicular to the tangent to the steel plate support roll 9 at the reference point P, the laser beam reflected by hitting the steel plate enters the optical system and the laser oscillator as it is, causing damage. This happens.

As described above, the laser irradiation facility according to this embodiment irradiates a laser beam to a position spaced apart from the reference point P by the separation angle R, so that the laser beam reflected back from the steel plate is not incident on the optical system. Accordingly, it is possible to prevent the above-described back reflection phenomenon and maintain the quality of the groove shape formed by the laser beam.

In this embodiment, the separation angle (R) may be set in the range of 3 to 7 ° along the outer peripheral surface from the center of the steel plate support roll (9) with respect to the reference point (P).

When the separation angle R, which is a position at which the laser beam is irradiated, is smaller than 3°, a part of the laser beam reflected back from the steel plate may be introduced into the optical system or the laser oscillator. When the separation angle R exceeds 7°, groove formation by the laser beam may not be properly performed, and poor formation of the groove may occur.

As such, the laser irradiation facility of this embodiment irradiates a laser to the steel plate at a point spaced apart from the reference point P by a predetermined angle, thereby preventing back reflection, and does not interfere with the incident optical path when reflecting the laser beam. It is possible to stably maintain the quality of the groove shape formed by the

On the other hand, the device is provided with a protection unit for protecting the surface of the steel sheet support roll 9, and has a structure to prevent damage to the surface of the steel sheet support roll by the laser beam irradiated outside the side end of the steel sheet.

4 and 5 are the structures according to the first embodiment of the protection unit, protecting the surface of the steel sheet support roll 9 from the laser beam 16 when the steel sheet 1 meanders with respect to the steel sheet support roll 9. structure is illustrated.

As shown in FIG. 4, in this embodiment, the protection part is disposed at both ends of the steel plate support roll 9 and covers the surface of the steel plate support roll 9 exposed under the steel plate to block the laser beam 16. A blocking plate 63 may be included.

In addition, the protection part has a structure that moves the blocking plate 63 according to the degree of surface exposure of the steel plate support roll 9 . To this end, the protection unit calculates the amount of movement of the steel plate detector 64 that detects the meandering of the steel plate 1 passing through the steel plate support roll 9 and the movement amount of the blocking plate 63 according to the detection signal of the steel plate detector 64 . a movement amount calculation unit 65 to further include a movement unit 66 for moving the blocking plate 63 along the axial direction of the steel plate support roll 9 according to the output signal of the movement amount calculation unit 65 can

The blocking plate 63 is arranged in pairs at both ends of the steel plate support roll 9 .

The blocking plate 63 is a plate structure extending sufficiently long along the axial direction of the steel plate support roll 9 and is located between the optical system 15 and the steel plate support roll 9 along the movement path of the laser beam 16 . do. The blocking plate 63 may be made of various materials as long as it is a material capable of blocking the laser beam 16 .

Accordingly, the blocking plate 63 covers the upper portions of the steel plate support roll 9 at both ends of the steel plate support roll 9 to prevent the laser beam 16 from being irradiated. Therefore, even if the steel plate passing through the steel plate support roll 9 is meandering and the surface of the steel plate support roll 9 is exposed, the blocking plate 63 disposed on the top of the steel plate support roll 9 is blocking the surface of the steel plate support roll 9, so that the laser beam 16 It is possible to prevent the surface of the steel plate support roll 9 from being irradiated.

The protection unit moves the blocking plate 63 according to the meandering amount of the steel sheet, thereby more reliably protecting the surface of the steel sheet support roll 9 exposed from the steel sheet.

As shown in FIG. 4 , the steel plate detector 64 is disposed at both end portions of the steel plate close to the steel plate support roll 9 , respectively. The steel plate detector 64 detects the position of the side end according to the meander of the steel plate 1 at both side ends of the steel plate, respectively.

The signal detected by the steel plate detector 64 is applied to the movement amount calculation unit 65 , and the movement amount calculation unit 65 calculates the movement amount of each blocking plate 63 according to the movement amount of the steel plate. Accordingly, the moving unit 66 is driven according to the output signal of the moving amount calculating unit 65 to move each blocking plate 63 along the axial direction of the steel sheet support roll 9 .

As each blocking plate 63 is moved by an appropriate distance according to the driving of the moving part 66 , the blocking plate 63 can completely block the upper portion of the steel sheet support roll 9 exposed along the meandering of the steel sheet.

In this way, even if the steel plate meanders with respect to the steel plate support roll 9 and the surfaces of both side ends of the steel plate support roll 9 are exposed, the steel plate support roll in which the blocking plate 63 disposed on the steel plate support roll 9 is exposed ( 9) It is possible to prevent the surface of the steel sheet support roll 9 from being damaged by the laser beam 16 by blocking the surface from the laser beam 16 .

6 shows another embodiment of the protection unit.

As shown in FIG. 6 , the protection unit may include a copper coating layer 67 coated to reflect the laser beam 16 on the surface of the steel plate support roll 9 . In this embodiment, the steel plate support roll 9 has a structure that does not require a separate structure for protection from the laser beam 16, and the steel plate support roll 9 itself reflects the laser beam 16 to prevent damage. is made of

The steel plate support roll 9 has a structure coated with high hardness chromium. In addition, a coating layer 67 made of a copper material having a higher reflectance of the laser beam 16 is formed on both ends of the steel plate support roll 9 . The size of the coating layer 67 may be formed with a sufficient width in consideration of the width of the steel sheet or the degree of meandering of the steel sheet.

When the steel sheet deviates from the one end of the steel sheet support roll 9 due to the meandering of the steel sheet, the coating layer 67 formed on the steel sheet is exposed to the outside. The laser beam 16 irradiated to the surface of the steel plate support roll 9 through the meandering side end of the steel plate is irradiated to the coating layer 67 formed on the steel plate. As mentioned above, the coating layer 67 is a region having a high reflectance, and directly reflects the laser beam 16 . Accordingly, since the energy of the laser beam 16 is not applied to the coating layer 67 , damage to the surface of the steel sheet support roll 9 can be minimized.

7 illustrates a structure for protecting the surface of the steel sheet support roll 9 from the laser beam 16 regardless of a change in the width of the steel sheet as a structure according to another embodiment of the protection unit. In the case of this embodiment, it is more effective when applied to an apparatus equipped with a steel plate central position control system 3 .

7, the protection part is installed under the optical system 15 of the laser irradiation equipment at a position corresponding to the surface of the steel plate support roll 9 exposed through both side ends in the width direction of the steel plate 1, and is installed from the optical system. A reflective member 68 for reflecting the laser beam 16 irradiated to the steel plate support roll 9 may be included.

In addition, the protection part may further include a cover amount adjusting part 69 for moving the reflective member 68 along the axial direction of the steel plate support roll 9 according to the width of the steel plate 1 .

The movement path of the laser beam 16 irradiated from the optical system 15 is directed in the width direction of the steel sheet. When the width of the steel sheet 1 is changed and reduced, the laser beam 16 moving along the width direction of the steel sheet is irradiated with the laser beam 16 while further moving past the side end of the steel sheet. In this way, the laser beam 16 irradiated past the side end of the steel sheet in the width direction is irradiated to the reflective member 68 installed below the optical system, and is reflected in different directions by the reflective member 68 . Accordingly, since the laser beam 16 irradiated beyond the side end of the steel plate is not irradiated to the surface of the steel plate support roll 9 , damage to the surface of the steel plate support roll 9 can be prevented.

As shown in FIG. 7 , the two reflective members 68 form a pair and are disposed below the optical system 15 at positions corresponding to both front ends of the steel sheet support roll 9 . The reflective member 68 is a plate structure extending sufficiently long along the axial direction of the steel plate support roll 9 and is positioned on the movement path of the laser beam 16 . The reflective member 68 may be made of various materials, including a mirror capable of reflecting the laser beam 16 .

The reflection member 68 is formed so that the surface in contact with the laser beam 16 is inclined, for example, 45° with respect to the irradiation direction of the laser beam 16, and the laser beam 16 irradiated from the optical system is changed by 90 degrees and reflected. It may be a structure that The reflection angle of the laser beam 16 of the reflection member 68 can be variously modified. The laser beam 16 is reflected at an angle of 90° by the reflective member 68 and is not irradiated toward the steel plate support roll 9 .

Accordingly, the reflective member 68 is disposed above both ends of the steel plate support roll 9 to block the laser beam 16 irradiated onto the surface of the steel plate support roll 9 . Therefore, the reflective member 68 blocks the exposed surface of the steel plate support roll 9 even if the laser beam 16 is continuously irradiated through the side end in the width direction of the steel plate because the width of the steel plate passing through the steel plate support roll 9 is small. It is possible to prevent the beam 16 from being irradiated to the surface of the steel plate support roll 9 .

In addition, the cover amount adjusting unit 69 moves the reflective member 68 along the axial direction of the steel sheet support roll 9 according to the width of the steel sheet.

The cover amount adjusting unit 69 is, for example, installed movably through a rail on which the reflective member 68 is installed along the width direction of the steel plate, etc., and reflects the reflection using a driving force such as a driving motor or a driving cylinder. It may be a structure for moving the member along the rail. The cover amount adjusting unit 69 can be variously deformed in terms of a structure capable of moving the reflective member 68 in the width direction of the steel sheet.

Accordingly, by moving the reflective member 68 by the cover amount adjusting unit 69 in response to the width of the steel plate, the spacing between the reflective members 68 is adjusted to the width of the steel plate. Accordingly, the reflective member 68 is positioned above the surfaces of both front ends of the steel plate support roll 9 exposed according to the width of the steel plate so as to block the surface of the steel plate support roll 9 .

As described above, even if the width of the steel sheet is changed with respect to the steel sheet support roll 9 and the degree of exposure of both ends of the steel sheet support roll 9 is changed, the distance between the reflective members 68 is appropriately adjusted so that the exposed steel sheet support roll 9 is formed. It becomes possible to prevent the surface from being damaged by the laser beam 16 .

As mentioned above, according to this embodiment, it is possible to prevent damage to the steel plate support roll caused by the laser beam 16 irradiated from the optical system passing through the steel plate and irradiated to the surface of the steel plate support roll 9 .

In addition, the laser irradiation equipment may further include a molten iron removal equipment for removing fumes and spatters generated according to the laser beam irradiation on the steel sheet.

The molten iron removal facility includes an air knife 17 for removing the molten iron remaining inside the groove by spraying compressed dry air into the groove of the steel sheet, and dust collection hoods 19A and 19B for suctioning and removing fumes and molten iron. may include Fume generated during laser irradiation is removed through the air knife and the dust collection hood, thereby preventing the fumes from flowing into the optical system. The air knife 17 removes molten iron remaining in the groove by spraying compressed dry air having a predetermined pressure (Pa) into the groove of the steel plate 1 . The compressed dry air in the air knife 17 preferably has a pressure (Pa) of 0.2 kg/cm ² or more. This is because, when the pressure of the compressed dry air is less than 0.2 kg/cm ² , it is impossible to remove the molten iron from the inside of the groove, and thus the effect of improving iron loss cannot be secured. The fume and spatter removed by the air knife are removed by the dust collecting hoods 19A and 19B disposed before and after the laser irradiation position.

In addition, the laser irradiation equipment may further include a shielding unit 18 to block the reflected light, scattered light, and radiant heat of the laser beam from flowing into the optical system. The shielding unit 18 blocks reflected and scattered light flowing into the optical system by reflection and scattering of the laser beam 16 irradiated to the steel plate, thereby preventing the optical system from being heated and thermally deformed by radiant heat from the reflected and scattered light. do.

The laser room 20 is a room structure having an internal space, and the laser irradiation equipment and the steel plate support roll 9 position control equipment are accommodated inside to isolate it from the outside, and provide an appropriate operating environment for their smooth operation. do.

An inlet and an outlet are respectively formed at the entrance and exit sides of the laser room 20 along the steel plate traveling direction. The laser room 20 is provided with a facility for blocking the inflow of contaminants so that the internal space is not polluted by external dust. To this end, the laser room 20 is provided with a positive pressure device 23 for increasing the internal pressure than the external. The positive pressure device 23 maintains the internal pressure of the laser room 20 relatively higher than the external pressure. Accordingly, it is possible to prevent foreign substances from being introduced into the laser room 20 . In addition, air curtains 22A, 22B, 22C, and 22D are installed at the inlet and outlet through which the steel plate enters and exits. The air curtain blocks the inflow of dust, etc. through the inlet and outlet by spraying air on the inlet and outlet, which are passages for the steel plate to enter and exit the laser room 20, to form a film. In addition, in order to prevent contamination inside the laser room 20 , a shower booth 21 may be installed in a door that is an entrance to the laser room 20 . The shower booth 21 removes foreign substances from the body of the person entering the laser room 20 .

The laser room 20 is a space in which a steel plate magnetic domain refinement process is substantially performed by a laser beam, and it is necessary to minimize changes in the internal environment and maintain an appropriate environment. To this end, the laser room 20 is an optical system lower frame 24 that separates the upper space where the laser oscillator 14 and the optical system 15 of the laser irradiation facility are located from the lower space through which the steel plate 1 passes, and a laser A constant temperature and humidity controller 25 for controlling the temperature and humidity inside the room 20 is provided.

The optical system lower frame 24 allows the laser oscillator 14 and the optical system 15 to more thoroughly manage the operating environment of the main facilities. The optical system lower frame 24 is installed to separate the optical system lower space where the steel plate passes in the laser room 20 and the optical system upper space where the laser oscillator and the optical system mirror are located. The upper space of the optical system is separated from the inside of the laser room 20 by the optical system lower frame 24, so that it is easier to prevent contamination of major equipment such as a laser oscillator or an optical system and control temperature and humidity.

The constant temperature and humidity controller 25 provides an appropriate environment by controlling the temperature and humidity inside the laser room 20 . In this embodiment, the constant temperature and humidity controller 25 may maintain the internal temperature of the laser room 20 at 20 to 25° C. and maintain the humidity at 50% or less.

In this way, the internal space of the laser room 20 is continuously maintained at a temperature and humidity suitable for the working environment, so that the magnetic domain refinement process can be performed on the steel sheet in an optimal state. Accordingly, it is possible to mass-produce high-quality products under the optimal operating environment required for the process.

The magnetic domain refinement apparatus of this embodiment may further include a post-treatment facility for removing hill-up and spatter formed on the surface of the steel sheet.

Heal-up and spatter cause a decrease in insulation and space factor of the product, and thus the quality of the product can be improved by completely removing it through the post-treatment facility.

The post-treatment facility may include brush rolls 26A and 26B disposed at the rear end of the laser room 20 along the moving direction of the steel sheet to remove heal-up and spatter on the surface of the steel sheet. The brush rolls 26A and 26B are rotated at high speed by a driving motor, and a current control system that controls the current value of the driving motor generated during operation to a set target value, and a brush position that controls the distance between the brush roll and the steel plate The rotation speed and the distance between the steel plate are controlled by the control system. The brush roll may be disposed only on one side of the steel sheet in which the groove by the laser beam is formed, or may be disposed on both sides of the steel sheet. The brush rolls 26A and 26B are in close contact with the surface of the steel plate and rotate at a high speed to remove the heel-up and spatter adhering to the surface of the steel plate. As shown in FIG. 1, a dust collection hood 19C for discharging the heal-up and spatter removed by the brush rolls is further installed in proximity to the brush rolls 26A and 26B. The dust collecting hood 19C sucks molten iron such as heel-up and spatter that has been separated from the steel plate by the brush rolls 26A and 26B and discharges it to the outside.

In addition, the post-treatment facility is disposed at the rear end of the brush rolls 26A and 26B and electrolytically reacts the steel sheet with an alkali solution to further remove heal-up and spatter remaining on the surface of the steel sheet. It may further include a filtering unit 30 for filtering out foreign substances contained in the alkaline solution of the clean unit from the alkaline solution connected to.

The steel sheet passes through the brush rolls 26A and 26B to firstly remove heal-up and spatter, and pass through the clean unit 29 to secondarily remove the remaining heal-up and spatter. Accordingly, it is possible to more completely remove the heel-up and spatter attached to the surface of the steel sheet, thereby improving product quality.

The cleaning unit 29 is filled with an alkali solution therein, and the filtering unit 30 is connected to one side. As the steel sheet is processed through the cleaning unit, heal-ups and spatters removed from the steel sheet are accumulated in the internal alkaline solution, and the cleaning performance of the steel sheet is deteriorated. The filtering unit 30 circulates the alkali solution of the clean unit and removes heal-up and spatters contained in the alkali solution. The filtering unit 30 manages the iron content of the alkali solution to 500ppm or less by removing heal-up and spatter. In this way, it is possible to continuously process the steel sheet by preventing deterioration of the cleaning performance of the cleaning unit.

Hereinafter, the magnetic domain refinement process of the electrical steel sheet according to the present embodiment will be described as follows.

The continuously transferred steel sheet enters the laser room through the meandering control facility and the tension control facility, and proceeds at a speed of 2 m/sec or more, and the magnetic domain is refined. The steel sheet that has entered the laser room is taken out of the laser room after permanent magnetic domain refinement treatment through the laser irradiation facility. The steel sheet drawn out of the laser room goes through a post-processing facility, and the heal-up and spatter remaining on the surface are removed and sent to the post-processing.

In this process, the laser room in which the laser irradiation on the surface of the steel sheet is carried out properly sets and maintains the internal operating environment to provide an optimal environment for refining the magnetic domain.

The laser room isolates the inside from the outside to block the inflow of external contaminants, and the temperature, pressure, and humidity inside the laser room are controlled according to the operating environment for forming magnetic domains.

The laser room can prevent foreign substances such as dust from entering the laser room by setting and maintaining the internal pressure higher than that of the outside. In addition, by forming a film by air at the inlet and outlet, which are passages through which the steel sheet is moved, it is possible to block foreign substances such as dust from entering the laser room while the steel sheet proceeds through the inlet and outlet.

In addition, the thermo-hygrostat installed in the laser room maintains the temperature inside the laser room at 20 to 25° C. and maintains the humidity at 50% or less, thereby providing optimal conditions for the magnetic domain refinement treatment by laser irradiation.

In this way, an optimal environment for laser beam irradiation is provided by the laser room, and the steel sheet is accurately positioned at the laser irradiation position while passing through the meander control facility, the tension control facility, and the steel sheet support roll position adjustment facility.

First, for magnetic domain refining treatment, the direction of the steel sheet is controlled through a meandering control facility, so that it moves straight along the center of the production line without being biased from side to side.

The meandering sensor continuously detects the meandering amount of the steel sheet, and when the steel sheet meanders, it calculates the signal detected by the meandering sensor so that the steel sheet central position control system rotates and moves the axis of the steering roll to move the steel sheet to the correct position. do. In this way, by continuously controlling the steering roll according to the position of the steel plate, it is possible to continuously move the steel plate without leaving the center of the production line.

The steel plate moves past the steering roll and through the tension bridle roll for tension control. The tension of the steel sheet past the tension bridle roll is detected by the tension sensor. The steel plate tension control system controls the speed of the tension bridle roll by calculating the measured value detected by the tension measuring sensor and applying the set tension. Accordingly, it is possible to continuously maintain the tension of the moving steel sheet within a set range.

The steel sheet passed through the tension bridle roll is introduced into the laser room through the entrance of the laser room. The direction of the steel sheet is changed by the bridle roll inside the laser room and moved in a state in close contact with the steel sheet support roll located between the two bridle rolls.

The steel plate support roll moves the steel plate up and down to position the steel plate within the depth of focus of the laser beam.

When a laser beam is irradiated to the steel plate from the laser irradiation facility, the luminance measuring sensor detects the brightness of the flame on the surface of the steel plate in real time. Place the steel plate within the depth of focus of the laser beam. Accordingly, the laser beam is effectively irradiated to the surface of the steel sheet to form high-quality radiation.

The laser oscillator controller turns on/off the laser oscillator according to the meandering degree of the steel sheet. The laser oscillator controller is connected to the meander measuring sensor, and when the meandering amount of the steel sheet measured from the meandering sensor is, for example, 15 mm or more, it is determined that the steel sheet deviated too much from the steel sheet support roll, and the laser oscillator is turned off. Accordingly, it is possible to prevent the roll from being damaged by the laser beam passing through the meandering steel plate and irradiated to the surface of the steel plate support roll.

The laser beam generated by the laser oscillator according to the command of the laser oscillator controller is irradiated to the surface of the steel sheet through the optical system. The laser oscillator oscillates the TEM ₀₀ continuous wave laser beam and transmits it to the optical system.

The optical system converts the direction of the laser beam and irradiates the laser to the surface of the steel sheet, thereby continuously forming a molten groove on the surface of the steel sheet to refine the magnetic domain.

As the surface of the steel sheet is melted by the laser beam irradiated to the steel sheet through the optical system, a molten groove is formed along the irradiation line. In this embodiment, a groove having an upper width, a lower width, and a depth of within 70 μm, within 10 μm, and 3 to 30 μm, respectively, is formed on the surface of the steel sheet through laser beam irradiation, and at the same time, when irradiated with laser, it is formed on the inner wall of the groove in the molten part. The laser oscillator and the optical system deliver the laser energy density within the range of 1.0 to 5.0 J/mm 2 necessary for melting the steel sheet to the steel sheet so that the remaining re-solidified portion is generated.

In addition, by irradiating the laser beam to a position spaced apart from the reference point in the process of irradiating the laser beam through the optical system, the laser beam reflected back from the steel plate is not incident on the optical system. Accordingly, the above-described back reflection phenomenon is prevented and the incident light path of the laser beam is not interfered with by the reflected light, so that the quality of the groove shape formed by the laser beam can be maintained.

In this embodiment, when the laser beam irradiated in the width direction of the steel sheet is irradiated to the surface of the steel sheet support roll outside the side end of the steel sheet during the laser irradiation process, the surface of the steel sheet support roll can be protected by blocking the laser beam.

The protection of the surface of the steel plate support roll by blocking the laser beam may be achieved by blocking the laser beam irradiated to the surface of the steel plate support roll exposed under the steel plate through the blocking plates disposed at both ends of the steel plate support roll. In the above-described blocking process, first, the meandering of the steel sheet traveling along the steel sheet support roll is detected, the movement amount of the blocking plate is calculated according to the detected meandering amount of the steel sheet, and the blocking plate is moved to the axis of the steel sheet supporting roll according to the calculated value. By moving along the direction, it is possible to block the laser beam by covering the surface of the steel sheet support roll exposed from the steel sheet with the blocking plate.

That is, the exposure amount of the steel plate support roll varies according to the meander amount of the steel plate with respect to the steel plate support roll, and the blocking plate moves to a value calculated according to the meander amount. By moving the blocking plate by the calculated movement amount, the blocking plate moves according to the changed exposure amount of the steel sheet support roll to completely block the exposed surface of the steel sheet support roll.

As described above, by properly blocking the laser beam irradiated to the exposed tip of the steel sheet support roll, it is possible to prevent the surface of the steel sheet support roll from being damaged by the laser beam.

Although the process of protecting the surface of the steel plate support roll through the blocking plate has been described above, the present embodiment is not limited thereto. For example, the surface of the steel plate support roll may be protected through a process of reflecting a laser beam from the surface of the steel plate support roll.

In another embodiment, it is possible to prevent the laser beam from being irradiated to the surface of the steel plate support roll by changing the irradiation angle of the laser beam irradiated to the steel plate support roll outside the width direction side end of the steel plate to protect the surface of the steel plate support roll. . In order to reflect the laser beam, the position of the reflective member for reflecting the laser beam may be moved and set according to the width of the steel sheet. Accordingly, the reflective member for reflecting the laser beam is positioned on both front end regions of the steel plate support roll exposed according to the change in the width of the steel plate. Accordingly, the reflective member blocks the exposed portion of the steel plate support roll regardless of the change in the width of the steel plate, thereby preventing the laser beam from being irradiated to the surface of the steel plate support roll.

The optical system has a function of controlling the laser scanning speed, so that the interval of the laser irradiation line can be adjusted with respect to the rolling direction. In addition, the optical system may have a rotation function to change the angle of the laser irradiation line. In this embodiment, it is possible to improve the iron loss of the steel sheet by minimizing the effect of the heat affected zone (HAZ, Heat Affected Zone) by the laser beam by enabling the optical system to adjust the interval of the laser beam to 2 to 30 mm in the rolling direction. have. In addition, the angle of the irradiation line of the laser beam irradiated to the surface of the steel sheet through the rotation of the optical system in the laser beam irradiation process can be converted. In this embodiment, the optical system may convert the irradiation angle of the laser beam in the range of ±4° with respect to the width direction of the steel sheet. That is, the irradiation line 31 of the laser beam may be formed by inclining within a range of ±4° with respect to the y-axis direction in FIG. 2 . Accordingly, the radiation formed on the surface of the steel sheet may be inclined in the range of 86 to 94° with respect to the rolling direction. As described above, by forming the irradiation line inclined with respect to the y-axis direction, it is possible to minimize the decrease in magnetic flux density due to the formation of the groove by the laser.

In the laser beam irradiation process, as the steel sheet is melted by the laser beam, a large amount of fumes and molten iron spatter are generated. Fume and spatters contaminate the optical system, and if molten iron remains inside the groove, it is difficult to form an accurate groove, and the iron loss does not occur, which impairs product quality. Accordingly, compressed dry air is sprayed into the grooves of the steel sheet to remove the molten iron remaining inside the grooves, and the fume and molten iron are directly sucked through the dust collection hood to be removed. Therefore, in the process of refining the magnetic domain of the steel sheet, it is possible to block the flow of fumes toward the optical system, and to rapidly remove the fumes and spatter, thereby increasing the efficiency of refining the domain. In addition, in the laser beam irradiation process, it is possible to further block the flow of scattered light and heat of the laser beam into the optical system of the laser irradiation facility.

The magnetic domain refining process is performed while a groove is formed on the surface of the steel sheet through laser beam irradiation, and the magnetic domain refining treatment is continuously moved and discharged to the outside through the exit of the laser room.

The steel sheet discharged from the laser room goes through a post-treatment process to remove the heal-up and spatter attached to the steel sheet surface.

The steel plate first passes through the brush rolls disposed outside the laser room, and the heel-up and spatter are primarily removed by the brush rolls that are in close contact with the steel plate and rotate at high speed.

The steel sheet that has been passed through the brush roll goes through a secondary cleaning unit, and the remaining heal-up and spatter are finally removed through an electrolytic reaction between the steel sheet and the alkali solution. The steel sheet from which heal-up and spatter are removed while going through the clean unit is transferred to the post-process.

iron loss
Improvement (%) after laser irradiation after heat treatment 9.5 11.6 9.7 12.9 11.5 13.5 8.4 11.6 8.6 11.8 8.5 11.7

Table 1 shows the iron loss improvement rate of the grain-oriented electrical steel sheet by the grooves formed on the surface of the steel sheet with a thickness of 0.27 mm by continuous wave laser beam irradiation according to the present embodiment. As shown in Table 1, in the case of the magnetic domain refining-treated steel sheet according to this embodiment, it can be confirmed that the iron loss is improved both after laser irradiation and after domain refining and heat treatment with a laser.

Although exemplary embodiments of the present invention have been illustrated and described as described above, various modifications and other embodiments may be made by those skilled in the art. All such modifications and other embodiments are intended to be contemplated and encompassed by the appended claims, without departing from the true spirit and scope of the present invention.

1: Steel plate 2A, 2B: Steering roll (SR)
3: steel plate central position control system 4: meander measurement sensor
5A, 5B: Tension bridal roll 6: Steel plate tension control system
7: steel plate tension measuring sensor 8A: deflector roll
8B: deflector roll 8C: middle deflector roll
9: steel plate support roll 10: luminance measuring sensor
11: distance measuring sensor 12: steel plate support roll position control system
13: laser oscillator controller 14: laser oscillator
15: optical system 16: laser beam
17: air knife 18: shielding part
19A, 19B, 19C: Dust collection hood 20: Laser room
21: shower booth 22A, 22B, 22C, 22D: air curtain
23: positive pressure device 24: optical system lower frame
25: constant temperature and humidity controller 26A, 26B: brush roll
27: motor current control system 28: brush position control system
29: clean unit 30: filtering unit
31: irradiation line 32: polygon mirror
33: rotation motor 34: drive motor
35: condensing mirror 36: driving unit
37: module plate 38: shutter
39: header 63: blocking plate
64: steel plate detector 65: movement amount calculation unit
66: moving part 67: coating layer
68: reflective member 69: cover amount control unit

Claims (25)

A steel plate support roll position adjustment step of controlling the vertical position of the steel plate while supporting the steel plate progressing along the production line, a laser irradiation step of irradiating a laser beam to the surface of the steel plate to melt the steel plate to form a groove on the surface of the steel plate And when the laser beam irradiated in the width direction of the steel sheet in the laser irradiation step is irradiated to the surface of the steel sheet support roll supporting the steel sheet beyond the side end of the steel sheet, a protection step for protecting the surface of the steel sheet support roll from the laser beam grain-oriented electrical steel sheet of magnetic domain refining method. The method of claim 1,
In the laser irradiation step, the laser beam irradiation position when the irradiation direction of the laser beam passes through the central axis of the steel plate support roll for the surface of the steel plate progressing in contact with the surface of the steel plate support roll in an arc shape as a reference point, the steel plate at the reference point A magnetic domain refining method of a grain-oriented electrical steel sheet in which a laser beam is irradiated to a position spaced apart at an angle along the outer circumferential surface from the center of the support roll. 3. The method of claim 2,
In the laser irradiation step, the laser beam is irradiated in a range spaced from 3 to 7 ° along the outer circumferential surface from the center of the steel sheet support roll with respect to the reference point. The method of claim 1,
The laser irradiation step, the magnetic domain refinement method of the grain-oriented electrical steel sheet further comprising an angle conversion step of converting the angle of the irradiation line of the laser beam irradiated to the surface of the steel sheet. 5. The method of claim 4,
The angle conversion step is a magnetic domain refining method of a grain-oriented electrical steel sheet for converting the irradiation angle of the laser beam in the range of ± 4 ° with respect to the width direction of the steel sheet. The method of claim 1,
Further comprising a setting maintenance step of setting and maintaining the internal operating environment of the laser room in which the laser irradiation is in progress,
The setting maintenance step is a magnetic domain refinement method of a grain-oriented electrical steel sheet comprising the steps of isolating the inside of the laser room from the outside to block the inflow of external contaminants, and controlling the temperature, pressure and humidity inside the laser room. The method of claim 1,
The magnetic domain refinement method of a grain-oriented electrical steel sheet further comprising a tension control step of applying a tension to the steel sheet to keep the steel sheet in a flat unfolded state. The method of claim 1,
The magnetic domain refining method of grain-oriented electrical steel sheet further comprising a meandering control step of allowing the steel sheet to move without bias from side to side along the center of the production line. The method of claim 1,
The magnetic domain refinement method of a grain-oriented electrical steel sheet further comprising a post-treatment step for removing the hill-up and spatter formed on the surface of the steel sheet through the laser irradiation step. 10. The method according to any one of claims 1 to 9,
The protection step includes blocking the laser beam irradiated to the surface of the steel sheet support roll exposed under the steel sheet through the blocking plates disposed at both ends of the steel sheet support roll. 11. The method of claim 10,
The protection step includes the steps of detecting a meandering of the steel sheet progressing along the steel sheet support roll, calculating the moving amount of the blocking plate according to the meandering amount of the steel sheet detected in the meandering detecting step, according to the value calculated in the calculation step A magnetic domain refining method of a grain-oriented electrical steel sheet comprising the step of moving the blocking plate along the axial direction of the steel sheet support roll to cover the surface of the steel sheet support roll exposed from the steel sheet with the blocking plate. 10. The method according to any one of claims 1 to 9,
The protecting step is a magnetic domain refining method of a grain-oriented electrical steel sheet comprising the step of reflecting a laser beam from the surface of the steel sheet support roll. 10. The method according to any one of claims 1 to 9,
The protection step is a magnetic domain refining method of a grain-oriented electrical steel sheet including a reflection step of converting the irradiation angle of the laser beam irradiated to the steel sheet support roll outside the width direction side end of the steel sheet. 14. The method of claim 13,
The protection step is a magnetic domain refining method of a grain-oriented electrical steel sheet further comprising the step of moving the laser beam reflection position according to the width of the steel sheet. A steel sheet support roll position adjusting facility for controlling the vertical position of the steel sheet while supporting the steel sheet moving along the production line, and a laser irradiation facility for melting the steel sheet by irradiating a laser beam to form a groove on the surface of the steel sheet, and a steel sheet A magnetic domain refining device for grain-oriented electrical steel sheet including a protection unit that protects the surface of the steel sheet support roll from a laser beam irradiated to the surface of the steel sheet support roll supporting the steel sheet outside the side edge of the steel sheet along the width direction. 16. The method of claim 15,
The laser irradiation facility is a reference point to the laser beam irradiation position when the irradiation direction of the laser beam passes through the central axis of the steel plate support roll for the surface of the steel plate advancing in contact with the surface of the steel plate support roll in an arc shape, and the steel plate at the reference point A magnetic domain refining device for grain-oriented electrical steel sheets in which a laser beam is irradiated to positions spaced apart at an angle along the outer circumferential surface from the center of the support roll. 16. The method of claim 15,
The magnetic domain refining device of the grain-oriented electrical steel sheet further comprising a laser room for accommodating the steel plate support roll position adjusting equipment and the laser irradiation equipment from the outside and providing an operating environment for laser irradiation. 16. The method of claim 15,
Magnetic domain refining apparatus of grain-oriented electrical steel sheet further comprising a tension control facility for applying tension to the steel sheet to keep the steel sheet in a flat unfolded state. 16. The method of claim 15,
Magnetic domain refining apparatus of grain-oriented electrical steel sheet further comprising a meandering control facility for allowing the steel sheet to move without bias from side to side along the center of the production line. 16. The method of claim 15,
The magnetic domain refining apparatus of the grain-oriented electrical steel sheet further comprising a post-treatment facility for removing the hill-up and spatter formed on the surface of the steel sheet. 21. The method according to any one of claims 15 to 20,
The protection unit is a magnetic domain refining device of a grain-oriented electrical steel sheet including a blocking plate disposed at both ends of the steel sheet support roll and covering the surface of the steel sheet support roll exposed under the steel sheet to block the laser beam. 22. The method of claim 21,
The protection unit includes a steel plate detector for detecting meandering of the steel plate passing through the steel plate support roll, a movement amount calculator for calculating the movement amount of the blocking plate according to the detection signal of the steel plate detector, and the axis of the steel plate support roll according to the output signal of the movement amount calculator A magnetic domain refining device of a grain-oriented electrical steel sheet further comprising a moving part for moving the blocking plate along the direction. 21. The method according to any one of claims 15 to 20,
The protection unit, a magnetic domain refining device of a grain-oriented electrical steel sheet comprising a coating layer of a copper material coated to reflect the laser beam on the surface of the steel sheet support roll. 21. The method according to any one of claims 15 to 20,
The protection unit is installed in the lower part of the optical system of the laser irradiation facility at a position corresponding to the surface of the steel plate support roll exposed through both side ends in the width direction of the steel plate and includes a reflective member for reflecting the laser beam irradiated from the optical system to the steel plate support roll. Magnetic domain refining device of steel sheet. 25. The method of claim 24,
The magnetic domain refining device of the grain-oriented electrical steel sheet further comprising a cover amount adjusting unit for moving the reflective member along the axial direction of the steel sheet support roll according to the width of the steel sheet.

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