KR20190077728A - Method and apparatus for refining magnetic domains grain-oriented electrical steel - Google Patents

Abstract

Provided is a method for refining magnetic domains of a grain-oriented electrical steel sheet, which can easily change a progress line of a steel sheet in accordance with production of steel sheets or equipment maintenance. To this end, the method for refining magnetic domains of a grain-oriented electrical steel sheet comprises: a movement step of moving a steel sheet along an operation line in which laser irradiation equipment is located; a laser irradiation step of irradiating a laser beam to a surface of the steel sheet through the laser irradiation equipment to form a groove on the surface of the steel sheet; and a line change step of changing progress of the steel sheet from the operation line to a passing line in which the progress of the steel sheet can skip the laser irradiation equipment if necessary.

Description

[0001] METHOD AND APPARATUS FOR REFINING MAGNETIC DOMAINS [0002] GRAIN-ORIENTED ELECTRICAL STEEL [

The present invention relates to a method of microminiaturizing a magnetic steel sheet and a method of micromachining the directional electric steel sheet.

For example, a directional electric steel sheet with low iron loss and high magnetic flux density is required in order to reduce power loss and improve efficiency of electric devices such as a transformer.

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

The magnetic microfabrication method can be broadly classified into microstructure of the temporary magnetic domain and microstructure of the permanent magnetic domain depending on whether the effect of improving the magnetic domain refinement after the stress relief annealing is maintained or not.

The method of microminiaturization of the temporary magnetic domain has a disadvantage of losing the effect of miniaturization of the magnetic domain after stress relieving annealing. In the method of microminiaturizing the temporary magnetic domain, a local compressive stress portion is formed on the surface of the steel sheet to miniaturize the magnetic domain. However, such a method requires re-coating because it causes damage to the insulating coating layer on the surface of the steel sheet, and there is a disadvantage that the manufacturing cost is high because the micro-processing is performed in the intermediate process, not the final product.

The permanent magnet finer method can maintain the iron loss improving effect even after the heat treatment. Techniques using an etching technique, a roll technique, and a laser technique are mainly used for the permanent magnetic microfabrication process. In the case of the etching method, it is difficult to control the groove forming depth and width, it is difficult to guarantee the iron loss characteristic of the final product, and it is disadvantageous in that it is not environmentally friendly because an acid solution is used. In the case of a roll-based method, there is a disadvantage in that the stability, reliability, and process for machining are complicated.

In the method of making the steel sheet finer by using a laser, a laser beam is irradiated to the surface of the steel sheet while the steel sheet is supported and the tension is adjusted, thereby forming a molten groove on the surface of the steel sheet. As described above, in order to miniaturize the magnetic domain using the laser, it is required to improve and optimize the process more effectively so that high-speed processing can be performed, iron loss of the electric steel sheet can be lowered, and magnetic flux density can be increased.

The present invention provides a method of miniaturizing a magnetic steel sheet for directional electric steel sheet, which is capable of increasing the miniaturization efficiency of the magnetic steel sheet and improving the workability by optimizing the equipment and the process.

A method of miniaturizing a magnetic steel sheet for directional electric steel sheet and an apparatus for miniaturizing the magnetic steel sheet so as to increase iron loss reduction efficiency and minimize magnetic flux density decrease.

Provided is a method of miniaturizing a magnetic steel sheet for directional electric steel sheet and an apparatus for removing contaminants such as heal-up and spatter formed by laser irradiation more effectively to improve the quality of a product.

The present invention also provides a method of miniaturizing a magnetic field of a directional electric steel sheet and an apparatus therefor, which are capable of providing an optimal operating environment necessary for the process.

Provided is a method for miniaturizing a magnetic steel plate for directional electric steel sheet and an apparatus for the same, which makes it possible to more easily change the progress line of the steel sheet according to the production of steel sheet or facility maintenance.

The magnetic domain refining method of this embodiment includes a moving step of moving a steel plate along a working line in which a laser irradiation equipment is located, a laser irradiation step of forming grooves on the surface of the steel plate by irradiating the surface of the steel plate with a laser beam through a laser irradiation equipment, And a line changing step of changing the progress of the steel sheet, if necessary, to a passing line that is skipped over the work line without going through the laser irradiation equipment.

The line changing step may include cutting the steel sheet at the entrance of the laser irradiation equipment, and switching the advancing direction of the cut steel sheet to the passing line.

The line changing step includes moving the cut leading steel plate along a work line, connecting the rear end of the preceding steel plate to the leading end of the following steel plate that has been redirected to the passing line, and moving the steel plate along the passing line .

The line changing step may further include a returning step of changing the movement line of the steel plate from the passing line to the operation line.

Wherein the returning step comprises the steps of connecting a transmission band to the rear end of the cut leading steel sheet and preparing a shipping band along the operation line in accordance with the movement of the preceding steel plate, , And pulling the band to pass the trailing steel sheet to a work line.

And controlling the position of the steel plate supporting roll to control the vertical position of the steel plate while supporting the steel plate proceeding along the operation line.

Wherein the laser irradiating step irradiates the surface of the steel sheet contacting and advancing in the form of a circular arc on the surface of the steel sheet supporting roll with the laser beam irradiation position when the irradiation direction of the laser beam passes the central axis of the steel sheet supporting roll as a reference point, It is possible to irradiate the laser beam at a position at an angle apart from the center of the support roll along the outer circumferential surface.

In the laser irradiation step, the laser beam may be irradiated to the reference point in a range of 3 to 7 degrees apart from the center of the steel plate supporting roll along the outer circumferential surface.

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

The magnetic domain refinement method may further include a tension control step of applying a tension to the steel plate so that the steel plate is kept flat and spread.

The magnetic domain refinement method may further include a skew control step of causing the steel strip to move left and right along the center of the work line without tilting.

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 laser room internal temperature, pressure, and humidity.

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

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

The post-treatment step may include a cleaning step of electrolytically reacting the steel sheet with an alkali solution to further remove the healing and spatter remaining on the surface of the steel sheet, a step of removing foreign substances contained in the alkali solution, And a filtering step for receiving the data.

Wherein the meander control step includes a meander amount measurement step of measuring a meander amount that is the center position of the width of the steel strip deviating from the center of the work line and a meander amount measurement step of measuring the amount of meander of the steered roll, And controlling a direction in which the steel sheet moves by rotating and moving the steel sheet so as to control the amount of meander of the steel sheet.

The amount of meandering of the steel sheet can be controlled within +/- 1 mm.

The tension control step may include a steel plate tension applying step of applying a tension to the steel plate by the tension bridle roll, a steel plate tension measuring step of measuring a tension of the steel plate subjected to the steel plate tension application step, And a steel plate tension control step of controlling the steel plate tension by adjusting the speed of the tension brick roll according to the tension of the steel plate measured in the steel plate tension measuring step.

The step of adjusting the position of the steel plate supporting roll may include a step of supporting a steel plate positioned in the laser irradiation step with a steel plate supporting roll, a brightness measuring step of measuring brightness of a flame generated upon laser irradiation of the steel plate in the laser irradiation step, A step of controlling the position of the steel plate supporting roll by the steel plate supporting roll position control system according to the brightness of the flame measured in the brightness measuring step and controlling the position of the steel plate in the depth of focus of the laser .

The laser irradiating step irradiates the laser beam irradiated by the laser oscillator onto the surface of the steel sheet by the optical system to form grooves having an upper width, a lower width and a depth of not more than 70 μm, not more than 10 μm, and 3 to 30 μm, respectively And a laser irradiation energy transfer step of transferring a laser beam energy density within a range of 1.0 to 5.0 J / mm 2 required for melting the steel sheet to the steel sheet so that a re-welding portion remaining on the inner wall surface of the groove of the molten portion during the laser beam irradiation is generated .

The laser irradiating step includes turning on a laser oscillator for oscillating a laser beam under normal operation conditions by a laser oscillator controller and controlling the laser oscillator to be turned off when a steel sheet meandering amount of 15 mm or more occurs And a beam oscillation control step.

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

In the laser irradiation step, the optical system controls the laser scanning speed to adjust the interval of 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 the angle of the irradiation line of the laser beam irradiated on the surface of the steel sheet.

The angle conversion step may convert the angle of the irradiation line of the laser beam to the range of +/- 4 degrees 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 when the laser beam is irradiated. The dust collecting step may include a spraying step of spraying compressed dry air into the grooves of the steel sheet to remove molten iron remaining in the grooves.

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

The magnetic microfabrication apparatus of this embodiment includes a laser irradiation facility for irradiating a laser beam to form a groove on a surface of a steel plate, a work line for moving the steel plate to a laser irradiation facility, a steel plate connected to the work line, And a line changing unit for switching the progress of the steel plate to the passing line.

The line changing unit may include a cutting unit disposed at a front end of the laser irradiation facility for cutting the steel sheet, and a switching roll for guiding the direction of the trailing steel sheet cut by the cutting unit toward the passing line.

The switching roll may be disposed between a tension brick roll that maintains the tension of the steel strip and a laser irradiation equipment.

The line changing unit may further include a welder for connecting the leading edge of the trailing steel sheet, which has been redirected to the passing line, to the trailing edge of the leading steel sheet moved along the working line.

The line changing unit may further include a through plate for passing the steel plate along the operation line when the line is changed.

The conveying unit may include a band connected to a front end of a steel plate along a work line, a drum on which the band is wound, and a driving unit for rotating the drum.

The conveying unit may further include a band guide which is installed on the frame on which the drum is installed and is movable in the axial direction of the drum, and guides the band along the drum axis direction.

And a position adjusting device for controlling the position of the steel plate supporting roll in the vertical direction while supporting the steel plate moved along the operation line.

The laser irradiating equipment has a laser beam irradiating position when the irradiation direction of the laser beam passes through the central axis of the steel plate supporting roll as a reference point with respect to the surface of the steel plate contacting and advancing in the form of an arc on the surface of the steel plate supporting roll, It may be a structure in which a laser beam is irradiated at a position spaced apart at an angle from the center of the support roll along the outer circumferential surface.

The laser irradiation equipment may be configured to irradiate the laser beam to the reference point in a range of 3 to 7 degrees apart from the center of the steel sheet supporting roll along the outer circumferential surface.

The apparatus may further include a laser room for isolating the steel plate supporting roll position adjusting device and the laser irradiation equipment from the outside and providing an operating environment for laser irradiation.

And a tension control device for applying a tension to the steel sheet so as to maintain the steel sheet flatly spread.

And a meander control facility for allowing the steel strip to move left and right along the center of the work line without tilting.

The laser room accommodates the laser irradiation equipment and the steel plate support roll position control equipment to form an inner space to isolate the laser irradiation equipment and the steel plate support roll position control equipment from each other. An optical system lower frame for separating the upper space where the optical system of the laser irradiation equipment is located from the lower space through which the steel sheet passes, and a constant temperature and humidity controller for controlling the laser room internal temperature and humidity.

And a post-treatment facility for removing hill-up and spatter formed on the surface of the steel sheet.

The post-treatment equipment may include a brush roll disposed at a rear end of the laser room to remove the heel-up and spatters of the steel sheet surface.

The post-treatment facility includes a clean unit disposed at the rear end of the brush roll and electrolytically reacting the steel plate with the alkali solution to further remove the healing and spatter remaining on the surface of the steel plate, and a clean unit connected to the clean unit, And a filtering unit for filtering foreign matters from the alkali solution.

Wherein the meandering control facility includes a steering roll for switching the moving direction of the steel plate, a meandering measurement sensor for measuring the degree of deviation of the central position of the steel plate from the center of the work line (meandering amount) And a strip center position control system for adjusting a moving direction of the steel sheet by rotating and moving the axis of the steering roll according to an output value of the sensor.

The tension control device includes a tension bridge roll for guiding movement of the steel plate while applying tension to the steel plate, a steel plate tension measuring sensor for measuring a tension of the steel plate passed through the tension brick roll, And a steel strip control system for adjusting the speed of the tension brick roll according to the tension of the steel strip measured by the tension measuring sensor.

Wherein the steel plate supporting roll position adjusting device includes a steel plate supporting roll for supporting the steel plate at the position of the laser irradiation equipment, a brightness measuring sensor for measuring the brightness of the flame generated upon laser irradiation of the steel plate in the laser irradiation equipment, And 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 irradiating equipment includes a laser oscillator for oscillating a continuous wave laser beam, a laser oscillator for irradiating the laser beam onto the surface of the steel plate, And an optical system for transferring the laser energy density within a range of 1.0 to 5.0 J / mm 2 required for melting the steel sheet to the steel sheet so as to form a groove having a thickness of 30 탆 and to generate a re-welded portion remaining on the inner wall surface of the groove of the molten portion during laser irradiation .

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 be off when the steel sheet steepness exceeds 15 mm.

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

The optical system controls the laser scanning speed so that the interval of the laser irradiation lines can be adjusted to 2 to 30 mm along the rolling direction.

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

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

The laser irradiation equipment may further include a molten iron removing facility for removing fumes and spatter generated by the laser beam irradiation on the steel plate.

The apparatus for removing molten iron may include an air knife for removing the molten iron remaining in the grooves by spraying compressed dry air into the grooves of the steel sheet, and a dust collecting hood for sucking and removing fumes and molten iron.

As described above, according to the present embodiment, the magnetic iron oxide microfabrication process is stably performed at a high speed of 2 m / sec or more, and the iron loss reduction rates before and after the heat treatment of the electrical steel sheet are respectively 5% Or more.

In addition, it is possible to prevent the surface of the steel plate supporting roll from being irradiated with the laser beam irrespective of the width of the steel plate and the meander of the steel plate relative to the steel plate supporting roll.

In addition, it is possible to increase the microfabrication efficiency of the magnetic domain and improve the workability.

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

In addition, by providing an optimum operating environment necessary for the process, it is possible to mass-produce high-quality products.

In addition, it is possible to easily change the movement line of the steel sheet when necessary, such as maintenance of the laser irradiation equipment, and to carry out work by easily passing the steel sheet to the work line during reworking.

Further, it is possible to easily carry out work such as maintenance and testing of the laser irradiation equipment without interfering with the steel plate by moving the steel plate along the passing line.

Fig. 1 is a view schematically showing a configuration of a magnetic domain refinement apparatus of a grain-oriented electrical steel sheet according to the present embodiment.
Fig. 2 is a schematic view showing a steel plate subjected to the micro-finishing process according to the present embodiment.
3 is a schematic view showing the optical system configuration of the laser irradiation equipment according to the present embodiment.
Fig. 4 is a schematic view showing a shipping section of the laser irradiation equipment according to the present embodiment.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms as used herein include plural forms as long as the phrases do not expressly express the opposite meaning thereto. Means that a particular feature, region, integer, step, operation, element and / or component is specified, and that other specific features, regions, integers, steps, operations, elements, components, and / And the like.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Accordingly, the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

In the following description, the present embodiment will be described by taking as an example a facility for finer permanent magnetic ball of a grain-oriented electrical steel sheet used for iron core material of a transformer.

FIG. 1 schematically shows a magnetic microfabrication apparatus for a directional electrical steel sheet according to the present embodiment, and FIG. 2 shows a steel plate subjected to magnetic microfabrication according to the present embodiment. In the following description, the rolling direction or the steel sheet moving direction means the x-axis direction in Fig. 2, the width direction means the y-axis direction in Fig. 2 in a direction orthogonal to the rolling direction, and the width in the y- Length. In Fig. 2, reference numeral 31 denotes a radiation line continuously formed on the surface of the steel plate 1 by being cut into a groove shape by a laser beam.

Referring to FIG. 1, the magnetic field refinement apparatus for a directional electric steel sheet according to the present embodiment stably performs permanent magnetic domain refinement even if the steel sheet 1 advances at a high speed of 2 m / s or higher.

The magnetic domain refinement apparatus of this embodiment comprises a laser irradiation facility for irradiating a laser beam to form a groove on the surface of the steel plate 1, a work line L1 for moving the steel plate to a laser irradiation facility, A passing line L2 for moving the steel plate to skip without passing through the laser irradiation equipment, and a line changing unit for converting the progress of the steel plate to the passing line L2.

In the following description, the work line L1 refers to a line in which a laser irradiation facility is disposed as a process line on which a steel strip is moved, and a laser beam is applied to the steel strip for miniaturization. The passing line L2 can be understood as a line skipped to the exit side of the work line L1 so as not to pass through the laser irradiation equipment. As shown in Fig. 1, for example, a line extending from the exit side of the tension bridle roll 5B supporting the steel sheet along the process line to the equipment exit side via the laser irradiation equipment may be referred to as a work line L1 . On the other hand, a line connected from the exit side of the tension brick roll 5B to the exit side of the work line L1 may be referred to as a passing line L2.

The deflector rolls 8A and 8B, the steel plate supporting roll 9, the optical system 15, the brush roll 26, the cleaning facility 29, and the like are disposed along the operation line L1 from the exit side of the tension bridle roll 5B So that the steel sheet can be finely processed. In this embodiment, the passing line L2 connects the steel plate advance line directly to the line on the outgoing side of the cleaning facility 29. [

The line changing unit switches the moving direction of the steel sheet from the working line L1 to the passing line L2 when necessary. The specific structure of the line changing unit will be described later.

A position adjusting device of a steel plate supporting roll for controlling the position of the steel plate in the vertical direction is disposed at one side of the laser irradiation equipment along the operation line L1 while supporting the steel plate 1 moved along the operation line L1.

Further, the magnetic domain refining apparatus may further include a laser room 20 for isolating the steel plate supporting-roll position adjusting facility and the laser irradiation equipment 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 that applies a tension to the steel plate so that the steel plate is not struck but spreads flat.

In addition, the magnetic domain refinement apparatus may further include a warp control facility for allowing the steel strip to move left and right along the center of the work line without deviation.

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 in accordance with the laser beam irradiation.

The hill up refers to a portion where molten iron is accumulated on both sides of the groove portion at a predetermined height or more when the groove is formed by irradiating the surface of the steel sheet with a laser beam. Spatter refers to molten iron generated during laser beam irradiation and solidified on the surface of a steel sheet.

Steering rolls 2A and 2B for switching the moving direction of the steel strip 1 are provided for measuring the degree of deviation of the central position of the width of the steel strip 1 from the center of the work line A steel strip central position control system (Strip Center) for adjusting the moving direction of the steel strip 1 by calculating the detection signals of the meander measurement sensor 4 and the meander measurement sensor 4 and rotating and moving the axes of the steering rolls 2A, Position Control System (3).

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

It is possible to form grooves on the surface of the steel sheet over the entire width of the steel sheet by the steel sheet being moved straightly along the center of the work line without swaying left and right.

In the meander control facility, the meandering amount of the steel sheet is measured by the meander measuring sensor 4 in the step before the surface groove formation of the steel sheet by the laser irradiation. The value measured by the meander measurement sensor 4 is output to the steel plate central position control system. The steel plate central position control system calculates the output value of the meander measurement sensor and rotates and rotates the axes of the steering rolls 2A, 2B according to the calculated degree of meandering. . As described above, the steering rolls 2A and 2B are rotated and moved, whereby the moving direction of the steel sheet wound around the steering roll is adjusted. Thus, the amount of meandering of the steel sheet is controlled, and the amount of meandering of the steel sheet 1 can be controlled within +/- 1 mm.

The tension control system includes tension bridge rolls (TBR) 5A and 5B for guiding movement of the steel plate 1 while applying a predetermined amount of tension to the steel plate 1, tension of the steel plate 1 passing through the tension bridge roll, A steel strip tension measuring sensor 7 for measuring the tension of the tension bridges 5A and 5B and a steel strip for adjusting the speed of the tension bridle rolls 5A and 5B according to the tension of the steel strip 1 measured by the steel strip tension measuring sensor 7. [ And a tension control system 6.

The steel plate tension measuring sensor 7 is disposed at the rear end of the tension bridle roll 5B and measures the actual tension of the steel plate subjected to the tension via the tension bridle roll 5B in real time.

In the present embodiment, the tensile force of the steel sheet can be set so that the surface of the steel sheet at the laser irradiation position of the laser irradiation equipment is made flat, and the steel sheet is not broken due to excessive tension.

The tension control apparatus is controlled by a tension control system 6 according to the tension of the steel plate measured by the steel plate tension measuring sensor 7 in order to operate the steel plate tension within a set range, ) (5A, 5B). Thus, the tension control system controls the tension error of the steel strip 1 so as to be within the set range, thereby imparting tension to the steel strip.

The steel plate having passed through the tension control facility flows into the laser room 20, is finely processed through the steel plate support roll position adjusting facility and the laser irradiation equipment, and then exits to the outside of the laser room 20. The laser room will be described later.

In this embodiment, a steel plate supporting roll 9 is disposed in the laser room 20 immediately below the laser irradiation equipment, and deflector rolls 8A and 8B are provided on both sides of the steel plate supporting roll, .

The moving direction of the steel strip 1 is switched to the steel strip supporting roll 9 by the deflector rolls 8A and 8B. The steel plate 1 is moved to the side of the steel plate supporting roll 9 through the deflector roll 8A so as to be moved toward the deflector roll 8B after the steel plate 1 is contacted with the steel plate supporting roll 9, Lt; / RTI >

The steel plate 1 is wound in the form of an arc along the steel plate supporting roll 9 by the deflector roll and passes over the steel plate supporting roll while being in surface contact. In order to minimize the fluctuation of the laser beam focal length due to the vibration of the steel sheet and the wave during the irradiation of the laser beam, the steel sheet must sufficiently contact the surface of the steel sheet supporting roll. In this state, You must investigate. In this embodiment, since the steel plate is in surface contact with the steel plate supporting roll as described above, the laser beam can be accurately irradiated to the steel plate.

The steel plate supporting-roll position adjusting device includes a steel plate supporting roll 9 for supporting the steel plate 1 to the laser irradiation position of the laser irradiation equipment, a flame sensor for measuring the brightness of the flame generated when the steel plate 1 is laser- (SPR) position control system 12 for controlling the position of the steel plate support roll 9 in accordance with the brightness of the flame measured by the brightness measurement sensor 10 have.

The steel plate supporting roll position adjusting device is a device for supporting the steel plate 1 to the position of the laser irradiation part by means of the steel plate supporting roll 9 so as to position the steel plate within the Depth of Focus The position of the steel plate supporting roll 9 is adjusted up and down as a whole so that the brightness of the flame generated at the time of irradiation becomes the best. The brightness of the flame generated when the steel plate is laser-irradiated is measured by using the luminance measurement sensor 10. [

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

The meander control facility, the tension control facility, and the steel plate support roll position adjustment facility are used to make the steel plate condition at the laser irradiation position so that the laser groove can be formed precisely by the laser irradiation equipment. The steel plate at the laser irradiation position should be located at the center position of the work 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 the continuous wave laser beam 16, and an optical system 15.

Fig. 3 shows an optical system of the laser irradiation equipment according to this embodiment.

3, the optical system 15 includes a module plate 37 rotatably installed to impart an angle of the laser beam irradiation line to the steel plate width direction, a driving unit 36 for rotating the module plate 37 A header 39 which is provided on the module plate 37 and which emits the laser beam applied from the laser oscillator 14 to the inside of the optical system 15; A polygon mirror 32 for reflecting the emitted laser beam, a rotation motor 33 for rotating the polygon mirror 32, a laser beam 16 provided on the module plate 37 and reflected by the polygon mirror 32 A driving motor 34 connected to the condenser mirror 35 for moving the condenser mirror 35 to adjust the focal distance of the laser beam, a condenser lens 35 for condensing the condenser mirror 35 on the module plate 37 Depending on whether or not the laser beam is irradiated, And a shutter 38 for selectively blocking the plate 37.

The optical system 15 is a body in which a header 39, a polygon mirror 32, a condenser mirror 35 and a shutter are disposed in a module plate 37 constituting an optical box. The laser oscillator 14 and the header 39 are connected to the optical cable 41, for example. Thus, the laser beam emitted from the laser oscillator 14 is transmitted to the header 39 via the optical cable 41. The header 39, the polygon mirror 32 and the condenser mirror 35 are disposed in position to reflect the laser beam 16 to a desired position inside the module plate 37 constituting the optical box. As shown in Fig. 3, for example, the header 39 may be arranged on both sides of the polygon mirror 32 to emit a laser beam toward the polygon mirror 32, respectively. Two condenser mirrors 35 are arranged in accordance with the respective laser beams reflected by the polygon mirror 32. [ The laser beam emitted from the header 39 is reflected by the polygon mirror 32 which rotates in accordance with the driving of the rotation motor 33 and is sent to the condensing mirror 35. The laser beam 16 reflected by the condenser mirror 35 is reflected from the condenser mirror 35 to the steel plate through the shutter 38 and condensed on the surface of the steel plate 1. [ Thus, the surface of the steel sheet is irradiated with the laser beam periodically to form continuous grooves in the width direction.

The entire focal distance of the laser beam 16 by the optical system 15 is adjusted by the upward and downward movement of the steel plate supporting roll 9 and the right and left focal lengths are not matched by the drive motor 34 ).

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. When the laser beam is not irradiated, the shutter 38 is closed so that external fumes or foreign substances are introduced into the optical system 15 Thereby blocking the inflow.

If the steel sheet meandering amount is excessive, the steel sheet is deviated from the laser irradiation position, and the steel sheet support roll 9 is irradiated with a laser, and damage occurs. In order to prevent the steel plate supporting roll from being damaged, 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 sheet steepness exceeds 15 mm .

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

The laser oscillator 14 and the optical system 15 irradiate the surface of the steel sheet with a laser beam to form grooves with an upper width, a lower width and a depth of 70 mu m or less, 10 mu m or less, 3 to 30 mu m, The laser energy density in the range of 1.0 to 5.0 J / mm 2 necessary for melting the steel sheet can be transmitted to the steel sheet so that a re-welded portion remaining on the inner wall surface of the groove in the molten portion during irradiation is generated.

The optical system 15 has a function of controlling the laser scanning speed so that the interval of the laser radiation (31 in Fig. 2) can be adjusted to 2 to 30 mm in the rolling direction. Thus, the influence of the heat affected zone (HAZ, heat affected zone) by the laser beam can be minimized and the iron loss of the steel sheet can be improved.

The laser irradiation equipment may be a structure for converting the angle of the irradiation line of the laser beam irradiated on the surface of the steel sheet with respect to the width direction of the steel sheet. In the present embodiment, the laser irradiation equipment can convert the angle of the irradiation line of the laser beam in the width direction of the steel plate into the range of +/- 4 degrees.

To this end, the laser irradiation equipment has a structure in which the optical system 15 for irradiating the steel plate with the laser beam is rotatable by the drive unit 36, and converts the angle of the irradiation line of the laser beam formed on the surface of the steel plate with respect to the width direction of the steel plate Structure. As the angle of the irradiation line of the laser beam by the optical system is changed as described above, the irradiation line 31 by the laser beam is formed by inclining in the range of +/- 4 degrees in the direction perpendicular to the rolling direction of the steel sheet. Therefore, it is possible to minimize the decrease in the magnetic flux density due to the groove formation by the laser.

Further, in this embodiment, the laser irradiation equipment controls the irradiating position of the laser beam on the steel plate 1 so as to prevent the back reflection phenomenon in which the laser beam irradiated on the steel plate is reflected by the steel plate and enters the optical system or the laser oscillator .

3, the laser irradiation facility irradiates the surface of the steel sheet, which is in contact with the surface of the steel plate support roll 9 in the form of an arc, in such a manner that the irradiation direction of the laser beam irradiated by the optical system 15, (The spacing angle R for the convenience of explanation hereinafter) from the reference point P to the center of the steel plate supporting roll 9 with the laser beam irradiation position when passing the center axis of the steel plate 9 as the reference point P, (Hereinafter referred to as " laser beam ").

The reference point P is a point where a line passing through the central axis of the steel plate supporting roll 9 meets the steel plate in Fig. When the irradiation direction of the laser beam passes the central axis of the steel plate supporting roll 9, the focal point of the laser beam is adjusted to the reference point P. In this case, as the irradiation direction of the laser beam is orthogonal to the tangent to the steel plate supporting roll 9 at the reference point P, the laser beam reflected by the steel plate is directly incident on the optical system and the laser oscillator, Lt; / RTI >

As described above, the laser irradiation apparatus according to this embodiment irradiates the laser beam at a position spaced apart from the reference point P by the spacing angle R, so that the laser beam reflected back from the steel plate is not incident on the optical system. Therefore, the above-described back reflection phenomenon can be prevented and the groove quality formed by the laser beam can be maintained.

In this embodiment, the spacing angle R can be set in the range of 3 to 7 degrees along the outer peripheral surface at the center of the steel plate supporting roll 9 with respect to the reference point P. [

When the spacing angle R, which is a position at which the laser beam is irradiated, is smaller than 3 DEG, a part of the laser beam reflected back from the steel sheet may be introduced into the optical system or the laser oscillator. If the spacing angle R is more than 7 degrees, the grooves formed by the laser beam may not be formed properly and the grooves may be formed defective.

As described above, the laser irradiation equipment according to the present embodiment prevents the back reflection phenomenon by irradiating the steel plate with the laser beam at a position spaced by a predetermined angle around the reference point P, and does not interfere with the incident optical path during laser beam reflection, So that it is possible to stably maintain the quality of the groove shape formed by the groove.

In addition, the laser irradiation equipment may further include a molten iron removing facility for removing fumes and spatter generated by the laser beam irradiation on the steel plate.

The molten iron removing apparatus includes an air knife 17 for spraying compressed dry air into the grooves of the steel sheet to remove molten iron remaining in the grooves, and dust collecting hoods 19A and 19B for sucking and removing fumes and molten iron can do. The fume generated during the laser irradiation through the air knife and the dust collecting hood is removed to prevent the fume from flowing into the optical system. The air knife 17 ejects compressed dry air having a predetermined pressure Pa into the groove of the steel plate 1 to remove the molten iron remaining in the groove. The compressed dry air in the air knife 17 preferably has a pressure (Pa) of 0.2 kg / cm ² or more. When the pressure of the compressed dry air is less than 0.2 kg / cm ² , it is impossible to remove the molten iron in the groove and the iron loss improving effect can not be secured. The fumes and spatters 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 portion 18 for shielding reflected light of the laser beam and scattered light and radiant heat from entering the optical system. The shielding portion 18 shields the reflected light and scattered light introduced into the optical system by reflection and scattering of the laser beam 16 irradiated on the steel plate to prevent the optical system from being thermally deformed by the radiant heat due to the reflected light and the scattered light .

The laser room 20 is a room structure having an inner space. The laser room 20 accommodates a laser irradiation facility and a steel plate support roll 9 position control facility to isolate the laser room 20 from the outside, and provides an appropriate operating environment for smooth driving thereof.

The entrance and exit of the laser room 20 are formed at the entrance and exit sides of the laser room 20 along the direction of the steel plate. The laser room 20 is equipped with a facility for blocking inflow of contaminants so that the internal space is not contaminated by external dust or the like. To this end, the laser room 20 has a positive pressure device 23 for raising the internal pressure beyond the outside. The positive pressure device 23 maintains the pressure inside the laser room 20 relatively higher than the external pressure. Accordingly, it is possible to prevent foreign substances from entering into the laser room 20. In addition, air curtains 22A, 22B, 22C, and 22D are provided at the entrance and exit of the steel sheet. The air curtain blocks the inflow of dust and the like through the inlet and the outlet by forming a film by spraying air to the inlet and the outlet which are the passages through which the steel sheet enters and exits the laser room 20. In order to prevent contamination of the interior of the laser room 20, a shower booth 21 may be installed on the door, which is an entrance of the laser room 20. The shower booth 21 removes foreign matter adhering to the body of the passerby entering the laser room 20.

The laser room 20 is a space in which the steel plate self-ballasting process is substantially performed by the laser beam, and it is necessary to minimize the change of the internal environment and maintain the proper environment. The laser room 20 includes an optical system lower frame 24 for separating the upper space where the laser oscillator 14 of the laser irradiation equipment and the optical system 15 are located from the lower space through which the steel plate 1 passes, Temperature and humidity controller (25) for controlling the internal temperature and humidity of the internal combustion engine (20).

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

The constant temperature and humidity controller 25 adjusts the temperature and humidity inside the laser room 20 to provide a proper environment. In the present embodiment, the constant temperature and humidity controller 25 can maintain the internal temperature of the laser room 20 at 20 to 25 DEG C and maintain the humidity at 50% or less.

As described above, the inner space of the laser room 20 is maintained at a temperature and a humidity suitable for the working environment, so that the micro-miniaturization process can be performed on the steel sheet in the optimum condition. Therefore, a high-quality product can be mass-produced under the optimal operating environment required for the process.

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

The heel-up and spatter cause the insulation of the product and the drop in the point rate, so the product quality can be improved by removing it completely through post-treatment equipment.

The post-treatment equipment may include brush rolls 26A and 26B disposed at the rear end of the laser room 20 along the steel sheet moving direction to remove the heel-up and spatters of the steel sheet surface. The brush rolls 26A and 26B are rotated at a high speed by a drive motor. The brush rolls 26A and 26B are controlled by a current control system 27 for controlling the current value of the drive motor generated during operation to a set target value, The rotation speed and the distance between the steel plate and the steel plate are controlled by the brush position control system 28. The brush roll may be disposed on only one side of the steel plate with grooves formed by the laser beam, or on both sides of the steel plate. The brush rolls 26A and 26B are brought into close contact with the surface of the steel sheet and are rotated at a high speed to remove the heel-up and spatter attached to the surface of the steel sheet. As shown in Fig. 1, a dust-collecting hood 19C for discharging the heel-up and the spatters removed by the brush roll in the vicinity of the brush rolls 26A and 26B is further provided. The dust collecting hood 19C sucks the heel-up and the molten iron, which are separated from the steel plate by the brush rolls 26A and 26B, and the spatters, and discharges the molten iron to the outside.

The post-treatment equipment includes a cleaning unit 29 disposed at the rear end of the brush rolls 26A and 26B for electrolytically reacting the steel sheet with the alkali solution to further remove the healing and spatter remaining on the surface of the steel sheet, And a filtering unit 30 for filtering the foreign substances contained in the alkali solution of the cleaning unit from the alkali solution.

The steel sheet is primarily healed and spatters are removed through the brush rolls 26A and 26B, and the remaining heal-up and spatters are secondarily removed through the clean unit 29. [ Thus, it is possible to more completely remove the heel-up and spatter attached to the surface of the steel sheet, thereby enhancing the product quality.

The cleaning unit 29 is filled with an alkali solution, and the filtering unit 30 is connected to one side. As the steel sheet is treated through the clean unit, the healing and spatters removed from the steel sheet are accumulated in the internal alkali solution, thereby deteriorating the cleaning performance of the steel sheet. The filtering unit 30 circulates the alkali solution of the cleaning unit and removes the healing and the spatter contained in the alkali solution. The filtering unit 30 removes the heal-up and the spatter to control the iron content of the alkali solution to 500 ppm or less. In this way, deterioration of the cleaning performance of the clean unit can be prevented, and the steel sheet can be continuously treated.

On the other hand, the present apparatus is provided with a line changing unit and can change the traveling direction of the steel sheet to the working line (L1) or the passing line (L2), if necessary.

The line changing portion can be disposed between the front end of the laser irradiation equipment, that is, the exit side of the tension brick roll 5B and the entrance side of the laser irradiation equipment. In the following description, the term " inlet " means the inlet side of the steel sheet along the direction of the steel sheet, and the outlet side may refer to the outlet side of the steel sheet.

Accordingly, the line changing unit can move the steel plate past the tension bridle roll 5B to the operation line L1 to normally perform the miniaturization process, or change the line to the passing line L2 if necessary, So that it can move directly to the exit side of the facility without going through.

The line changing portion of this embodiment includes a cutter 52 disposed at the entrance of the laser irradiation equipment for cutting the steel sheet and a switch roll 50 for guiding the direction of the trailing steel sheet cut by the cutter 52 to the passing line L2 .

The cutter 52 cuts the steel plate past the tension bridle roll 5B in the width direction before drawing the laser irradiation equipment. The cutter 52 may be disposed between the tension bridle roll 5B and the switching roll 50. [ The steel plate is cut by the cutter 52 and divided into two. The leading steel sheet is passed to the working line L1, and the trailing steel sheet is supported by the tension bridle roll 5B. The term "trailing steel plate" refers to a steel plate which is cut off from the cutter 52 and separated from the steel plate along the moving direction of the steel plate. On the contrary, the leading steel sheet may refer to the steel sheet located on the front side. Also, the term "shear" means the front end of the steel plate along the moving direction of the steel plate, and the term "rear end" means the back end of the steel plate.

The switching roll 50 is disposed on the exit side of the tension brick roll along the steel plate advancing direction and guides the leading end of the trailing steel plate cut by the cutter 52.

The line changing unit may further include a welder 54 for connecting the tip of the trailing steel plate which has been redirected to the passing line L2, to the rear end of the preceding steel plate moved along the working line L1. The welder 54 may be disposed separately from the cutter 52 or may be installed at the cutter 52 position. In the present embodiment, the welder 54 is disposed at the front side of the switching roll 50 and welds the leading edge of the trailing steel sheet past the switching roll 50 to the trailing edge of the trailing steel sheet.

The leading steel sheet passes through the laser beam-guiding apparatus after passing through the laser beam-guiding apparatus and is then moved to the welder 54 after welding and is welded to the leading edge of the trailing steel sheet which has been converted into the passing line L2 in the welder. Thus, the steel sheet is completely advanced in the working line L1, and proceeds to the passing line L2 passing through the tension rollers 5B and the switching rollers 50 without passing through the laser irradiation equipment.

The line changing portion may further include a through-plate portion 60 for passing the steel plate along the operation line L1 when the line is changed.

As shown in Fig. 4, the carrying section 60 includes a band 62 connected to the tip of the steel plate which is passed along the working line L1, a drum 64 around which the band 62 is wound, And may include a driving unit.

The band 62 may be prepared in a pre-commissioned state along the operation line L1. In the present embodiment, the conveyor unit 60 can be prepared by moving the band 62 to the operation line L1 in the process of moving the preceding steel sheet cut when switching to the passing line L2.

That is, the band 62 is connected to the rear end of the preceding steel sheet cut by the cutter 52. When the preceding steel sheet moves to the exit of the lay-up equipment, the band 62 connected to the preceding steel sheet moves along with the preceding steel sheet, and passes through each roll of the laser irradiation equipment and is transmitted to the progress line.

Therefore, the band 62 can be prepared by passing along the work line L1 from the exit side of the tension brick roll 5B, instead of the steel plate, through the laser irradiation equipment to the position of the switch roll 50. [

Thus, by preparing the band 62 of the conveyor section 60 in advance as a work line L1, the line changer can move the steel plate to the work line L1 by using the band 62 prepared in the subsequent line change So that it can be easily put on the market.

The band (62) is a long elongated band-shaped constituent part, and a clamp (66) for fixing the bar (62) to the steel plate is provided at the tip end. The drum 64 is rotatably mounted on the frame 61, and a driving unit is connected to the rotating shaft. Thus, when the drum 64 is rotated through the driving unit, the band 62 is wound around the drum 64, and the band 62 pulls the steel plate to form a shipping plate. The driving portion may include, for example, a driving motor 67 and a speed reducer 68.

The conveying section 60 further includes a band guide 69 provided on the frame 61 so as to be movable in the axial direction of the drum 64 and to guide the band 62 along the axial direction of the drum 64 . The band 62 is wound on the drum 64 via the band guide 69. As the band guide 69 moves in the axial direction of the drum 64, the band winding position with respect to the drum 64 is changed. Thus, the band guide 69 prevents the band from being wound on only one side of the drum 64 and winds the band uniformly in the axial direction of the drum. The band guide 69 can be reciprocated in the drum axial direction, for example, by receiving the power of the driving unit.

Hereinafter, the process of miniaturization of the electric steel sheet according to the present embodiment will be described.

First, the work process of moving the steel plate along the operation line of the equipment and finely finishing the steel plate will be described.

The steel plate continuously transported along the operation line enters the laser room through the meander control facility and the tension control facility and proceeds at a speed of 2 m / sec or more, and is finely processed. The steel sheet entering the laser room is finely processed through the laser irradiation equipment and then drawn out of the laser room. The steel sheet drawn to the outside of the laser room is passed through the post-treatment facility and the heal-up and spatter remaining on the surface are removed and sent to the post-process.

In this process, the laser room in which laser irradiation is performed on the surface of the steel sheet appropriately sets and maintains the internal operating environment so as to provide an optimum environment for microfabrication.

The laser room isolates the inside from the outside to block the inflow of external contaminants, and controls the internal temperature, pressure and humidity of the laser room according to the operating environment for microfabrication.

The inner pressure of the laser room is set higher than the external pressure, so that foreign substances such as dust can be prevented from entering into the laser room. In addition, by forming a film of air on the entrance and the exit, which are passages through which the steel sheet is moved, foreign substances such as dust can be prevented from flowing into the laser room during the process of the steel sheet through the entrance and exit.

The constant temperature and humidity controller installed in the laser room maintains the temperature inside the laser room at 20 to 25 DEG C and maintains the humidity at 50% or less, thereby providing an optimum condition for the magnetic domain refining treatment by laser irradiation.

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

Firstly, the steel plate is controlled by the meander control facility and is moved straightly along the center line of the work line.

The meander detection sensor continuously detects the meandering amount of the steel sheet. When the steel sheet meanders, the signal detected by the meandering sensor is calculated, and the steel plate central position control system rotates and moves the shaft of the steering roll to move the steel plate to the correct position do. By continuously controlling the steering roll in accordance with the position of the steel sheet, the steel sheet can be continuously moved continuously without departing from the center of the work line.

The steel plate is moved past the steering roll through the tension bridle roll for controlling the tension. Tension The tension of the steel plate past the bridle roll is detected by the tension measuring sensor. The steel plate tension control system calculates the measured value detected by the tension measuring sensor and controls the speed of the tension bridle roll with the set tension. Thus, the tension of the steel sheet to be moved can be maintained constantly in accordance with the set range.

The steel plate passed through the tensile bridle roll enters the laser room through the entrance of the laser room. The steel sheet is turned inside the laser room by the bridle roll and moved in a state of being in close contact with the steel plate supporting roll located between the two bridle rolls.

The steel plate supporting roll moves the steel plate up and down to place the steel plate in the depth of focus of the laser beam.

When the laser beam is irradiated from the laser irradiation equipment to the steel plate, the brightness measuring sensor detects the brightness of the flame on the steel plate in real time, and the steel plate supporting roll position control system moves the steel plate supporting roll up and down according to the measured value detected by the luminance measuring sensor So that the steel sheet is positioned within the focal depth of the laser beam. Thus, the surface of the steel sheet is effectively irradiated with the laser beam, and high quality radiation can be formed.

The laser oscillator controller turns on / off the laser oscillator according to the degree of skew of the steel sheet. The laser oscillator controller is connected to the meander measuring sensor, and determines that the steel plate has deviated too much from the steel plate supporting roll when the meander amount of the steel sheet measured from the meander measurement sensor is 15 mm or more, for example, and turns off the laser oscillator. Thus, it is possible to prevent the laser beam from being irradiated to the surface of the steel plate supporting roll through the meandered steel plate to damage the roll.

The laser beam generated by the laser oscillator is irradiated onto the surface of the steel plate through the optical system in response to the command from the laser oscillator controller. The laser oscillator oscillates the TEM ₀₀ continuous wave laser beam and transmits it to the optical system.

The optical system changes the direction of the laser beam and irradiates the surface of the steel sheet with a laser to continuously form a molten groove on the surface of the steel sheet to carry out micro-finishing.

 The surface of the steel sheet is melted by the laser beam irradiated to the steel sheet through the optical system, and a melted groove is formed along the irradiation line. In this embodiment, grooves having an upper width, a lower width and a depth of not more than 70 mu m, not more than 10 mu m, and 3 to 30 mu m, respectively, are formed on the surface of the steel sheet through laser beam irradiation, The laser oscillator and the optical system transmit the laser energy density within the range of 1.0 to 5.0 J / mm 2 to the steel sheet necessary for melting the steel sheet so that the re-irradiated portion is formed.

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

The present embodiment can protect the surface of the steel plate supporting roll by blocking the laser beam when the laser beam irradiated in the width direction of the steel plate is irradiated on the surface of the steel plate supporting roll after the laser beam irradiated in the width direction of the steel plate.

The surface protection of the steel plate supporting rolls through the interruption of the laser beam can be accomplished by blocking the laser beam irradiated to the surface of the steel plate supporting rolls exposed below the steel plate through the blocking plate disposed at both ends of the steel plate supporting roll. The blocking process includes first detecting a meander of a steel sheet running along a steel support roll, calculating a movement amount of the shield plate according to the detected amount of meander of the steel plate, , The surface of the steel plate supporting roll exposed from the steel plate can be covered with the shield plate to shield the laser beam.

That is, the amount of exposure of the steel plate supporting roll varies depending on the amount of skewing of the steel sheet relative to the steel sheet supporting roll, and the shielding plate moves to a value calculated according to the amount of skewing. By moving the blocking plate to the calculated movement amount, the blocking plate moves according to the changed exposure amount of the steel plate supporting roll to completely block the exposed surface of the steel plate supporting roll.

As described above, by properly shielding the laser beam irradiated to the exposed tip of the steel plate supporting roll, the surface of the steel plate supporting roll can be prevented from being damaged by the laser beam.

The process of protecting the surface of the steel plate supporting roll through the blocking plate has been described above, but the present embodiment is not limited thereto. For example, the steel plate supporting roll surface can be protected through a process of reflecting the laser beam on the steel plate supporting roll surface.

In another embodiment, the irradiation angle of the laser beam irradiated to the steel plate supporting roll is shifted off the side edge in the width direction of the steel plate to protect the surface of the steel plate supporting roll, thereby preventing the surface of the steel plate supporting roll from being irradiated with the laser beam. In order to reflect the laser beam, the position of the reflecting member for reflecting the laser beam may be moved and set corresponding to the width of the steel sheet. Accordingly, a reflecting member for reflecting the laser beam is positioned on both front end regions of the steel plate supporting roll exposed in accordance with the variation of the width of the steel sheet. Therefore, irrespective of changes in the width of the steel sheet, the reflecting member is blocked by the exposed portion of the steel plate supporting roll, thereby preventing the laser beam from being irradiated on the steel plate supporting roll surface.

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. Further, the optical system has a rotation function and can change the angle of the laser radiation line. In the present embodiment, the distance between the laser irradiation lines can be adjusted to 2 to 30 mm in the rolling direction by the optical system, thereby minimizing the influence of the heat affected zone (HAZ, heat affected zone) have. Further, in the laser beam irradiation process, the angle of the irradiation line of the laser beam irradiated on the surface of the steel sheet can be changed through the rotation of the optical system. In this embodiment, the optical system can convert the angle of the irradiation line of the laser beam into the range of +/- 4 degrees with respect to the width direction of the steel sheet. In other words, the irradiation line 31 of the laser beam can be formed so as to be inclined in the range of ± 4 degrees with respect to the y-axis direction in FIG. Therefore, the radiation rays formed on the surface of the steel sheet can be formed by inclining in the range of 86 to 94 degrees with respect to the rolling direction. By forming the irradiation line inclined with respect to the y-axis direction in this manner, it is possible to minimize the decrease in the magnetic flux density due to the formation of grooves by the laser.

During the laser beam irradiation process, the steel sheet is melted by the laser beam, and a large amount of fume and molten iron spatter are generated. The fume and spatter contaminate the optical system, and if molten iron remains in the groove, it is difficult to form a precise groove and damage of the iron loss is not made and the product quality is deteriorated. Thus, compressed dry air is sprayed into the grooves of the steel sheet to remove the residual iron in the grooves, and the fumes and molten iron are immediately sucked through the dust collecting hood to be removed. Accordingly, it is possible to prevent the fume from flowing into the optical system in the process of finishing the steel plate magnetic domain, and to rapidly remove the fume and the spatter, thereby improving the efficiency of microfabrication. Further, it is possible to further prevent the scattered light and the heat of the laser beam from being introduced into the optical system of the laser irradiation equipment during the laser beam irradiation process.

Grooves are formed on the surface of the steel sheet through the laser beam irradiation, and the steel plate subjected to the micro-finishing process is continuously moved and discharged to the outside through the exit of the laser room.

The steel sheet discharged from the laser room is subjected to a post-treatment process to remove the heel-up and spatters attached to the surface of the steel sheet.

The steel plate is firstly passed through the brush roll disposed outside the laser room, and is firstly heel-up and spatters are removed by the brush roll which is closely attached to the steel plate and rotates at high speed.

The steel plate after the brush roll is finally passed through the clean unit, and the remaining healing and spatter are finally removed through the electrolysis reaction between the steel sheet and the alkali solution. The steel plate with the heel-up and spatter removed through the clean unit is transferred to the post-process.

In this process, in the event that equipment malfunction occurs and maintenance is required, the traveling direction of the steel sheet is changed to a passing line which is skipped without going through the laser irradiation equipment in the work line.

In this embodiment, the line change can be made by cutting the steel sheet at the entrance of the laser irradiation equipment and converting the advancing direction of the cut steel sheet to the passing line.

The steel sheet is cut and divided into two pieces. The leading steel sheet is carried on the working line and the trailing steel sheet is supported on the tension bridle roll.

The trailing steel sheet cut in this state changes direction to the switching roll and moves along the passing line passing the switching roll.

The preceding steel sheet continues along the progress line. When the leading steel sheet is moved to the exit side of the proceeding line and the trailing edge of the leading steel sheet reaches the turning roll side, it is connected to the leading edge of the trailing steel sheet which is turned to the passing line.

Thus, the traveling direction of the steel sheet is completely switched to the passing line passing through the switching roll. Therefore, the steel plate travels along the passing line passing through the tension rollers roll and then to the equipment exit side through the switching roll.

When the test or maintenance of the laser irradiation equipment is completed, the advancing direction of the steel sheet is returned from the passing line to the working line.

In order to return to the work line, the workbench band is prepared along the work line and prepared in advance. The preparation of the band can be made in the process of changing the steel plate direction to the passing line. First, the pass band is connected to the rear end of the preceding steel sheet cut in the pass line conversion process. Then, prepare a mail order band along the operation line according to the movement of the preceding steel sheet. As the leading steel sheet moves along the working line in the state that the band is connected to the rear end of the preceding steel sheet, the band is moved along with the steel sheet and is ready for shipping on the working line.

The band can be separated from the rear end of the preceding steel sheet after the rear end of the preceding steel sheet is moved toward the switching roll. The rear end of the leading steel sheet from which the band has been separated is welded to the leading end of the trailing steel sheet converted into the passing line, as mentioned above.

When the direction of the steel sheet is changed from the passing line to the proceeding line in the state in which the band is prepared as described above, the steel sheet can be easily passed through the progress line by using the band.

In order to change the line, first, the steel plate that goes to the passing line is cut. Attach the band to the tip of the trailing steel sheet cut after cutting. And the band can be pulled to easily pass the trailing steel sheet to the working line.

For example, if a band is wound through a rotating drum, the band is pulled and the trailing steel plate connected to the band is moved through the working line.

The steel plate continues to move along the band and passes through the facility exit. The trailing steel plate is pulled to the diverting roll side by the band and connected to the rear end of the preceding steel plate which is cut off and moved to the passing line when it reaches the diverting roll side. Thus, the traveling direction of the steel sheet is completely switched to the working line passing through the laser irradiation equipment. Therefore, the steel sheet proceeds along the operation line moving to the facility exit through the laser irradiation equipment.

In this manner, by switching the direction of advance of the steel sheet when necessary and passing the steel sheet through the laser irradiation equipment, it becomes possible to easily carry out operations such as maintenance and testing for the laser irradiation equipment without interfering with the steel sheet. Further, after the work, it is possible to carry out the miniaturization work by simply passing the steel sheet through the operation line easily and easily.

Iron loss
Improvement rate (%) 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 ratio of the grain-oriented electrical steel sheet by grooves formed on the surface of the steel sheet of 0.27 mm thickness by the continuous wave laser beam irradiation according to the present embodiment. As shown in Table 1, in the case of the steel sheet subjected to the micro-finishing treatment in this embodiment, iron loss was improved both after the laser irradiation and after the heat treatment after miniaturization by the laser.

While the illustrative embodiments of the present invention have been shown and described, various modifications and alternative embodiments may be made by those skilled in the art. Such variations and other embodiments will be considered and included in the appended claims, all without departing from the true spirit and scope of the invention.

1: steel plate 2A, 2B: steering roll (SR)
3: Steel plate center position control system 4: Meander measurement sensor
5A, 5B: tension bridle roll 6: steel plate tension control system
7: steel plate tension measuring sensor 8A, 8B: deflector roll
9: steel plate supporting roll 10: luminance measuring sensor
11: distance measuring sensor 12: steel plate supporting roll position control system
13: laser oscillator controller 14: laser oscillator
15: optical system 16: laser beam
17: Air knife 18: Shield
19A, 19B, 19C: dust collecting 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: Survey line 32: Polygon mirror
33: rotation motor 34: drive motor
35: condensing mirror 36:
37: module plate 38: shutter
39: Header 50: Conversion Roll
52: cutter 54: welder
60: Transmission section 62: Band
64: Drum 66: Clamp
67: Driving motor 69: Band guide

Claims (12)

A moving step of moving the steel plate along a work line where the laser irradiation equipment is located,
A laser irradiation step of irradiating a surface of the steel sheet with a laser beam through a laser irradiation equipment to form a groove on the surface of the steel sheet,
A line changing step of changing the progress of the steel sheet, if necessary, from a work line to a passing line to be skipped without going through a laser irradiation facility
Wherein the magnetic steel sheet has a thickness of 10 mm or less. The method according to claim 1,
Wherein the line changing step includes cutting the steel sheet at the entrance of the laser irradiation equipment and converting the traveling direction of the cut steel sheet to the passing line. 3. The method of claim 2,
The line changing step includes moving the cut leading steel plate along a work line, connecting the rear end of the preceding steel plate to the leading end of the following steel plate which is redirected to the passing line, and moving the steel plate along the passing line Further comprising the steps of: 4. The method according to any one of claims 1 to 3,
Wherein the line changing step further includes a returning step of changing the moving line of the steel strip from the passing line to the working line. 5. The method of claim 4,
Wherein the returning step comprises the steps of connecting a transmission band to the rear end of the cut leading steel sheet and preparing a shipping band along the operation line in accordance with the movement of the preceding steel plate, And pulling said band to pass said trailing steel strip through a working line. ≪ Desc / Clms Page number 19 > A laser irradiation equipment for irradiating a laser beam to form a groove on the surface of the steel sheet,
An operation line for moving the steel plate to a laser irradiation facility,
A passing line connected to the work line to move the steel plate to skip without going through the laser irradiation equipment, and
A line changing unit for changing the progress of the steel sheet to the passing line,
Wherein the magnetic steel sheet has a thickness of 10 mm or less. The method according to claim 6,
Wherein the line changing portion includes a cutting device disposed at a front end of the laser irradiation facility for cutting the steel sheet and a switching roll for guiding the direction of the trailing steel sheet cut by the cutting device to the passing line side. 8. The method of claim 7,
Wherein the switching roll is disposed between a tension bridle roll and a laser irradiation equipment that maintains the tension of the steel plate. 8. The method of claim 7,
Wherein the line changing unit further includes a welder for connecting the leading edge of the trailing steel plate which has been redirected to the passing line to the trailing edge of the leading steel plate moved along the working line. 10. The method according to any one of claims 6 to 9,
Wherein the line changing portion further includes a through plate portion for passing the steel plate along a working line upon line change. 11. The method of claim 10,
Wherein the conveying section includes a band connected to a front end of the steel plate through a work line, a drum around which the band is wound, and a driving section for rotating the drum. 12. The method of claim 11,
Wherein the conveying section further comprises a band guide which is installed on the frame on which the drum is installed and is movable in the axial direction of the drum and which guides the band along the drum axis direction.

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