KR101913367B1 - Method and apparatus for refining magnetic domains grain-oriented electrical steel - Google Patents

Abstract

A steel plate supporting roll position for controlling the position of the steel plate in the vertical direction while supporting the steel plate proceeding along the production line so as to detect whether the grooves are defective by accurately checking the machining state of the groove- A laser irradiating step of irradiating the surface of the steel sheet with a laser beam to form a groove on the surface of the steel sheet by melting the steel sheet and a detecting step of detecting a defect in the groove formed on the surface of the steel sheet in the course of the steel sheet progressing, A method of miniaturization of an electric steel sheet is provided.

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.

Provided is a magnetic billet refining method and apparatus of a directional electric steel plate which can detect whether a groove is defective by accurately confirming a machining state of a magnetic microfabricated groove formed on a surface of a steel sheet in a work process.

The method includes a step of adjusting a position of a steel plate supporting roll to control a position of the steel plate in the vertical direction while supporting a steel plate running along a production line, a step of irradiating a laser beam on the surface of the steel plate to melt the steel plate, And a detecting step of detecting a defect in the groove formed on the surface of the steel sheet in the course of the steel plate proceeding.

The detecting step may include measuring a size of a groove formed in the steel sheet.

The detecting step may further include detecting a forming interval of the grooves formed in the steel sheet.

The detecting step may measure the groove of the steel sheet by a leakage magnetic flux measuring method.

The detecting step may include magnetizing the surface of the steel sheet by applying a magnetic force, detecting a leakage magnetic flux formed by the grooves, and calculating defects of the groove by calculating the detected leakage magnetic flux.

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 production line without shifting.

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.

The meandering control step may include a meander amount measuring step of measuring a meandering amount of the central position of the steel plate which is deviated from the center of the production line and a meandering amount measuring step of measuring the amount of meandering 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 domain refining apparatus of this embodiment includes a steel plate support roll position adjusting device for controlling the position of the steel plate in the up and down direction while supporting the steel plate moved along the production line and a laser beam for melting the steel plate, And a detection unit for detecting whether or not the groove is defective by confirming the state of the groove formed on the surface of the steel sheet.

Wherein the detecting unit comprises: a nonconductive roll supporting a moving steel plate; A leakage flux measuring unit including a magnetizer for magnetizing the surface of the steel sheet passing through the nonconductive roll and magnetizing the surface of the steel sheet, and a magnetic sensor for measuring a leakage magnetic field of the groove formed in the steel sheet, And a control unit for calculating an output signal of the magnetic sensor to check whether the groove is defective.

The control unit may include a signal converter for converting the leakage magnetic field signal detected by the magnetic sensor into a magnitude signal of a groove, a comparison unit for comparing a set groove size reference value with a preset groove size reference value and a groove size actual value output from the signal converter, And an operation unit for determining the operation state of the vehicle.

The arithmetic unit may be configured to determine whether there is a defect by comparing the pre-set steady-state groove spacing reference value with the actual gap spacing output from the signal converting unit.

The control unit may further include a facility control unit for controlling driving of the facility according to an output signal of the operation unit.

The detecting unit may further include a driving unit that adjusts an interval between the leakage magnetic flux measuring unit and the steel plate.

The driving unit may include a rail installed on the apparatus toward the steel plate, a moving truck moving along the rail, and a moving frame movably installed on the moving truck and having the leakage magnetic flux measuring unit at its tip.

The control unit may further include a drive control unit connected to the drive unit and controlling the drive unit according to an output signal of the equipment control unit.

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.

The steel sheet may further include a skew control device that allows the steel sheet to move left and right along the center of the production 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 meander control facility comprises a steering roll for switching the moving direction of the steel strip, a meander measuring sensor for measuring the degree of deviation of the central position of the steel strip from the center of the production 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 accurately measure the presence or absence of a defect in real time by detecting the state of a finely formed groove on the surface of the steel sheet in a state in which the steel sheet is continuously moved in accordance with the continuous magnetic microfabrication process. By stopping, the production of defective products can be minimized.

It is possible to precisely detect whether the grooves formed in the steel plate are defective in the width direction to accurately ascertain the position where the problem has occurred in the optical system of the facility and to solve the problem more easily and promptly through the selective supplementary maintenance.

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.

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.
4 is a schematic view showing a configuration of a detection portion of a magnetic domain refinement apparatus of a grain-oriented electrical steel sheet according to the present embodiment.
5 is a view for explaining the operation of the detecting unit according to the present embodiment.
FIG. 6 is a view showing defect detection results of grooves formed in the steel sheet according to the present embodiment. FIG.

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 refining apparatus of the present embodiment includes a steel plate supporting roll position adjusting device for controlling the position of the steel plate in the vertical direction while supporting the steel plate 1 moved along the production line, A laser irradiation equipment for forming a groove, and a detection unit 50 for detecting whether or not the groove is defective by confirming the state of the groove formed on the surface of the steel plate.

As shown in FIG. 1, the detection unit 50 detects the presence or absence of a defect by checking the state of the groove formed in the steel plate that is disposed at the rear end of the apparatus and continuously running. The detection unit will be described later in detail.

In addition, 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 facility from the outside and providing an operating environment for laser irradiation.

In addition, the magnetic domain refinement apparatus may further include a tension control device for applying a tension to the steel strip so that the steel strip is not struck but spread flat.

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

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 direction of movement of the steel strip 1 are disposed at the center of the width of the steel strip 1, (4) for calculating a detection signal of the meandering measurement sensor (4) and for rotating and moving the axis of the steering rolls (2A, 2B) to adjust the moving direction of the steel plate (1) And a position control system (Strip Center 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 full width of the steel sheet by moving the steel sheet straightly along the center of the production line without side-to-side bias.

In the meander control facility, the meandering amount of the steel sheet is measured by the meander measuring sensor 4 in the pre-formation step of the steel sheet surface by 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. Therefore, the meandering amount of the steel sheet is controlled, and the meandering amount of the steel sheet 1 can be controlled within +/- 1 mm.

The tension control facility includes tension braille rolls (TBR) 5A and 5B for guiding movement of the steel strip 1 while applying a predetermined tension to the steel strip 1, 5B according to the tension of the steel strip 1 measured by the steel strip tension measuring sensor 7 and the steel strip tension measuring sensor 7 for measuring the tension of the tension bridle rolls 5A, And a steel strip control system 6 for controlling the tension of the steel strip.

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.

In order to operate the steel plate tension within a predetermined range, the tension control facility is controlled by a steel strip tension control system 6 according to the tension of the steel plate measured by the steel plate tension measurement sensor 7, TBR) (5A, 5B). Thus, the tension control device controls the tension error of the steel strip 1 to be within the set range to apply 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 supporting 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, And a steel plate support roll (SPR) position control system 12 for controlling the position of the steel plate support roll 9 according to the brightness of the flame measured by the brightness measurement sensor 10 ).

The steel plate supporting roll position adjusting apparatus is configured such that the steel plate 1 is supported by the steel plate supporting roll 9 to the position of the laser irradiation portion and the steel plate 1 is supported on the steel plate so that the steel plate is positioned 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 in the laser 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 roll 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, As shown in FIG.

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

3, the optical system 15 includes a module plate 37 rotatably installed to impart an angle of the laser beam irradiation line with respect to the width direction of the steel plate, A header 39 installed on the module plate 37 and for emitting a laser beam applied from the laser oscillator 14 to the inside of the optical system 15; A polygon mirror 32 for reflecting the laser beam emitted from the polygon mirror 32 and a rotating motor 33 for rotating the polygon mirror 32; A condenser mirror 35 which reflects the laser beam 16 toward the steel plate and focuses the laser beam onto the steel plate, a driving motor 34 connected to the condenser mirror 35 to move the condenser mirror 35 to adjust the focal distance of the laser beam, , And the module plate 37 The values may include a shutter 38 for selectively blocking the module plate 37, depending on whether the laser beam irradiation.

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. A header 39, a polygon mirror 32 and a condensing mirror 35 are disposed in a correct position to reflect the laser beam 16 to a desired position inside the module plate 37 constituting the optical box. 3, for example, the header 39 may be disposed on both sides of the polygon mirror 32, and may 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 generated inside the optical system 15 .

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 damage to the steel plate supporting roll, the laser oscillator controller 13 turns on the laser oscillator under normal working conditions and controls the laser oscillator to turn off when the steel sheet steepness exceeds 15 mm do.

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.

Further, 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 this 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 is structured such that the optical system 15 for irradiating the steel plate with a laser beam is rotatable by the drive unit 36, and the angle of the irradiation line of the laser beam formed on the surface of the steel plate is changed Lt; / RTI > 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 a 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 Structure.

3, the laser irradiation facility irradiates the surface of the steel sheet, which is in contact with the surface of the steel plate supporting 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 laser beam irradiation position when passing the central axis of the roll 9 is set as a reference point P and an angle from the reference point P to the center along the outer peripheral surface at the center of the steel plate supporting roll 9 R) (hereinafter referred to as " R ").

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 the present embodiment, the spacing angle R may 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) exceeds 7, grooves formed by the laser beam may not be formed properly and 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.

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 . The fume generated during the laser irradiation through the air knife and the dust-collecting hood is removed and the fume can be prevented from being introduced into the optical system. The air knife 17 injects 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 smaller 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, scattered light, and radiant heat of the laser beam from entering the optical system. The shielding portion 18 shields the reflected light and the 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 scattered light do.

The laser room 20 is a room structure having an internal space. The laser irradiation facility and the steel plate supporting roll 9 are accommodated in the inside of the room structure to isolate it from the outside and provide an appropriate operating environment for smooth driving do.

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 has 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 is provided with 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 blows air to the inlet and the outlet, which are passages through which the steel sheet enters and exits the laser room 20 to form a film, thereby blocking dust and the like from entering through the inlet and the outlet. In order to prevent contamination of the inside 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-ballast finishing process by the laser beam proceeds, 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 in which 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 constant temperature and humidity controller 25 for controlling the internal temperature and humidity of the room 20.

The optical system lower frame 24 makes it possible to more thoroughly manage the operation 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 plate 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 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.

Since the heel-up and spatter cause deterioration of the insulation and viscosity of the product, the quality of the product can be improved by completely removing the product through the 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 driving motor. The brush rolls 26A and 26B are controlled by a current control system that controls the current value of the driving motor generated during operation to a predetermined target value, The rotation speed and the distance between the steel plate are controlled by the control system. The brush roll may be disposed on only one side of the steel plate having grooves formed by the laser beam, or on both sides of the steel plate. The brush rolls 26A and 26B come into close contact with the surface of the steel sheet and rotate 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 spatters and discharges the molten iron to the outside.

The post-treatment facility 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 foreign substances contained in the alkali solution of the clean 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 clean unit 29 is filled with an alkali solution, and the filtering unit 30 is connected to one side. As the steel sheet is processed through the clean unit, the heel-up 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 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.

FIG. 4 shows a detection unit 50 provided at the rear end of the apparatus according to the present embodiment.

The detection unit 50 is disposed at the rear end of the post-treatment facility and finally detects the presence or absence of a defect by monitoring the processing state of the groove 31 formed on the surface of the steel plate 1. [

4, the detecting unit 50 includes a non-conductive roll 51 for supporting a moving steel plate, a leakage magnetic flux measuring unit 52 including a magnetizer 53 and a magnetic sensor 54, And a controller 55 for calculating an output signal of the sensor 54 to check whether the groove is defective.

The magnetizer 53 is magnetized by applying a magnetic force to the surface of the steel plate passing through the nonconductive roll 51. The magnetic sensor 54 is disposed on the steel plate so as to be spaced apart from the steel plate, .

The nonconductive roll 51 is a roll made of a nonconductive material that does not transmit electricity itself. The nonconductive roll 51 stably supports the steel sheet against the leakage magnetic flux measuring part 52 while contacting the steel sheet with a sufficient area. The steel sheet can be advanced by touching the surface of the nonconductive roll 51 in the form of an arc.

The leakage magnetic flux measuring unit 52 measures a magnetic field leaking from the discontinuous portion of the surface of the steel sheet, that is, the groove, using the magnetic flux leakage.

To this end, the leakage magnetic flux measuring unit 52 includes a magnetizer 53 for magnetizing and applying a magnetic field to the surface of the steel plate, and a magnetic field leaking from the groove as a discontinuous section of the steel plate magnetized by the magnetizer 53 And a magnetic sensor 54 for measuring.

One or two or more of the magnetizer 53 and the magnetic sensor 54 may be arranged along the width direction on the surface of the steel sheet. Accordingly, the leakage magnetic flux measuring unit 52 can measure the size of the groove, for example, the depth and width of the groove with respect to the entire length of the groove formed in the width direction of the steel plate. Further, since the steel plate continuously passes through the leakage magnetic flux measuring unit 52, the leakage magnetic flux measuring unit 52 can detect the gap formed in the surface of the steel plate.

5 shows a principle of measurement by the leaked magnetic flux measuring unit.

As shown in FIG. 5, the magnetisation magnetizes the object to be measured by applying a magnetic field to the surface of the object to be measured, which is a magnetic metal. In a discontinuous section such as grooves, erosion, cracks, and the like formed on the surface of the object to be measured, a magnetic leak occurs. Such a magnetic field is measured on a magnetic sensor which is placed on the object to be measured. By analyzing the measured leakage magnetic field, it is possible to confirm the size of the discontinuous section formed on the object to be measured.

According to this principle, the leakage magnetic flux measuring unit 52 of this embodiment can accurately detect the leakage magnetic flux for the groove formed on the surface of the steel sheet, which is a ferromagnetic body, in a state in which the steel sheet 1 is continuously running.

The control unit 55 calculates a leakage magnetic field signal detected by the leakage magnetic flux measuring unit 52 to detect whether the groove is defective.

In the present embodiment, the control unit 55 includes a signal conversion unit 56 for converting the leakage magnetic field signal detected by the magnetic sensor 54 into a depth signal of the groove, And an operation unit 57 for comparing the actual groove size value output from the conversion unit 56 to determine the presence or absence of a defect.

The signal applied from the magnetic sensor 54 is a leakage magnetic field value and the signal converter 56 converts the signal applied from the magnetic sensor 54 into a groove size value. The actual value of the groove size is obtained through the signal conversion unit 56. [

The operation unit 57 stores a reference value for a groove size in a steady state as data. The operation unit 57 is connected to the signal conversion unit 56 and compares the groove size actual value applied from the signal conversion unit 56 with the groove size reference value stored therein to determine the presence or absence of a defect. That is, when the actual value of the groove size is close to the groove size reference value, the operation unit 57 can determine the normal state, and if it deviates greatly from the groove size reference value, it can be determined that there is a defect.

In addition, the operation unit 57 stores a reference value for a groove forming interval in the steady state as data. The arithmetic operation unit 57 can determine the presence or absence of a defect by comparing the actual gap value of the groove determined through the signal applied from the signal converter 56 with the groove gap reference value stored therein.

In addition, since the calculator 57 detects the presence or absence of a defect in the groove with respect to the entire length of the groove along the width direction of the steel plate, it is possible to more specifically check the defective position of the groove with respect to the defected groove. A plurality of necessary components such as a condensing mirror for laser irradiation may be arranged along the width direction of the steel plate in accordance with the lengthwise direction of the steel plate. By detecting the presence of defects in the groove, it is possible to precisely check whether there is a problem in a plurality of constituent parts arranged along the steel plate width direction. Therefore, it is possible to selectively perform supplemental measures such as maintenance on the constituent parts.

In this manner, the detection unit 50 can monitor the machining state of the grooves formed on the surface of the actual steel plate in the process state of forming the groove of the magnetic ball on the steel plate, and confirm whether or not the ball is defective. .

The control unit 55 may further include a facility controller 58 for controlling the operation of the facility according to an output signal of the operation unit 57.

The facility control unit 58 controls the driving of the apparatus by applying control signals to the respective constituent units constituting the steel plate magnetic bead microfabrication apparatus according to the output signal of the operation unit 57. For example, the facility control unit 58 may stop the movement of the steel plate by controlling the driving unit that moves the steel plate along the line, or may stop the laser groove processing by controlling the operation of the laser irradiation equipment. Accordingly, when defects are formed in the grooves formed in the steel strip, the operation is immediately stopped in accordance with the signal from the equipment control section 58, thereby preventing the production of the defective steel strip.

As shown in FIG. 4, the detecting unit 50 may further include a driving unit for adjusting the gap between the leakage magnetic flux measuring unit 52 and the steel plate, if necessary. The detecting unit 50 may include a leakage magnetic flux measuring unit 52 and a magnetic flux measuring unit 52 according to various work environments such as maintenance of the leakage magnetic flux measuring unit 52, waiting for operation, and adjustment of a measurement distance between the magnetic sensor 54 and the steel plate, It is necessary to adjust the distance between the steel plates.

In the present embodiment, the driving unit includes a rail 60 installed on the equipment toward the steel plate, a moving car 61 moved along the rail 60, a movable rail 61 movably installed on the moving car 61, And a moving frame 62 provided with the leakage magnetic flux measuring unit 52.

The control unit 55 may further include a drive control unit 59 connected to the drive unit for controlling the drive unit according to an output signal of the equipment control unit 58.

When the moving carriage 61 is moved along the rail 60, the moving frame 62 provided with the leakage magnetic flux measuring unit 52 is moved back and forth toward the steel plate and the moving frame 62 ) Is moved to precisely adjust the gap between the steel strip and the leakage magnetic flux measuring portion 52 provided on the moving frame 62. [

The movement of the moving carriage 61 and the moving frame 62 can be variously set, for example, by using a driving force of a driving cylinder, a step motor or the like.

The drive control unit 59 applies a control signal to the moving carriage 61 and the moving frame 62 in accordance with the output signal of the equipment control unit 58 so that the leakage flux measuring unit 52 is moved closer to or away from the steel plate . For example, when the coil information is transmitted from the central operating room to the control unit 55, the facility control unit 58 of the control unit 55 controls the magnetic flux density between the magnetic sensor 54 of the leakage magnetic flux measuring unit 52 and the steel plate And a control signal is applied to the drive control unit 59 at an appropriate distance. The drive control unit 59 drives the moving carriage 61 and the moving frame 62 in accordance with a signal applied from the facility control unit 58 to position the magnetic sensor 54 of the leakage magnetic flux measuring unit 52 on the surface of the steel plate do.

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

Continuous steel plates are passed through the meandering control equipment and the tension control equipment, enter the laser room, proceed at a speed of 2 m / sec or more, and 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 of the laser room from the outside and blocks the inflow of external contaminants, and controls the internal temperature, pressure, and humidity of the laser room according to the operating environment for miniaturization.

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.

First, the steel plate is controlled in a straight line through the meander control facility, and moves straight along the center of the production 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 according to the position of the steel sheet, the steel sheet can be continuously moved continuously without departing from the center of the production 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 position 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 measurement sensor, and determines that the steel plate has deviated too much from the steel plate supporting roll when the amount of meander of the steel sheet measured by 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 optical system has a function of controlling the laser scanning speed so that the interval of the laser irradiation lines with respect to the rolling direction can be adjusted. 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 a 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.

In the laser beam irradiation process, a steel sheet is melted by a 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. In addition, 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. After passing through the clean unit, the steel plate from which the heel-up and spatters have been removed is finally passed through the detection unit and checked for defects in the grooves formed on the surface of the steel sheet, and then transferred to the post-process.

In this embodiment, the presence or absence of a defect in the groove formed on the surface of the steel sheet is determined by measuring a leakage magnetic flux with respect to the groove of the steel sheet by a leakage magnetic flux measuring method. The magnetic flux leakage on the surface of the steel sheet magnetized by the magnetizer is detected through the magnetic sensor. By calculating the leakage magnetic flux detected in the groove of the steel sheet, it is possible to confirm whether or not the groove is defective.

Fig. 6 shows defect detection results of grooves formed in the steel sheet according to this embodiment. 6 (a) shows a measurement result in which the grooved state is good, and Fig. 6 (b) shows a measurement result in which the grooved state is poor.

As described above, it is possible to accurately detect the groove machining state of the steel sheet through the measurement of the leakage magnetic flux, thereby confirming whether or not there is a defect.

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 directional electric steel sheet by grooves formed on the surface of the steel sheet with a thickness of 0.27 mm 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: Deflector roll
8B: Deflector roll 8C: Medium 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:
51: nonconductive roll 52: leak magnetic flux measuring part
53: Magnetizer 54: Magnetic sensor
55: control unit 56: signal conversion unit
57: operation unit 58; Facility controller
59: drive control section 60: rail
61: Moving carriage 62: Moving frame

Claims (25)

A step of adjusting a position of a steel plate supporting roll to control a position of the steel plate in a vertical direction while supporting a steel plate running along a production line, a laser irradiation step of forming a groove on the surface of the steel plate by irradiating a laser beam onto the surface of the steel plate, And a detecting step of detecting a defect in the groove formed on the surface of the steel sheet in the steel plate proceeding,
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, And irradiating a laser beam at a position spaced apart at an angle from the center of the support roll along the outer circumferential surface. delete The method according to claim 1,
Wherein the laser beam is 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 thereof in the laser irradiation step. The method according to claim 1,
Wherein the laser irradiation step further comprises an angle conversion step of converting an angle of an irradiation line of the laser beam irradiated on the surface of the steel sheet. 5. The method of claim 4,
Wherein the angle conversion step converts the angle of the irradiation line of the laser beam in the width direction of the steel sheet into a range of +/- 4 degrees. 6. The method according to any one of claims 1 to 5,
Wherein the detecting step measures the groove of the steel sheet by a leakage magnetic flux measuring method. The method according to claim 6,
The detecting step includes magnetizing the surface of the steel sheet by applying a magnetic force, detecting leakage magnetic fluxes formed by the grooves, and calculating defects of the grooves by calculating the detected magnetic flux leakage, Method of micronization. 8. The method of claim 7,
Further comprising a setting maintaining step of setting and maintaining an internal operating environment of the laser room in which laser irradiation is performed,
Wherein the setting and maintaining step includes the step of isolating the inside of the laser room from the outside to block inflow of external contaminants, and controlling the internal temperature, pressure, and humidity of the laser room. 8. The method of claim 7,
Further comprising a tension control step of applying a tension to the steel plate so as to maintain the steel plate in a flattened unfolded state. 8. The method of claim 7,
And a skew control step of causing the steel sheet to move left and right along the center of the production line without tilting. 8. The method of claim 7,
Further comprising a post-treatment step of removing hill-up and spatter formed on a surface of the steel sheet through the laser irradiation step. A steel plate support roll position adjusting device for controlling the position of the steel plate in the vertical direction while supporting the steel plate moved along the production line and a laser irradiation equipment for melting the steel plate by irradiating with a laser beam to form grooves on the surface of the steel plate, And a detector for detecting whether the groove is defective by checking the state of the groove formed on the surface,
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, Wherein the laser beam is irradiated at a position spaced at an angle from the center of the support roll along the outer circumferential surface. delete 13. The method of claim 12,
Wherein the laser irradiation equipment irradiates the laser beam 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 thereof. 13. The method of claim 12,
Wherein the optical system of the laser irradiation equipment has a structure rotatable by a driving unit and rotates with respect to the steel plate to change the angle of the irradiation line of the laser beam in the width direction of the steel plate. 16. The method according to any one of claims 12, 14 or 15,
Wherein the detecting unit comprises: a nonconductive roll supporting a moving steel plate;
A leakage flux measuring unit including a magnetizer for magnetizing the surface of the steel sheet passing through the nonconductive roll and magnetizing the surface of the steel sheet, and a magnetic sensor for measuring a leakage magnetic field of the groove formed in the steel sheet, And
A controller for calculating an output signal of the magnetic sensor to check whether the groove is defective,
Wherein the magnetic steel sheet has a thickness of 10 mm or less. 17. The method of claim 16,
The control unit includes a signal conversion unit for converting the leakage magnetic field signal detected by the magnetic sensor into a groove size signal, and a comparator for comparing a groove size reference value of a predetermined steady state with a groove size actual value output from the signal conversion unit, And a calculation unit for determining whether or not the directional electric steel sheet has been formed. 18. The method of claim 17,
Wherein the calculation unit compares the pre-set steady-state groove spacing reference value with the actual gap spacing output from the signal converting unit to determine the presence or absence of a defect. 18. The method of claim 17,
Wherein the control unit further includes a facility control unit for controlling driving of the facility in accordance with an output signal of the operation unit. 17. The method of claim 16,
Wherein the detecting unit further comprises a driving unit that adjusts a gap between the leakage magnetic flux measuring unit and the steel plate. 17. The method of claim 16,
Further comprising a laser room for isolating the steel plate supporting roll position adjusting facility and the laser irradiation facility from the outside and providing an operating environment for laser irradiation. 22. The method of claim 21,
The laser room accommodates the laser irradiation equipment and the steel plate support roll position control equipment to form an inner space for isolating the laser irradiation equipment and the steel plate support roll position control equipment from each other. The entrance and exit are formed on both sides along the progress direction of the steel plate, A directional electric steel plate including an optical system lower frame for separating the upper space in which 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, . 17. The method of claim 16,
And a tensile force control device for applying a tensile force to the steel plate so as to maintain the steel plate in a flattened unfolded state. 17. The method of claim 16,
Further comprising a warp control device for causing the steel strip to move left and right along the center of the production line without tilting. 17. The method of claim 16,
Further comprising post-treatment equipment for removing hill-up and spatter formed on the surface of the steel sheet.

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