SISTEMA DE MONITORAMENTO DE PROFUNDIDADE DE RANHURA, APARELHO DE FABRICAÇÃO DE CHAPAS DE AÇO ELÉTRICO, MÉTODO DE MONITORAMENTO DE PROFUNDIDADE DE RANHURA, E, MEIO DE ARMAZENAMENTO NÃO TRANSITÓRIO LEGÍVEL POR COMPUTADOR

Abstract

This groove-depth monitoring system comprises: a torque acquisition unit that acquires a rotational torque generated when a polishing brush roll is used to remove an adhering substance adhered to the surface of a steel plate which has a groove formed therein by a beam; and a groove-depth determination unit that determines whether the depth of the groove formed in the surface of the steel plate is equal to or greater than a reference value on the basis of the rotational torque acquired by the torque acquisition unit and a reference rotational torque set in advance.

Description

66 GROOVE DEPTH MONITORING SYSTEM, ELECTRIC STEEL SHEET MANUFACTURING APPARATUS, GROOVE DEPTH MONITORING METHOD, AND COMPUTER-READABLE NON-TRANSIENTIAL STORAGE MEDIUM Technical Field

[001] The technology described in this application relates to a groove depth monitoring system, an electrical apparatus for manufacturing electric steel sheets, a method for monitoring groove depth and instructions for monitoring groove depth. Fundamentals of the Technique

[002] There is a method for manufacturing a grain-oriented electrical steel sheet in which a groove is formed by irradiating a front surface of the grain-oriented electrical steel sheet with a laser beam to refine the magnetic domains of the grain-oriented electrical steel sheet and reduce iron loss (see, for example, Japanese Publicly Open Patent Application (JP-A) No. 2017-122264).

[003] In addition, there is a laser groove monitoring method for monitoring a groove shape formed on a front surface of an electrically grained steel sheet using a laser beam (see, for example, JP-A No. 2019-512047).

[004] In the laser groove monitoring method described in document JP-A No. 2019-512047, spatter generated when forming the groove by irradiating the front surface of the grain-oriented electrical steel sheet with the laser beam is monitored, and the shape of the groove formed on the front surface of the grain-oriented electrical steel sheet is determined based on the spatter. SUMMARY OF THE INVENTION Petition 870250101208, dated 05 / 11 / 2025, page 10 / 158 / 66 Technical Problem

[005] By forming a groove by irradiating a front surface of a rolled steel sheet, which is a material of an electrical steel sheet, with a beam such as a laser beam or an electron beam, in a case where the beam output decreases or a focus (focal point) of the beam on the surface changes, the groove becomes shallow, which can reduce the iron loss reduction rate of the electrical steel sheet.

[006] However, there is a case in which it is not possible to detect a decrease in the beam output to the front surface of the rolled steel sheet or a change in beam focus by simply monitoring the amount of spatter generated when forming the groove by irradiating the front surface of the rolled steel sheet with the beam, and there is a possibility that the depth of the groove formed on the front surface of the electrical steel sheet will decrease.

[007] Considering the above fact, an objective of the technology described in the present application is to suppress a decrease in the depth of a groove formed on a front surface of an electrical steel sheet. Solution to the Problem

[008] A groove depth monitoring system according to a first aspect includes: A torque acquisition unit for acquiring rotational torque generated by removing deposits adhering to the front surface of a steel plate in which a groove is formed by a beam, by a polishing brush roller; and a groove depth determination unit for determining whether a groove depth formed on the front surface of the steel plate is equal to or greater than a reference value based on the rotational torque acquired by the torque acquisition unit and a predetermined reference rotational torque.

[009] In accordance with the above aspect, the torque acquisition unit Petition 870250101208, dated 05 / 11 / 2025, page 11 / 158 / 66 acquires the rotational torque generated when removing deposits adhering to the front surface of the steel plate where the groove is formed by the polishing brush roller beam. The groove depth determination unit determines whether the depth of the groove formed on the front surface of the steel plate is equal to or greater than the reference value based on the rotational torque acquired by the torque acquisition unit and the predetermined reference rotational torque.

[0010] Here, for example, it is possible to detect the steel plate in which the groove depth is less than the reference value due to a decrease in the beam output, by monitoring the rotational torque acquired by the torque acquisition unit. Therefore, a decrease in the groove depth formed on the front surface of the steel plate can be suppressed.

[0011] According to a second aspect, the groove depth monitoring system according to the first aspect further includes a spatter quantity acquisition unit to acquire a quantity of spatter generated when forming the groove, irradiating the front surface of the steel plate with the beam, wherein the groove depth determination unit determines whether the depth of the groove formed on the front surface of the steel plate is equal to or greater than the reference value based on the quantity of spatter acquired by the spatter quantity acquisition unit, a predetermined reference spatter quantity, the rotational torque acquired by the torque acquisition unit and the reference rotational torque.

[0012] According to the above aspect, the spatter quantity acquisition unit acquires the amount of spatter generated when forming the groove, irradiating the front surface of the steel plate with the beam. Then, the groove depth determination unit determines whether or not the depth of the groove formed on the front surface of the steel plate is sufficient. Petition 870250101208, dated 05 / 11 / 2025, page 12 / 158 / 66 equal to or greater than the reference value based on the amount of splashes acquired by the splash quantity acquisition unit, the predetermined reference splash quantity, the rotational torque acquired by the torque acquisition unit and the reference rotational torque.

[0013] As a result, for example, it is possible to detect a steel plate in which the groove depth is less than the reference value due to a decrease in beam output, a change in beam focus relative to the front surface of the steel plate, or something similar. Therefore, a decrease in the groove depth formed on the front surface of the steel plate can be suppressed.

[0014] Here, the amount of spatter generated when forming the groove by irradiating the front surface of the steel plate with the beam decreases basically as the depth of the groove formed on the surface decreases. Therefore, the depth of the groove formed on the front surface of the steel plate can be estimated by monitoring the amount of spatter acquired by the spatter quantity acquisition unit.

[0015] However, in a case where the amount of beam focus shift relative to the front surface of the steel plate is small, the amount of spatter decreases once and then increases again as the amount of beam focus shift increases. Therefore, in some cases, beam focus shift cannot be detected in a case where the amount of beam focus shift relative to the front surface of the steel plate is small by monitoring only the amount of spatter acquired by the spatter quantity acquisition unit.

[0016] Here, in a case where the amount of beam focus shift relative to the front surface of the steel plate is small, the viscosity of the generated spatter increases due to a temperature change or similar on the front surface of the steel plate, and the particle size of the deposits, such as the spatter adhering to the front surface of the steel plate, Petition 870250101208, dated 05 / 11 / 2025, page 13 / 158 / 66 increases. As a result, the rotational torque generated when removing deposits adhering to the front surface of the steel sheet by the polishing brush roller also increases.

[0017] Therefore, the groove depth determination unit monitors the rotational torque acquired by the torque acquisition unit, in addition to the amount of spatter acquired by the spatter quantity acquisition unit. As a result, it is possible to detect the beam focus shift even in a case where the amount of beam focus shift relative to the front surface of the steel plate is small. Therefore, a decrease in the groove depth formed on the front surface of the steel plate can be further suppressed.

[0018] According to a third aspect, in the groove depth monitoring system according to the second aspect, the groove depth determination unit determines that the depth of the groove formed on the front surface of the steel plate is equal to or greater than the reference value in a case where the amount of spatter acquired by the spatter quantity acquisition unit is equal to or greater than the reference spatter quantity and the rotational torque acquired by the torque acquisition unit is equal to or less than the reference rotational torque.

[0019] According to the above aspect, the groove depth determination unit determines that the depth of the groove formed on the front surface of the steel plate is equal to or greater than the reference value in a case where the amount of spatter acquired by the spatter quantity acquisition unit is equal to or greater than the reference spatter quantity and the rotational torque acquired by the torque acquisition unit is equal to or less than the reference rotational torque. As a result, it is possible to easily determine whether or not the depth of the groove formed on the front surface of the steel plate is equal to or greater than the Petition 870250101208, dated 05 / 11 / 2025, p. 14 / 158 / 66 reference value.

[0020] According to a fourth aspect, in the groove depth monitoring system according to the second or third aspect, the reference amount of spatter is determined based on the amount of spatter generated when forming the groove whose depth is equal to the reference value on the front surface of the steel plate, and the reference rotational torque is determined based on the rotational torque generated when removing the deposits that adhere to the front surface of the steel plate in which the groove whose depth is equal to the reference value is formed by the polishing brush roller.

[0021] According to the above aspect, the reference spatter quantity is determined based on the amount of spatter generated when forming the groove whose depth is equal to the reference value on the front surface of the steel plate. The reference rotational torque is determined based on the rotational torque generated when removing the deposits adhering to the front surface of the steel plate in which the groove whose depth is equal to the reference value is formed, by the polishing brush roller.

[0022] Thus, the groove depth determination unit determines whether the depth of the groove formed on the front surface of the steel plate is equal to or greater than the reference value based on the amount of spatter acquired by the spatter quantity acquisition unit, the predetermined reference spatter quantity, the rotational torque acquired by the torque acquisition unit, and the reference rotational torque. As a result, the accuracy of the groove depth determination unit is improved. Therefore, a decrease in the depth of the groove formed on the front surface of the steel plate can be further suppressed.

[0023] According to a fifth aspect, in the groove depth monitoring system according to the fourth aspect, Petition 870250101208, dated 05 / 11 / 2025, page 15 / 158 / 66: the reference quantity of spatter is determined based on the quantity of spatter generated when forming the groove on the front surface of the steel plate by the beam, in a case where the amount of beam focus change with which the front surface of the steel plate is irradiated is 0 and the beam power is equal to a reference value; the reference rotational torque is determined based on the rotational torque generated when removing the deposits adhering to the front surface of the steel plate where the groove is formed by the beam using the polishing brush roller, in a case where the amount of beam focus change with which the front surface of the steel plate is irradiated is 0 and the beam power is equal to the reference value.and the unit for determining groove depth determines that the depth of the groove formed on the front surface of the steel plate is equal to or greater than the reference value in a case where Formula (1) is satisfied. > S / S0 > C1 and C2 < T / T0 < C3 ··· (1)

[0024] Here, S: the quantity of splashes acquired by the splash quantity acquisition unit, S0: the reference amount of splashes, C1: S1 / S0, S1: the minimum amount of spatter generated when forming a groove whose depth is equal to the reference value on the front surface of the steel plate. T: the rotational torque acquired by the torque acquisition unit, T0: the reference rotational torque, C2: T1 / T0, T1: the minimum rotational torque generated when removing deposits Petition 870250101208, dated 05 / 11 / 2025, p. 16 / 158 / 66 that adhere to the front surface of the steel plate in which the groove is formed, the depth of which is equal to the reference value, by the polishing brush roller, C3: T2 / T0, and T2: the maximum rotational torque generated when removing deposits adhering to the front surface of the steel plate where the groove is formed whose depth is equal to the reference value, by the polishing brush roller.

[0025] According to the above aspect, in a case where Formula (1) is satisfied, the unit for determining the groove depth determines that the depth of the groove formed on the front surface of the steel plate is equal to or greater than the reference value. As a result, it is possible to easily determine whether or not the depth of the groove formed on the front surface of the steel plate is equal to or greater than the reference value.

[0026] According to a sixth aspect, in the groove depth monitoring system according to the fifth aspect, C1 is 0.83, C2 is 0.89, and C3 is 1.11.

[0027] Based on the above aspect, it is possible to easily determine whether the depth of the groove formed on the front surface of the steel plate is equal to or greater than the reference value.

[0028] According to a seventh aspect, in the groove depth monitoring system according to the fourth aspect, the reference amount of spatter is determined based on the amount of spatter generated when forming the groove on the front surface of the steel plate by the beam in a case where the amount of beam focus change with which the front surface of the steel plate is irradiated is 0 and the beam power is equal to a reference value, the reference rotational torque is determined based on the rotational torque generated when removing deposits adhering to the surface. Petition 870250101208, of 05 / 11 / 2025, page 17 / 158 / 66 front of the steel plate in which the groove is formed by the beam by the polishing brush roller in a case where the amount of change of focus of the beam with which the front surface of the steel plate is irradiated is 0 or the beam power is equal to the reference value, and the unit of determination of groove depth determines that the depth of the groove formed on the front surface of the steel plate is equal to or greater than the reference value in a case where Formula (2) is satisfied. > S / S0 > C1 and T1 < T < T2 ··· (2)

[0029] Here, S: the quantity of splashes acquired by the splash quantity acquisition unit, S0: the reference amount of splashes, C1: S1 / S0, S1: a minimum amount of spatter generated when forming the groove whose depth is equal to the reference value on the front surface of the steel plate. T: the rotational torque acquired by the torque acquisition unit, T1: the reference rotational torque, which is the minimum rotational torque generated when removing deposits adhering to the front surface of the steel sheet where the groove is formed, the depth of which is equal to the reference value by the polishing brush roller, and T2: the reference rotational torque, which is the maximum rotational torque generated when removing deposits adhering to the front surface of the steel sheet where the groove is formed, the depth of which is equal to the reference value, by the polishing brush roller.

[0030] According to the above aspect, in a case where Formula (2) is satisfied, the unit of determination of the groove depth determines Petition 870250101208, dated 05 / 11 / 2025, p. 18 / 158 / 66, states that the depth of the groove formed on the front surface of the steel plate is equal to or greater than the reference value. As a result, it is possible to easily determine whether or not the depth of the groove formed on the front surface of the steel plate is equal to or greater than the reference value.

[0031] According to an eighth aspect, in the groove depth monitoring system according to the seventh aspect, C1 is 0.83, T1 is 800 [Nm], and T2 is 1000 [Nm].

[0032] Based on the above aspect, it is possible to easily determine whether the depth of the groove formed on the front surface of the steel plate is equal to or greater than the reference value.

[0033] According to a ninth aspect, in the groove depth monitoring system according to the first aspect, the reference rotational torque is determined based on a rotational torque generated when removing deposits adhering to the front surface of the steel sheet in which the groove whose depth is equal to the reference value is formed by the beam by the polishing brush roller in a case where a focus shift quantity of the beam with which the front surface of the steel sheet is irradiated is 0.

[0034] According to the above aspect, the reference rotational torque is determined based on a rotational torque generated when removing deposits adhering to the front surface of the steel plate in which the groove whose depth is equal to the reference value is formed by the beam by the polishing brush roller in a case where a quantity of beam focus change with which the front surface of the steel plate is irradiated is 0.

[0035] So, the unit for determining groove depth that determines whether the depth of the groove formed on the front surface of the steel plate is equal to or greater than a reference value based on Petition 870250101208, dated 05 / 11 / 2025, page 19 / 158 / 66 rotational torque acquired by the torque acquisition unit and a predetermined reference rotational torque. Therefore, a decrease in the depth of the groove formed on the front surface of the steel plate can be suppressed.

[0036] According to a tenth aspect, in the groove depth monitoring system according to the ninth aspect, the reference rotational torque is determined based on the rotational torque generated when removing deposits adhering to the front surface of the steel plate in which the groove whose depth is equal to the reference value is formed by the beam, by the polishing brush roll in a case where the amount of beam focus change with which the front surface of the steel plate is irradiated is 0 and beam power is equal to a reference value, and the groove depth determination unit determines that the depth of the groove formed on the front surface of the steel plate is equal to or greater than the reference value in a case where Formula (3) is satisfied. T1 < T < T0 ··· (3)

[0037] Here, T: the rotational torque acquired by the torque acquisition unit, T0: the reference rotational torque, and T1: a minimum rotational torque generated when removing deposits adhering to the front surface of the steel plate in which the groove is formed, the depth of which is equal to the reference value, by the polishing brush roller.

[0038] According to an eleventh aspect, in the groove depth monitoring system according to the tenth aspect, T0 is 900 [Nm], and T1 is 800 [Nm]. Petition 870250101208, dated 05 / 11 / 2025, p. 20 / 158 / 66

[0039] According to the above aspect, in a case where Formula (3) is satisfied, the unit for determining the depth of the groove determines that the depth of the groove formed on the front surface of the steel plate is equal to or greater than the reference value. As a result, it is possible to easily determine whether or not the depth of the groove formed on the front surface of the steel plate is equal to or greater than the reference value.

[0040] A sheet metal fabrication apparatus according to a twelfth aspect includes: a beam irradiation device that irradiates a front surface of a steel plate, which is a material of an electrical steel plate, with a beam to form a groove; a polishing brush roller that removes deposits adhering to the front surface of the steel sheet where the groove is formed; and the groove depth monitoring system for an electrical steel sheet according to any one of the first to eleventh aspects.

[0041] According to the above aspect, it is possible to manufacture a steel sheet having a front surface in which a groove is formed whose depth is equal to or greater than a reference value.

[0042] A method of monitoring groove depth according to a thirteenth aspect includes: A torque acquisition step to acquire rotational torque generated by removing deposits adhering to the front surface of a steel plate where a groove is formed by a beam, using a polishing brush roller; and a groove depth determination step to determine whether the depth of the groove formed on the front surface of the steel plate is equal to or greater than a reference value based on the rotational torque acquired in the torque acquisition step and a torque Petition 870250101208, dated 05 / 11 / 2025, page 21 / 158 / 66 predetermined reference rotational.

[0043] According to the above aspect, in the torque acquisition step, the rotational torque generated by removing the deposits adhering to the front surface of the steel plate where the groove is formed by the polishing brush roller is acquired. In the groove depth determination step, it is determined whether the depth of the groove formed on the front surface of the steel plate is equal to or greater than the reference value based on the rotational torque acquired in the torque acquisition step and the predetermined reference rotational torque.

[0044] Here, for example, it is possible to detect the steel plate in which the groove depth is less than the reference value due to a decrease in the beam output, by monitoring the rotational torque acquired in the torque acquisition step. Therefore, a decrease in the groove depth formed on the front surface of the steel plate can be suppressed.

[0045] Instructions for monitoring groove depth according to a fourteenth aspect that is executable by a computer to perform processing, including: A torque acquisition step to acquire a rotational torque generated by removing deposits adhering to the front surface of a steel plate in which a groove is formed by a beam, using a polishing brush roller; and a groove depth determination step to determine whether a groove depth formed on the front surface of the steel plate is equal to or greater than a reference value based on the rotational torque acquired in the torque acquisition step and a predetermined reference rotational torque.

[0046] According to the above aspect, actions and effects similar to those of the groove depth monitoring method according to the thirteenth aspect can be obtained. Petition 870250101208, dated 05 / 11 / 2025, page 22 / 158 / 66 Advantageous Effects of the Invention

[0047] According to the technology described in this application, it is possible to eliminate a decrease in the depth of the groove formed on the front surface of the electrical steel sheet. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 is a side view of a grain-oriented electrical steel sheet manufacturing apparatus according to an embodiment when viewed from a width direction of a cold-rolled steel sheet.

[0049] Figure 2 is a side view of the grain-oriented electrical steel sheet manufacturing apparatus according to an embodiment when viewed from a direction of the width of the cold-rolled steel sheet.

[0050] Figure 3 is a flowchart illustrating an example of a method for manufacturing grain-oriented electrical steel sheet according to an embodiment.

[0051] Figure 4 is a perspective view of a groove depth monitoring system included in the grain-oriented electric steel sheet manufacturing apparatus according to an embodiment, when viewed from a front side in a cold-rolled steel sheet transport direction.

[0052] Figure 5 is a hardware configuration diagram of a slot depth monitoring system control device according to one embodiment.

[0053] Figure 6 is a functional block diagram of the slot depth monitoring system control apparatus according to one embodiment.

[0054] Figure 7 is a flowchart that illustrates an example of groove depth monitoring processing according to a modality.

[0055] Figure 8 is a table that illustrates the results of the tests of Petition 870250101208, dated 05 / 11 / 2025, page 23 / 158 / 66 manufacturing of grain-oriented electrical steel sheets according to an embodiment.

[0056] Figure 9 is a graph illustrating a relationship between the depth of a groove formed on the front surface of grain-oriented electrical steel sheet and the rate of iron loss reduction of the grain-oriented electrical steel sheet in the grain-oriented electrical steel sheet manufacturing test according to an embodiment.

[0057] Figure 10 is a graph illustrating a relationship between a change in focus of a laser beam relative to the front surface of the grain-oriented electrical steel sheet and the depth of the groove formed on the front surface of the grain-oriented electrical steel sheet in the grain-oriented electrical steel sheet fabrication test according to an embodiment.

[0058] Figure 11 is a graph illustrating a relationship between the amount of laser beam focus change relative to the front surface of the grain-oriented electrical steel sheet and the amount of spatter generated when the groove is formed by irradiating the front surface of the grain-oriented electrical steel sheet with the laser beam in the grain-oriented electrical steel sheet manufacturing test according to an embodiment.

[0059] Figure 12 is a graph illustrating a relationship between the amount of laser beam focus change relative to the front surface of the grain-oriented electrical steel sheet and a rotational torque generated in a polishing brush roller when polishing the front surface of the grain-oriented electrical steel sheet by the polishing brush roller in the grain-oriented electrical steel sheet manufacturing test according to an embodiment.

[0060] Figure 13 is a graph illustrating the relationship between the amount of spatter generated when a groove is formed by irradiating the front surface of the grain-oriented electrical steel sheet with a laser beam and the depth of the groove formed on the front surface of the steel sheet. Petition 870250101208, dated 05 / 11 / 2025, page 24 / 158 / 66 electrically oriented grain in the manufacturing test of electrically oriented grain steel sheet according to an embodiment.

[0061] Figure 14 is a graph illustrating a relationship between the rotational torque generated in the polishing brush roller when polishing the front surface of the grain-oriented electrical steel sheet by the polishing brush roller and the depth of the groove formed on the front surface of the grain-oriented electrical steel sheet in the grain-oriented electrical steel sheet manufacturing test according to an embodiment.

[0062] Figure 15 is a graph illustrating a relationship between a ratio of the amount of spatter to a reference amount of spatter and the rotational torque generated on the polishing brush roller when polishing the front surface of the grain-oriented electrical steel sheet by the polishing brush roller in the grain-oriented electrical steel sheet manufacturing test according to an embodiment.

[0063] Figure 16 is a graph illustrating a relationship between the ratio of the amount of spatter to the reference amount of spatter and a ratio of a rotational torque T to a reference rotational torque in the grain-oriented electrical steel sheet fabrication test according to an embodiment. DESCRIPTION OF THE MODALITIES

[0064] Next, an embodiment will be described with reference to the drawings. In the drawings, the same components or equivalent components are indicated by the same reference signs. Furthermore, unless otherwise specified, the number of components is not limited to one, and a plurality of components may be present. (Grain Oriented Electrical Steel Sheet)

[0065] First, an configuration of a grain-oriented electrical steel sheet according to the present embodiment will be described.

[0066] Grain-oriented electrical steel sheet is a steel sheet Petition 870250101208, dated 05 / 11 / 2025, page 25 / 158 / 66 electrical in which the easy magnetization axes of the crystal grains ( <100> The orientations of body-centered cubic crystals are substantially aligned in a rolling direction of the steel sheet (a longitudinal direction or a transport direction). Furthermore, grain-oriented electrical steel sheet has a plurality of magnetic domains in which the magnetization directions are aligned in the rolling direction. Grain-oriented electrical steel sheet is an example of electrical steel sheet.

[0067] Grain-oriented electrical steel sheet has the characteristic of having a lower iron loss than ordinary steel sheet due to its characteristic magnetic domain configuration. To further reduce the iron loss of grain-oriented electrical steel sheet, a front surface of the grain-oriented electrical steel sheet (or a cold-rolled steel sheet that is a material of the grain-oriented electrical steel sheet) is irradiated with a laser beam to form a plurality of grooves. The plurality of grooves is formed so as to extend in a width direction of the grain-oriented electrical steel sheet (a direction perpendicular to the rolling direction of the grain-oriented electrical steel sheet) or in a slightly inclined direction relative to the width direction of the grain-oriented electrical steel sheet, and is formed so as to be arranged at regular intervals in the rolling direction of the grain-oriented electrical steel sheet.The grooves refine the magnetic domains of the grain-oriented electrical steel sheet, so that the iron loss of the grain-oriented electrical steel sheet is reduced.

[0068] Because grain-oriented electrical steel sheet has the property of being easily magnetized in the direction of lamination of the grain-oriented electrical steel sheet, grain-oriented electrical steel sheet is used as a material for a wound iron core (iron core material) of a wound transformer in which the direction in which a magnetic field line flows is substantially constant. The wound iron core is Petition 870250101208, dated 05 / 11 / 2025, page 26 / 158 / 66 formed, for example, by the layered arrangement of a plurality of grain-oriented electrical steel sheets and by bending (winding) the grain-oriented electrical steel sheets in layers so as to form an iron core shape.

[0069] When forming the groove on the front surface of grain-oriented electrical steel sheet, it is desirable to form the groove so as to extend in the direction of the width of the grain-oriented electrical steel sheet, as the efficiency in reducing iron loss can be improved. However, for example, when attempting to bend the grain-oriented electrical steel sheet in which the groove is formed in a bending line along the width direction of the grain-oriented electrical steel sheet to form the wound iron core of the transformer using the grain-oriented electrical steel sheet, the grain-oriented electrical steel sheet is more likely to break from the groove. Therefore, the groove is formed so as to extend in a slightly inclined direction relative to the width direction of the grain-oriented electrical steel sheet.In this case, although the efficiency in reducing iron loss of the grain-oriented electrical steel sheet is slightly impaired, the possibility of breakage when the grain-oriented electrical steel sheet is bent can be reduced. In a case where the groove extending in a slightly inclined direction relative to the width direction of the grain-oriented electrical steel sheet is formed on the front surface of the grain-oriented electrical steel sheet, a groove inclination angle can be defined, if appropriate. The groove inclination angle is preferably, for example, greater than 0° and equal to or less than 20° in consideration of the efficiency in reducing iron loss of the grain-oriented electrical steel sheet and the possibility of breakage.

[0070] Grain-oriented electrical steel sheet is made of an iron alloy containing Si. A composition of grain-oriented electrical steel sheet is, for example, 2.5% by mass or more and 4.0% by mass or less of Si, 0.001% Petition 870250101208, dated 05 / 11 / 2025, page 27 / 158 / 66 by mass or more and 0.10% by mass or less of C, 0.05% by mass or more and 0.20% by mass or less of Mn, 0.001% by mass or more and 0.040% by mass or less of acid-soluble Al, 0.0002% by mass or more and 0.012% by mass or less of N, 0.1% by mass or more and 0.030% by mass or less of S, and 0.01% by mass or more and 0.04% by mass or less of P, with the remainder being Fe and unavoidable impurities. The grain-oriented electrical steel sheet has a thickness of, for example, 0.15 mm or more and 0.35 mm or less.

[0071] The front surface of the grain-oriented electrical steel sheet is coated with a glass film. The glass film is made of a compound oxide, such as forsterite (Mg2SiO4), spinel (MgAl2O4), or cordierite (Mg2Al4Si5O18). The glass film has a thickness of, for example, 1 μm.

[0072] The glass film is further coated with an insulating film. The insulating film contains, for example, an insulating coating agent (coating liquid) containing mainly colloidal silica and phosphate (magnesium phosphate, aluminum phosphate or similar), or an insulating coating agent (coating liquid) obtained by mixing an alumina sol and boric acid. (Grain-Oriented Electric Steel Sheet Manufacturing Apparatus)

[0073] Next, a configuration of an electrically oriented grain steel sheet fabrication apparatus according to the present embodiment will be described.

[0074] Figures 1 and 2 are side views of a grain-oriented electrical steel sheet manufacturing apparatus 10 according to the present embodiment, when viewed from a width direction of a cold-rolled steel sheet 12. The grain-oriented electrical steel sheet manufacturing apparatus 10 (hereinafter also referred to as “manufacturing apparatus 10”) is an apparatus that manufactures a grain-oriented electrical steel sheet 14 (see Figure 2). Figures 1 and 2 are continuous views illustrating a Petition 870250101208, dated 05 / 11 / 2025, page 28 / 158 / 66 manufacturing line of manufacturing apparatus 10. A hot-rolled steel sheet that is a material of grain-oriented electrical steel sheet 14 is processed by each apparatus included in manufacturing apparatus 10, as illustrated in figure 1, and then processed by each apparatus included in manufacturing apparatus 10, as illustrated in figure 2, to obtain grain-oriented electrical steel sheet 14 with a reduced iron loss. Cold-rolled steel sheet is an example of a rolled steel sheet and a steel sheet.

[0075] As an example, the manufacturing apparatus 10 includes a finishing laminator 15, an oil film removal apparatus 20, a beam irradiation apparatus 30, a polishing apparatus 40, a decarburizing annealing apparatus 50, an annealing separator application apparatus 55, a final finishing annealing apparatus 60, an insulating coating agent application apparatus 70 and a flattening annealing apparatus 80.The finishing laminator 15, the oil film removal apparatus 20, the beam irradiation apparatus 30, the polishing apparatus 40, the decarburization annealing apparatus 50, the annealing separator application apparatus 55, the final finishing annealing apparatus 60, the insulating coating agent application apparatus 70 and the flattening annealing apparatus 80 are arranged in this order in the transport direction of the grain-oriented electrical steel sheet 14 along the grain-oriented electrical steel sheet 14 manufacturing line (see figure 2). (Finishing Laminator)

[0076] As illustrated in Figure 1, the finishing mill 15 is a mill that produces cold-rolled steel sheet 12 by rolling (cold rolling) hot-rolled steel sheet, which is produced by rolling with a plurality of known rough mills and is the material of the grain-oriented electrical steel sheet 14 (see Petition 870250101208, dated 05 / 11 / 2025, page 29 / 158 / 66 figure 2), in order to have a desired thickness. A known finishing mill may be used as finishing mill 15 according to the present embodiment, if appropriate.

[0077] An arrow X indicates the transport direction and the rolling direction of cold-rolled steel sheet 12 (grain-oriented electrical steel sheet 14). Hereafter, a direction indicated by the arrow X is referred to as the transport direction X. The transport direction X coincides with the longitudinal direction of cold-rolled steel sheet 12 (grain-oriented electrical steel sheet 14). (Oil Film Removal Device)

[0078] The oil film removal apparatus 20 is an apparatus that removes oil films adhered to a front surface 12A and a rear surface 12B of the cold-rolled steel sheet 12 produced by the finishing mill 15.

[0079] Here, when producing cold-rolled steel sheet 12 by the finishing mill 15, oil (rolling oil) is applied to at least one of the rolling rolls and to the cold-rolled steel sheet 12 (hot-rolled steel sheet) to reduce friction between a rolling roll of the finishing mill 15 and the cold-rolled steel sheet 12 (hot-rolled steel sheet), and then the cold-rolled steel sheet 12 (hot-rolled steel sheet) is rolled. Therefore, the rolling oil adheres as oil films to the front surface 12A and the back surface 12B of the cold-rolled steel sheet 12 immediately after rolling. The oil film removal apparatus 20 removes rolling oil (oil films) adhered to the front surface 12A and the rear surface 12B of the cold-rolled steel sheet 12 in this manner.

[0080] The oil film removal apparatus 20 includes a pair of cleaning brush rollers 22. The pair of cleaning brush rollers 22 is arranged to face the front surface 12A and the surface Petition 870250101208, dated 05 / 11 / 2025, p. 30 / 158 / 66 rear 12B of cold-rolled steel sheet 12.

[0081] The cleaning brush roll 22 comprises a roll 22A and a cleaning brush 22B. Roll 22A is arranged so that one direction of the axis of rotation of roll 22A is parallel to the width direction of the cold-rolled steel sheet 12. Both lateral ends of roll 22A in an axial direction are supported rotationally by bearings (not shown). Roll 22A, i.e., the cleaning brush roll 22, is rotated by a motor (not shown) or similar. The direction of rotation of the cleaning brush roll 22 is not particularly limited. However, it is preferable that the direction of rotation of the cleaning brush roll 22 be opposite to the transport direction X of the cold-rolled steel sheet 12 to efficiently clean the front surface 12A and the rear surface 12B of the cold-rolled steel sheet 12.

[0082] The cleaning brush 22B has a plurality of bristles extending radially from the roller 22A. The cleaning brush 22B is arranged so that the tip portions of the plurality of bristles come into contact with the front surface 12A or the rear surface 12B of the cold-rolled steel sheet 12, so that the oil film adhered to the front surface 12A or the rear surface 12B of the cold-rolled steel sheet 12 can be removed. The bristles of the cleaning brush 22B are made of nylon or similar material, softer than a polishing brush 44B described below, to avoid damage such as scratches on the front surface 12A or the rear surface 12B of the cold-rolled steel sheet 12. A cleaning agent capable of removing the oil film is supplied to the cleaning brush 22B from a cleaning fluid supply nozzle (not shown). For example, an alkaline cleaning agent is used as the cleaning agent.The oil film removal apparatus 20 sequentially rubs the front surface 12A or the back surface 12B of the cold-rolled steel sheet 12 with the plurality of bristles of the cleaning brush 22B according to the rotation of the roller 22A. As a result, the oil film removal apparatus... Petition 870250101208, dated 05 / 11 / 2025, page 31 / 158 / 66 can scrape off the oil film spread on the front surface 12A or on the rear surface 12B of the cold-rolled steel sheet 12 while using the cleaning agent, if appropriate.

[0083] A dryer (not shown) for drying the cleaning agent or similar adhered to the front surface 12A and the rear surface 12B of the cold-rolled steel sheet 12 may be provided in a position immediately downstream of the oil film removal apparatus 20. (Beam Irradiation Device)

[0084] As an example, beam irradiation apparatus 30 is an apparatus that irradiates the front surface 12A of the cold-rolled steel sheet 12 from which the oil film has been removed by the oil film removal apparatus 20 with a laser beam L to form the groove.

[0085] Specifically, the beam irradiation apparatus 30 irradiates the front surface 12A of the cold-rolled steel sheet 12 from the front surface 12A and the back surface 12B of the cold-rolled steel sheet 12 with the laser beam L. Then, the beam irradiation apparatus 30 scans the front surface 12A of the cold-rolled steel sheet 12 with the laser beam L to form the groove that extends in a direction parallel to the width direction of the cold-rolled steel sheet 12 or in a direction inclined at a predetermined angle (preferably an angle greater than 0° and equal to or less than 20°) relative to the width direction of the cold-rolled steel sheet 12 (which are also called scanning directions) on the front surface 12A.

[0086] Furthermore, the beam irradiation apparatus 30 forms a plurality of grooves that extend in the scanning direction at a predetermined pitch in the transport direction X of the cold-rolled steel sheet 12. The grooves refine the magnetic domains of the grain-oriented electrical steel sheet 14 (see figure 2), so that the iron loss of the grain-oriented electrical steel sheet 14 is reduced. Petition 870250101208, dated 05 / 11 / 2025, page 32 / 158 / 66

[0087] Examples of the L-type laser beam may include a fiber laser, a YAG laser, or a CO2 laser. The wavelength of the L-type laser beam may be, for example, from 1060 to 1090 nm or 10.6 μm. Additionally, the wavelength of the L-type laser beam may be, for example, from 150 nm to 11000 nm (11 μm). Each groove has a depth of, for example, 20 μm. The groove has a width of, for example, 50 μm. The interval (pitch) between the grooves is, for example, 3 mm.

[0088] The beam irradiation apparatus 30 is not limited to using the laser beam and may be, for example, an apparatus that irradiates the front surface 12A of the cold-rolled steel sheet 12 with an electron beam to form the groove. (Polishing Device)

[0089] The polishing apparatus 40 is an apparatus that removes, by polishing or grinding, deposits such as molten protrusions or dispersed matter adhered to the front surface 12A of the cold-rolled steel sheet 12 due to spatter, fusion or similar effects generated when forming the groove on the front surface 12A, after irradiation with the laser beam L by the beam irradiation apparatus 30 and before decarburization annealing by the decarburization annealing apparatus 50 described below.

[0090] The polishing apparatus 40 includes a pair of support rollers 42 and a polishing brush roller 44. The support roller 42 is arranged so that one direction of the axis of rotation of the support roller 42 is parallel to the width direction of the cold-rolled steel sheet 12. Both lateral ends of the support roller 42 in an axial direction are rotationally supported by bearings (not shown). The support roller 42 is arranged so as to face the rear surface 12B, in which no groove is formed from the front surface 12A and the rear surface 12B of the cold-rolled steel sheet 12, and supports the rear surface 12B.

[0091] The 44 polishing brush roller is arranged on one side of the Petition 870250101208, dated 05 / 11 / 2025, p. 33 / 158 / 66 cold-rolled steel sheet 12 (one side adjacent to the front surface 12A in which the groove is formed) which is opposite the support roller 42. The polishing brush roller 44 includes a roller 44A and the polishing brush 44B. Roller 44A is arranged so that one direction of the axis of rotation of roller 44A is parallel to the width direction of the cold-rolled steel sheet 12. Both lateral ends of roller 44A in the axial direction are rotationally supported by bearings (not shown). Roller 44A, i.e., the polishing brush roller 44, is rotated by a motor (not shown) or similar. The direction of rotation of the polishing brush roller 44 is not particularly limited. However, it is preferable that the direction of rotation of the polishing brush roller 44 be opposite to the transport direction X of the cold-rolled steel sheet 12 in order to efficiently polish the front surface 12A of the cold-rolled steel sheet 12.

[0092] The polishing brush 44B has a plurality of bristles extending radially from the roller 44A. The plurality of bristles is made of nylon harder than the cleaning brush 22B, nylon containing abrasive grains or similar. The tip portions of the plurality of bristles are arranged so as to come into contact with the front surface 12A of the cold-rolled steel sheet 12. The polishing apparatus 40 sequentially rubs the front surface 12A of the cold-rolled steel sheet 12 with the tip portions of the bristles of the polishing brush 44B in accordance with the rotation of the polishing brush roller 44. As a result, the polishing apparatus 40 can scrape off deposits, such as the molten protrusions that project from the front surface 12A of the cold-rolled steel sheet 12.

[0093] In the present embodiment, the directions of the rotation axes of the cleaning brush roller 22 and the polishing brush roller 44 are directions parallel to the width direction of the cold-rolled steel sheet 12, regardless of whether the scanning direction of the laser beam L of the beam irradiation apparatus 30 described above is a direction parallel to the width direction of the cold-rolled steel sheet 12 or a direction inclined by a Petition 870250101208, dated 05 / 11 / 2025, page 34 / 158 / 66 predetermined angle in relation to the width direction of the cold-rolled steel sheet 12. However, in a case where the scanning direction of the laser beam L is a direction inclined at a predetermined angle in relation to the width direction of the cold-rolled steel sheet 12, and the deviation of the cold-rolled steel sheet 12 can be suppressed by adjusting a transport speed or similar of the cold-rolled steel sheet 12, the directions of the rotation axes of the cleaning brush roller 22 and the polishing brush roller 44 can be inclined in relation to the width direction of the cold-rolled steel sheet 12 within a range of the predetermined angle of a direction parallel to the width direction of the cold-rolled steel sheet 12.

[0094] In addition, a dryer (not shown) for drying a polishing agent, moisture or similar adhered to the front surface 12A and the rear surface 12B of the cold-rolled steel sheet 12 may be provided in a position immediately downstream of the polishing apparatus 40. (Decarburization Annealing Apparatus)

[0095] The decarburization annealing apparatus 50 is an apparatus that decarburizes and anneales the cold-rolled steel sheet 12 in which the groove is formed. More specifically, the decarburization annealing apparatus 50 performs decarburization annealing (continuous annealing) on ​​the cold-rolled steel sheet 12 in which the groove is formed at a predetermined temperature (e.g., 700°C to 900°C) for a predetermined heating time (e.g., 1 to 3 minutes), or similar. As a result, as described below, primary recrystallization (crystal grain size: 10 to 30 μm) occurs on the cold-rolled steel sheet 12, and oxide layers containing mainly silica (SiO2) are formed on the front surface 12A and the back surface 12B of the cold-rolled steel sheet 12.

[0096] Here, when the cold-rolled steel sheet 12 is decarburized and annealed by the decarburization annealing apparatus 50, the cold-rolled steel sheet 12 is decarburized and primary recrystallization (size of Petition 870250101208, dated 05 / 11 / 2025, page 35 / 158 / 66 crystal grain size: 10 to 30 μm) occurs in cold-rolled steel sheet 12. When cold-rolled steel sheet 12 is decarbonized and annealed, oxide layers containing mainly silica (SiO2) are formed on the front surface 12A and on the back surface 12B of cold-rolled steel sheet 12.

[0097] For example, it is also possible to nitrid the cold-rolled steel sheet 12 (e.g., 150 to 300 ppm) by heat treatment in an atmosphere containing ammonia during or after decarburization annealing and before applying an annealing separator to the front surface 12A and the back surface 12B of the cold-rolled steel sheet 12. (Annealing Separator Application Device)

[0098] The annealing separator application apparatus 55 is an apparatus that applies annealing separator containing mainly magnesia (MgO) to the oxide layers formed on the front surface 12A and the back surface 12B of cold-rolled steel sheet 12 by decarburization annealing. The cold-rolled steel sheet 12 is wound into a coil shape by a winding apparatus (not shown) after the annealing separator is applied by the annealing separator application apparatus 55. (Final Finishing Annealing Apparatus)

[0099] As illustrated in Figure 2, the final finishing annealing apparatus 60 is an apparatus that anneals the cold-rolled steel sheet 12, decarburized and annealed by the decarburization annealing apparatus 50, to cause secondary recrystallization. More specifically, the final finishing annealing apparatus 60 performs the heat treatment by inserting the cold-rolled steel sheet in coil form 12, which has been decarburized and annealed by the decarburization annealing apparatus 50 and to which the annealing separator has been applied by the annealing separator application apparatus 55, into a batch furnace. The heat treatment conditions are, for example, a heating temperature of 1100°C at Petition 870250101208, dated 05 / 11 / 2025, page 36 / 158 / 66 1300°C and a heating time of 20 to 24 hours. Through heat treatment, a so-called Goss grain, in which an easy magnetization axis coincides with the X transport direction of the cold-rolled steel sheet 12, is preferably subjected to crystal growth (secondary recrystallization occurs) in the cold-rolled steel sheet 12. As a result, an electrical steel sheet 14 with a high crystal orientation is obtained. Furthermore, at the time of performing the final finish annealing by the final finish annealing apparatus 60, the oxide layers and the annealing separator react with each other, and glass films made of forsterite (Mg2SiO4) are formed on the front surface 12A and on the back surface 12B of the cold-rolled steel sheet 12 to form the grain-oriented electrical steel sheet 14. (Insulating Coating Agent Application Apparatus)

[00100] The insulating coating agent application apparatus 70 unwinds the grain-oriented electrical steel sheet 14, which is wound in coil form and in which secondary recrystallization has occurred, into a plate form. Furthermore, the insulating coating agent application apparatus 70 applies the insulating coating agent (coating liquid) which can provide an electrical insulation property and can apply a predetermined voltage to the front surface 14A and the rear surface 14B on the glass films on the front surface 14A and the rear surface 14B of the unwound grain-oriented electrical steel sheet 14. (Flat Annealing Apparatus)

[00101] The flattening annealing apparatus 80 performs annealing at a predetermined temperature (e.g., 800°C to 850°C) for a predetermined time (e.g., 10 seconds or more and 120 seconds or less) while conveying the grain-oriented electrical steel sheet 14 to which the insulating coating agent is applied by a conveying apparatus, and bakes the insulating coating agent onto the front surface 14A and the rear surface 14B of the grain-oriented electrical steel sheet. Petition 870250101208, dated 05 / 11 / 2025, page 37 / 158 / 66 oriented 14. As a result, insulating films are formed on the front surface 14A and the rear surface 14B of the grain-oriented electrical steel sheet 14. A voltage (sheet passage voltage) is applied to the grain-oriented electrical steel sheet 14 from the conveying apparatus in the X conveying direction of the grain-oriented electrical steel sheet 14. As a result, the coil assembly and deformation that occur in the grain-oriented electrical steel sheet 14 at the time of final finish annealing are removed, and the grain-oriented electrical steel sheet 14 is flattened. Furthermore, the electrical insulation property is provided to the grain-oriented electrical steel sheet 14 by the insulating films on the front surface 14A and the rear surface 14B of the grain-oriented electrical steel sheet 14. (Manufacturing Method for Grain-Oriented Electrical Steel Sheet)

[00102] Next, an example of a method for manufacturing grain-oriented electrical steel sheet according to the present embodiment will be described.

[00103] As illustrated in Figure 3, the method for manufacturing grain-oriented electrical steel sheet according to the present embodiment includes, as an example, a casting step, a hot rolling step, an annealing step, a cold rolling step, an oil film removal step, a beam irradiation step, a polishing step, a decarburization annealing step, an annealing separator application step, a final finishing annealing step, an insulating coating agent application step, and a flattening annealing step. (From Casting Stage to Annealing Stage)

[00104] First, in the casting stage (stage P10 and continuous casting stage), a plate is formed by a continuous casting machine (not shown). Then, in the hot rolling stage (stage P12), the plate is hot rolled by a rough rolling mill (not shown) or similar to form a steel sheet (hereinafter referred to as “hot rolled steel sheet”). Petition 870250101208, dated 05 / 11 / 2025, page 38 / 158 / 66 hot”) with a predetermined thickness. Then, in the annealing step (step P14), the hot-rolled steel sheet is annealed at a predetermined temperature. (Cold Rolling Stage)

[00105] Next, as illustrated in figure 1, in the cold rolling stage (stage P16), for example, the hot-rolled steel sheet having a front surface and a back surface coated with rolling oil (cold rolling oil) is rolled by the finishing mill 15 and stretched in the transport direction X to form the cold-rolled steel sheet 12 having a predetermined thickness. (Oil Film Removal Step)

[00106] Next, in the oil film removal step (step P18), the oil films adhered to the front surface 12A and the rear surface 12B on both sides of the cold-rolled steel sheet 12 are removed by the oil film removal apparatus 20. (Beam Irradiation Stage)

[00107] Next, in the beam irradiation stage (stage P20), the front surface 12A of the cold-rolled steel sheet 12, which is transported by the transport apparatus and from which the oil film has been removed, is irradiated with the laser beam L by the beam irradiation apparatus 30 to form the plurality of grooves (laser grooves).

[00108] Specifically, the front surface 12A of the cold-rolled steel sheet 12 transported by the transport apparatus is irradiated with the laser beam L of the beam irradiation apparatus 30, and grooves are formed on the front surface 12A in a direction parallel to the width direction of the cold-rolled steel sheet 12 or in a direction inclined by a predetermined angle (preferably, an angle greater than 0° and equal to or less than 20°) relative to the width direction of the cold-rolled steel sheet 12.

[00109] In addition, the beam irradiation apparatus 30 forms the Petition 870250101208, dated 05 / 11 / 2025, page 39 / 158 / 66 plurality of grooves at predetermined intervals (steps) in the X transport direction of cold-rolled steel sheet 12 on the front surface 12A of cold-rolled steel sheet 12. The grooves refine the magnetic domains of the grain-oriented electrical steel sheet 14 and reduce the iron loss of the grain-oriented electrical steel sheet 14. (Polishing Stage)

[00110] Next, in the polishing stage (stage P22), deposits, such as molten protrusions and dispersed matter adhered to the front surface 12A of the cold-rolled steel sheet 12, in which grooves are formed by the laser beam L, are removed by the polishing apparatus 40 before the cold-rolled steel sheet 12 is decarburized and annealed by the decarburizing annealing apparatus 50.

[00111] Specifically, in the polishing apparatus 40, the polishing brush roller 44 is rotated by the motor (not shown) while supplying a polishing liquid containing abrasive grains from a polishing liquid supply nozzle (not shown) to the front surface 12A of the cold-rolled steel sheet 12. Alternatively, in the polishing apparatus 40, the polishing brush roller 44 with bristles such as nylon containing abrasive grains is rotated by the motor (not shown) while supplying the water-based polishing liquid from the polishing liquid supply nozzle to the front surface 12A of the cold-rolled steel sheet 12. As a result, the deposits adhering to the front surface 12A of the cold-rolled steel sheet 12 are polished and removed by the polishing brush 44B attached to the rotating polishing brush roller 44. (Decarburization Annealing Stage)

[00112] Next, in the decarburization annealing step (step P24), the cold-rolled steel sheet 12, in which the grooves are formed, is subjected to decarburization annealing (continuous annealing) at a predetermined temperature (e.g., 700°C to 900°C) using the apparatus Petition 870250101208, dated 05 / 11 / 2025, page 40 / 158 / 66 of decarburization annealing 50. As a result, the cold-rolled steel sheet 12 is decarburized and primary recrystallization (crystal grain size: 10 to 30 μm) occurs in the cold-rolled steel sheet 12. As the cold-rolled steel sheet 12 is decarburized and annealed, oxide layers containing mainly silica (SiO2) are formed on the front surface 12A and the back surface 12B of the cold-rolled steel sheet 12. (Annealing Separator Application Stage)

[00113] Next, in the annealing separator application step (step P26), the annealing separator containing mainly magnesia (MgO) is applied to the oxide layers on the front surface 12A and the back surface 12B of the cold-rolled steel sheet 12 formed during decarburization annealing by the annealing separator application apparatus 55. Then, the cold-rolled steel sheet 12 is wound into a coil shape by the winding apparatus (not shown). (Final Finishing Annealing Stage)

[00114] Next, as illustrated in figure 2, in the final finishing annealing step (step P28), the cold-rolled steel sheet in coil form 12 is annealed (batch annealing) at a predetermined temperature (e.g., about 1200°C) for a predetermined time (e.g., about 20 hours) by the final finishing annealing apparatus 60. The heat treatment conditions are, for example, a heating temperature of 1100°C to 1300°C and a heating time of 20 to 24 hours.

[00115] As a result, secondary recrystallization occurs in the cold-rolled steel sheet 12, the crystal orientation in which the easy magnetization axes are substantially aligned in the X transport direction of the cold-rolled steel sheet 12 is achieved, and glass films are formed on the front surface 12A and the back surface 12B of the cold-rolled steel sheet 12. As a result, the grain-oriented electrical steel sheet 14 Petition 870250101208, dated 05 / 11 / 2025, page 41 / 158 / 66 is formed. Then, the 14-gauge oriented grain electrical steel sheet in coil form is unwound.

[00116] Here, the grain-oriented electrical steel sheet 14 contains, for example, an inhibitor such as MnS or AlN. As a result, in the final finishing annealing step, the Goss-oriented crystal grains, in which the magnetization easy axes are substantially aligned in the X transport direction of the grain-oriented electrical steel sheet 14, are preferably subjected to crystal growth. As a result, grain-oriented electrical steel sheet 14 with a high crystal orientation is formed. (Insulating Coating Agent Application Step)

[00117] Next, in the insulating coating agent application step (step P30), the insulating coating agent (coating liquid) which has the property of electrical insulation and is capable of applying a predetermined voltage to the front surface 14A and the rear surface 14B of the grain-oriented electrical steel sheet 14 is applied to the front surface 14A and the rear surface 14B of the grain-oriented electrical steel sheet 14 by the insulating coating agent application apparatus 70. Normally, the insulating coating agent is applied by the insulating coating agent application apparatus 70 after the unreacted magnesia remaining on the front surface 14A and the rear surface 14B of the grain-oriented electrical steel sheet 14 has been cleaned and dried. (Flat Annealing Stage)

[00118] Next, in the flattening annealing step (step P32), the grain-oriented electrical steel sheet 14, to which the insulating coating agent is applied, is annealed (flattening annealing) at a predetermined temperature (e.g., 800°C to 850°C) for a predetermined time (e.g., 10 seconds or more and 120 seconds or less) by the flattening annealing apparatus 80 while being transported by Petition 870250101208, dated 05 / 11 / 2025, page 42 / 158 / 66 transport device.

[00119] At this moment, the tension (sheet passage tension) is applied to the grain-oriented electrical steel sheet 14 of the conveying apparatus in the X conveying direction of the grain-oriented electrical steel sheet 14. As a result, the coil assembly and deformation of the grain-oriented electrical steel sheet 14 at the time of final finish annealing are removed, and the grain-oriented electrical steel sheet 14 is flattened.

[00120] Furthermore, when the grain-oriented electrical steel sheet 14 is annealed in the flattening annealing step, the insulating coating agent is baked onto the front surface 14A and the rear surface 14B of the grain-oriented electrical steel sheet 14, and the front surface 14A and the rear surface 14B of the grain-oriented electrical steel sheet 14 are subjected to insulating coating by the insulating coating agent. Then, the grain-oriented electrical steel sheet 14 is cooled. (Slot Depth Monitoring System)

[00121] A groove depth monitoring system included in the grain-oriented electric steel sheet manufacturing apparatus according to the present embodiment will be described below.

[00122] Figure 4 is a perspective view of a groove depth monitoring system 100 according to the present embodiment when viewed from the front in the transport direction X of the cold-rolled steel sheet 12. The groove depth monitoring system 100 according to the present embodiment is a system that monitors whether the depth of a groove G formed on the front surface 12A of the cold-rolled steel sheet 12 is equal to or greater than a reference value. As illustrated in Figure 4, the groove depth monitoring system 100 includes a control device 130. In the embodiment illustrated in Figure 4, the groove depth monitoring system 100 includes the control device 130, a spatter quantity detection device. Petition 870250101208, dated 05 / 11 / 2025, page 43 / 158 / 66 110 and a torque detection device 120. The splash quantity detection device 110 and the torque detection device 120 (see figure 1) are connected to the control device 130 so that they can communicate with each other in a wired or wireless manner. (Splash Quantity Detection Device)

[00123] The spatter quantity detection apparatus 110 is an apparatus that detects the amount of spatter generated when groove G is formed on the front surface 12A of cold-rolled steel sheet 12 by the beam irradiation apparatus 30. The spatter quantity detection apparatus 110 includes an image-forming device 112 and a light-reducing filter 114.

[00124] The imaging device (imaging unit) 112 is, for example, a camera that generates images of splashes SP scattered around the groove G when forming the groove G on the front surface 12A of the cold-rolled steel sheet 12 by the beam irradiation apparatus 30. As an example, when forming the groove G on the front surface 12A of the cold-rolled steel sheet 12 by the beam irradiation apparatus 30, the imaging device 112 creates images of a predetermined region around the groove G from the outside in the direction of the width of the cold-rolled steel sheet 12 transported by a transport apparatus 16 and sends the captured image information to the control apparatus 130 described below.

[00125] The imaging device 112 can capture a moving image or a static image of the predetermined region around the G slot.

[00126] The light-reducing filter 114 is a filter that reduces light other than SP splashes incident on the imaging device 112 when generating images of the SP splashes by the imaging device 112. A light reduction rate of the light-reducing filter 114 is defined for example, 75%. Petition 870250101208, dated 05 / 11 / 2025, p. 44 / 158 / 66

[00127] The light reduction rate of the light-reducing filter 114 is preferably 10% or more, and more preferably 50% or more. The light reduction rate of the light-reducing filter 114 is preferably 95% or less, and more preferably 75% or less. (Torque Detection Device)

[00128] The torque detection device 120 detects the rotational torque generated in the polishing brush roller 44 when removing deposits adhering to the front surface 12A of the cold-rolled steel sheet 12 by the polishing brush roller 44. That is, as illustrated in figure 1, the torque detection device 120 is a device that detects the rotational torque generated in the polishing brush roller 44 when deposits, such as SP spatter (see figure 4) adhering to the front surface 12A of the cold-rolled steel sheet 12, generated during groove formation G by the beam irradiation device 30, are removed by the polishing device 40.

[00129] The torque detection device 120 is, for example, an ammeter that measures a current value supplied to the motor (not shown) that rotatably drives the polishing brush roller 44. The torque detection device 120 transmits the measured current value to the control device 130 described below. (Sketch of the Control Device)

[00130] The control device 130 controls a general operation of the groove depth monitoring system 100. In addition, the control device 130 determines whether the groove depth G formed on the front surface 12A of the cold-rolled steel sheet 12 is equal to or greater than the reference value. In a case where the groove depth G formed on the front surface 12A of the cold-rolled steel sheet 12 is less than the reference value, for example, a warning or similar is displayed on a display unit of an input / output device 148 (see Figure 5) described below. Petition 870250101208, dated 05 / 11 / 2025, page 45 / 158 / 66 (Hardware Configuration of the Control Device)

[00131] First, a hardware configuration of the control device 130 will be described.

[00132] The control apparatus 130 is implemented by, for example, a computer 140 illustrated in figure 5. The computer 140 includes a central processing unit (CPU) 142, a memory 144 as a temporary storage area, and a non-volatile storage unit 146. The computer 140 includes the input / output apparatus 148. The CPU 142, the memory 144, the storage unit 146, and the input / output apparatus 148 are connected to each other by means of a bus 149. The CPU 142 is an example of a control unit.

[00133] The storage unit 146 is implemented by, for example, a hard disk drive (HDD), a solid-state drive (SSD), or a flash memory. Slot depth monitoring instructions to make the computer 140 function as the control device 130 are stored in advance in the storage unit 146 as a recording medium. In addition, a storage area for storing various data is provided in the storage unit 146.

[00134] Input / output device 148 includes a pointing device, such as a mouse, a keyboard and the display unit, and is used to perform various inputs.

[00135] CPU 142 reads the slot depth monitoring instructions from storage unit 146, loads the instructions into memory 144, and executes the instructions. As a result, computer 140 that executed the slot depth monitoring instructions functions as the control device 130. (Control Device Functions)

[00136] The functions of control device 130 will be described below.

[00137] As illustrated in figure 6, the control device 130 Petition 870250101208, dated 05 / 11 / 2025, page 46 / 158 / 66 implements several functions using the above hardware resources when executing the groove depth monitoring instructions described above. Specifically, the control device 130 functionally includes a splash quantity acquisition unit 132, a torque acquisition unit 133, a groove depth determination unit 134, and a notification unit 136. The splash quantity acquisition unit 132, the groove depth determination unit 134, and the notification unit 136 are implemented by the CPU 142 reading and executing the groove depth monitoring instructions stored in the storage unit 146. (Unit of Acquisition of Splash Quantity)

[00138] The splash quantity acquisition unit 132 acquires the splash quantity detected by the splash quantity detection apparatus 110. Specifically, the splash quantity acquisition unit 132 processes the image information captured by the imaging device 112 of the splash quantity detection apparatus 110 and calculates and acquires the amount of splashes scattered around the groove G when forming the groove G on the front surface 12A of the cold-rolled steel sheet 12 by the beam irradiation apparatus 30.

[00139] The amount of spatter is the amount of SP spatter (see figure 4) scattered around groove G when groove G is formed on the front surface 12A of the cold-rolled steel sheet 12 by the beam irradiation apparatus 30.

[00140] As an example, the splash quantity acquisition unit 132 classifies each pixel of the image information entered into the imaging device 112 into a plurality of classifications (e.g., 256 levels (0 to 255)) according to a brightness (luminance value). Then, the splash quantity acquisition unit 132 calculates (counts) the number of pixels classified into a classification of Petition 870250101208, dated 05 / 11 / 2025, page 47 / 158 / 66 reference or higher in the image information input of the imaging device 112 such as the amount of splashes (the number of splash pixels).

[00141] The reference rating is defined as 150, for example. The pixel reference rating is defined based on the light reduction rate of the light-reducing filter 114 and the illuminance of an environment in which the SP splashes are visualized, if appropriate. In addition, the amount of splashes (the number of splash pixels) can be considered as an area of ​​a region where the pixel brightness rating is equal to or greater than the reference rating in a predetermined region (imaging region) around the G slot captured by the imaging device 112. (Torque Acquisition Unit)

[00142] The torque acquisition unit 133 acquires the rotational torque of the polishing brush roller 44 detected by the torque detection device 120. Specifically, the torque acquisition unit 133 acquires the motor current value detected by the torque detection device 120 and calculates the rotational torque of the polishing brush roller 44 based on the acquired current value.

[00143] As an example, the torque acquisition unit 133 calculates rotational torque based on the following formula. Rotational torque (Nm) = Kt x Ia

[00144] Here, Kt: a torque constant (N · m / A), and Ia: the value of the motor current (A).

[00145] The torque constant Kt is defined according to the specifications (a material, a length, and the like) of the 44B polishing brush, specifications (a type, a supply quantity, and the like) of the polishing fluid, specifications (an output, and the like) of the Petition 870250101208, dated 05 / 11 / 2025, p. 48 / 158 / 66 motor that rotates the polishing brush roller 44 and similar.

[00146] Furthermore, the torque detection device 120 is not limited to detecting the current value supplied to the motor that rotationally drives the polishing brush roller 44, and can detect the rotational torque of the polishing brush roller 44 by a known method.

[00147] In the present embodiment, the torque acquisition unit 133 calculates the rotational torque of the polishing brush roller 44 based on the current value detected by the torque detection device 120. However, the torque detection device 120 may have a function to calculate the rotational torque of the polishing brush roller 44. In this case, the torque acquisition unit 133 acquires the rotational torque of the polishing brush roller 44 from the torque detection device 120. (Slot Depth Determination Unit)

[00148] The groove depth determination unit 134 determines whether the groove depth G formed on the front surface 12A of the cold-rolled steel sheet 12 is equal to or greater than the reference value based on the amount of spatter acquired by the spatter quantity acquisition unit 132, a predetermined reference spatter quantity, the rotational torque of the polishing brush roller 44 acquired by the torque acquisition unit 133, and a predetermined reference rotational torque.

[00149] Specifically, the groove depth determination unit 134 determines that the groove depth G is equal to or greater than the reference value in a case where the following Formula (1) obtained from a manufacturing test result described below is satisfied. Conversely, the groove depth determination unit 134 determines that the groove depth G is less than the reference value in a case where the following Formula (1) is not satisfied. > S / S0 > C1 and C2 < T / T0 < C3 ··· (1) Petition 870250101208, dated 05 / 11 / 2025, p. 49 / 158 / 66

[00150] Here, S: the quantity of splashes acquired by the splash quantity acquisition unit, S0: the reference splash quantity, C1: S1 / S0, S1: a minimum amount of spatter generated when forming the groove whose depth is equal to the reference value on the front surface of the cold-rolled steel sheet (steel plate). T: the rotational torque acquired by the torque acquisition unit, T0: the reference rotational torque, C2: T1 / T0, T1: a minimum rotational torque generated when removing deposits adhering to the front surface of the cold-rolled steel sheet (steel plate) in which the groove is formed, the depth of which is equal to the reference value set by the polishing brush roller. C3: T2 / T0, and T2: a maximum rotational torque generated when removing deposits adhering to the front surface of the cold-rolled steel sheet (steel plate) in which the groove is formed whose depth is equal to the reference value by the polishing brush roller.

[00151] Formula (1) is described below in the manufacturing test. (Notification Unit)

[00152] In a case where the groove depth determination unit 134 determines that the groove depth G is less than the reference value, the notification unit 136 displays a message, such as a warning, on the input / output device display unit 148, for example. The notification unit 136 is not limited to displaying a message, such as a warning, and can be configured to issue an alert or something similar, by Petition 870250101208, dated 05 / 11 / 2025, page 50 / 158 / 66 example. (Method for monitoring the groove depth of grain-oriented electrical steel sheet)

[00153] Next, an example of a method for monitoring the groove depth of grain-oriented electrical steel sheet will be described, while at the same time describing an operation of the control device 130.

[00154] During the passage of the cold-rolled steel sheet 12 described above (during the manufacture of the grain-oriented electrical steel sheet 14), the control device 130 periodically performs, for example, groove depth monitoring processing. The groove depth monitoring processing includes a spatter quantity acquisition step, a torque acquisition step, and a groove depth determination step. The groove depth monitoring processing is an example of the groove depth monitoring method for electrical steel sheets. The spatter quantity acquisition step and the torque acquisition step can be performed during the passage of the cold-rolled steel sheet 12, and the groove depth determination step can be performed during the passage of the cold-rolled steel sheet 12.The step of determining the groove depth can be performed after the fabrication of the 14-grain oriented electrical steel sheet. (Spatter Quantity Acquisition Stage)

[00155] As illustrated in figure 7, first, in step S10, CPU 142 executes the splash quantity acquisition step in parallel with the beam irradiation step described above, and acquires the quantity S of splashes generated when forming the groove G on the front surface 12A of the cold-rolled steel sheet 12 by the beam irradiation apparatus 30.

[00156] Specifically, CPU 142 can control the device of Petition 870250101208, dated 05 / 11 / 2025, page 51 / 158 / 66 image formation 112 of the spatter quantity detection device 110 when forming groove G on the front surface 12A of the cold-rolled steel sheet 12 by the beam irradiation device 30. As a result, the spatter SP scattered around groove G when forming groove G on the front surface 12A of the cold-rolled steel sheet 12 by the beam irradiation device 30 are captured by the image formation device 112, and the captured image information is sent to the control device 130. The CPU 142 calculates (detects) the quantity S of spatter by determining a portion with a high luminance value based on the image information sent by the image formation device 112. (Torque Acquisition Stage)

[00157] Next, in step S12, CPU 142 performs the torque acquisition step in parallel with the polishing step described above and acquires a rotational torque T generated in the polishing brush roller 44 when polishing the deposits adhering to the front surface 12A of the cold-rolled steel sheet 12 by the polishing brush roller 44.

[00158] Specifically, CPU 142 can control torque sensing device 120 when polishing deposits adhering to the front surface 12A of cold-rolled steel sheet 12 by polishing brush roller 44. Torque sensing device 120 detects the current value supplied to the motor (not shown) that rotates polishing brush roller 44 when polishing deposits adhering to the front surface 12A of cold-rolled steel sheet 12 by polishing brush roller 44 of polishing device 40, and sends the detected current value to control device 130. CPU 142 acquires the rotational torque T by calculating the rotational torque T generated on polishing brush roller 44 based on the current value sent from torque sensing device 120.

[00159] The splash quantity acquisition step and the torque acquisition step are performed continuously or periodically during the Petition 870250101208, dated 05 / 11 / 2025, page 52 / 158 / 66 passage of cold-rolled steel sheet 12 (during the manufacture of grain-oriented electrical steel sheet 14). (Step for Determining Groove Depth)

[00160] Next, in step S14, CPU 142 performs the groove depth determination step and determines whether the groove depth G formed on the front surface 12A of the cold-rolled steel sheet 12 is equal to or greater than the reference value based on the spatter quantity S acquired in the spatter quantity acquisition step, the reference spatter quantity S0, the rotational torque T of the polishing brush roller 44 acquired in the torque acquisition step, and the reference rotational torque.

[00161] Specifically, in a case where Formula (1) above is satisfied, CPU 142 determines that the depth of slot G is equal to or greater than the reference value and terminates processing. Conversely, in a case where Formula (1) above is not satisfied, CPU 142 determines that the depth of slot G is less than the reference value and proceeds to step S16.

[00162] In step S16, CPU 142 displays a warning or similar message on the display unit of input / output device 148 and terminates processing. (Actions and Effects)

[00163] The actions and effects of this modality will be described below.

[00164] The groove depth monitoring system 100 according to the present embodiment acquires the quantity S of spatter generated when forming the groove G by irradiating the front surface 12A of the cold-rolled steel sheet 12 with the laser beam L of the beam irradiation apparatus 30. In addition, the groove depth monitoring system 100 acquires the rotational torque generated in the polishing brush roller 44 when removing the deposits adhering to the front surface 12A of the steel sheet. Petition 870250101208, dated 05 / 11 / 2025, page 53 / 158 / 66 cold-rolled 12 in which groove G is formed by the laser beam L from the beam irradiation apparatus 30 by the polishing brush roller 44.

[00165] Next, the groove depth monitoring system 100 determines whether the groove depth G formed on the front surface 12A of the cold-rolled steel sheet 12 is equal to or greater than the reference value based on the acquired spatter quantity S, the predetermined spatter quantity S0, the acquired rotational torque T from the polishing brush roll 44, and the predetermined reference rotational torque T0. More specifically, the monitoring system 100 determines whether the groove depth G formed on the front surface 12A of the cold-rolled steel sheet 12 is equal to or greater than the reference value based on Formula (1) above.

[00166] As a result, for example, the cold-rolled steel sheet 12 in which the groove depth G is less than the reference value due to a decrease in the laser beam output L of the beam irradiation apparatus 30 and a change in focus of the laser beam L relative to the front surface 12A of the cold-rolled steel sheet 12 can be detected. Therefore, a decrease in the groove depth G formed on the front surface 14A of the grain-oriented electrical steel sheet 14 can be suppressed.

[00167] The groove depth monitoring system 100 also monitors the depth of the groove G formed on the front surface 12A of the cold-rolled steel sheet 12 in real time. Therefore, cold-rolled steel sheets 12 in which the groove depth G is less than the reference value can be detected early. Therefore, the quantity of manufactured grain-oriented electrical steel sheets 14 in which the groove depth G is less than the reference value can be reduced.

[00168] Here, the quantity S of spatter generated when forming the groove G on the front surface 12A of the cold-rolled steel sheet 12 by the beam irradiation apparatus 30 decreases basically as the depth of Petition 870250101208, dated 05 / 11 / 2025, page 54 / 158 / 66 groove G formed on the front surface 12A decreases. Therefore, the depth of the groove G formed on the front surface 12A of the cold-rolled steel sheet 12 can be estimated by monitoring the amount S of spatter detected by the spatter quantity detection device 110.

[00169] However, in a case where the amount of shift in focus of the laser beam L relative to the front surface 12A of the cold-rolled steel sheet 12 is small, the amount S of spatter decreases once and then increases again as the amount of shift in focus of the laser beam L increases. Therefore, in some cases, the shift in focus of the laser beam L cannot be detected in a range where the amount of shift in focus of the laser beam L relative to the front surface 12A of the cold-rolled steel sheet 12 is small by monitoring only the amount S of spatter detected by the spatter quantity detection device 110.

[00170] Here, in a case where the amount of laser beam focus change L relative to the front surface 12A of the cold-rolled steel sheet 12 is small, the viscosity of the generated spatter increases due to a temperature change or similar of the front surface 12A of the cold-rolled steel sheet 12, and the particle size of the deposits, such as the spatter adhering to the front surface 12A of the cold-rolled steel sheet 12, increases. As a result, the rotational torque T generated on the polishing brush roller 44 when polishing the deposits adhering to the front surface 12A of the cold-rolled steel sheet 12 by the polishing brush roller 44 also increases.

[00171] Therefore, in the groove depth monitoring system 100, the rotational torque T of the polishing brush roller 44 detected by the torque detection device 120 is also monitored, in addition to the amount S of spatter detected by the spatter quantity detection device 110.

[00172] Specifically, in a case where Formula (1) above is satisfied, the CPU 142 of the slot depth monitoring system Petition 870250101208, dated 05 / 11 / 2025, page 55 / 158 / 66 100 determines that the depth of the groove G formed on the front surface 12A of the cold-rolled steel sheet 12 is equal to or greater than the reference value. As a result, it is possible to detect the change in focus of the laser beam L even in a case where the amount of change in focus of the laser beam L relative to the front surface 12A of the cold-rolled steel sheet 12 is small. Therefore, the accuracy of the groove depth monitoring system 100 is improved. Furthermore, it is possible to further suppress a decrease in the depth of the groove G formed on the front surface 12A of the cold-rolled steel sheet 12. (Manufacturing Test)

[00173] The manufacturing test will be described next.

[00174] In the fabrication test, firstly, as Test 1, a grain-oriented electrical steel sheet was fabricated by the fabrication method described above using a focus shift (focal point) of a laser beam relative to a front surface of the grain-oriented electrical steel sheet as a parameter. Then, a groove depth and the iron loss reduction rate of the fabricated grain-oriented electrical steel sheet were evaluated.

[00175] Next, as Test 2, a grain-oriented electrical steel sheet was manufactured by the manufacturing method described above using laser power (output) from a laser beam with which a front surface of the grain-oriented electrical steel sheet was irradiated from a beam irradiation apparatus as a parameter. Then, the groove depth and the iron loss reduction rate of the manufactured grain-oriented electrical steel sheet were evaluated. (Groove Processing Conditions)

[00176] The processing conditions for the groove formed on the front surface of the grain-oriented electrical steel sheet by the beam irradiation apparatus are as follows. Petition 870250101208, dated 05 / 11 / 2025, page 56 / 158 / 66

[00177] Laser beam scanning speed: 45 [m / s]

[00178] Groove pitch (spacing): 3 [mm]

[00179] Laser beam format: 25 x 50 [μm]

[00180] Laser power (Test 1): 2000 [W]

[00181] Laser power (Test 2): see figure 8 (Polishing Brush Roller)

[00182] Polishing brush material, etc.: Nylon brush with abrasive grains, wire diameter (diameter) of 1.4 [mm], abrasive grain size of #80, three-beam type brush

[00183] Polishing brush roller rotation speed: 1200 [rpm]

[00184] Direction of rotation of the polishing brush roller: Opposite direction to the direction of transport of the grain-oriented electric steel sheet

[00185] Polishing brush roller indentation depth: 3 [mm]

[00186] Polishing liquid: Water (not containing abrasive grains)

[00187] Polishing fluid temperature: 50°C

[00188] One pass per cycle: Support roller method

[00189] Grain-oriented electric steel sheet conveying speed: 60 [m / m]

[00190] Torque constant Kt: 9.5 (Nm / A) (Test Results)

[00191] Figure 8 illustrates the results of Tests 1 and 2. Figure 9 illustrates a relationship between the depth of the groove formed on the front surface of the grain-oriented electrical steel sheet and the iron loss reduction rate η in each of Tests 1 and 2.

[00192] As illustrated in Figure 8, in each of Tests 1 and 2, the grain-oriented electrical steel sheets that had the following reference values ​​or higher were considered acceptable (examples), and the steel sheets Petition 870250101208, dated 05 / 11 / 2025, page 57 / 158 / 66 electrically oriented grain that had values ​​lower than the reference values ​​were considered comparative examples. <Valores de Referência>

[00193] Groove depth: 20 [μm]

[00194] Rate of reduction of iron loss η: 18 [%]

[00195] The reference value for the groove depth can be changed, if appropriate, and is defined in a range of, for example, 20 [μm] to 25 [μm]. Similarly, the reference value for the iron loss reduction rate η can also be changed, if appropriate.

[00196] The depth of the groove formed on the front surface of the grain-oriented electrical steel sheet was measured using a measuring device (KEYENCE (registered trademark) WI-5000 and WI-001). The groove depth can be obtained, for example, by measuring a length corresponding to a difference (H0 - H) using the measuring device, where H0 (> 0) represents an average height of the front surface of the grain-oriented electrical steel sheet measured in an arbitrary strip without the groove, and H (> 0) represents a height of a maximum groove depth (a lower part of the groove).

[00197] Furthermore, the iron loss reduction rate η of the grain-oriented electrical steel sheet was obtained from the following formula based on the iron loss of a raw steel sheet.

[00198] Iron loss reduction rate η [%] = ((Iron loss of raw steel sheet - Iron loss of grain-oriented electrical steel sheet) / Iron loss of raw steel sheet) x 100

[00199] Here, a manufacturing method for a raw steel sheet differs from the manufacturing method according to the modality above, as the beam irradiation step and the polishing step are not performed. That is, no groove is formed in the raw steel sheet.

[00200] In addition, the iron loss [W / kg] of each of the plates of Petition 870250101208, dated 05 / 11 / 2025, page 58 / 158 / 66 raw steel and grain-oriented electrical steel sheets, according to Examples 1 to 6 and Comparative Examples 1 to 10, was an iron loss when a 50 Hz magnetic field with a maximum magnetic flux density of 1.7 Tesla was applied to the following ten test specimens and was measured with a single-plate tester (SST). The iron loss of the raw steel sheet is 0.86 [W / kg]. <Corpo de Prova>

[00201] Specimen dimensions: 60 x 300 [mm]

[00202] Specimen thickness: 0.23 [mm]

[00203] In the manufacturing test, the amount of spatter acquired by the spatter quantity acquisition unit 132 under the slot processing conditions in Example 1, i.e., in a case where the laser beam focus shift quantity was 0 [mm] and the laser beam power was equal to the reference value (2000 [W]), was defined as the reference quantity S0 of spatter (= 120000 [pixels]). Similarly, the rotational torque of the polishing brush roller 44 acquired by the torque acquisition unit 133 under the slot processing conditions in Example 1 was defined as the reference rotational torque T0 (= 900 [Nm]).

[00204] Next, for each of Examples 1 to 6 and Comparative Examples 1 to 10, a ratio (S / S0) of the quantity S of splashes to the reference quantity S0 of splashes and a ratio (T / T0) of the rotational torque T to the reference rotational torque T0 was obtained.

[00205] Figure 10 illustrates a relationship between the amount of laser beam focus shift and the slit depth. As illustrated in Figure 10, the slit depth decreases as the amount of laser beam focus shift increases.

[00206] Figure 11 below illustrates a relationship between the amount of laser beam focus shift and the amount S of spatter. As Petition 870250101208, dated 05 / 11 / 2025, page 59 / 158 / 66 illustrated in figure 11, in a case where the amount of laser beam focus shift is 0.6 [mm] or more, the amount S of spatter decreases as the amount of laser beam focus shift increases.

[00207] On the other hand, in a case where the amount of laser beam focus shift is 0.6 [mm] or less, the following occurs. That is, in a case where the amount of laser beam focus shift is in a range of 0 to 0.3 [mm], the amount S of spatter decreases as the amount of laser beam focus shift increases. Conversely, in a case where the amount of laser beam focus shift is in a range of 0.3 to 0.6 [mm], the amount S of spatter increases as the amount of laser beam focus shift increases.

[00208] It can be observed that it is difficult to detect the change in focus of the laser beam in a case where the amount of change in focus of the laser beam relative to the front surface 12A of the cold-rolled steel sheet 12 is small (0.6 [mm] or less) by only monitoring the amount S of spatter detected by the spatter quantity detection device 110.

[00209] Figure 12 below illustrates a relationship between the amount of laser beam focus shift and the rotational torque T. As illustrated in Figure 12 and Figure 11 described above, the rotational torque T and the amount S of spatter have the same trend in a range where the amount of laser beam focus shift is from 0.3 to 0.6 [mm]. That is, in a case where the amount of laser beam focus shift is in a range of 0.3 to 0.6 [mm], the rotational torque T and the amount S of spatter increase as the amount of laser beam focus shift increases.

[00210] Here, in a case where the amount of laser beam focus shift is in the range of 0.3 to 0.6 [mm], the viscosity of the generated spatter increases due to the temperature change or similar of the front surface 12A of the cold-rolled steel sheet 12, and the particle size of the deposits, such as the spatter adhering to the front surface 12A of the sheet. Petition 870250101208, dated 05 / 11 / 2025, page 60 / 158 / 66 cold-rolled steel 12, increases. Therefore, in a case where the amount of laser beam focus shift is in a range of 0.3 to 0.6 [mm], the rotational torque T generated when polishing the deposits adhering to the front surface 12A of the cold-rolled steel sheet 12 is considered to have increased.

[00211] It can be observed that the shift in focus can be detected in a case where the amount of shift in focus of the laser beam is in a range of 0.3 to 0.6 [mm] by monitoring the rotational torque T. That is, the accuracy in estimating the depth of the groove can be enhanced by monitoring the rotational torque T in addition to the amount S of spatter.

[00212] Specifically, Figure 13 illustrates a relationship between the amount S of spatter and the groove depth. As illustrated in Figure 13, a condition of the amount S of spatter under which the groove depth becomes equal to or greater than the reference value of 20 [μm] is 100000 [pixels] or more. Figure 14 illustrates a relationship between the rotational torque T and the groove depth. As illustrated in Figure 14, a condition of the rotational torque T under which the groove depth becomes equal to or greater than the reference value of 20 [μm] is 800 [Nm] to 1000 [Nm]. That is, the conditions of the amount S of spatter and the rotational torque T that can reach the reference value of 20 [μm] of the groove depth are expressed by the following Formula (a). S > 100000 [pixels] and 800 [Nm] < T < 1000 [Nm] ··· (a)

[00213] Here, S: the quantity of splashes purchased by the splash quantity acquisition unit, and T: the rotational torque acquired by the torque acquisition unit.

[00214] Here, when the condition for the quantity S of splashes in Formula (a) above is generalized, the quantity of splashes becomes equal to or greater than the minimum quantity of splashes (100000 [pixels]) generated when forming Petition 870250101208, dated 05 / 11 / 2025, p. 61 / 158 / 66 The groove G, whose depth is equal to the reference value, is formed on the front surface 12A of the cold-rolled steel sheet 12 by the beam irradiation apparatus 30. When the rotational torque T condition in Formula (a) above is generalized, the rotational torque T becomes equal to or less than the maximum rotational torque (1000 [Nm]) generated in the polishing brush roller 44 when removing the deposits adhering to the front surface 12A of the cold-rolled steel sheet 12 in which the groove G, whose depth is equal to the reference value, is formed by the beam irradiation apparatus 30 by the polishing brush roller 44. Therefore, in Formula (a) above, the minimum amount of spatter is the reference amount of spatter, and the maximum rotational torque is the reference rotational torque.

[00215] Here, in Formula (a) above, it is possible to determine whether the depth of the groove formed on the front surface 12A of the cold-rolled steel sheet 12 is equal to or greater than the reference value in a case where the quantity S of spatter acquired by the spatter quantity acquisition unit 132 is equal to or greater than the reference quantity of spatter and the rotational torque T acquired by the torque acquisition unit 133 is equal to or less than the reference rotational torque.

[00216] As illustrated in figure 8, in a case where the quantity S of splashes acquired by the splash quantity acquisition unit 132 is equal to or greater than the reference quantity of splashes (100000 [pixels]), the rotational torque T acquired by the torque acquisition unit 133 becomes equal to or greater than 800 [Nm]. Therefore, a lower limit value (800 [Nm]) of the rotational torque T in Formula (a) above can be omitted.

[00217] Figure 15 below illustrates a relationship between the ratio (S / S0) of the quantity S of splashes to the reference quantity S0 of splashes and the rotational torque T. As described above, the reference quantity S0 of splashes here is the quantity of splashes (= 120000 [pixels]) acquired by the splash quantity acquisition unit 132 under the conditions of Petition 870250101208, dated 05 / 11 / 2025, page 62 / 158 / 66 groove processing in Example 1, i.e., in a case where the amount of laser beam focus shift is 0 [mm] and the laser beam power is equal to the reference value (2000 [W]).

[00218] As illustrated in figure 15, a condition under which the groove depth becomes equal to or greater than the reference value (20 [μm]) is expressed by the following Formula (2). > S / S0 > C1 and T1 < T < T2 ··· (2)

[00219] Here, S: the quantity of splashes acquired by the splash quantity acquisition unit, S0: the reference amount of splashes, C1: S1 / S0, S1: a minimum amount of spatter generated when forming the groove whose depth is equal to the reference value on the front surface of the cold-rolled steel sheet (steel plate). T: the rotational torque acquired by the torque acquisition unit, T1: the reference rotational torque, which is the minimum rotational torque generated when removing deposits adhering to the front surface of the cold-rolled steel sheet (steel plate) in which the groove is formed, the depth of which is equal to the reference value, by the polishing brush roller, and T2: the reference rotational torque which is the maximum rotational torque generated when removing deposits adhering to the front surface of the cold-rolled steel sheet (steel plate) in which the groove is formed whose depth is equal to the reference value by the polishing brush roll.

[00220] In the manufacturing test, C1 is 0.83, T1 is 800 [Nm] and T2 is 1000 [Nm], but C1, T1 and T2 may be changed if appropriate.

[00221] Figure 16 illustrates a relationship between the ratio (S / S0) of the quantity S of splashes to the reference quantity S0 of splashes and the Petition 870250101208, dated 05 / 11 / 2025, p. 63 / 158 / 66 ratio (T / T0) of rotational torque T to reference rotational torque T0. As described above, the reference rotational torque T0 here is the rotational torque (=900 [Nm]) of the polishing brush roll 44 acquired by the torque acquisition unit 133 under the slot processing conditions in Example 1.

[00222] As illustrated in figure 16, a condition under which the groove depth becomes equal to or greater than the reference value (20 [μm]) is expressed by Formula (1) above. > S / S0 > C1 and C2 < T / T0 < C3 ··· (1)

[00223] Here, S: the quantity of splashes acquired by the splash quantity acquisition unit, S0: the reference amount of splashes, C1: S1 / S0, S1: the minimum amount of spatter generated when forming the groove whose depth is equal to the reference value on the front surface of the cold-rolled steel sheet (steel plate). T: the rotational torque acquired by the torque acquisition unit, T0: the reference rotational torque, C2: T1 / T0, T1: the minimum rotational torque generated when removing deposits adhering to the front surface of the cold-rolled steel sheet (steel plate) in which the groove is formed whose depth is equal to the reference value by the polishing brush roller, C3: T2 / T0, and T2: the maximum rotational torque generated when removing deposits adhering to the front surface of the cold-rolled steel sheet (steel plate) in which the groove is formed, the depth of which is equal to the reference value. Petition 870250101208, dated 05 / 11 / 2025, p. 64 / 158 / 66 regarding the polishing brush roller.

[00224] In the manufacturing test, C1 is 0.83, C2 is 0.89 and C3 is 1.11, but C1, C2 and C3 can be changed if appropriate.

[00225] Using Formula (a), Formula (1) or Formula (2) in this manner, it is possible to determine whether the depth of the groove formed on the front surface 12A of the cold-rolled steel sheet 12 is equal to or greater than the reference value (20 [μm]). (Modified Examples)

[00226] A modified example of this modality will be explained next.

[00227] In Formula (a) above, the reference quantity of spatter may be, for example, the quantity of spatter obtained by multiplying the minimum quantity of spatter by a predetermined safety factor. In Formula (a) above, the reference quantity of spatter may be, for example, an average value of a plurality of measured quantities of spatter obtained by measuring the quantity of spatter generated when forming the groove G whose depth is equal to or greater than the reference value on the front surface 12A of the cold-rolled steel sheet 12 by the beam irradiation apparatus 30 a plurality of times.

[00228] As described above, the reference amount of spatter in Formula (a) can be determined based on the amount of spatter generated when forming groove G whose depth is equal to or greater than the reference value on the front surface 12A of the cold-rolled steel sheet 12 by the beam irradiation apparatus 30.

[00229] In Formula (a) above, the reference rotational torque can be, for example, a rotational torque obtained by multiplying the maximum rotational torque by a predetermined safety factor. In Formula (a) above, the reference rotational torque can be, for example, an average value of a plurality of measured rotational torques obtained by measuring the Petition 870250101208, dated 05 / 11 / 2025, p. 65 / 158 / 66 rotational torque generated in the polishing brush roller 44 when removing deposits adhering to the front surface 12A of the cold-rolled steel sheet 12 in which the groove G whose depth is equal to or greater than the reference value is formed by the beam irradiation apparatus 30 by the polishing brush roller 44 a plurality of times.

[00230] As described above, the reference rotational torque in Formula (a) can be determined based on the rotational torque generated in the polishing brush roller 44 removing the deposits adhering to the front surface 12A of the cold-rolled steel sheet 12 in which the groove G whose depth is equal to or greater than the reference value is formed by the beam irradiation apparatus 30 by the polishing brush roller 44.

[00231] Next, in Formulas (1) and (2) above, the reference quantity S0 of spatter can be, for example, the quantity of spatter obtained by multiplying, by a predetermined safety factor, the quantity of spatter generated when forming the groove G on the front surface 12A of the cold-rolled steel sheet 12 by the laser beam L in a case where the amount of focus change of the laser beam L with which the front surface 12A of the cold-rolled steel sheet 12 is irradiated is 0 and the laser power of the laser beam L is equal to the reference value.Furthermore, the reference quantity S0 of spatter can also be, for example, an average value of a plurality of measured quantities of spatter obtained by measuring the quantity of spatter generated when forming the groove G on the front surface 12A of the cold-rolled steel sheet 12 by the laser beam L a plurality of times in a case where the amount of focus change of the laser beam L with which the front surface 12A of the cold-rolled steel sheet 12 is irradiated is 0 and the laser power of the laser beam L is equal to the reference value.

[00232] As described above, the reference quantity S0 of splashes in Formulas (1) and (2) above can be determined based on Petition 870250101208, dated 05 / 11 / 2025, page 66 / 158 / 66 quantity of spatter generated when forming groove G on the front surface 12A of the cold-rolled steel sheet 12 by the laser beam L in a case where the amount of focus change of the laser beam L with which the front surface 12A of the cold-rolled steel sheet 12 is irradiated is 0 and the laser power of the laser beam L is equal to the reference value.

[00233] Furthermore, in Formulas (1) and (2) above, for example, the reference rotational torque T0 can be a rotational torque obtained by multiplying, by a predetermined safety factor, the rotational torque generated by removing the deposits adhering to the front surface 12A of the cold-rolled steel sheet 12 in which the groove G is formed by the laser beam L by the polishing brush roller 44 in a case where the amount of focus change of the laser beam L with which the front surface 12A of the cold-rolled steel sheet 12 is irradiated is 0 and the laser power of the laser beam L is equal to the reference value.Furthermore, for example, in Formulas (1) and (2) above, for example, the reference rotational torque T0 can be an average value of a plurality of measured rotational torques obtained by measuring the rotational torque generated when removing deposits adhering to the front surface 12A of the cold-rolled steel sheet 12 in which the groove G is formed by the laser beam L by the polishing brush roller 44 in a case where the amount of focus change of the laser beam L with which the front surface 12A of the cold-rolled steel sheet 12 is irradiated is 0 and the laser power of the laser beam L is equal to the reference value a plurality of times.

[00234] As described above, the reference rotational torque T0 in Formulas (1) and (2) above can be determined based on the rotational torque generated when removing deposits adhering to the front surface 12A of the cold-rolled steel sheet 12 in which the groove G is formed by the laser beam L by the polishing brush roller 44 in a case where the amount of focus change of the laser beam L with which the front surface 12A of the cold-rolled steel sheet 12 is irradiated is 0, and the laser power of the beam is Petition 870250101208, dated 05 / 11 / 2025, p. 67 / 158 / 66 laser L is equal to the reference value.

[00235] In the above embodiment, the control device 130 (groove depth determination unit 134) determines whether the groove depth G formed on the front surface 12A of the cold-rolled steel sheet 12 is equal to or greater than the reference value based on the spatter quantity S detected by the spatter quantity detection device 110, the predetermined reference spatter quantity S0, the rotational torque T of the polishing brush roller 44 detected by the torque detection device 120 and the predetermined reference rotational torque.

[00236] However, for example, in a case where there is no change in focus of the laser beam L with which the front surface 12A of the cold-rolled steel sheet 12 is irradiated by the beam irradiation apparatus 30, or in a case where the change in focus is insignificantly small, the control apparatus 130 (groove depth determination unit 134) can perform the following determination. That is, the control apparatus 130 (groove depth determination unit 134) can determine whether the groove depth G formed on the front surface 12A of the cold-rolled steel sheet 12 is equal to or greater than the reference value based on the rotational torque T of the polishing brush roll 44 detected by the torque detection apparatus 120 and the predetermined reference rotational torque T0.

[00237] More specifically, the control device 130 (groove depth determination unit 134) can determine whether the groove depth G formed on the front surface 12A of the cold-rolled steel sheet 12 is equal to or greater than the reference value in a case where the following Formula (3) is satisfied. The reference rotational torque T0 in the following Formula (3) is determined based, for example, on the rotational torque generated when removing deposits adhering to the front surface 12A of the cold-rolled steel sheet 12 in which the groove G whose Petition 870250101208, dated 05 / 11 / 2025, p. 68 / 158 / 66 depth is equal to the reference value is formed by the laser beam L by the polishing brush roller 44 in a case where the amount of focus change of the laser beam L with which the front surface 12A of the cold-rolled steel sheet 12 is irradiated is 0. T1 < T < T0 ··· (3)

[00238] Here, T: the rotational torque acquired by the torque acquisition unit, T0: the reference rotational torque, and T1: the minimum rotational torque generated when removing deposits adhering to the front surface of the steel sheet where the groove is formed, whose depth is equal to the reference value, by the polishing brush roller.

[00239] In this case, as can be seen in the results of Test 2 illustrated in figure 8, it is possible to detect the cold-rolled steel sheet 12 in which the depth of the groove G formed on the front surface 12A of the cold-rolled steel sheet 12 is less than the reference value due to a decrease in the laser beam output of the beam irradiation apparatus 30. Therefore, a decrease in the depth of the groove G formed on the front surface 12A of the cold-rolled steel sheet 12 can be suppressed.

[00240] In the manufacturing test above, T0 is 900 [Nm] and T1 is = 800 [Nm], but T0 and T1 can be changed if appropriate.

[00241] A criterion for determining whether a groove depth formed on the front surface 12A of cold-rolled steel sheet 12 is equal to or greater than the reference value is not limited to Formulas (a), (1), (2) and (3), and may be changed if appropriate.

[00242] In addition, the shape, size, rotation speed, rotation direction, material and the like of the polishing brush 44B of the polishing brush roller 44 in the above embodiment may be changed appropriately, if necessary. Petition 870250101208, dated 05 / 11 / 2025, p. 69 / 158 / 66

[00243] In the embodiment above, the finishing laminator 15, the oil film removal apparatus 20, the decarburization annealing apparatus 50, the annealing separator application apparatus 55, the final finishing annealing apparatus 60, the insulating coating agent application apparatus 70 and the flattening annealing apparatus 80 are provided in the manufacturing apparatus 10. However, the finishing laminator 15, the oil film removal apparatus 20, the decarburization annealing apparatus 50, the annealing separator application apparatus 55, the final finishing annealing apparatus 60, the insulating coating agent application apparatus 70 and the flattening annealing apparatus 80 may be provided in the manufacturing apparatus 10, if necessary, and may be omitted, if appropriate.

[00244] In the embodiment above, the slot depth monitoring processing performed by the instructions of CPU 142 can be performed by several processors different from CPU 142. Examples of the processor in this case include a programmable logic device (PLD) in which a circuit configuration can be changed after fabrication, a field-programmable gate array (FPGA) or similar, and a dedicated electrical circuit that is a processor having a circuit configuration designed exclusively to perform specific processing, such as an application-specific integrated circuit (ASIC). Furthermore, the slot depth monitoring processing can be performed by one of several processors or it can be performed by a combination of two or more processors of the same type or of different types (e.g., a plurality of FPGAs and a combination of a CPU and an FPGA).More specifically, the hardware structure of various processors is an electrical circuit in which circuit elements, such as semiconductor elements, are combined.

[00245] In the above mode, the monitoring instructions of Petition 870250101208, dated 05 / 11 / 2025, page 70 / 158 / 66 slot depth data are stored in storage unit 146 in advance. However, slot depth monitoring instructions may also be provided in a form of storage on a recording medium (a non-transient recording medium and a computer-readable recording medium), such as a compact disc read-only memory (CD-ROM), a digital versatile disc read-only memory (DVD-ROM), or a USB (Universal Serial Bus) memory. Furthermore, instructions may be downloaded from an external device to the control device 130 via a network.

[00246] Although one embodiment has been described above, the present description is not limited to such embodiment, and one embodiment and several modified examples may be combined and used as appropriate, and it is natural that several modes may be implemented without departing from the essence of the description.

[00247] The description of Japanese Patent Application No. 2023-036047 filed March 8, 2023 is incorporated herein by reference in its entirety.

[00248] All documents, patent applications and technical standards mentioned in this descriptive report are incorporated herein by reference to the same extent as if each individual document, patent application and technical standard were specifically and individually stated.

[00249] The following supplementary notes are described in addition to the above modality. (Supplementary Note 1)

[00250] An electric grain-oriented steel sheet fabrication apparatus, including: a beam irradiation device that irradiates the front surface of a cold-rolled steel sheet, which is a grain-oriented electrical steel sheet material, with a laser beam to form a groove; a polishing brush roller that buffs and removes deposits Petition 870250101208, dated 05 / 11 / 2025, page 71 / 158 / 66 that adhere to the front surface of the cold-rolled steel sheet in which the groove is formed during rotation; and a groove depth monitoring system to determine the depth of the groove formed on the front surface of the cold-rolled steel sheet, wherein the groove depth monitoring system includes: a spatter quantity detection unit that detects the amount of spatter generated when forming the groove on the front surface of the cold-rolled steel sheet using the laser irradiation device; A polishing torque detection unit that detects torque generated on the polishing brush roll by removing deposits adhering to the front surface of the cold-rolled steel sheet by the polishing brush roll; and a groove depth determination unit that determines whether the groove depth formed on the front surface of the cold-rolled steel sheet is equal to or greater than a reference value based on the amount of spatter detected by the spatter quantity detection unit, a predetermined reference spatter quantity, the polishing brush roll torque detected by the polishing torque detection unit, and a predetermined reference polishing torque. (Supplementary Note 2)

[00251] The grain-oriented electric steel sheet manufacturing apparatus according to Supplementary Note 1, wherein the spatter reference quantity is a minimum spatter quantity generated when forming the groove whose depth is equal to or greater than the reference value on the front surface of the cold-rolled steel sheet using the laser irradiation apparatus, and Petition 870250101208, dated 05 / 11 / 2025, page 72 / 158 / 66 the reference polishing torque is a maximum torque generated in the polishing brush roller when removing deposits adhering to the front surface of the cold-rolled steel sheet in which the groove whose depth is equal to the reference value is formed using the laser irradiation apparatus by the polishing brush roller. (Supplementary Note 3)

[00252] The grain-oriented electric steel sheet manufacturing apparatus according to Supplementary Note 2, in which the groove depth determination unit determines that the groove depth formed on the front surface of the cold-rolled steel sheet is equal to or greater than the reference value in a case where the amount of spatter detected by the spatter quantity detection unit is equal to or greater than the reference amount of spatter and the polishing brush roller torque detected by the polishing torque detection unit is equal to or less than the reference polishing torque. (Supplementary Note 4)

[00253] The grain-oriented electric steel sheet manufacturing apparatus according to Supplementary Note 2, in which the groove depth determination unit determines that the groove depth formed on the front surface of the cold-rolled steel sheet is equal to or greater than the reference value in a case where the reference polishing torque is 1000 [Nm] and Formula (1) is satisfied. S / S0 > 0.83 and 800 [Nm] < T < 1000 [Nm] ··· (1)

[00254] Here, S: the amount of splashing detected by the splashing quantity detection unit. S0: the reference spatter quantity, and T: the torque of the polishing brush roller detected by the polishing torque detection unit. Petition 870250101208, dated 05 / 11 / 2025, p. 73 / 158 / 66 (Supplementary Note 5)

[00255] The grain-oriented electrical steel sheet manufacturing apparatus according to Supplementary Note 2, in which the groove depth determination unit determines that the groove depth formed on the front surface of the cold-rolled steel sheet is equal to or greater than the reference value in a case where Formula (2) is satisfied. S / S0 > 0.83 and 0.89 < T / T0 < 1.11 ··· (2)

[00256] Here, S: the amount of splashing detected by the splashing quantity detection unit. S0: the reference splash quantity, T: the torque of the polishing brush roller detected by the polishing torque detection unit and T0: the reference polishing torque. (Supplementary Note 6)

[00257] A method for manufacturing grain-oriented electrical steel sheet using a manufacturing apparatus including a laser irradiation apparatus that irradiates a front surface of a cold-rolled steel sheet that is a material of a grain-oriented electrical steel sheet with a laser beam to form a groove, a polishing brush roller that polishes and removes deposits adhering to the front surface of the cold-rolled steel sheet in which the groove is formed during rotation; and a groove depth monitoring system that determines the depth of the groove formed on the front surface of the cold-rolled steel sheet, method of manufacturing grain-oriented electrical steel sheet using the groove depth monitoring system, including: a splash quantity detection step to detect, Petition 870250101208, dated 05 / 11 / 2025, page 74 / 158 / 66 for a spatter quantity detection unit, the amount of spatter generated when forming the groove on the front surface of the cold-rolled steel sheet using the laser irradiation device; A polishing torque detection step to detect, by a polishing torque detection unit, a torque generated on the polishing brush roller when removing deposits adhering to the front surface of the cold-rolled steel sheet by the polishing brush roller; and a groove depth determination step to determine, by a groove depth determination unit, whether the groove depth formed on the front surface of the cold-rolled steel sheet is equal to or greater than a reference value based on the amount of spatter detected by the spatter quantity detection unit, a predetermined reference spatter quantity, the polishing brush roller torque detected by the polishing torque detection unit, and a predetermined reference polishing torque. Petition 870250101208, dated 05 / 11 / 2025, p. 75 / 158

Claims

1 / 7 CLAIMS 1. Groove depth monitoring system, characterized in that it comprises: a torque acquisition unit for acquiring a rotational torque generated when removing deposits adhering to a front surface of a steel plate in which a groove is formed by a beam, by a polishing brush roller; and a groove depth determination unit for determining whether a groove depth formed on the front surface of the steel plate is equal to or greater than a reference value based on the rotational torque acquired by the torque acquisition unit and a predetermined reference rotational torque.

2. Groove depth monitoring system according to claim 1, characterized in that it further comprises a spatter quantity acquisition unit for acquiring a quantity of spatter generated when forming the groove, irradiating the front surface of the steel plate with the beam, wherein the groove depth determination unit determines whether the depth of the groove formed on the front surface of the steel plate is equal to or greater than the reference value based on the quantity of spatter acquired by the spatter quantity acquisition unit, a predetermined spatter reference quantity, the rotational torque acquired by the torque acquisition unit and the reference rotational torque.

3. Groove depth monitoring system according to claim 2, characterized in that the groove depth determination unit determines that the depth of the groove formed on the front surface of the steel sheet is equal to or greater than the reference value in a case where the amount of spatter acquired by the spatter quantity acquisition unit is equal to or greater than the reference spatter quantity and the rotational torque acquired by the torque acquisition unit is equal to or less than the reference rotational torque.

4. Groove depth monitoring system according to claim 2 or 3, characterized in that: the reference amount of spatter is determined based on the amount of spatter generated when forming the groove whose depth is equal to the reference value on the front surface of the steel plate, and the reference rotational torque is determined based on the rotational torque generated when removing the deposits adhering to the front surface of the steel plate in which the groove whose depth is equal to the reference value is formed, by the polishing brush roller.

5. Groove depth monitoring system according to claim 4, characterized in that: the reference amount of spatter is determined based on the amount of spatter generated when forming the groove on the front surface of the steel plate by the beam in a case where the amount of beam focus change with which the front surface of the steel plate is irradiated is 0 and the beam power is equal to a reference value; the reference rotational torque is determined based on the rotational torque generated when removing the deposits adhering to the front surface of the steel plate where the groove is formed by the beam, by the polishing brush roller in a case where the amount of beam focus change with which the front surface of the steel plate is irradiated is 0 and the beam power is equal to the reference value.and the unit for determining groove depth determines that the depth of the groove formed on the front surface of the steel plate is equal to or greater than the reference value in a case where Formula (1) is Petition 870250101208, dated 05 / 11 / 2025, page. 77 / 158 3 / 7 satisfied, 1 > S / S0 > C1 and C2 < T / T0 < C3 ··· (1) where S: the amount of spatter acquired by the spatter quantity acquisition unit, S0: the reference amount of spatter, C1: S1 / S0, S1: a minimum amount of spatter generated when forming the groove whose depth is equal to the reference value on the front surface of the steel plate, T: the rotational torque acquired by the torque acquisition unit, T0: the reference rotational torque, C2: T1 / T0, T1: a minimum rotational torque generated when removing the deposits that adhere to the front surface of the steel plate in which the groove whose depth is equal to the reference value is formed, by the polishing brush roller, C3: T2 / T0,T2: the maximum rotational torque generated when removing deposits adhering to the front surface of the steel sheet where the groove is formed, the depth of which is equal to the reference value, by the polishing brush roller.

6. Groove depth monitoring system according to claim 5, characterized in that: C1 is 0.83, C2 is 0.89, and C3 is 1.

11.

7. Groove depth monitoring system according to claim 4, characterized in that: Petition 870250101208, dated 05 / 11 / 2025, page 78 / 158 4 / 7 the reference quantity of spatter is determined based on a quantity of spatter generated when forming the groove on the front surface of the steel plate by the beam in a case where the amount of beam focus change with which the front surface of the steel plate is irradiated is 0 and the beam power is equal to a reference value, the reference rotational torque is determined based on a rotational torque generated when removing the deposits adhering to the front surface of the steel plate in which the groove is formed by the beam, by the polishing brush roller in a case where the amount of beam focus change with which the front surface of the steel plate is irradiated is 0 or the beam power is equal to the reference value,and the groove depth determination unit determines that the depth of the groove formed on the front surface of the steel plate is equal to or greater than the reference value in a case where Formula (2) is satisfied, 1 > S / S0 > C1 and T1 < T < T2 ··· (2) where S: the amount of spatter acquired by the spatter quantity acquisition unit, S0: the reference amount of spatter, C1: S1 / S0, S1: a minimum amount of spatter generated when forming the groove whose depth is equal to the reference value on the front surface of the steel plate, T: the rotational torque acquired by the torque acquisition unit, T1: the reference rotational torque which is a minimum rotational torque generated when removing the deposits that adhere to the front surface of the steel plate in which the groove is formed whose depth is equal to the value of Petition 870250101208, of 05 / 11 / 2025, page. 79 / 158 5 / 7 reference, by polishing brush roller,T2: the reference rotational torque, which is the maximum rotational torque generated when removing deposits adhering to the front surface of the steel sheet where the groove is formed, the depth of which is equal to the reference value, by the polishing brush roller.

8. Groove depth monitoring system according to claim 7, characterized in that: C1 is 0.83, T1 is 800 [Nm], and T2 is 1000 [Nm].

9. Groove depth monitoring system according to claim 1, characterized in that the reference rotational torque is determined based on a rotational torque generated when removing deposits adhering to the front surface of the steel sheet in which the groove whose depth is equal to the reference value is formed by the beam, by the polishing brush roller in a case where a quantity of beam focus change with which the front surface of the steel sheet is irradiated is 0.

10. Groove depth monitoring system according to claim 9, characterized in that: the reference rotational torque is determined based on a rotational torque generated when removing deposits adhering to the front surface of the steel sheet in which the groove whose depth is equal to the reference value is formed by the beam, by the polishing brush roller in a case where the amount of beam focus change with which the front surface of the steel sheet is irradiated is 0 and beam power is equal to a reference value, and the unit of groove depth determination determines that the depth of the groove formed on the front surface of the steel sheet is Petition 870250101208, dated 05 / 11 / 2025, p.80 / 158 6 / 7 equal to or greater than the reference value in a case where Formula (3) is satisfied, T1 < T < T0 ··· (3) wherein T: the rotational torque acquired by the torque acquisition unit, T0: the reference rotational torque, and T1: a minimum rotational torque generated when removing deposits adhering to the front surface of the steel plate in which the groove is formed whose depth is equal to the reference value, by the polishing brush roller.

11. Groove depth monitoring system according to claim 10, characterized in that: T0 is 900 [Nm], and T1 is 800 [Nm].

12. Electrical steel sheet manufacturing apparatus, characterized in that it comprises: a beam irradiation apparatus that irradiates a front surface of a steel sheet that is a material of an electrical steel sheet with a beam to form a groove; a polishing brush roller that removes deposits adhering to the front surface of the steel sheet in which the groove is formed; and the groove depth monitoring system for an electrical steel sheet as defined in any one of claims 1 to 11.

13. Groove depth monitoring method, characterized in that it comprises: a torque acquisition step to acquire a rotational torque generated by removing deposits adhering to a front surface of a steel plate in which a groove is formed by a beam, by a polishing brush roller; and a groove depth determination step to determine whether a groove depth formed on the front surface of the steel plate is equal to or greater than a reference value based on the rotational torque acquired in the torque acquisition step and a predetermined reference rotational torque.

14. A computer-readable non-transient storage medium, characterized in that it comprises a series of operational instructions stored therein for performing groove depth monitoring, the operational instructions being executable by a computer for processing, including: a torque acquisition step to acquire a rotational torque generated by removing deposits adhering to a front surface of a steel plate in which a groove is formed by a beam, by a polishing brush roller; and a groove depth determination step to determine whether a groove depth formed on the front surface of the steel plate is equal to or greater than a reference value based on the rotational torque acquired in the torque acquisition step and a predetermined reference rotational torque. Petition 870250101208, dated 05 / 11 / 2025, p. 82 / 158

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