Laser processing device and laser processing method

Abstract

This laser processing device comprises a gas injection part for injecting a gas from an opening toward a region of the surface of a steel plate irradiated with laser light. The gas injection part includes a nozzle part provided with an outer surface which is inclined, toward the opening side from a side opposite to the opening side in the injection direction, so as to approach the center of the opening from outside the opening, in a direction parallel to the surface of the steel plate. A first adhesion-inhibiting part for inhibiting adhesion of laser spatter is disposed on at least a section of the outer surface of the nozzle part.

Description

Laser processing device and laser processing method

[0001] The present disclosure relates to a laser processing apparatus and a laser processing method.

[0002] Conventionally, in the steel industry, a process has been known in which a laser beam is irradiated onto the surface of a steel sheet being transported in a predetermined direction or a stationary steel sheet to form grooves or other processing on the surface of the steel sheet. For example, Japanese Patent Application Laid-Open No. 2020-138226 discloses a technique in which multiple laser processing units each having a laser light source unit are arranged along the width direction of a grain-oriented electrical steel sheet. In Japanese Patent Application Laid-Open No. 2020-138226, a processed groove extending along the width direction of the steel sheet is formed on the surface of the steel sheet by irradiating the laser beam.

[0003] Dust particles called laser spatter are generated from the area irradiated with laser light (i.e., the irradiation position) on the surface of the steel sheet. In this specification, foreign matter such as laser spatter and chips is also referred to as "spatter." If spatter adheres to the surface of the steel sheet, it may adversely affect the performance of the steel sheet. For this reason, techniques have been proposed for removing spatter from around the steel sheet.

[0004] As a technology for removing spatter, for example, Japanese Patent Application Laid-Open No. 2020-138226 discloses a laser processing device that includes a laser irradiation facility, a dust collection mechanism that sucks up the spatter, and an air nozzle that serves as a gas injection unit that injects air toward the area irradiated with the laser light.

[0005] Patent Document 1: JP 2020-138226 A

[0006] The present inventors have discovered that when a gas injection unit that injects gas from a nozzle toward an irradiation site is used, spatter easily adheres to the outer surface of the nozzle. The term "nozzle" here refers to a portion of the gas injection unit that has an outer surface that slopes from the outside of the opening toward the center of the opening in a direction parallel to the surface of the steel sheet as it moves from the side opposite the opening for gas injection in the injection direction toward the opening. In particular, the present inventors have discovered that fine spatter generated by groove processing on the surface of the steel sheet adheres to the nozzle of the gas injection unit over long periods of use of the laser processing device. The groove depth is approximately 10 μm to 50 μm. Furthermore, the dimensions of the spatter generated by groove formation are approximately 10 μm to 50 μm, similar to the groove depth.

[0007] In this regard, Japanese Patent Application Laid-Open No. 2020-138226 does not consider a technology for suppressing adhesion of spatter to the outer surface of the nozzle portion in a laser processing process when the nozzle portion is provided with a gas injection portion.

[0008] The present disclosure has been made in consideration of the above, and provides a laser processing device and a laser processing method that can suppress adhesion of laser sputter to the outer surface of a nozzle portion of a gas injection unit.

[0009] The laser processing apparatus according to the present disclosure is a gas injection unit that injects gas from an opening toward the laser light irradiation site on the surface of a steel plate, and has a nozzle portion with an outer surface that slopes from the outside of the opening toward the center of the opening in a direction parallel to the surface of the steel plate as it moves from the opposite side of the opening in the injection direction toward the opening, and has a first adhesion inhibition portion for inhibiting adhesion of laser spatter arranged on at least a part of the outer surface of the nozzle portion.

[0010] The laser processing method according to the present disclosure irradiates the surface of a steel plate with laser light, and uses a gas injection unit having a nozzle section with an outer surface that slopes from the outside of the opening toward the center of the opening in a direction parallel to the surface of the steel plate as it moves from the opposite side of the opening in the injection direction toward the opening side, and an adhesion-preventing section for inhibiting the adhesion of laser spatter arranged on at least a part of the outer surface of the nozzle section, to inject gas from the opening toward the irradiation site so as to lift up the laser spatter generated from the irradiation site of the laser light from the surface of the steel plate.

[0011] According to the present disclosure, it is possible to suppress adhesion of laser sputters to the outer surface of the nozzle portion of the gas injection unit.

[0012] FIG. 1 is a plan view illustrating a laser processing apparatus according to a first embodiment of the present disclosure. FIG. 1 is a cross-sectional view taken along line 2-2 in FIG. 1. FIG. 1 is a cross-sectional view illustrating a laser processing apparatus according to a first modified example of the first embodiment, cut at the position of line 2-2 in FIG. 1. FIG. 1 is a cross-sectional view illustrating a laser processing apparatus according to a second modified example of the first embodiment, cut at the position of line 2-2 in FIG. 1. FIG. 1 is a cross-sectional view illustrating a laser processing apparatus according to a third modified example of the first embodiment, cut at the position of line 2-2 in FIG. 1. FIG. 1 is a graph illustrating the adhesion rate of sputter to the gas injection portion in each of the laser processing apparatuses according to the first embodiment and the first to third modified examples. FIG. 1 is a cross-sectional view illustrating a laser processing apparatus according to a second embodiment of the present disclosure, cut at the position corresponding to line 2-2 in FIG. 1. FIG. 1 is a cross-sectional view illustrating a gas injection portion of a laser processing apparatus according to a fourth modified example of the second embodiment, cut at the position corresponding to line 2-2 in FIG. 1. FIG. 1 is a front view illustrating the gas injection portion of a laser processing apparatus according to a fourth modified example of the second embodiment, viewed along the conveying direction. FIG. 1 is a cross-sectional view illustrating a laser processing apparatus according to a fifth modified example of the second embodiment, cut at the position corresponding to line 2-2 in FIG. 1. 16. A cross-sectional view illustrating a laser processing apparatus according to a sixth modified example of the second embodiment, taken at a position corresponding to line 2-2 in FIG. 1. FIG. 17 is a graph illustrating the adhesion rate of sputters to the gas injection section in each of the laser processing apparatuses according to the second embodiment and the fourth to sixth modified examples. FIG. 18 is a cross-sectional view illustrating a laser processing apparatus according to a third embodiment of the present disclosure, taken at a position corresponding to line 2-2 in FIG. 1. FIG. 19 is a cross-sectional view illustrating a laser processing apparatus according to a seventh modified example of the third embodiment, taken at a position corresponding to line 2-2 in FIG. 1. FIG. 20 is a cross-sectional view illustrating a laser processing apparatus according to an eighth modified example of the third embodiment, taken at a position corresponding to line 2-2 in FIG. 1. FIG. 21 is a plan view illustrating a first peeling mechanism in a standby state in a dust collection mechanism unit of a laser processing apparatus according to an eighth modified example of the third embodiment. A cross-sectional view taken at a position corresponding to line 17-17 in FIG. 16. A cross-sectional view taken at a line 18-18 in FIG. 16. FIG. 22 is a plan view illustrating a first peeling mechanism in a push-out state in a dust collection mechanism unit of a laser processing apparatus according to an eighth modified example of the third embodiment. FIG. 23 is a cross-sectional view illustrating a first peeling mechanism in a push-out state in a dust collection mechanism unit of a laser processing apparatus according to an eighth modified example of the third embodiment, taken at a position corresponding to line 17-17 in FIG.21 is a plan view illustrating a second peeling mechanism in a standby state in a dust collection mechanism unit of a laser processing apparatus according to an eighth modified example of the third embodiment. It is a cross-sectional view taken along line 22-22 in FIG. 21. It is a front view illustrating a peeling mechanism in a standby state on the bottom side in a dust collection mechanism unit of a laser processing apparatus according to an eighth modified example of the third embodiment. It is a plan view illustrating a second peeling mechanism in a push-out state in a dust collection mechanism unit of a laser processing apparatus according to an eighth modified example of the third embodiment. It is a cross-sectional view illustrating a second peeling mechanism in a push-out state in a dust collection mechanism unit of a laser processing apparatus according to an eighth modified example of the third embodiment, taken along a line 22-22 in FIG. 21. It is a cross-sectional view illustrating a laser processing apparatus according to a ninth modified example of the third embodiment, taken along a line 2-2 in FIG. 1. It is a graph illustrating the adhesion rate of spatter to the dust collection mechanism unit in each of the laser processing apparatuses according to the third embodiment and the seventh to ninth modified examples.

[0013] A first embodiment and a second embodiment are described below. In the following description of the drawings, identical or similar parts are designated by the same or similar reference numerals. However, the drawings are schematic, and the relationship between thickness and planar dimensions, the thickness ratio of each device or component, etc., differ from the actual ones. Therefore, specific thicknesses and dimensions should be determined with reference to the following description. Furthermore, parts with different dimensional relationships and ratios are included between the drawings. Furthermore, unless otherwise specified in the specification, the number of each component element of the present disclosure is not limited to one, and multiple elements may be present.

[0014] 1 and 2, the laser processing apparatus 1 according to the first embodiment includes a laser light source unit 10, a gas injection unit 20, a dust collection mechanism unit 30, and a ceiling panel 90. The operating states of the laser light source unit 10, the gas injection unit 20, and the dust collection mechanism unit 30 are controlled by various computers (not shown), such as a process computer that comprehensively controls the steel plate manufacturing process.

[0015] (Steel Plate) The processing target of the laser processing device 1 according to the first embodiment is a steel plate S. The type of steel plate S is not particularly limited, and various known steel plates S, such as grain-oriented electromagnetic steel plates (for example, JIS C 2553:2012), can be used. The type of processing using laser light is also not limited. The laser processing device 1 according to the first embodiment is applicable to various known processing using laser light that is performed at any timing in the manufacturing process for manufacturing various steel plates S.

[0016] The steel sheet S is transported by transport rolls R provided at predetermined intervals along a transport direction C. The transport direction C is set in advance. The laser processing device 1 according to the first embodiment is installed between adjacent transport rolls R. Note that, in the present disclosure, the installation position of the laser processing device is not limited to between adjacent transport rolls.

[0017] Furthermore, although not shown in the drawings, in the present disclosure, the laser processing device may be installed facing a portion of the roll surface of a steel plate support roll that changes the conveying direction C of the steel plate S, where the conveyed steel plate and the irradiation direction overlap. For example, the steel plate support roll may change the path line of the steel plate S being conveyed horizontally to an oblique direction. Furthermore, the steel plate support roll may change the path line of the steel plate S being conveyed diagonally upward to an obliquely downward direction. In the present disclosure, the laser processing device may be installed at any position on the conveying line along which the steel plate S is conveyed.

[0018] (Steel strip coil) A steel strip coil is used as the steel sheet S in the first embodiment. Note that in the present disclosure, the steel sheet is not limited to a steel strip coil, and for example, a cut sheet cut in advance from a steel strip coil or the like may be used as the steel sheet. A steel strip coil can be produced by winding a long steel strip having a certain width.

[0019] When laser processing is performed on the surface of the steel sheet S, one end of the wound steel strip coil located on the center side is rotatably supported at one end of the longitudinal direction of the processing equipment, and the other end of the steel strip coil located on the outside is connected to the other end of the longitudinal direction of the processing equipment. Then, the other end of the steel strip coil is wound while being pulled out at a substantially constant speed toward the other end of the processing equipment. In the first embodiment, the steel strip coil being wound passes through the laser processing device 1 installed in the processing equipment, thereby performing laser processing on the surface of the steel sheet S of the steel strip coil, which is also referred to as "sheet passing."

[0020] (Continuous Processing) In the first embodiment, laser processing performed while the steel sheet S of the steel strip coil is threaded is also referred to as "continuous processing." On the other hand, laser processing performed on the surface of a cut sheet without unwinding the steel strip coil is referred to as "batch processing." In batch processing, the steel sheet, for example, a rectangular cut sheet, is fixed on a processing support table or supported on a conveying line, and laser processing is performed on each cut sheet, while the laser processing device moves along the length of the cut sheet as needed. Furthermore, each cut sheet requires work to fix it to the support table and to load and unload it onto the conveying line. Therefore, in batch processing, the cost of groove processing tends to be high, resulting in relatively low productivity.

[0021] On the other hand, in continuous laser processing such as the first embodiment, processing in the sheet width direction, for example, by continuously and repeatedly scanning the laser beam LB, can be performed after winding the steel strip coil, and substantially uniform grooves can be machined over substantially the entire length of the steel strip coil in a relatively short time. Furthermore, there is no need to move the laser processing device 1 over the entire length of the steel strip coil, i.e., to move it along the conveying direction C. Therefore, continuous processing can reduce the cost of groove processing compared to batch processing, thereby improving productivity.

[0022] (Laser light source unit) The laser light source unit 10 irradiates the surface of the transported steel sheet S with laser light LB of a predetermined wavelength. The laser light source unit 10 has a laser light source (not shown) for irradiating laser light LB having a wavelength and intensity necessary to achieve the target process, and an optical system (not shown) for guiding the laser light LB irradiated from the laser light source to the surface of the steel sheet S.

[0023] The laser light source is not particularly limited, and various laser light sources such as various solid-state laser light sources, gas laser light sources, semiconductor laser light sources, etc. The optical system is also not particularly limited, and various optical systems for guiding the laser light LB to the surface of the steel sheet S can be used.

[0024] The installation position of the laser light source unit 10 as described above is not particularly limited, but it is preferable that it be installed vertically above the steel sheet S so that the irradiation optical axis of the laser light LB is approximately perpendicular to the surface of the steel sheet S, as shown schematically in Figure 2, for example.

[0025] 1 and 2, the gas injection unit 20 is disposed at both an upstream position in the conveying direction C and a downstream position in the conveying direction C of the emission unit 12 of the laser light source unit 10 for emitting the laser light LB. As shown in Fig. 2, an air supply pump P1 is connected to the gas injection unit 20 via an air supply duct 24.

[0026] In the first embodiment, the gas injection unit 20 is an air nozzle that injects gas 20A from an opening 21B1 toward the irradiation area SA of the laser beam LB in a direction parallel to the optical axis direction of the laser beam LB. The opening 21B1 of the gas injection unit 20 in the first embodiment is rectangular in shape with long sides extending along the width direction (the up-and-down direction in FIG. 1 ) in a plan view. The opening of the gas injection unit of the present disclosure is not limited to a rectangular shape and may have other geometric shapes. The gas injection unit 20 injects dry air, supplied from an air supply pipe (not shown), as an example of the gas 20A toward the irradiation area SA of the laser beam LB on the surface of the steel sheet S.

[0027] The gas injection unit 20 has a base 21A and a nozzle unit 21B. The base 21A in FIG. 2 has a pair of outer surfaces that face each other in the longitudinal direction of the steel sheet S. The pair of outer surfaces extend along the width direction (the up-and-down direction in FIG. 1) and are closed at both ends. The pair of outer surfaces of the base 21A in FIG. 2 are vertical. The upper part of the base 21A in FIG. 2 is attached to the ceiling board 90, and the lower part of the base 21A is continuous with the nozzle unit 21B. The shape of the base 21A is not limited to that shown in FIG. 2, and may be any shape that allows gas to be guided to the nozzle unit 21B.

[0028] As shown in Figure 2, the nozzle portion 21B is connected to the side of the base portion 21A opposite to the ceiling panel 90. The nozzle portion 21B has an outer surface that slopes from the outside of the opening 21B1 to the center of the opening 21B1 in a direction parallel to the surface of the steel sheet S as it moves from the opposite side of the opening 21B1 (upper side in Figure 2) to the side of the opening 21B1 (lower side in Figure 2) in the injection direction (up-down direction in Figure 2). The center of the opening 21B1 is the center position of the opening 21B1 in the longitudinal direction of the steel sheet S (left-right direction in Figure 2). The center of the opening 21B1 in Figure 2 overlaps with the laser light LB illustrated by the dashed line.

[0029] In other words, the length of a pair of outer surfaces of the nozzle portion 21B that face each other in the longitudinal direction of the steel sheet S, measured along the longitudinal direction of the steel sheet S, decreases from the side of the emission portion 12 toward the side of the irradiation area SA. The opening surface of the nozzle portion 21B is perpendicular to the spraying direction. The outer surface of the nozzle portion 21B is inclined with respect to the conveyance direction C. The outer surface of the nozzle portion 21B includes a target surface whose normal faces in the direction in which the steel sheet S exists.

[0030] When the steel sheet S is transported during laser processing as in the first embodiment, the longitudinal direction of the steel sheet S is parallel to the transport direction C (i.e., the left-right direction in FIG. 1 ). The transport direction C is perpendicular to the width direction of the steel sheet S (i.e., the up-down direction in FIG. 1 ). Furthermore, when the steel sheet S is stationary during laser processing, the longitudinal direction of the steel sheet S is a length direction that is parallel to the surface of the steel sheet S and perpendicular to the width direction of the steel sheet S.

[0031] The gas injection unit 20 is arranged so that, when viewed along the conveying direction C, the injected gas 20A, which is dry air, overlaps with the laser beam LB across the entire scanning width of the laser beam LB in the sheet width direction of the steel sheet S (i.e., the up-and-down direction in FIG. 1 ). That is, the gas injection unit 20 is arranged so that the injected dry air is directed toward at least a portion of the laser beam LB. The discharge jet of the gas 20A injected from the gas injection unit 20 prevents spatter LS from adhering to the emission unit 12. Portions of the surface of the steel sheet S are heated and expand in volume by the energy of the laser beam LB, and the expanded portions fly out from the surface of the steel sheet S as spatter LS. The flying spatter LS is carried by the suction airflow DF generated by the dust collection mechanism 30 and collected by the dust collection mechanism 30.

[0032] The laser processing apparatus 1 according to the first embodiment does not use an air knife having a flow rate that scrapes out spatter from inside the grooves G on the surface of the steel sheet, but uses a gas injection unit 20 that injects dry air at a flow rate slower than that of an air knife. This allows the spatter LS to be lifted up from the surface of the steel sheet S and superimposed on the air flow by the dust collection mechanism unit 30 without disturbing the air flow for dust collection, as with an air knife.

[0033] In other words, in the laser processing apparatus 1 according to the first embodiment, dry air is injected from the gas injection unit 20 toward the irradiation area SA of the laser light LB to an extent that allows the spatter LS to be lifted up from the surface of the steel sheet S. For this reason, in the present disclosure, not all of the dry air needs to reach the irradiation area SA. Alternatively, only a portion of the dry air may reach the irradiation area SA. As a result, it is possible to prevent the lifted spatter LS from adhering to the laser processing apparatus, particularly the emission unit 12 and the gas injection unit 20. In order to lift up the spatter LS from the surface of the steel sheet S, it is sufficient to determine injection conditions, including the injection speed, based on, for example, experiments, and to inject a gas such as dry air under the determined injection conditions.

[0034] On the other hand, unlike the air nozzle of the first embodiment, the dry air sprayed by the air knife reaches the groove G and blows away the spatter inside the groove G. As a result, the blown-away spatter LS adheres to the laser processing device, including the emission unit 12. More specifically, the use of an air knife can generate molten particles called chips, which have a diameter of 100 μm or more. Because chips are difficult to cool and difficult to overlap with the air flow generated by the dust collection mechanism 30, the chips tend to adhere to peripheral equipment. In contrast, the use of an air nozzle like the first embodiment suppresses the generation of molten particles with a diameter of 100 μm or more. As a result, it is possible to limit the generated particles to only particles of 10 to 50 μm, which are relatively easy to cool and easily overlap with the air flow generated by the dust collection mechanism 30.

[0035] The installation position of the gas injection unit 20 is not particularly limited as long as it is a position where dry air can be injected onto the surface of the steel sheet S. However, the gas injection unit 20 is preferably provided directly above the steel sheet S, as shown in Figures 1 and 2. Furthermore, the gas injection unit 20 is more preferably provided parallel to the optical axis of the laser light LB so that the nozzle main axis direction of the gas injection unit 20, in other words, the traveling direction of the injected dry air, is approximately coaxial with the optical axis direction of the laser light LB in the laser light source unit 10. The dry air exemplified in Figure 2 is injected toward the surface of the steel sheet S parallel to the optical axis direction of the laser light LB and approximately perpendicular to the surface of the steel sheet S.

[0036] Here, in the first embodiment, it is preferable that the amount of dry air injected from the gas injection unit 20 be set to be equal to or less than the suction amount of the dust collection mechanism 30. By setting the amount of dry air injected from the gas injection unit 20 to be equal to or less than the suction amount of the dust collection mechanism 30, it is possible to more reliably suppress the dry air from disturbing the air flow for suctioning the spatter LS and the generation of chips while still stirring up the spatter LS from the surface of the steel sheet S. Therefore, it is possible to more reliably improve the dust collection efficiency of the spatter LS. It is more preferable that the amount of dry air injected from the gas injection unit 20 be more precisely controlled. Note that, in the present disclosure, the amount of dry air injected is not limited to being equal to or less than the suction amount of the dust collection mechanism 30, and can be changed as desired.

[0037] Furthermore, it is preferable that the discharge flow rate of the dry air injected from the gas injection unit 20 be set to a value equal to or less than the suction flow rate by the dust collection mechanism unit 30. By setting the discharge flow rate of the dry air equal to or less than the suction flow rate by the dust collection mechanism unit 30, it is possible to further improve the dust collection efficiency by the dust collection mechanism unit 30. Note that in the present disclosure, the discharge flow rate of the dry air is not limited to being equal to or less than the suction flow rate by the dust collection mechanism unit 30, and can be changed as desired.

[0038] Furthermore, the specific example of the gas injection unit 20 that realizes the injection of dry air is not particularly limited, and various known air injection nozzles can be used. Examples of air injection nozzles include slit nozzles. Furthermore, the gas 20A injected from the gas injection unit 20 is not limited to the dry air described above, and may be, for example, nitrogen, argon, carbon dioxide, helium, or the like.

[0039] (Adhesion-preventing portion) An adhesion-preventing portion 22A containing elemental carbon and intended to inhibit adhesion of spatter LS is disposed on the surface of the gas injection portion 20 of the first embodiment. The adhesion-preventing portion provided on each of the gas injection portions 20 of the first embodiment and the modified example of the first embodiment corresponds to the first adhesion-preventing portion of the present disclosure. Specifically, in the first embodiment, the entire gas injection portion 20, including the base portion 21A and the nozzle portion 21B, is formed as the adhesion-preventing portion 22A using elemental carbon. "The entire gas injection portion 20" means, in other words, the main body of the air nozzle serving as the gas injection portion 20.

[0040] Furthermore, a connection port between the gas injection unit 20 and the air supply pump P1, such as a pipe, may also be formed from a simple carbon material and be included in "the entire gas injection unit 20." Note that in the present disclosure, it is not essential that the entire gas injection unit 20 be formed from a simple carbon material, and for example, a portion of the gas injection unit 20 on the steel plate side may be formed from a simple carbon material.

[0041] The gas injection part 20 made of elemental carbon has improved surface flatness compared to a gas injection part that does not contain elemental carbon and is made of, for example, a metal such as steel, a resin, or the like. As a result, surface irregularities are significantly reduced. Similarly, the gas injection part 20 made of elemental carbon has superior heat resistance compared to a gas injection part that does not contain elemental carbon and is made of a metal such as steel, a resin, or the like. In the first embodiment, the improved flatness and heat resistance make it difficult for relatively high-temperature sputter LS to adhere.

[0042] The carbon element in the present disclosure can be defined as a structure formed by bonding a plurality of carbon atoms together. In the first embodiment, the carbon element is, for example, isotropic graphite that can be produced by cold isostatic pressing (CIP) molding, but the present disclosure is not limited thereto and may be, for example, other graphite materials. For example, the carbon element may be anisotropic graphite, carbon fiber, carbon sheet, etc.

[0043] In the first embodiment, the bulk density of carbon alone is about 1.7 g / cm ３ It is preferable that the bulk density is 1.7 g / cm or more. ３ If it is less than this, there is a concern that the durability of the carbon element in the laser processing device will decrease.

[0044] In the present disclosure, for example, when the carbon element is anisotropic graphite, the bulk density of the carbon element is about 1.5 g / cm ３ However, as in the first embodiment, it is preferable to use isotropic graphite as the carbon element, since the durability of the carbon element can be improved compared to when other materials are used.

[0045] (Dust Collection Mechanism) The dust collection mechanism 30 is a mechanism that collects spatter LS floating near the irradiation site SA of the laser light LB by injecting dry air from the gas injection unit 20, while suppressing adhesion of the spatter LS to the emission unit 12. The dust collection mechanism 30 has an exterior that is configured, for example, as a cylindrical dust collection hood or the like having a dust collection port 30A for collecting the spatter LS on one side in the axial direction. The dust collection mechanism 30 has a dust collection flow path (not shown) for sucking the spatter LS, a dust collection duct 34 connected to the dust collection flow path, and a suction pump P2 connected to the dust collection duct 34.

[0046] The dust collection mechanism 30 is configured to suck in the atmosphere around the dust collection port 30A at a predetermined suction volume. The dust collection mechanism 30 collects spatter LS generated from the area SA irradiated with the laser light LB through the dust collection port 30A by its suction operation. The specific configuration of the dust collection mechanism 30 is not particularly limited, and various known mechanisms can be used as appropriate. Furthermore, the number of dust collection mechanisms 30 is not limited to one, and may be multiple.

[0047] 1 and 2, the dust collection mechanism 30 is provided only either upstream of the irradiation area SA of the laser beam LB or downstream of the irradiation area SA of the laser beam LB in the conveying direction C of the steel sheet S. In other words, the dust collection mechanism 30 is not provided both upstream and downstream of the irradiation area SA of the laser beam LB. By providing the dust collection mechanism 30 only upstream or only downstream of the irradiation area SA of the laser beam LB, it is possible to prevent stagnation of the flow of air for sucking the spatter LS in the vicinity of the irradiation area SA of the laser beam LB, and it is possible to reliably collect the spatter LS.

[0048] Furthermore, if the dust collection mechanism 30 were to be disposed on one of the upstream and downstream sides, interference between the dust collection mechanism 30 and components of the laser processing apparatus 1 could make it difficult to secure space for the dust collection mechanism 30. In the first embodiment, the dust collection mechanism 30 can be disposed on either the upstream or downstream side. Therefore, even if it is difficult to secure space for the dust collection mechanism 30 on one side, space can be secured on the other side. In other words, the position of the dust collection mechanism 30 can be easily and flexibly changed. In the present disclosure, the dust collection mechanism 30 may be provided on both the upstream and downstream sides of the irradiation area SA of the laser light LB in the conveying direction C of the steel sheet S.

[0049] 2, it is more preferable that the dust collection mechanism 30 be provided only downstream of the irradiation area SA of the laser beam LB. When the steel sheet S to be processed is transported along the transport direction C, an air flow (i.e., an accompanying flow) is generated from the upstream side to the downstream side of the transport direction C. Therefore, by providing the dust collection mechanism 30 only downstream of the irradiation area SA of the laser beam LB, it is possible to utilize the accompanying flow, and as a result, it is possible to more reliably collect the spatter LS.

[0050] The amount of suction by the dust collection mechanism 30 is preferably equal to or greater than the amount of dry air injected from the gas injection unit 20. This more reliably prevents stagnation of the air flow around the irradiation site SA of the laser light LB, making it possible to more reliably collect the spatter LS. Note that in the present disclosure, the amount of suction by the dust collection mechanism 30 is not limited to equal to or greater than the amount of gas 20A injected from the gas injection unit 20, and can be changed as desired.

[0051] Furthermore, the suction flow velocity of the dust collection mechanism 30 is preferably, for example, 15 m / s or more and 50 m / s or less, and more preferably 20 m / s or more and 30 m / s or less. By setting the suction flow velocity to 15 m / s or more and 50 m / s or less, the air flow around the irradiation area SA of the laser light LB is not disturbed. As a result, it is possible to more reliably collect the spatter LS.

[0052] If the suction flow rate is less than 15 m / s, the spatter suction rate decreases. Furthermore, if the suction flow rate exceeds 50 m / s, power consumption increases. Furthermore, if the suction flow rate exceeds 50 m / s, negative pressure increases due to suction, which can cause air pressure vibrations and cause problems with the stability of the sheet threading and the laser equipment. In the present disclosure, the suction flow rate of the dust collection mechanism 30 is not limited to a range between 15 m / s and 50 m / s, and can be changed as desired.

[0053] (Laser processing unit and laser processing set) In the present disclosure, one "laser processing unit" may be configured by one laser light source unit 10, one gas injection unit 20, and one dust collection mechanism unit 30 that correspond to each other. Also, one "laser processing set" may be configured by a plurality of laser processing units arranged along the width direction of the steel sheet S.

[0054] In the present disclosure, the number of laser processing units constituting one laser processing set may be one or more. Furthermore, in the present disclosure, two or more laser processing sets may be arranged in multiple stages along the conveying direction C for one steel sheet S.

[0055] (Ceiling Panel) The laser light source unit 10 and the gas injection unit 20 are attached to the ceiling panel 90. In the present disclosure, the "laser processing unit" may be configured to include the ceiling panel. As shown in FIG. 2 , the ceiling panel 90 separates the space on the steel sheet S side from the space on the opposite side of the steel sheet S at a position at the height of the emission unit 12 of the laser light source unit 10. In other words, the ceiling panel 90 functions as a partition wall that prevents spatter LS from adhering above the emission unit 12 of the laser light source unit 10.

[0056] The laser processing apparatus 1 according to the first embodiment makes it possible to more efficiently collect spatter LS generated by irradiation with laser light LB, and more easily achieve a dust collection efficiency of, for example, 90% or more. The dust collection efficiency of spatter LS can be calculated as (the number of spatter LS particles that reach the depths of the dust collection flow path provided in the dust collection mechanism 30) / (the number of spatter LS particles generated).

[0057] Furthermore, as a result of the improved collection efficiency of the spatter LS, it is possible to reduce the amount of spatter LS that reaches the wall surface of the laser light source unit 10, thereby further improving the cleanliness and ease of maintenance of the laser light source unit 10. Therefore, when the laser processing apparatus 1 according to the first embodiment is applied to, for example, magnetic domain control processing of grain-oriented electromagnetic steel sheets, it is possible to more reliably collect the generated spatter LS even when a further increase in the irradiation power of the irradiated laser light LB is required.

[0058] (Laser processing method) The laser processing method according to the first embodiment can be realized by using the laser processing apparatus 1 according to the first embodiment. The laser processing method according to the first embodiment is a method for collecting spatters LS that are generated from an irradiation site SA of the laser beam LB due to the laser beam LB being irradiated onto the surface of the steel sheet S.

[0059] In the laser processing method according to the first embodiment, as a continuous process, a laser beam LB is irradiated from the laser light source unit 10 onto the surface of a steel sheet S being transported in a preset transport direction C (i.e., a moving steel sheet S). Furthermore, dry air is injected from the opening 21B1 of the nozzle unit 21B of the gas injection unit 20 toward an irradiation area SA of the laser beam LB, in parallel with the optical axis direction of the laser beam LB. By injecting the dry air, spatter LS generated from the irradiation area SA can be lifted up, i.e., raised, from the surface of the steel sheet S.

[0060] In the first embodiment, even if the spatter LS is blown up, the gas injection section 20 serving as the adhesion-preventing section 22A containing simple carbon prevents the spatter LS from adhering to the surface of the gas injection section 20. Then, the spatter LS is collected from a dust collection port 30A of a dust collection mechanism section 30 provided only on either the upstream side or the downstream side of the irradiation site SA of the laser light LB in the transport direction C of the steel sheet S.

[0061] (Effects of the First Embodiment) In the first embodiment, an adhesion-preventing portion 22A containing elemental carbon and inhibiting adhesion of spatter LS is disposed on the outer surface of the nozzle portion 21B of the gas injection unit 20. Here, as described in Example 1 below, the present inventors have discovered that when the adhesion-preventing portion 22A containing elemental carbon is disposed on the outer surface of the nozzle portion 21B of the gas injection unit 20, the effect of suppressing adhesion of spatter LS generated from the irradiation area SA to the outer surface of the nozzle portion 21B is higher than when the adhesion-preventing portion 22A is not disposed. Spatter LS whose adhesion to the outer surface of the nozzle portion 21B is prevented by the adhesion-preventing portion 22A is collected by the dust collection mechanism 30. According to the first embodiment, adhesion of spatter LS to the outer surface of the nozzle portion 21B of the gas injection unit 20, which injects gas 20A from the opening 21B1 toward the irradiation area SA of the laser light LB, can be suppressed.

[0062] In the first embodiment, the adhesion inhibition portion 22A is configured by forming the entire gas injection portion 20 from simple carbon. As a result, the adhesion inhibition portion 22A is disposed on the entire outer surface of the nozzle portion 21B. Therefore, there is no need to prepare a component separate from the gas injection portion 20 as the adhesion inhibition portion 22A.

[0063] Here, the present inventors have found that spatters are likely to adhere to the outer surface of the nozzle portion when the gas injection direction from the gas injection unit is parallel to the optical axis direction of the laser light. In the first embodiment, even when the injection direction of the gas 20A from the gas injection unit 20 is parallel to the optical axis direction of the laser light LB, the adhesion prevention unit 22A can suppress adhesion of spatters LS to the nozzle portion 21B of the gas injection unit 20. Note that in the present disclosure, the injection direction of the gas from the gas injection unit is not limited to being parallel to the optical axis direction of the laser light, and it is not excluded that the injection direction of the gas from the gas injection unit may intersect with the optical axis direction.

[0064] Moreover, in the first embodiment, the laser processing device 1 includes a transport roll R that transports the steel sheet S in a preset transport direction C, and a laser light source unit 10 that irradiates the surface of the steel sheet S transported in the transport direction C with laser light LB. Therefore, laser processing can be performed on the steel sheet S during transport.

[0065] In particular, when a dust collection mechanism is installed in a laser processing device having a nozzle, the nozzle functions significantly as a gas flow guide depending on the relative positions of the nozzle and the dust collection mechanism. Therefore, it has been found that prolonged use of the laser processing device causes spatter to adhere to the nozzle, and this adhesion causes stagnation in the flow of gas such as air, resulting in a decrease in dust collection efficiency. However, by providing a spatter adhesion inhibitor in the nozzle, as disclosed herein, the laser processing device can be operated for even longer periods of time, thereby reducing maintenance burden and improving availability (i.e., continuous operation capability).

[0066] (First Modification) As shown in FIG. 3, the first modification differs from the first embodiment in that a carbon plate 22B made of a single carbon as an adhesion-inhibiting portion is arranged in the gas injection portion 20 as a separate part from the gas injection portion 20.

[0067] Specifically, unlike the gas injection unit 20 of the first embodiment, which is made of simple carbon, the gas injection unit 20 of the laser processing apparatus 1A according to the first modification is made of, for example, a metal such as steel or a resin. The adhesion-preventing portion is a plate-like member disposed on a portion of the surface of the gas injection unit 20. Note that, in the present disclosure, the carbon plate is not limited to one made of a single plate-like member. For example, a carbon plate may be used as the carbon plate of the present disclosure even if the adhesion-preventing portion is made of a single carbon sheet or a stack of two or more carbon sheets.

[0068] The carbon plate 22B is disposed on the outer surface of the nozzle portion 21B, which is the tip (lower end in FIG. 3) side of the gas injection unit 20 on the side of the irradiation site SA. Note that in the present disclosure, the position of the carbon plate 22B is not limited to this, and it may be between the irradiation site SA of the laser light LB and the gas injection unit 20. It is preferable to dispose the carbon plate 22B in close contact with the lower end of the gas injection unit 20 in FIG. 3 in order to suppress micro-vibrations during processing. The other configurations of the first modified example are the same as those of the first embodiment, so repeated explanations will be omitted.

[0069] (Action and Effect of First Modification) Also, in the first modification, as in the first embodiment, it is possible to suppress adhesion of spatter LS to the outer surface of the nozzle portion 21B of the gas injection unit 20 that injects gas from the opening 21B1 toward the irradiation site SA of the laser light LB. Furthermore, in the first modification, the adhesion-preventing portion is a plate-like member that is arranged on a portion of the surface of the gas injection unit 20. That is, a carbon plate 22B made of simple carbon as the adhesion-preventing portion is arranged on the entire outer surface of the nozzle portion 21B of the gas injection unit 20 as a separate part from the gas injection unit 20. Note that, in the present disclosure, it is sufficient that the adhesion-preventing portion made of simple carbon is arranged on at least a portion of the outer surface of the nozzle portion of the gas injection unit as a separate part from the gas injection unit.

[0070] Therefore, it is easy to separately attach an adhesion-preventing portion to an existing gas injection unit 20 that does not have an adhesion-preventing portion. Also, since the adhesion-preventing portion is a separate part from the gas injection unit 20, it is less likely to be damaged even when subjected to vibrations, etc., from the laser processing device. Other effects of the first modified example are the same as those of the first embodiment.

[0071] (Second Modification) As shown in Fig. 4, the second modification differs from the first embodiment in that the gas injection unit 20 has an adhesion inhibition portion 22A made of simple carbon, and further includes a charge application device 40 that applies a charge 22C of the same polarity as the charge of the sputter LS to the gas injection unit 20 as an adhesion inhibition portion. That is, in the second modification, the adhesion of the sputter LS to the gas injection unit 20 is further inhibited by an electrical repulsive force. In the present disclosure, it is not essential to use both an adhesion inhibition portion made of simple carbon and an adhesion inhibition portion of a charge of the same polarity as the charge of the sputter LS. An adhesion inhibition portion of a charge may be used alone.

[0072] Specifically, the laser processing apparatus 1B according to the second modification is provided with a charge application device 40 having a power supply 42 and an electric wire 44 connected at one end to the power supply 42. The other end of the electric wire 44 is connected to the gas injection unit 20. Here, the charge of the sputter LS is generally about -1 kV to -50 kV. In the first embodiment, for example, the charge of the sputter LS can be set to about -10 kV.

[0073] Then, an electric charge 22C of approximately -10 kV is applied to the gas injection unit 20 using the charge application device 40, thereby generating an electrical repulsive force against the spatter LS on the surface of the gas injection unit 20. To prevent short circuits, it is preferable that the gas injection unit 20 be electrically insulated from the members surrounding the gas injection unit 20. Other configurations in the second modified example are the same as those in the first embodiment, so a duplicated description will be omitted.

[0074] (Effects of the Second Modification) As in the first embodiment, the second modification also makes it possible to suppress adhesion of spatter LS to the gas injection unit 20, which injects gas parallel to the optical axis direction of the laser light LB toward the irradiation site SA of the laser light LB. Furthermore, in the second modification, the laser processing apparatus is provided with a charge application device 40 as an adhesion-preventing unit, which applies a charge 22C of the same polarity as the charge of the spatter LS to the gas injection unit 20. In other words, the adhesion-preventing unit includes the charge application device 40. The electrical repulsive force further inhibits adhesion of the spatter LS to the gas injection unit 20, thereby further improving the effect of suppressing adhesion of the spatter LS. Other effects of the second modification are the same as those of the first embodiment.

[0075] 5, the third modification differs from the first embodiment in that the gas injection unit 20 is made of simple carbon and further includes a coating agent supply device that supplies a coating agent that coats the sputter LS. That is, the third modification differs from the first embodiment in that the adhesion of the sputter LS to the gas injection unit 20 is further inhibited by supplying a coating agent that coats the sputter LS to the sputter LS.

[0076] Specifically, the laser processing apparatus 1C according to the third modified example is provided with a coating agent supply device 50 having a coating agent source 52, a supply pipe 54 connected at one end to the coating agent source 52, and a supply nozzle 56 connected at the other end of the supply pipe 54.

[0077] (Coating Agent) The coating agent of the first embodiment is sandy or powdery. Specifically, for example, a commercially available pre-coating agent for preventing sparks during polishing work or the like can be used as the coating agent. For example, calcium carbonate or hydrated lime (i.e., calcium hydroxide) can be used as the powdered pre-coating agent. Note that in the present disclosure, the coating agent is not limited to sandy or powdery, and any shape and chemical composition can be used as long as it can coat the sputter LS.

[0078] The coating agent is supplied toward the spatters LS that fly up due to the formation of the groove G. Specifically, the coating agent may be supplied toward the irradiation site SA where the spatters LS are generated and its surroundings, or may be directed mainly toward the downstream side of the groove G in the transport direction C. By covering the spatters LS with the coating agent, they are less likely to adhere to the gas injection unit 20.

[0079] In the first embodiment, the supply flow rate of the coating agent is preferably set according to the amount of spatter LS generated. Specifically, the supply flow rate of the coating agent may be set to the same amount as the amount of spatter LS generated per unit time, or may be set within a certain range relative to the amount of spatter LS generated per unit time. For example, the supply flow rate of the coating agent can be set to 60% or more and 150% or less of the amount of spatter LS generated per unit time.

[0080] If the supply flow rate of the coating agent is less than 60% of the amount of spatter LS generated per unit time, the amount of coating agent that can cover the spatter LS is too low, reducing the effect of suppressing adhesion of spatter LS to the gas injection part 20. On the other hand, if the supply flow rate of the coating agent is more than 150% of the amount of spatter LS generated per unit time, the amount of coating agent becomes too large, increasing the cost of the coating agent and the burden of handling it.

[0081] Furthermore, it is preferable that the supply flow rate of the coating agent be equal to or less than the suction flow rate of the dust collection mechanism 30 by the suction pump P2, in order to avoid interference with the suction airflow. Note that in the present disclosure, the supply flow rate of the coating agent is not prevented from exceeding the suction flow rate of the dust collection mechanism. The other configurations of the third modified example are the same as those of the first embodiment, and therefore, redundant explanations will be omitted.

[0082] (Effects of the Third Modification) As in the first embodiment, the third modification also suppresses adhesion of spatter LS to the gas injection unit 20, which injects gas parallel to the optical axis direction of the laser beam LB toward the irradiation site SA of the laser beam LB. Furthermore, in the third modification, the laser processing apparatus 1C includes a coating agent supply device that supplies a coating agent that coats the spatter LS. That is, the adhesion of spatter LS to the gas injection unit 20 can be reduced by the amount that the spatter LS is coated with the coating agent. This further improves the effect of suppressing adhesion of spatter LS. Other effects of the third modification are the same as those of the first embodiment. Furthermore, by combining the configuration of the laser processing apparatus 1C according to the third modification with the laser processing apparatus according to any one of the first embodiment, the first modification, and the second modification described above, an even greater effect of suppressing adhesion of spatter can be obtained.

[0083] (Example 1) Next, Example 1 in which the deposition rate of sputter LS was measured using the laser processing apparatuses according to the first embodiment and the first to third modified examples illustrated in Figures 1 to 5 will be described with reference to Figure 6.

[0084] The adhesion rate of spatter LS in Figure 6 is the ratio of the number of spatter LS particles that have reached the outer surface of the nozzle portion 21B of the gas injection section 20 calculated in each of the first embodiment and the first to third modified examples, when the number of spatter LS particles that have reached the outer surface of the nozzle portion 21B of the gas injection section 20 in the first comparative example is set to 1.

[0085] The gas injection unit of the laser processing device according to the first comparative example did not have an adhesion-preventing portion that contained elemental carbon and prevented spatter adhesion. The laser processing devices according to the first comparative example, the first embodiment, and the first to third modified examples all had similar shapes and dimensions. In Example 1, the thickness of the carbon plate 22B attached to the gas injection unit 20 of the first modified example was approximately 1 mm.

[0086] In Example 1, analysis was performed by computer simulation using Fluent, a commercially available numerical calculation software. First, analytical models corresponding to the laser processing apparatuses according to the first comparative example, the first embodiment, and the first to third modified examples were set up. Then, using each of the set analytical models, an analysis equivalent to laser processing in which a steel plate was continuously irradiated with laser light LB for approximately 100 hours was performed. In each analytical model, the number of spatter particles LS generated from the irradiation area SA was the same. Then, the number of spatter particles LS that reached the outer surface of the nozzle portion of each gas injection unit from the irradiation area SA was calculated.

[0087] As shown in Figure 6, in the first embodiment, the amount of spatter adhesion was reduced to about 1 / 10 of that in the first comparative example. Furthermore, in the first modified example, the amount of spatter adhesion could be reduced to the same extent as in the first embodiment. Furthermore, in the second modified example, the amount of spatter adhesion was reduced to about 1 / 20 of that in the first comparative example. Furthermore, in the third modified example, the amount of spatter adhesion was reduced to about 1 / 40 of that in the first comparative example. It was found from Example 1 that when a carbon simple substance adhesion inhibition portion is provided, the amount of spatter adhesion LS can be significantly reduced compared to when a carbon simple substance adhesion inhibition portion is not provided.

[0088] Furthermore, in Example 1, verification by laboratory testing was also performed. Specifically, experimental models corresponding to the laser processing apparatuses according to the first comparative example, the first embodiment, and the first to third modified examples were set up. Then, using each of the set up experimental models, laser processing was performed in which the steel plate was continuously irradiated with laser light LB for approximately 100 hours. In each experimental model, the weight increase at each location was measured and the amount of adhesion was calculated. The verification by laboratory testing also yielded results similar to those of the analysis by computer simulation described above.

[0089] Next, a second embodiment and a third embodiment will be described. A duplicated description of the same configurations as those of the first embodiment in the second and third embodiments will be omitted. The adhesion inhibiting portion provided in each gas injection unit 20 of the second embodiment and the modified example of the second embodiment corresponds to the first adhesion inhibiting portion of the present disclosure.

[0090] 7, an adhesion-inhibiting portion 22D containing elemental copper and intended to inhibit adhesion of sputters LS is disposed on the outer surface of the gas injection portion 20 of the laser processing apparatus 2 according to the second embodiment. Specifically, in the second embodiment, the entire gas injection portion 20 is formed as the adhesion-inhibiting portion 22D from elemental copper. "The entire gas injection portion 20" means, in other words, the main body of the air nozzle serving as the gas injection portion 20.

[0091] The gas injection part 20, which is made of simple copper, has higher thermal conductivity than a gas injection part that does not contain simple copper, which is made of, for example, a metal such as steel, a resin, etc. Therefore, even if spatter LS adheres to the outer surface of the nozzle part 21B, the temperature of the spatter LS drops quickly, and as a result, it is difficult for the spatter LS to accumulate.

[0092] As shown in Fig. 7, the box-shaped dust collection mechanism 30 has a top 31 above the dust collection port 30A and a bottom 32 below the dust collection port 30A. Fig. 7 illustrates a state in which a deposit A1 of sputter LS has adhered and accumulated on the inner surface of the top 31. Fig. 7 illustrates a state in which a deposit A2 of sputter LS has adhered and accumulated on the end face of the bottom 32. Fig. 7 illustrates a state in which a deposit A3 of sputter LS has adhered and accumulated on the outer surface of the nozzle portion 21B.

[0093] The inner surface of the top portion 31 in FIG. 7 is the highest point from the steel plate S in the dust collection mechanism 30. FIG. 7 illustrates the height x of the inner surface of the top portion 31 from the steel plate S and the height y of the upper end of the outer surface of the nozzle portion 21B from the steel plate S. The height x of the inner surface of the top portion 31 from the steel plate S in FIG. 7 is greater than the height y of the upper end of the nozzle portion 21B from the steel plate S. In other words, x > y. Therefore, the flow of gas sucked into the dust collection mechanism 30 is promoted toward the dust collection mechanism 30 by the inclined outer surface of the nozzle portion 21B. In other words, the inclined outer surface of the nozzle portion 21B guides the flow of gas being sucked.

[0094] Here, when grooves G having a depth of approximately 10 μm to 50 μm are machined, if an air knife having a flow rate that scrapes out spatter from inside the groove G on the surface of the steel plate is used, chips, which are particles having a size of more than 100 μm, tend to be generated as dust, unlike the present disclosure. The chips are difficult to cool and do not easily overlap with the air flow generated by the dust collection mechanism 30, so they tend to adhere to peripheral equipment.

[0095] When dust collection mechanisms are provided both upstream and downstream of the laser light irradiation site, and the height of the inner surface of the top of the dust collection mechanism from the steel plate is greater than the height of the upper end of the nozzle from the steel plate (in other words, when x<y in Figure 7), the flow of gas sucked into the dust collection mechanism 30 is unlikely to be promoted toward the dust collection mechanism 30.

[0096] On the other hand, in the second embodiment, the dust collection mechanism 30 is provided only upstream of the irradiation area SA of the laser light LB in the conveying direction C of the steel sheet S, and the height x of the inner surface of the top portion 31 from the steel sheet S is greater than the height y of the upper end of the nozzle portion 21B from the steel sheet S. For this reason, in the second embodiment, the deposition rate of spatter LS on the nozzle portion 21B and the dust collection mechanism 30 during continuous use of the laser processing apparatus is lower than in the case of an air knife. For example, in the case of a laser processing apparatus using an air knife without an adhesion-preventing portion, the deposition rate is about 10 mm / hour, whereas in the case of the second embodiment, the deposition rate is kept to about 0.1 mm / hour.

[0097] Furthermore, in the second embodiment, compared to an air knife, the intervals between maintenance operations for removing deposits that have adhered and accumulated during continuous use of the laser processing apparatus from the nozzle portion 21B and the dust collection mechanism 30 are longer. For example, in the case of a laser processing apparatus that uses an air knife without an adhesion-preventing portion, the intervals between maintenance operations are about 30 minutes, whereas in the case of the second embodiment, the intervals between maintenance operations are about 3000 minutes. That is, in the second embodiment, spatters LS are less likely to come into contact with the nozzle portion 21B and the dust collection mechanism 30.

[0098] (Effects of the Second Embodiment) In the second embodiment, an adhesion-inhibiting portion 22D containing elemental copper and inhibiting adhesion of spatter LS is disposed on the outer surface of the nozzle portion 21B of the gas injection unit 20. Here, as described in Example 2 below, the present inventors have discovered that when an adhesion-inhibiting portion 22D containing elemental copper is disposed on the outer surface of the nozzle portion 21B of the gas injection unit 20, the effect of inhibiting adhesion of spatter LS generated from the irradiation area SA to the outer surface of the nozzle portion 21B is higher than when the adhesion-inhibiting portion 22D is not disposed. The spatter LS whose adhesion to the outer surface of the nozzle portion 21B is inhibited by the adhesion-inhibiting portion 22D is collected by the dust collection mechanism 30. According to the second embodiment, the adhesion-inhibiting portion 22D can inhibit adhesion of spatter LS to the outer surface of the nozzle portion 21B of the gas injection unit 20.

[0099] In the second embodiment, the adhesion inhibiting portion 22D is configured by forming the entire gas injection portion 20 from a single piece of copper. As a result, the adhesion inhibiting portion 22D is disposed on the entire outer surface of the nozzle portion 21B. Therefore, there is no need to prepare a component separate from the gas injection portion 20 as the adhesion inhibiting portion 22D.

[0100] (Fourth Modification) As shown in Figure 8, the fourth modification differs from the second embodiment in that a copper plate 22E made of a single piece of copper as an adhesion-inhibiting portion is arranged in the gas injection portion 20 as a separate part from the gas injection portion 20.

[0101] Specifically, unlike the gas injection unit 20 of the second embodiment, which is made of a single copper material, the gas injection unit 20 of the laser processing apparatus 2A according to the fourth modification is made of, for example, a metal such as steel or a resin. The adhesion-inhibiting portion is a plate-like member disposed on a portion of the surface of the gas injection unit 20. Note that, in the present disclosure, the copper plate is not limited to one made of a single plate-like member. For example, the copper plate according to the present disclosure may be an adhesion-inhibiting portion made of a single copper plate or a laminate of two or more copper plates.

[0102] The copper plate 22E is disposed on the outer surface of the nozzle portion 21B of the gas injection unit 20. In the present disclosure, the position of the copper plate 22E is not limited to this, and may be any position between the irradiation site SA of the laser light LB and the gas injection unit 20. It is preferable that the copper plate 22E is disposed in close contact with the outer surface of the nozzle portion 21B of the gas injection unit 20 in order to suppress the effects of micro-vibrations during processing.

[0103] As shown in FIG. 8 , copper plates 22E are arranged on the two outer surfaces of the nozzle portion 21B in the conveyance direction C, taking into consideration the ease of adhesion of spatter LS. As shown in FIG. 9 , the copper plates 22E can be detachably attached to the outer surface of the nozzle portion 21B using connectors 23. The connectors 23 in FIG. 8 are mechanical devices such as screws. Note that it is not essential that the copper plates be arranged on the outer surface of the nozzle portion 21B in the width direction (left-right direction in FIG. 9 ). In addition, in the present disclosure, the adhesion-inhibiting portion may be formed by combining elemental carbon and elemental copper. For example, the material of the connectors 23 that join the copper plates 22E in FIG. 8 may be composed of elemental carbon.

[0104] (Action and Effect of Fourth Modification) As in the second embodiment, the fourth modification can also suppress adhesion of spatter LS to the outer surface of the nozzle portion 21B of the gas injection unit 20, which injects gas from the opening 21B1 toward the irradiation site SA of the laser light LB. Furthermore, in the fourth modification, the adhesion-preventing portion is a plate-like member arranged on a portion of the surface of the gas injection unit 20. That is, a copper plate 22E made of simple copper as the adhesion-preventing portion is arranged on the entire outer surface of the nozzle portion 21B of the gas injection unit 20 as a separate component from the gas injection unit 20. Note that, in the present disclosure, it is sufficient that the adhesion-preventing portion made of simple copper is arranged on at least a portion of the outer surface of the nozzle portion of the gas injection unit as a separate component from the gas injection unit.

[0105] Therefore, it is easy to separately attach an adhesion inhibiting portion to an existing gas injection unit 20 that does not have an adhesion inhibiting portion. Also, since the adhesion inhibiting portion is a separate part from the gas injection unit 20, it is easy to replace it if it is damaged. Other effects of the fourth modified example are the same as those of the second embodiment.

[0106] 10 , a laser processing apparatus 2B according to a fifth modification differs from the fourth modification in that a copper plate 22E is disposed on the outer surface of the nozzle portion 21B of the fourth modification, and further includes a peeling mechanism 22F as an additional adhesion-inhibiting portion. Note that, in the present disclosure, the use of the peeling mechanism 22F is not limited to a combination with another adhesion-inhibiting portion such as the copper plate 22E, and it can also be used as a standalone adhesion-inhibiting portion.

[0107] The peeling mechanism 22F includes a drive unit 22F1 and a movable plate 22F2. The peeling mechanism 22F can be configured using, for example, a known linear motion mechanism. Although not shown, the drive unit 22F1 can be physically supported at any position using, for example, the empty space around the gas injection unit 20.

[0108] The driving unit 22F1 reciprocates the movable plate 22F2 along the inclined outer surface of the nozzle portion 21B. The lower end of the movable plate 22F2 in FIG. 10 approaches and moves away from the nozzle portion 21B. The movable plate 22F2 extends in the width direction. As the movable plate 22F2 approaches the inclined outer surface of the nozzle portion 21B, the edge of the tip of the movable plate 22F2 on the side opposite the driving unit 22F1 slides on the outer surface of the nozzle portion 21B, thereby peeling off the deposit A3 on the outer surface.

[0109] (Actions and Effects of Fifth Modification) As in the second embodiment, the fifth modification can also suppress adhesion of spatters LS to the outer surface of the nozzle portion 21B of the gas injection unit 20, which injects gas from the opening 21B1 toward the irradiation site SA of the laser light LB. Furthermore, in the fifth modification, the peeling mechanism 22F, which serves as an additional adhesion prevention unit, causes the movable plate 22F2 to reciprocate along the inclined outer surface of the nozzle portion 21B. This further suppresses adhesion of spatters LS to the outer surface of the nozzle portion 21B of the gas injection unit 20. Other actions and effects of the fifth modification are the same as those of the second embodiment.

[0110] 10 , a laser processing apparatus 2B according to a sixth modification differs from the fourth modification in that a copper plate 22E is disposed on the outer surface of the nozzle portion 21B of the fourth modification, and further includes a vibration imparting device 22G as an additional adhesion-inhibiting portion. Note that, in the present disclosure, the use of the vibration imparting device 22G is not limited to a combination with another adhesion-inhibiting portion such as the copper plate 22E, and it can also be used as a standalone adhesion-inhibiting portion.

[0111] The vibration imparting device 22G can be configured using, for example, a known vibrator. The vibration imparting device 22G may impart vibration, for example, by striking. The vibration imparting device 22G is attached to the outer surface of the base 21A of the gas injection unit 20. In the present disclosure, the number of vibration imparting devices may be one or more, and is arbitrary. The attachment position of the vibration imparting device may also be changed as appropriate. In the present disclosure, it is not essential that the vibration imparting device be attached in a state of constant contact with the gas injection unit 20. The vibration imparting device may be disposed around the gas injection unit 20 while being separated from the gas injection unit 20. Although not shown, the vibration imparting device may have a movable part that contacts the gas injection unit as needed even from a remote position, and may impart vibration to the nozzle unit by striking the movable part, etc.

[0112] (Actions and Effects of the Sixth Modification) In the sixth modification, as in the second embodiment, it is possible to suppress adhesion of spatters LS to the outer surface of the nozzle portion 21B of the gas injection unit 20 that injects gas from the opening 21B1 toward the irradiation site SA of the laser light LB. Furthermore, in the sixth modification, the vibration imparting device 22G as an additional adhesion inhibitor can further suppress adhesion of spatters LS to the outer surface of the nozzle portion 21B of the gas injection unit 20. Other actions and effects of the sixth modification are similar to those of the second embodiment.

[0113] (Example 2) Next, Example 2, in which the adhesion rate of sputter LS was measured using the laser processing apparatuses according to the second embodiment and the fourth to sixth modified examples illustrated in Figures 7 to 11, will be described with reference to Figure 12.

[0114] The adhesion rate of spatter LS in Figure 12 is the ratio of the number of spatter LS particles that have reached the outer surface of the nozzle portion 21B of the gas injection section 20 calculated in each of the second embodiment and the fourth to sixth variants, when the number of spatter LS particles that have reached the outer surface of the nozzle portion 21B of the gas injection section 20 in the second comparative example is set to 1.

[0115] The gas injection unit of the laser processing device according to the second comparative example contained copper alone and did not have an adhesion-preventing portion for inhibiting spatter adhesion. The laser processing devices according to the second comparative example, the second embodiment, and the fourth to sixth modified examples all had similar shapes and dimensions. In Example 2, the thickness of the copper plate 22E attached to the gas injection unit 20 of the fourth to sixth modified examples was approximately 1 mm.

[0116] In Example 2, verification was carried out by laboratory testing. First, experimental models corresponding to the laser processing apparatuses according to the second comparative example, the second embodiment, and the fourth to sixth modifications were set up. Then, using each of the set up experimental models, laser processing was carried out in which a steel plate was continuously irradiated with laser light LB for approximately 100 hours. In each experimental model, the weight increase at each location was measured and the amount of adhesion was calculated.

[0117] As shown in Figure 12, in the second embodiment, the amount of sputter adhesion was reduced to about 1 / 10 of that in the second comparative example. Furthermore, in the fourth modified example, the amount of sputter adhesion could be reduced to the same extent as in the second embodiment. Furthermore, in the fifth modified example, the amount of sputter adhesion was reduced to about 1 / 20 of that in the second comparative example. Furthermore, in the sixth modified example, the amount of sputter adhesion was reduced to about 1 / 20 of that in the second comparative example. Example 2 revealed that when an adhesion inhibition portion for simple copper is provided, the amount of sputter adhesion LS can be significantly reduced compared to when an adhesion inhibition portion for simple copper is not provided.

[0118] Next, a third embodiment will be described. The third embodiment and seventh to ninth modifications of the third embodiment differ from the second embodiment in that, in the laser processing apparatus 2A according to the fourth modification of the second embodiment, an adhesion inhibiting section for inhibiting adhesion of spatters LS to the dust collection mechanism section 30 is arranged in the dust collection mechanism section 30 separately from the adhesion inhibiting section for inhibiting adhesion of spatters LS to the gas injection section 20. Therefore, a duplicated description of the same configuration in the third embodiment as in the fourth modification of the second embodiment will be omitted.

[0119] In the present disclosure, it is not essential that the adhesion inhibiting portion for inhibiting adhesion of spatters LS to the dust collection mechanism portion 30 be used in combination with the adhesion inhibiting portion of the gas injection portion 20. The adhesion inhibiting portion for inhibiting adhesion of spatters LS to the dust collection mechanism portion 30 may be used without being accompanied by an adhesion inhibiting portion for inhibiting adhesion of spatters LS to the gas injection portion 20.

[0120] 13 , an adhesion-inhibiting portion 33A containing elemental copper and configured to inhibit adhesion of spatter LS is disposed on the outer surface of the dust collection mechanism 30 of the laser processing apparatus 2A according to the third embodiment. The adhesion-inhibiting portion provided on each of the dust collection mechanism 30 of the third embodiment and the modified example of the third embodiment corresponds to the second adhesion-inhibiting portion of the present disclosure. Specifically, in the third embodiment, the entire dust collection mechanism 30 is formed as the adhesion-inhibiting portion 33A using elemental copper. In other words, "the entire dust collection mechanism 30" refers to the main body of the dust collection nozzle as the dust collection mechanism 30.

[0121] The dust collection mechanism 30, which is made of elemental copper, has higher thermal conductivity than a dust collection mechanism that does not contain elemental copper and is made of, for example, a metal such as steel or a resin. Therefore, even if spatter LS adheres to the inner surface and end face of the dust collection mechanism 30, the temperature of the spatter LS drops quickly, making it difficult for the spatter LS to accumulate. The inner surface and end face of the dust collection mechanism 30 of the third embodiment correspond to the "surface of the dust collection mechanism" to which adhesion of spatter LS is inhibited by the second adhesion-inhibiting portion of the present disclosure.

[0122] (Effects of the Third Embodiment) In the third embodiment, an adhesion-inhibiting portion 33A containing elemental copper and inhibiting adhesion of spatter LS is disposed on the inner surface and end face of the dust collection mechanism 30. Here, as described in Example 3 below, the present inventors have discovered that when an adhesion-inhibiting portion containing elemental copper is disposed on the inner surface and end face of the dust collection mechanism 30, the effect of inhibiting adhesion of spatter LS generated from the irradiation area SA to the inner surface and end face of the dust collection mechanism 30 is greater than when an adhesion-inhibiting portion is not disposed. According to the third embodiment, the adhesion-inhibiting portion 33A can inhibit adhesion of spatter LS to the inner surface and end face of the dust collection mechanism 30. As a result, the burden of maintenance work to remove adhesions can be reduced.

[0123] In the third embodiment, the adhesion inhibiting portion 33A is configured by forming the entire dust collection mechanism 30 from a single piece of copper. As a result, the adhesion inhibiting portion 33A is disposed on the entire inner surface and end face of the dust collection mechanism 30. Therefore, there is no need to prepare a component separate from the dust collection mechanism 30 as the adhesion inhibiting portion 33A.

[0124] (Seventh Modification) As shown in FIG. 8 , the seventh modification differs from the third embodiment in that a copper plate 33B made of a single piece of copper as an adhesion-inhibiting portion is arranged in the dust collection mechanism portion 30 as a separate part from the dust collection mechanism portion 30.

[0125] Specifically, unlike the dust collection mechanism 30 of the third embodiment, which is made of a single copper material, the dust collection mechanism 30 of the laser processing apparatus 2A according to the seventh modification is made of, for example, a metal such as steel or resin. The adhesion-inhibiting portion is a plate-like member disposed on a portion of the surface of the dust collection mechanism 30. Note that, in the present disclosure, the copper plate is not limited to a copper plate formed of a single plate-like member. For example, the copper plate of the present disclosure may be a copper plate, or an adhesion-inhibiting portion formed of a single copper plate or a laminate of two or more copper plates.

[0126] The copper plates 33B are disposed on both the inner surface and the end face of the dust collection mechanism 30. In the present disclosure, the copper plates 33B may be disposed on at least one of the inner surface and the end face of the dust collection mechanism 30. As shown in FIG. 14 , the copper plates 33B are disposed on both the inner surface of the dust collection mechanism 30 to which the attachment A1 adheres and the end face of the dust collection mechanism 30 to which the attachment A2 adheres. While FIG. 14 illustrates an example in which the lower surface of the upper copper plate 33B is flush with the inner surface of the dust collection mechanism 30 and the lower surface of the lower copper plate 33B is flush with the outer surface of the dust collection mechanism 30, this is not limiting. A step may also be formed between the surface of the copper plate and the surface of the dust collection mechanism 30.

[0127] (Effects of the Seventh Modification) In the seventh modification, the adhesion inhibiting portion is a plate-like member arranged on a portion of the surface of the dust collection mechanism 30. That is, a copper plate 33B made of a single material of copper as the adhesion inhibiting portion is arranged on both the inner surface and end face of the dust collection mechanism 30 as a separate part from the dust collection mechanism 30. This makes it easy to separately attach an adhesion inhibiting portion to an existing dust collection mechanism 30 that does not have an adhesion inhibiting portion. Other effects of the seventh modification are similar to those of the third embodiment.

[0128] 15 , a laser processing apparatus 2A according to an eighth modification differs from the seventh modification in that a copper plate 33B is disposed on the inner surface and end face of the dust collection mechanism 30 of the seventh modification, and further includes a first peeling mechanism 33C and a second peeling mechanism 33D as additional adhesion-inhibiting parts. Note that, in the present disclosure, the use of the first peeling mechanism 33C and the second peeling mechanism 33D is not limited to a combination with another adhesion-inhibiting part such as the copper plate 33B, and each can be used as a standalone adhesion-inhibiting part.

[0129] 16 and 17 , the first peeling mechanism 33C includes a drive unit 34A, a shaft 34B, a connection unit 34C, a movable plate 34D, and a support unit 34E. As shown in Fig. 17 , the dust collection mechanism 30 is L-shaped. The suction airflow DF enters the inside of the dust collection mechanism 30 through the dust collection port 30A and then moves upward from the periphery of the left sidewall 30B that faces the right dust collection port 30A in Fig. 17 .

[0130] The driving unit 34A is provided on the outer surface of the top portion 31. As shown in Fig. 16, the movable plate 34D extends in the width direction. As shown in Fig. 17, the upper end of the connecting unit 34C is attached to the left end of the shaft 34B, and the lower end of the connecting unit 34C is attached to the left end of the movable plate 34D.

[0131] As shown in Fig. 18, a slit 31A into which a rod-shaped connecting portion 34C is inserted is formed in the top portion 31. As shown in Figs. 16 to 18, the support portion 34E is a plate-like member provided on each of the inner surfaces of the side walls facing each other in the width direction inside the dust collection mechanism portion 30, protruding horizontally inward from the inner surface. The support portion 34E supports the sliding movable plate 34D from below. In the present disclosure, the support portion is not essential.

[0132] The drive unit 34A and shaft 34B can be configured with a known linear motion mechanism, such as an air cylinder with a piston rod or a screw feed mechanism. The drive unit 34A can reciprocate the movable plate 34D horizontally along the inner surface of the top portion 31 of the dust collection mechanism 30 (see FIG. 17) via the shaft 34B and the connecting portion 34C. The right end of the movable plate 34D in FIG. 17 can move outward, further to the right of the dust collection port 30A. In a standby state where maintenance work to remove deposits is not being performed, the right end of the movable plate 34D in FIG. 17 is separated from the dust collection port 30A. An example of a standby distance C1 of the movable plate 34D is shown in FIG. 17.

[0133] As shown in Fig. 19, when the drive unit 34A moves the shaft 34B to the right, the connecting portion 34C moves to the right within the slit 31A in conjunction with the shaft 34B. As shown in Fig. 20, in conjunction with the movement of the connecting portion 34C, the right end of the movable plate 34D slides on the inner surface of the top portion 31 of the dust collection mechanism 30. The sliding pushes the deposit A1 on the inner surface outward from the dust collection port 30A, resulting in the deposit A1 being peeled off. Fig. 20 illustrates an example of the push-out distance C2 of the movable plate 34D.

[0134] 21 and 22, the second peeling mechanism 33D includes a drive unit 34A, a shaft 34B, a connection unit 34C, a movable plate 34D1, and a support unit 34E1. The drive unit 34A is provided on the outer surface of the left side wall 30B of the dust collection mechanism 30 in FIG. 22. As shown in FIG. 21, the movable plate 34D1 extends in the width direction. As shown in FIG. 22, the upper end of the connection unit 34C is attached to the left end of the shaft 34B, and the lower end of the connection unit 34C is attached to the left end of the movable plate 34D1.

[0135] As shown in Figures 21 to 23, the support members 34E1 are plate-like members with an L-shaped cross section that are provided at each end in the width direction on the outer surface of the bottom 32 of the dust collection mechanism 30 (i.e., the underside of the bottom 32 in Figure 23). As shown in Figure 23, one end (i.e., the upper end) of the L-shaped plate-like member is attached to the underside of the bottom 32, and the other end (i.e., the inner end) extends inward in the width direction. The support members 34E1 support the sliding movable plate 34D1 from below at the inner part of the L shape. In the present disclosure, support members are not essential.

[0136] The drive unit 34A and shaft 34B can be configured with a known linear motion mechanism, such as an air cylinder with a piston rod or a screw feed mechanism. The drive unit 34A can reciprocate the movable plate 34D1 horizontally along the outer surface of the bottom 32 of the dust collection mechanism 30 (see FIG. 22) via the shaft 34B and the connecting portion 34C. The right end of the movable plate 34D1 (see FIG. 22) can move outward, further to the right of the dust collection port 30A. In a standby state where maintenance work to remove deposits is not being performed, the right end of the movable plate 34D1 (see FIG. 22) is separated from the dust collection port 30A. An example of the standby distance D1 of the movable plate 34D1 is shown in FIG. 22.

[0137] As shown in Figure 24, when the drive unit 34A moves the shaft 34B to the right, the connecting portion 34C moves to the right in conjunction with the shaft 34B. As shown in Figure 25, in conjunction with the movement of the connecting portion 34C, the right end of the movable plate 34D1 protrudes outward from the end face of the bottom portion 32 of the dust collection mechanism 30. The sliding movement pushes the deposits A2 on the end face outward from the position of the dust collection port 30A, resulting in the deposits A2 being peeled off. Figure 25 illustrates an example of the push-out distance D2 of the movable plate 34D1.

[0138] (Effects of the Eighth Modification) In the eighth modification, the first peeling mechanism 33C and the second peeling mechanism 33D, which serve as additional adhesion-preventing units, cause the movable plate to reciprocate along the surface of the dust collection mechanism 30. This further reduces adhesion of spatters LS to the inner surface and end faces of the dust collection mechanism 30. Other effects of the eighth modification are similar to those of the second embodiment.

[0139] 26 , a laser processing apparatus 2A according to a ninth modification differs from the seventh modification in that, in addition to the copper plates 33B being disposed on the inner surface and end faces of the dust collection mechanism 30 of the seventh modification, a vibration imparting device 33E is further provided as an additional adhesion-inhibiting unit. Note that, in the present disclosure, the use of the vibration imparting device 33E is not limited to a combination with another adhesion-inhibiting unit such as the copper plates 33B, and it can also be used as a standalone adhesion-inhibiting unit.

[0140] The vibration imparting device 33E can be configured using, for example, a known vibrator. The vibration imparting device 33E may impart vibration, for example, by striking. The vibration imparting device 33E is attached to the outer surface of the top portion 31 of the dust collection mechanism 30. In the present disclosure, the number of vibration imparting devices may be one or more. The attachment position of the vibration imparting device may also be changed as appropriate. In the present disclosure, it is not essential that the vibration imparting device be attached in constant contact with the dust collection mechanism 30. The vibration imparting device may be disposed around the dust collection mechanism 30 at a distance from the dust collection mechanism 30. Although not shown, the vibration imparting device may have a movable part that contacts the dust collection mechanism 30 as needed even from a distance, and may impart vibration to the nozzle portion by striking the movable part, etc.

[0141] (Functions and Effects of the Ninth Modification) In the ninth modification, the vibration imparting device 33E as an additional adhesion inhibitor can further suppress adhesion of spatters LS to the inner surface and end face of the dust collection mechanism 30. Other functions and effects of the ninth modification are similar to those of the third embodiment.

[0142] (Example 3) Next, Example 3 in which the adhesion rate of sputter LS was measured using the laser processing apparatuses according to the third embodiment and the seventh to ninth modified examples illustrated in Figures 13 to 15 and Figure 26 will be described with reference to Figure 27.

[0143] The adhesion rate of sputter LS in Figure 27 is the ratio of the number of sputter LS particles that have reached the inner surface and end face of the dust collection mechanism part 30 calculated in each of the third embodiment and the seventh to ninth variants, when the number of sputter LS particles that have reached the inner surface and end face of the dust collection mechanism part 30 in the third comparative example is set to 1.

[0144] The dust collection mechanism of the laser processing apparatus according to the third comparative example did not have an adhesion-preventing portion for preventing spatter adhesion, which contained copper as a single substance. The laser processing apparatuses according to the third comparative example, the third embodiment, and the seventh to ninth modifications all had the same shape and dimensions. In Example 3, the thickness of the copper plate 33B attached to the dust collection mechanism 30 of the seventh to ninth modifications was approximately 1 mm.

[0145] In Example 3, verification was carried out by laboratory testing. First, experimental models corresponding to the laser processing apparatuses according to the third comparative example, the third embodiment, and the seventh to ninth modifications were set up. Then, using each of the set up experimental models, laser processing was carried out in which a steel plate was continuously irradiated with laser light LB for approximately 100 hours. In each experimental model, the weight increase at each location was measured and the amount of adhesion was calculated.

[0146] As shown in Figure 27, in the third embodiment, the amount of sputter adhesion was reduced to about 1 / 10 of that in the third comparative example. Furthermore, in the seventh modified example, the amount of sputter adhesion could be reduced to the same extent as in the third embodiment. Furthermore, in the eighth modified example, the amount of sputter adhesion was reduced to about 1 / 20 of that in the third comparative example. Furthermore, in the ninth modified example, the amount of sputter adhesion was reduced to about 1 / 20 of that in the third comparative example. Example 3 revealed that when an adhesion inhibition portion for simple copper is provided, the amount of sputter adhesion LS can be significantly reduced compared to when an adhesion inhibition portion for simple copper is not provided.

[0147] Although the present disclosure has been described based on the above disclosed embodiments, the descriptions and drawings forming part of this disclosure should not be understood to limit the present disclosure. It should be considered that various alternative embodiments, examples, and operating techniques will become apparent to those skilled in the art from this disclosure.

[0148] For example, the present disclosure may be configured by partially combining the configurations illustrated in the attached drawings. As described above, the present disclosure includes various embodiments not described above, and the technical scope of the present disclosure is defined only by the invention-specifying matters in the claims that are appropriate from the above description.

[0149] <<Additional Notes>> The following aspects are conceptualized from this specification.

[0150] Aspect 1 is a laser processing device comprising: a gas injection unit that injects gas from an opening toward a portion of the surface of a steel plate that is irradiated with laser light, the gas injection unit having a nozzle portion with an outer surface that slopes from the outside of the opening toward the center of the opening in a direction parallel to the surface of the steel plate as it moves from the opposite side of the opening in the injection direction toward the opening, and a first adhesion inhibition portion for inhibiting adhesion of laser spatter is arranged on at least a part of the outer surface of the nozzle portion.

[0151] Aspect 2 is the laser processing apparatus according to aspect 1, wherein the first adhesion inhibition portion includes elemental carbon or elemental copper.

[0152] Aspect 3 is the laser processing device according to aspect 2, wherein the first adhesion inhibiting portion is configured such that the entire gas injection portion including the nozzle portion is formed from the elemental carbon or the elemental copper.

[0153] Aspect 4 is the laser processing device according to Aspect 2, wherein the first adhesion inhibiting portion is a plate-like member disposed on at least the portion of the outer surface of the nozzle portion of the gas ejection unit.

[0154] Aspect 5 is the laser processing apparatus according to any one of Aspects 1 to 4, wherein the first adhesion inhibition unit includes a charge application device that applies a charge of the same polarity as a charge of the laser sputtering to the gas injection unit.

[0155] Aspect 6 is the laser processing apparatus according to any one of Aspects 1 to 5, further comprising a coating agent supplying device that supplies a coating agent that coats the laser sputter.

[0156] Aspect 7 is the laser processing apparatus according to any one of Aspects 1 to 6, wherein the gas injection unit injects the gas parallel to the optical axis direction of the laser light.

[0157] Aspect 8 is the laser processing apparatus according to any one of Aspects 1 to 7, further comprising: a transport roll that transports the steel plate in a preset transport direction; and a laser light source unit that irradiates the laser light onto a surface of the steel plate transported in the transport direction.

[0158] Aspect 9 is the laser processing apparatus according to aspect 8, further comprising: a dust collection mechanism unit provided only on either the upstream side or the downstream side of the irradiated portion in the conveying direction, and collecting the laser spatter through a dust collection port.

[0159] Aspect 10 is the laser processing apparatus according to aspect 9, wherein the dust collection mechanism is provided with a second adhesion inhibition portion for inhibiting adhesion of the laser sputter to a surface of the dust collection mechanism.

[0160] Aspect 11 is a laser processing method comprising: irradiating a surface of a steel plate with laser light; and using a gas injection unit having a nozzle portion with an outer surface that slopes from the outside of the opening toward the center of the opening in a direction parallel to the surface of the steel plate as it moves from the opposite side of the opening to the opening side in the injection direction, and having an adhesion prevention portion for preventing adhesion of laser spatter arranged on at least a part of the outer surface of the nozzle portion, injecting gas from the opening toward the irradiation site so as to lift up the laser spatter generated from the irradiation site of the laser light from the surface of the steel plate.

[0161] <Other Aspects> Furthermore, the following other aspects are conceptualized from this specification.

[0162] Another aspect 1 is a laser processing device comprising: a laser light source unit that irradiates a surface of a steel plate being transported in a preset transport direction with laser light; and a gas injection unit that injects gas parallel to the optical axis direction of the laser light toward the irradiation site of the laser light, the gas injection unit having an adhesion-inhibiting portion that contains simple carbon and inhibits adhesion of laser spatter arranged on its surface.

[0163] Another aspect 2 is the laser processing device according to aspect 1, wherein the adhesion inhibiting portion is configured such that the entire gas injection portion is formed from the simple substance of carbon.

[0164] Another aspect 3 is the laser processing device according to aspect 1, wherein the adhesion inhibiting portion is a plate-like member disposed on a part of the surface of the gas ejecting portion.

[0165] Another aspect 4 is the laser processing apparatus according to any one of aspects 1 to 3, further comprising a charge application device that applies a charge of the same polarity as the charge of the laser sputtering to the gas injection part.

[0166] Another aspect 5 is the laser processing apparatus according to any one of aspects 1 to 4, further comprising a coating agent adding device that adds a coating agent that coats the laser sputter.

[0167] Another aspect 6 is a laser processing method comprising: using a laser light source unit to irradiate a surface of a steel plate being transported in a preset transport direction with laser light; and using a gas injection unit having an adhesion-preventing portion on its surface that contains simple carbon and inhibits the adhesion of laser spatter, to inject gas parallel to the optical axis direction of the laser light toward the irradiated portion of the laser light, thereby lifting up laser spatter generated from the irradiated portion from the surface of the steel plate.

[0168] According to another aspect, the efficiency of collecting laser sputter dust can be increased, and adhesion of laser sputter dust can be prevented across the width of the plate.

[0169] The disclosure of Japanese Patent Application No. 2023-149623, filed on September 14, 2023, is incorporated herein by reference in its entirety. In addition, all documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard was specifically and individually indicated to be incorporated by reference.

[0170] DESCRIPTION OF SYMBOLS 1, 1A to 1C Laser processing device 2, 2A to 2C Laser processing device 10 Laser light source unit 12 Emission unit 20 Gas injection unit 20A Gas 21A Vertical unit 21B Nozzle unit 21B1 Opening 22A Adhesion inhibition unit (first adhesion inhibition unit) 22B Carbon plate (first adhesion inhibition unit) 22C Electric charge (first adhesion inhibition unit) 22D Adhesion inhibition unit (first adhesion inhibition unit) 22E Copper plate (first adhesion inhibition unit) 23 Joiner 24 Air supply duct 22F Peeling mechanism (first adhesion inhibition unit) 22F1 Drive unit 22F2 Movable plate 22G Vibration mechanism (first adhesion inhibition unit) 33A Adhesion inhibition unit (second adhesion inhibition unit) 33B Copper plate (second adhesion inhibition unit) 33C First peeling mechanism (second adhesion-inhibiting portion) 33D Second peeling mechanism (second adhesion-inhibiting portion) 34A Drive portion 34B Shaft 34C Connection portion 34D Movable plate 34E Support portion 30 Dust collection mechanism portion 30A Dust collection port 30B Side wall 31 Top portion 31A Slit 32 Bottom portion 33E Vibration mechanism (second adhesion-inhibiting portion) 34 Dust collection duct 40 Charge application device 42 Power source 44 Electric wire 50 Coating agent supply device 52 Coating agent source 54 Supply pipe 56 Supply nozzle 90 Ceiling panel A1 to A3 Adherent matter C Conveying direction C1 Waiting distance C2 Pushing distance D1 Waiting distance D2 Pushing distance DF Suction airflow G Groove LB Laser light LS Sputter (laser sputter) P1 Air supply pump P2 Suction pump R Transport roll S Steel plate SA Irradiation area x Height from the steel plate to the top of the inner wall surface of the dust collection mechanism y Height from the steel plate to the top of the nozzle part of the gas injection part

Claims

1. A laser processing device comprising: a gas injection unit which injects gas from an opening towards the irradiated portion of the surface of a steel plate to which laser light is applied, the gas injection unit having a nozzle portion with an outer surface which slopes from the outside of the opening towards the center of the opening in a direction parallel to the surface of the steel plate as it moves from the opposite side of the opening in the injection direction to the side of the opening, and a first adhesion inhibition portion for inhibiting adhesion of laser sputter is disposed on at least a part of the outer surface of the nozzle portion.

2. The laser processing device according to claim 1, wherein the first adhesion inhibition portion contains elemental carbon or elemental copper.

3. The laser processing device according to claim 2, wherein the first adhesion-inhibiting portion is configured such that the entire gas injection portion, including the nozzle portion, is formed from the carbon element or the copper element.

4. The laser processing device according to claim 2, wherein the first adhesion-inhibiting portion is a plate-like member arranged on at least a portion of the outer surface of the nozzle portion of the gas injection section.

5. A laser processing device as claimed in any one of claims 1 to 4, wherein the first adhesion inhibition section includes a charge application device that applies a charge of the same polarity as the charge of the laser sputter to the gas injection section.

6. The laser processing device according to any one of claims 1 to 5, further comprising a coating agent supplying device for supplying a coating agent for coating the laser sputter.

7. The laser processing device according to any one of claims 1 to 6, wherein the gas injection section injects the gas parallel to the optical axis direction of the laser light.

8. A laser processing device according to any one of claims 1 to 7, further comprising: a transport roll for transporting a steel plate in a preset transport direction; and a laser light source unit for irradiating the laser light onto a surface of the steel plate transported in the transport direction.

9. The laser processing device according to claim 8, further comprising: a dust collection mechanism section provided only on either the upstream side or downstream side of the irradiated portion in the transport direction, for collecting the laser spatter through a dust collection port.

10. The laser processing device according to claim 9, wherein the dust collection mechanism is provided with a second adhesion inhibition section for inhibiting adhesion of the laser sputter to a surface of the dust collection mechanism.

11. A laser processing method comprising: irradiating a surface of a steel plate with laser light; and using a gas injection unit having a nozzle portion with an outer surface that slopes from the outside of the opening to the center of the opening in a direction parallel to the surface of the steel plate as it moves from the opposite side to the opening in the injection direction toward the opening side, and an adhesion inhibition portion for inhibiting adhesion of laser spatter is arranged on at least a part of the outer surface of the nozzle portion, to inject gas from the opening toward the irradiated portion so as to lift up the laser spatter generated from the irradiated portion of the laser light from the surface of the steel plate.

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