Laser processing apparatus 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

Technical Field

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

Background Art

[0002] Conventionally, in the steel industry, a process of performing processing such as grooves on the surface of a steel sheet conveyed in a preset direction or a stopped steel sheet by irradiating the surface of the steel sheet with laser light is known. For example, Japanese Unexamined Patent Application Publication No. 2020-138226 discloses a technique in which a plurality of laser processing units having laser light source units are arranged along the width direction of a non-oriented electrical steel sheet. In Japanese Unexamined Patent Application Publication No. 2020-138226, processing grooves extending along the width direction are formed on the surface of the steel sheet by irradiation with laser light.

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

[0004] As a technique for removing spatter, for example, Japanese Unexamined Patent Application Publication No. 2020-138226 discloses a laser processing apparatus including a laser irradiation facility, a dust collection mechanism for sucking spatter, and an air nozzle as a gas injection unit that injects air toward the irradiation site of the laser light.

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2020-138226

Summary of the Invention

Problems to be Solved by the Invention

[0006] Here, the Discloser has found that when a gas injection unit is used that injects gas from a nozzle towards the irradiation area, spatter is likely to adhere to the outer surface of the nozzle. The nozzle, in this context, is the part of the gas injection unit that has an outer surface that slopes from the outside of the opening towards the center of the opening in a direction parallel to the surface of the steel plate, starting from the opposite side of the opening for gas injection in the injection direction and moving towards the opening. In particular, the Discloser has found that fine spatter generated by groove processing on the surface of the steel plate adheres to the nozzle of the gas injection unit due to prolonged use of the laser processing device. The groove depth is approximately 10 μm to 50 μm. The size of the spatter generated by groove formation is also approximately 10 μm to 50 μm, similar to the groove depth.

[0007] In this regard, Japanese Patent Publication No. 2020-138226 does not examine any techniques for suppressing sputter adhesion to the outer surface of a nozzle in laser processing when the nozzle portion is part of a gas injection portion.

[0008] This disclosure, made in view of the above, provides a laser processing apparatus and a laser processing method that can suppress the adhesion of laser sputter to the outer surface of the nozzle portion of the gas injection unit. [Means for solving the problem]

[0009] The laser processing apparatus according to this disclosure includes a gas injection unit that injects gas from an opening toward a laser beam irradiation area on the surface of a steel plate, and has a nozzle unit having an outer surface that is inclined in a direction parallel to the surface of the steel plate, moving from the opposite side of the opening in the injection direction toward the side of the opening, so as to move toward the center of the opening, and a first adhesion inhibiting unit for inhibiting the adhesion of laser sputter is disposed on at least a part of the outer surface of the nozzle unit.

[0010] The laser processing method according to this disclosure involves irradiating the surface of a steel plate with laser light, and using a gas injection unit which has a nozzle portion having 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 toward the opening in the injection direction, and an adhesion inhibiting portion for inhibiting the adhesion of laser sputter is disposed on at least a part of the outer surface of the nozzle portion, the gas is injected from the opening toward the irradiation site so as to lift the laser sputter generated from the laser light irradiation site away from the surface of the steel plate. [Effects of the Invention]

[0011] According to this disclosure, the adhesion of laser sputtering to the outer surface of the nozzle portion of the gas injection unit can be suppressed. [Brief explanation of the drawing]

[0012] [Figure 1] This is a plan view illustrating a laser processing apparatus according to the first embodiment of this disclosure. [Figure 2] This is a cross-sectional view taken along line 2-2 in Figure 1. [Figure 3] This 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 Figure 1. [Figure 4] This 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 Figure 1. [Figure 5] This 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 Figure 1. [Figure 6] This graph illustrates the adhesion rate of sputter to the gas injection section in the laser processing apparatus according to the first embodiment and the first to third modified examples. [Figure 7] This is a cross-sectional view illustrating a laser processing apparatus according to a second embodiment of the present disclosure, cut at a position corresponding to line 2-2 in Figure 1. [Figure 8]It is a cross-sectional view for explaining the gas injection part of the laser processing apparatus according to the fourth modification of the second embodiment, cut at a position corresponding to the line 2-2 in FIG. 1. [Figure 9] It is a front view for explaining the gas injection part of the laser processing apparatus according to the fourth modification of the second embodiment, viewed along the conveyance direction. [Figure 10] It is a cross-sectional view for explaining the laser processing apparatus according to the fifth modification of the second embodiment, cut at a position corresponding to the line 2-2 in FIG. 1. [Figure 11] It is a cross-sectional view for explaining the laser processing apparatus according to the sixth modification of the second embodiment, cut at a position corresponding to the line 2-2 in FIG. 1. [Figure 12] It is a graph for explaining the adhesion rate of sputter to the gas injection part in each of the laser processing apparatuses according to the second embodiment and the fourth to sixth modifications. [Figure 13] It is a cross-sectional view for explaining the laser processing apparatus according to the third embodiment of the present disclosure, cut at a position corresponding to the line 2-2 in FIG. 1. [Figure 14] It is a cross-sectional view for explaining the laser processing apparatus according to the seventh modification of the third embodiment, cut at a position corresponding to the line 2-2 in FIG. 1. [Figure 15] It is a cross-sectional view for explaining the laser processing apparatus according to the eighth modification of the third embodiment, cut at a position corresponding to the line 2-2 in FIG. 1. [Figure 16] It is a plan view for explaining the first peeling mechanism in a standby state in the dust collection mechanism part of the laser processing apparatus according to the eighth modification of the third embodiment. [Figure 17] It is a cross-sectional view taken along the line 17-17 in FIG. 16. [Figure 18] It is a cross-sectional view taken along the line 18-18 in FIG. 16. [Figure 19] It is a plan view for explaining the first peeling mechanism in an extrusion state in the dust collection mechanism part of the laser processing apparatus according to the eighth modification of the third embodiment. [Figure 20] It is a cross-sectional view for explaining the first peeling mechanism in an extrusion state in the dust collection mechanism part of the laser processing apparatus according to the eighth modification of the third embodiment, cut at a position corresponding to the line 17-17 in FIG. 16. [Figure 21] It is a plan view for explaining a second peeling mechanism in a dust collection mechanism part of a laser processing apparatus according to an eighth modification of the third embodiment, which is in a standby state. [Figure 22] It is a sectional view taken along line 22-22 in FIG. 21. [Figure 23] It is a front view for explaining a peeling mechanism in a dust collection mechanism part of a laser processing apparatus according to an eighth modification of the third embodiment, which is in a standby state on the bottom side. [Figure 24] It is a plan view for explaining a second peeling mechanism in a dust collection mechanism part of a laser processing apparatus according to an eighth modification of the third embodiment, which is in an extrusion state. [Figure 25] It is a sectional view for explaining a second peeling mechanism in a dust collection mechanism part of a laser processing apparatus according to an eighth modification of the third embodiment, which is in an extrusion state and is cut at a position corresponding to line 22-22 in FIG. 21. [Figure 26] It is a sectional view for explaining a laser processing apparatus according to a ninth modification of the third embodiment, which is cut at a position corresponding to line 2-2 in FIG. 1. [Figure 27] It is a graph for explaining the adhesion rate of sputter to a dust collection mechanism part in each of the laser processing apparatuses according to the third embodiment and the seventh to ninth modifications.

Embodiments for Carrying Out the Invention

[0013] The first embodiment and the second embodiment will be described below. In the description of the following drawings, the same parts and similar parts are denoted by the same reference numerals or similar reference numerals. However, the drawings are schematic, and the relationship between the thickness and the planar dimensions, the ratio of the thicknesses of each device and each member, etc. are different from the actual ones. Therefore, specific thicknesses and dimensions should be determined in consideration of the following description. Also, there are parts where the dimensional relationships and ratios are different between the drawings. Further, unless otherwise specified in the specification, the number of each component of the present disclosure is not limited to one, and a plurality may exist.

[0014] <00​​As shown in Figures 1 and 2, the laser processing apparatus 1 according to the first embodiment comprises a laser light source unit 10, a gas injection unit 20, a dust collection mechanism unit 30, and a ceiling plate 90. The operating state of the laser light source unit 10, the gas injection unit 20, and the dust collection mechanism unit 30 is controlled by various computers (not shown), such as a process computer that comprehensively controls the steel plate manufacturing process.

[0015] (steel plate) The object to be processed by the laser processing apparatus 1 according to the first embodiment is a steel sheet S. The type of steel sheet S is not particularly limited, and various known steel sheets S, such as grain-oriented electrical steel sheets (e.g., JIS C 2553:2012), can be used. Furthermore, the type of processing using laser light is not limited. The laser processing apparatus 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 producing various types of steel sheets S.

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

[0017] Furthermore, although not shown in the figures, in this disclosure, the laser processing apparatus may be installed facing the portion of the roll surface of the steel plate support roll that changes the transport direction C of the steel plate S, where the transported steel plate and the irradiation direction overlap. For example, the steel plate support roll can change the pass line of a steel plate S being transported horizontally to an oblique direction. Also, the steel plate support roll can change the pass line of a steel plate S being transported obliquely upward to an oblique downward direction. In this disclosure, the laser processing apparatus can be installed at any position on the transport line through which the steel plate S is being transported.

[0018] (Steel strip coil) In the first embodiment, a steel strip coil is used as the steel plate S. However, in this disclosure, the steel plate is not limited to a steel strip coil; for example, a cut plate pre-cut from a steel strip coil may be used as the steel plate. A steel strip coil can be produced by winding a long steel strip having a certain width.

[0019] When laser processing is applied to the surface of a steel sheet S, one end of the wound steel strip coil, located towards the center, is rotatably supported at one end of the processing equipment in the longitudinal direction, while the other end, located on the outside of the steel strip coil, is connected to the other end of the processing equipment in the longitudinal direction. The other end of the steel strip coil is then pulled out and wound towards the other end of the processing equipment at a nearly constant speed. In the first embodiment, the process of laser processing being applied to the surface of the steel sheet S of the steel strip coil as it passes through the laser processing device 1 installed in the processing equipment is also referred to as "passing through the sheet."

[0020] (Continuous processing) In the first embodiment, laser processing performed while the steel sheet S of the steel strip coil is being passed through is also referred to as "continuous processing." On the other hand, laser processing applied to the surface of cut sheets without pulling out the steel strip coil is referred to as "batch processing." In batch processing laser processing, the steel sheets are, for example, rectangular cut sheets fixed on a processing support stand, or supported on a conveyor line, and laser processing is performed on each cut sheet, with the laser processing device moving along the length of the cut sheet as needed. In addition, each cut sheet requires work to be fixed to the support stand, and to be fed into or retrieved from the conveyor line. For this reason, the cost of groove processing tends to be high in batch processing, resulting in relatively lower productivity.

[0021] On the other hand, in continuous laser processing as in the first embodiment, by simply repeatedly performing processing in the width direction of the sheet, for example, scanning the laser beam LB, a nearly uniform groove can be machined over almost the entire length of the steel strip coil after winding, in a relatively short time. Furthermore, there is no need to move the laser processing device 1 along the entire length of the steel strip coil, that is, to move it along the transport direction C. For this reason, continuous processing can reduce the cost of groove machining compared to batch processing, and as a result, productivity can be improved.

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

[0023] The laser light source is not particularly limited, and various laser light sources such as solid-state lasers, gas lasers, and semiconductor lasers can be used. Similarly, the optical system is not particularly limited, and various optical systems can be used to guide the laser beam LB to the surface of the steel plate S.

[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 above the steel plate S in the vertical direction, as schematically shown in Figure 2, such that the irradiation axis of the laser beam LB is substantially perpendicular to the surface of the steel plate S.

[0025] (Gas injection unit) As shown in Figures 1 and 2, the gas injection unit 20 is positioned both upstream and downstream in the transport direction C at the laser beam emission unit 12 of the laser light source unit 10. As shown in Figure 2, the gas injection unit 20 is connected to the supply air pump P1 via the supply air duct 24.

[0026] In the first embodiment, the gas injection unit 20 is an air nozzle that injects gas 20A from an opening 21B1 parallel to the optical axis direction of the laser beam LB toward the laser beam irradiation area SA. The opening 21B1 of the gas injection unit 20 in the first embodiment is rectangular in shape, with a long side extending along the width direction (vertical direction in Figure 1) in a plan view. The opening of the gas injection unit in this 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 gas 20A toward the laser beam irradiation area SA on the surface of the steel plate S.

[0027] The gas injection unit 20 has a base 21A and a nozzle 21B. The base 21A in Figure 2 has a pair of outer surfaces that face each other in the longitudinal direction of the steel plate S. The pair of outer surfaces extend along the width direction (vertical direction in Figure 1) and are closed at both ends. The pair of outer surfaces of the base 21A in Figure 2 are vertical. The upper part of the base 21A in Figure 2 is attached to the ceiling plate 90, and the lower part of the base 21A is continuous with the nozzle 21B. Note that the shape of the base 21A is not limited to that in Figure 2, and any shape that can guide gas to the nozzle 21B is acceptable.

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

[0029] In other words, the length of a pair of opposing outer surfaces of the nozzle section 21B along the longitudinal direction of the steel plate S decreases as you move from the side of the ejection section 12 towards the side of the irradiation area SA. The opening surface of the nozzle section 21B is perpendicular to the injection direction. The outer surface of the nozzle section 21B is inclined with respect to the transport direction C. The outer surface of the nozzle section 21B includes a symmetrical surface whose normal vector points in the direction in which the steel plate S is located.

[0030] In the case where the steel plate S is transported during laser processing, as in the first embodiment, the longitudinal direction of the steel plate S is parallel to the transport direction C (i.e., the left-right direction in Figure 1). The transport direction C is perpendicular to the width direction of the steel plate S (i.e., the up-down direction in Figure 1). Also, when the steel plate S is stopped during laser processing, the longitudinal direction of the steel plate S is the length direction parallel to the surface of the steel plate S and perpendicular to the width direction of the steel plate S.

[0031] The gas injection unit 20 is positioned such that, when viewed along the transport direction C, the dry air, which is the gas 20A being injected, overlaps with the laser beam LB across the entire scanning width of the laser beam LB in the width direction of the steel plate S (i.e., the vertical direction in Figure 1). In other words, the gas injection unit 20 is positioned so that the injected dry air is directed toward at least a portion of the laser beam LB. The discharge jet of gas 20A injected from the gas injection unit 20 suppresses the adhesion of sputtered LS to the ejection unit 12. As the surface portion of the steel plate S heats up and expands in volume due to the energy of the laser beam LB, the expanded portion is ejected from the surface of the steel plate S as sputtered LS. The ejected sputtered LS is carried by the suction airflow DF of the dust collection mechanism 30 and collected in the dust collection mechanism 30.

[0032] In the laser processing apparatus 1 according to the first embodiment, instead of using an air knife with a flow velocity that scrapes spatter from inside the grooves G on the surface of the steel plate, a gas injection unit 20 that injects dry air with a flow velocity lower than that of the air knife is used. This allows the spatter LS to be lifted from the surface of the steel plate S and superimposed on the airflow of the dust collection mechanism 30 without disturbing the airflow for dust collection as an air knife would.

[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 beam LB to an extent that allows the sputtered LS to be lifted from the surface of the steel plate S. For this reason, in this disclosure, it is not necessary for all of the dry air 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 sputtered LS from adhering to the laser processing apparatus, particularly the ejection unit 12 and the gas injection unit 20. In order to lift the sputtered LS from the surface of the steel plate S, injection conditions including injection speed can be determined based on experiments, for example, and a gas such as dry air can be injected under the determined injection conditions.

[0034] On the other hand, unlike the air nozzle in 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 apparatus, including the ejection unit 12. More specifically, using an air knife can generate molten particles with a diameter of 100 μm or more, called tips. Since tips are difficult to cool and do not easily overlap with the airflow from the dust collection mechanism 30, tips tend to adhere to peripheral equipment. In contrast, by using an air nozzle as in the first embodiment, the generation of molten particles with a diameter of 100 μm or more can be suppressed, and as a result, the generated particles can be controlled to be only 10 to 50 μm particles, which are relatively easy to cool and easily overlap with the airflow from the dust collection mechanism 30.

[0035] The installation position of the gas injection unit 20 is not particularly specified, as long as it is a position that can inject dry air onto the surface of the steel plate S. However, it is preferable that the gas injection unit 20 be installed directly above the steel plate S, as shown in Figures 1 and 2. Furthermore, it is even more preferable that the gas injection unit 20 be installed parallel to the optical axis direction of the laser beam LB, such that the nozzle main axis direction of the gas injection unit 20, in other words, the direction of travel of the injected dry air, is substantially coaxial with the optical axis direction of the laser beam LB in the laser light source unit 10. The dry air exemplified in Figure 2 is injected toward the surface of the steel plate S parallel to the optical axis direction of the laser beam LB and substantially perpendicular to the surface of the steel plate S.

[0036] In the first embodiment, it is preferable that the amount of dry air injected from the gas injection unit 20 is set to be less than or equal to 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 less than or equal to the suction amount of the dust collection mechanism 30, it is possible to more reliably suppress the disturbance of the airflow for sucking up the sputtered LS and the generation of chips, while still lifting the sputtered LS from the surface of the steel plate S. Therefore, it is possible to more reliably improve the dust collection efficiency of the sputtered LS. It is more preferable that the amount of dry air injected from the gas injection unit 20 be controlled more precisely. In this disclosure, the amount of dry air injected is not limited to being less than or equal to the suction amount of the dust collection mechanism 30, but can be changed arbitrarily.

[0037] Furthermore, it is preferable that the discharge velocity of the dry air injected from the gas injection unit 20 be set to a value less than or equal to the suction velocity of the dust collection mechanism 30. By setting the discharge velocity of the dry air to be less than or equal to the suction velocity of the dust collection mechanism 30, the dust collection efficiency of the dust collection mechanism 30 can be further improved. In this disclosure, the discharge velocity of the dry air is not limited to being less than or equal to the suction velocity of the dust collection mechanism 30, but 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. Also, the gas 20A injected from the gas injection unit 20 is not limited to the dry air described above, but may be nitrogen, argon, carbon dioxide, helium, etc.

[0039] (Adhesion inhibiting part) In the first embodiment, an adhesion inhibiting portion 22A containing elemental carbon is arranged on the surface of the gas injection portion 20 to inhibit the adhesion of sputtered LS. The adhesion inhibiting portions provided in the gas injection portion 20 of the first embodiment and the modified version thereof correspond to the first adhesion inhibiting portion of this 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 an adhesion inhibiting portion 22A by elemental carbon. "The entire gas injection portion 20" means, in other words, the body of the air nozzle as the gas injection portion 20.

[0040] Furthermore, a portion of the connection between the gas injection unit 20 and the air supply pump P1, such as a pipe, may also be included in the "entire gas injection unit 20" by being formed from pure carbon. It should be noted that in this disclosure, it is not essential that the entire gas injection unit 20 be formed from pure carbon; for example, a portion of the steel plate side of the gas injection unit 20 may be formed from pure carbon.

[0041] In the gas injection section 20, which is made of elemental carbon, the surface flatness is improved compared to gas injection sections made of materials such as steel or resin, which do not contain elemental carbon. As a result, surface irregularities are greatly suppressed. Similarly, the gas injection section 20, which is made of elemental carbon, has superior heat resistance compared to gas injection sections made of materials such as steel or resin, which do not contain elemental carbon. In the first embodiment, the improved flatness and heat resistance make it difficult for relatively high-temperature sputtered LS to adhere.

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

[0043] In the first embodiment, the bulk density of elemental carbon is approximately 1.7 g / cm³. 3 Preferably, the bulk density is 1.7 g / cm³. 3 If the value is less than this, there is a concern that the durability of elemental carbon in laser processing equipment will decrease.

[0044] In this disclosure, for example, if elemental carbon is anisotropic graphite, the bulk density of elemental carbon is approximately 1.5 g / cm³. 3 The above is preferable. However, as in the first embodiment, using isotropic graphite as elemental carbon is preferable because it can improve the durability of elemental carbon compared to using other materials.

[0045] (Dust collection mechanism) The dust collection mechanism 30 is a mechanism that collects sputtered LS floating near the irradiation area SA of the laser beam LB while suppressing the adhesion of sputtered LS to the discharge section 12 by injecting dry air from the gas injection section 20. The dust collection mechanism 30 has an appearance such as a cylindrical dust collection hood having a dust collection port 30A for collecting sputtered LS on one side in the axial direction. The dust collection mechanism 30 includes a dust collection channel (not shown) for sucking up sputtered LS, a dust collection duct 34 connected to the dust collection channel, and a suction pump P2 connected to the dust collection duct 34.

[0046] The dust collection mechanism 30 is configured to suck up the atmosphere around the dust collection port 30A at a predetermined suction volume. The dust collection mechanism 30 collects sputter LS generated from the laser beam LB irradiation site SA through the dust collection port 30A by 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, but may be multiple.

[0047] As schematically shown in Figures 1 and 2, the dust collection mechanism 30 is provided either upstream of the laser beam LB irradiation area SA or downstream of the laser beam LB irradiation area SA in the transport direction C of the steel plate S. In other words, the dust collection mechanism 30 is not provided on both the upstream and downstream sides of the laser beam LB irradiation area SA. By providing the dust collection mechanism 30 only on the upstream side or only on the downstream side of the laser beam LB irradiation area SA, it is possible to prevent stagnation of the airflow for sputtering LS in the vicinity of the laser beam LB irradiation area SA, and to reliably collect sputtering LS.

[0048] Furthermore, if the dust collection mechanism 30 is positioned on either the upstream or downstream side, it may be difficult to secure space for the dust collection mechanism 30 due to interference between the dust collection mechanism 30 and the components of the laser processing device 1. In this first embodiment, however, the dust collection mechanism 30 can be positioned 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 set on the other side. In other words, the position of the dust collection mechanism 30 can be easily and flexibly changed. 、 In this disclosure, the dust collection mechanism may be provided both upstream and downstream of the laser beam LB irradiation area SA in the transport direction C of the steel plate S.

[0049] Furthermore, it is more preferable that the dust collection mechanism 30 be provided only downstream of the laser beam LB irradiation area SA, as schematically shown in Figure 2. As the steel plate S to be processed is transported along the transport direction C, an airflow (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 laser beam LB irradiation area SA, it becomes possible to utilize the accompanying flow, and as a result, sputtered LS can be collected more reliably.

[0050] Preferably, the amount of suction by the dust collection mechanism 30 is greater than or equal to the amount of dry air injected from the gas injection unit 20. This more reliably prevents stagnation of airflow around the laser beam LB irradiation area SA, and enables more reliable dust collection of sputtered LS. In this disclosure, the amount of suction by the dust collection mechanism 30 is not limited to being greater than or equal to the amount of gas 20A injected from the gas injection unit 20, but can be changed as desired.

[0051] Furthermore, the suction flow rate by the dust collection mechanism 30 is preferably, for example, 15 m / sec or more and 50 m / sec or less, and more preferably 20 m / sec or more and 30 m / sec or less. By having a suction flow rate of 15 m / sec or more and 50 m / sec or less, the airflow around the laser beam LB irradiation area SA is not disturbed. As a result, dust collection of sputtered LS becomes possible more reliably.

[0052] If the suction flow rate is less than 15 m / sec, the sputtering suction rate decreases. Also, if the suction flow rate exceeds 50 m / sec, power consumption increases. Furthermore, if the suction flow rate exceeds 50 m / sec, the negative pressure increases due to the suction, which may cause pressure oscillations and raise concerns about problems with the stability of the sheet metal and the laser equipment. In this disclosure, the suction flow rate of the dust collection mechanism 30 is not limited to 15 m / sec or more and 50 m / sec or less, but can be changed as desired.

[0053] (Laser processing unit and laser processing set) In this 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, which are corresponding to each other. Alternatively, one "laser processing set" may be configured by a plurality of laser processing units arranged along the width direction of the steel plate S.

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

[0055] (Ceiling panel) The ceiling plate 90 is fitted with the laser light source unit 10 and the gas injection unit 20. In this disclosure, the ceiling plate may be included in the "laser processing unit". As shown in Figure 2, the ceiling plate 90 separates the space on the steel plate S side from the space on the opposite side of the steel plate S at the height of the emission part 12 of the laser light source unit 10. In other words, the ceiling plate 90 acts as a partition to prevent sputtering LS from adhering above the emission part 12 of the laser light source unit 10.

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

[0057] Furthermore, as the dust collection efficiency of sputtered LS is further improved, it becomes possible to reduce the amount of sputtered 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 electrical steel sheets, it becomes possible to more reliably collect the generated sputtered LS even when a further increase in the irradiation power of the irradiated laser beam LB is required.

[0058] (Laser processing method) The laser processing apparatus 1 according to the first embodiment can be used to realize the laser processing method according to the first embodiment. The laser processing method according to the first embodiment is a method for collecting sputter LS generated from the laser beam LB irradiation site SA on the surface of a steel plate S due to the laser beam LB irradiated onto the surface of the steel plate 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 plate S being transported in a preset transport direction C (i.e., a moving steel plate S). In addition, dry air is injected from the opening 21B1 of the nozzle 21B of the gas injection unit 20 parallel to the optical axis direction of the laser beam LB towards the irradiation area SA of the laser beam LB. By injecting dry air, the spatter LS generated from the irradiation area SA can be lifted up from the surface of the steel plate S, i.e., raised.

[0060] In the first embodiment, even if sputtered LS is swirled up, the gas injection unit 20, which acts as an adhesion inhibiting unit 22A containing elemental carbon, prevents the sputtered LS from adhering to the surface of the gas injection unit 20. Then, in the transport direction C of the steel plate S, the sputtered LS is collected from the dust collection port 30A of the dust collection mechanism unit 30, which is provided only on either the upstream or downstream side of the laser beam LB irradiation area SA.

[0061] (Effects of the first embodiment) In the first embodiment, an adhesion inhibiting portion 22A containing elemental carbon is arranged on the outer surface of the nozzle portion 21B of the gas injection unit 20 to inhibit the adhesion of sputtered LS. Here, the Discloser has found that, as described in Example 1 later, when the adhesion inhibiting portion 22A containing elemental carbon is arranged on the outer surface of the nozzle portion 21B of the gas injection unit 20, the effect of suppressing the adhesion of sputtered LS generated from the irradiation site SA to the outer surface of the nozzle portion 21B is higher than when the adhesion inhibiting portion 22A is not arranged. The sputtered LS whose adhesion to the outer surface of the nozzle portion 21B is inhibited by the adhesion inhibiting portion 22A is collected by the dust collection mechanism 30. According to the first embodiment, the adhesion of sputtered 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 site SA of the laser beam LB, can be suppressed.

[0062] Furthermore, in the first embodiment, the adhesion inhibiting portion 22A is constructed by forming the entire gas injection portion 20 from a single element of carbon. As a result, the adhesion inhibiting portion 22A is arranged across the entire outer surface of the nozzle portion 21B. Therefore, there is no need to prepare a separate component for the adhesion inhibiting portion 22A from the gas injection portion 20.

[0063] Here, the Disclosing Party has found that when the direction of gas injection in the gas injection unit is parallel to the optical axis direction of the laser beam, sputter is more likely to adhere to the outer surface of the nozzle. In the first embodiment, even when the direction of gas injection in the gas injection unit 20 is parallel to the optical axis direction of the laser beam LB, the adhesion inhibiting unit 22A can suppress the adhesion of sputter LS to the nozzle 21B of the gas injection unit 20. In this disclosure, the direction of gas injection in the gas injection unit is not limited to being parallel to the optical axis direction of the laser beam, nor is it excluded from intersecting the optical axis direction.

[0064] Furthermore, in the first embodiment, the laser processing apparatus 1 includes a transport roll R that transports the steel plate S in a preset transport direction C, and a laser light source unit 10 that irradiates the surface of the steel plate S being transported in the transport direction C with laser light LB. Therefore, laser processing can be performed on the steel plate S while it is being transported.

[0065] In particular, when a dust collection mechanism is located in a laser processing apparatus having a nozzle, the nozzle can significantly function as a guide for the gas flow, depending on the positional relationship between the nozzle and the dust collection mechanism. As a result, it has been found that prolonged use of the laser processing apparatus causes spatter to adhere to the nozzle, and this adhesion creates stagnation in the flow of gas such as air, resulting in a decrease in dust collection efficiency. However, as disclosed herein, by arranging a spatter adhesion inhibiting part in the nozzle, the laser processing apparatus can be operated for even longer periods, thereby reducing the maintenance burden and improving availability (in other words, the ability to operate continuously).

[0066] (First variation) As shown in Figure 3, the first modified example differs from the first embodiment in that the carbon plate 22B, which is made of a single element of carbon and serves as an adhesion inhibitor, is arranged in the gas injection unit 20 as a separate component from the gas injection unit 20.

[0067] Specifically, the gas injection unit 20 of the laser processing apparatus 1A according to the first modified example differs from the gas injection unit 20 of the first embodiment, which is made of a single carbon material, in that it is made of, for example, a metal such as steel or a resin. Furthermore, the adhesion inhibiting unit is a plate-shaped member arranged on a part of the surface of the gas injection unit 20. In this disclosure, the carbon plate is not limited to being made of a single plate-shaped member. For example, the carbon plate can be an adhesion inhibiting unit made of a single carbon sheet or a laminate of two or more carbon sheets, and can be used as the carbon plate of this disclosure.

[0068] The carbon plate 22B is positioned on the outer surface of the nozzle portion 21B, which is the tip (lower end in Figure 3) side of the gas injection portion 20 facing the irradiation area SA. However, in this disclosure, the position of the carbon plate 22B is not limited to this, and it may be positioned anywhere between the irradiation area SA of the laser beam LB and the gas injection portion 20. It is preferable that the carbon plate 22B be positioned in close contact with the lower end of the gas injection portion 20 in Figure 3 in order to suppress micro-vibrations during processing. Other configurations in the first modified example are the same as in the first embodiment, so a redundant explanation is omitted.

[0069] (Effects of the first modification) Furthermore, in the first modified example, similar to the first embodiment, the adhesion of sputtered material 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 laser beam LB irradiation area SA, can be suppressed. In the first modified example, the adhesion inhibiting portion is a plate-shaped member disposed on a part of the surface of the gas injection unit 20. That is, a carbon plate 22B made of pure carbon, which serves as the adhesion inhibiting portion, is disposed 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. In this disclosure, it is sufficient that the adhesion inhibiting portion made of pure carbon is disposed on at least a part of the outer surface of the nozzle portion of the gas injection unit as a separate component from the gas injection unit.

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

[0071] (Second variation) As shown in Figure 4, the second modification differs from the first embodiment in that, in addition to the gas injection unit 20 being an adhesion inhibitor 22A which is a single element of carbon, it is equipped with a charge application device 40 which applies a charge 22C having the same polarity as the charge of the sputtered LS to the gas injection unit 20 as an adhesion inhibitor. That is, in the second modification, the adhesion of the sputtered LS to the gas injection unit 20 is further inhibited by electrical repulsion. In this disclosure, the combined use of an adhesion inhibitor that is a single element of carbon and an adhesion inhibitor with a charge of the same polarity as the charge of the sputtered LS is not essential. The charge adhesion inhibitor may be used alone.

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

[0073] Then, by applying a charge 22C equivalent to -10kV to the gas injection unit 20 using the charge application device 40, an electrical repulsive force against the sputtered LS is generated on the surface of the gas injection unit 20. It is preferable that the gas injection unit 20 be electrically insulated from the surrounding components to prevent short circuits. Other configurations in the second modified example are the same as in the first embodiment, so a redundant explanation is omitted.

[0074] (Effects of the second modification) In the second modified example, as in the first embodiment, the adhesion of sputtered 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, can be suppressed. Furthermore, in the second modified example, the laser processing apparatus is equipped with a charge application device 40 as an adhesion inhibiting unit, which applies a charge 22C with the same polarity as the charge of sputtered LS to the gas injection unit 20. That is, the adhesion inhibiting unit includes the charge application device 40. Since the adhesion of sputtered LS to the gas injection unit 20 is further inhibited by the electrical repulsive force, the effect of suppressing the adhesion of sputtered LS can be further improved. Other effects in the second modified example are the same as in the first embodiment.

[0075] (Third variation) As shown in Figure 5, the third modified example differs from the first embodiment in that the gas injection unit 20 is made of elemental carbon and is equipped with a coating supply device that supplies a coating agent to coat the sputtered LS. In other words, it differs from the first embodiment in that the adhesion of the sputtered LS to the gas injection unit 20 is further inhibited by supplying a coating agent to the sputtered 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 with one end connected to the coating agent source 52, and a supply nozzle 56 connected to the other end of the supply pipe 54.

[0077] (Coating agent) The coating agent in the first embodiment is in the form of sand or powder. Specifically, for example, a commercially available precoat agent used to prevent sparks during polishing work can be used as the coating agent. As a powdered precoat agent, for example, calcium carbonate or slaked lime (i.e., calcium hydroxide) can be used. In this disclosure, the coating agent is not limited to being in the form of sand or powder, and any shape and chemical composition can be adopted as long as it can cover the sputtered LS.

[0078] The coating agent is supplied towards the spatter LS that is ejected by the formation of grooves G. Specifically, it may be supplied towards the irradiation area SA where spatter LS is generated and its surroundings, or mainly towards the downstream side in the transport direction C from grooves G. By being coated with the coating agent, the spatter LS becomes 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 sputtered LS generated. Specifically, the supply flow rate of the coating agent may be set to the same amount as the amount of sputtered LS generated per unit time, or it may be set within a certain range relative to the amount of sputtered 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 sputtered LS generated per unit time.

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

[0081] Furthermore, it is preferable that the supply flow rate of the coating agent be less than or equal to the suction flow rate of the dust collection mechanism 30 by the suction pump P2, in order to avoid interference with the flow of the suction airflow. In this disclosure, it is not prohibited for the supply flow rate of the coating agent to exceed the suction flow rate of the dust collection mechanism. The other configurations in the third modified example are the same as in the first embodiment, so a redundant explanation will be omitted.

[0082] (Effects of the third modified example) In the third modification, as in the first embodiment, the adhesion of sputtered LS to the gas injection unit 20, which injects gas parallel to the optical axis direction of the laser beam LB toward the irradiation area SA of the laser beam LB, can be suppressed. Furthermore, in the third modification, the laser processing apparatus 1C is equipped with a coating agent supply device that supplies a coating agent to cover the sputtered LS. That is, the adhesion of sputtered LS to the gas injection unit 20 can be reduced by the amount that the sputtered LS is covered by the coating agent. Therefore, the effect of suppressing the adhesion of sputtered LS can be further improved. Other effects of the third modification are the same as in 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 of the first embodiment, the first modification, and the second modification described above, an even higher sputter adhesion suppression effect can be obtained. [Examples]

[0083] (Example 1) Next, Example 1, in which the adhesion rate of sputtered LS was measured using the laser processing apparatus 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 sputtered LS in Figure 6 is the ratio of the number of sputtered LS particles that reached the outer surface of the nozzle portion 21B of the gas injection unit 20, calculated in each of the first embodiment and the first to third modified examples, with the number of sputtered LS particles that reached the outer surface of the nozzle portion 21B of the gas injection unit 20 in the first comparative example being set to 1.

[0085] The gas injection section of the laser processing apparatus according to the first comparative example did not have an adhesion inhibiting section to inhibit sputter adhesion, which contained elemental carbon. Furthermore, the shape and dimensions of the laser processing apparatus according to the first comparative example, the first embodiment, and the first to third modified examples were the same. In Example 1, the thickness of the carbon plate 22B attached to the gas injection section 20 of the first modified example was approximately 1 mm.

[0086] In Example 1, computer simulation analysis was performed using Fluent, a commercially available numerical calculation software. First, analysis models corresponding to the laser processing apparatus 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 analysis models, an analysis equivalent to laser processing in which a steel plate is continuously irradiated with laser light LB for approximately 100 hours was performed. In each analysis model, the number of sputtered particles LS generated from the irradiation site SA was the same. Then, the number of sputtered particles LS that reached the outer surface of the nozzle of each gas injection unit from the irradiation site SA was calculated.

[0087] As shown in Figure 6, in the first embodiment, the amount of sputter deposited was reduced to about 1 / 10 compared to the first comparative example. In the first modified example, the amount of sputter deposited was reduced to the same level as in the first embodiment. In the second modified example, the amount of sputter LS deposited was reduced to about 1 / 20 compared to the first comparative example. In the third modified example, the amount of sputter deposited was reduced to about 1 / 40 compared to the first comparative example. Example 1 showed that when a carbon element adhesion inhibiting part is provided, the amount of sputter LS deposited can be significantly reduced compared to when a carbon element adhesion inhibiting part is not provided.

[0088] Furthermore, in Example 1, verification was conducted through laboratory testing. Specifically, experimental models corresponding to the laser processing apparatus of the first comparative example, the first embodiment, and the first to third modified examples were set up. Using each of the set up experimental models, laser processing was performed by continuously irradiating a steel plate with laser light LB for approximately 100 hours. In each experimental model, the weight increase of each part was measured and the amount of adhesion was calculated. The verification through laboratory testing yielded results similar to those obtained by the computer simulation analysis described above.

[0089] Next, the second and third embodiments will be described. Repetitive explanations of configurations in the second and third embodiments that are the same as those in the first embodiment will be omitted. The adhesion inhibiting portion provided in the gas injection portion 20 of the second embodiment and the modified version of the second embodiment corresponds to the first adhesion inhibiting portion of this disclosure.

[0090] <Second Embodiment> (Adhesion inhibiting part) As shown in Figure 7, the outer surface of the gas injection unit 20 of the laser processing apparatus 2 according to the second embodiment is provided with an adhesion inhibiting unit 22D containing copper to inhibit the adhesion of sputtered LS. Specifically, in the second embodiment, the entire gas injection unit 20 is formed as the adhesion inhibiting unit 22D by copper. "The entire gas injection unit 20" means, in other words, the main body of the air nozzle as the gas injection unit 20.

[0091] In the gas injection section 20, which is made of pure copper, the thermal conductivity is higher compared to gas injection sections that do not contain pure copper, such as those made of metals like steel or resin. Therefore, even if sputtered LS adheres to the outer surface of the nozzle section 21B, the temperature of the sputtered LS drops rapidly, and as a result, it is less likely to accumulate.

[0092] Furthermore, as shown in Figure 7, the box-shaped dust collection mechanism 30 has an upper top portion 31 above the dust collection port 30A and a lower bottom portion 32 below the dust collection port 30A. The inner surface of the top portion 31 in Figure 7 is illustrated with sputtered LS deposits A1 attached and accumulated. The end face of the bottom portion 32 in Figure 7 is illustrated with sputtered LS deposits A2 attached and accumulated. The outer surface of the nozzle portion 21B in Figure 7 is illustrated with sputtered LS deposits A3 attached and accumulated.

[0093] The inner surface of the top 31 in Fig. 7 is the highest from the steel plate S in the dust collection mechanism part 30. In Fig. 7, the height x from the steel plate S of the inner surface of the top 31 and the height y from the steel plate S of the upper end of the outer surface of the nozzle part 21B are illustrated. The height x from the steel plate S of the inner surface of the top 31 in Fig. 7 is larger than the height y from the steel plate S of the upper end of the nozzle part 21B. That is, x > y. For this reason, the flow of the gas sucked into the dust collection mechanism part 30 is promoted to head toward the dust collection mechanism part 30 by the inclined outer surface of the nozzle part 21B. In other words, the inclined outer surface of the nozzle part 21B guides the flow of the sucked gas.

[0094] Here, in the grooving where the depth of the groove G is about 10 μm to 50 μm, when an air knife having a flow velocity capable of scraping out sputter from the inside of the groove G on the surface of the steel plate is used, different from the present disclosure, chips which are particles having a size exceeding 100 μm as dust are likely to be generated. The chips are difficult to be cooled and are difficult to be superimposed on the air flow by the dust collection mechanism part 30, so they are likely to adhere to peripheral devices.

[0095] When the dust collection mechanism part is provided on both the upstream side and the downstream side of the laser beam irradiation part, and the height from the steel plate of the inner surface of the top of the dust collection mechanism part is larger than the height from the steel plate of the upper end of the nozzle part (in other words, in the state where x < y in Fig. 7), the flow of the gas sucked into the dust collection mechanism part 30 is difficult to be promoted to head toward the dust collection mechanism part 30.

[0096] On the other hand, in the second embodiment, the dust collection mechanism part 30 is provided only on the upstream side of the laser beam LB irradiation part SA in the conveyance direction C of the steel plate S, and the height x from the steel plate S of the inner surface of the top 31 is larger than the height y from the steel plate S of the upper end of the nozzle part 21B. For this reason, in the second embodiment, compared with the air knife, during continuous use of the laser processing apparatus, the deposition rate of the sputter LS on the nozzle part 21B and the dust collection mechanism part 30 is low. For example, in the case of a laser processing apparatus using an air knife without an adhesion inhibiting part, the deposition rate is about 10 mm / hour, while in the case of the second embodiment, the deposition rate can be suppressed to about 0.1 mm / hour.

[0097] Furthermore, in the second embodiment, compared to an air knife, the interval between maintenance operations to remove deposits that have adhered and accumulated from the nozzle section 21B and the dust collection mechanism section 30 during continuous use of the laser processing device is longer. For example, in the case of a laser processing device using an air knife without an adhesion inhibitor, the interval between maintenance operations is about 30 minutes, whereas in the case of the second embodiment, the interval between maintenance operations is about 3000 minutes. In other words, in the second embodiment, sputtering LS is less likely to come into contact with the nozzle section 21B and the dust collection mechanism section 30.

[0098] (Effects of the second embodiment) In the second embodiment, an adhesion inhibiting portion 22D containing copper particles is placed on the outer surface of the nozzle portion 21B of the gas injection unit 20 to inhibit the adhesion of sputtered LS. Here, the Disclosing Party has found that, as described in Embodiment 2 later, when the adhesion inhibiting portion 22D containing copper particles is placed on the outer surface of the nozzle portion 21B of the gas injection unit 20, the effect of suppressing the adhesion of sputtered LS generated from the irradiation site SA to the outer surface of the nozzle portion 21B is higher than when the adhesion inhibiting portion 22D is not placed. The sputtered 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 suppress the adhesion of sputtered LS to the outer surface of the nozzle portion 21B of the gas injection unit 20.

[0099] Furthermore, in the second embodiment, the adhesion inhibiting portion 22D is constructed by forming the entire gas injection portion 20 from a single piece of copper. As a result, the adhesion inhibiting portion 22D is arranged across the entire outer surface of the nozzle portion 21B. Therefore, there is no need to prepare a separate component for the adhesion inhibiting portion 22D from the gas injection portion 20.

[0100] (Fourth variation) As shown in Figure 8, the fourth modified example differs from the second embodiment in that the copper plate 22E, which is made of a single piece of copper and serves as an adhesion inhibitor, is arranged in the gas injection unit 20 as a separate component from the gas injection unit 20.

[0101] Specifically, the gas injection unit 20 of the laser processing apparatus 2A according to the fourth modified example differs from the gas injection unit 20 of the second embodiment, which is made of a single piece of copper, in that it is made of a metal such as steel or a resin. Furthermore, the adhesion inhibiting unit is a plate-shaped member arranged on a part of the surface of the gas injection unit 20. In this disclosure, the copper plate is not limited to being made of a single plate-shaped member. For example, the copper plate can be a single copper plate or an adhesion inhibiting unit made of a laminate of two or more copper plates, and can be used as the copper plate in this disclosure.

[0102] The copper plate 22E is placed on the outer surface of the nozzle portion 21B of the gas injection unit 20. However, in this disclosure, the placement position of the copper plate 22E is not limited to this, and it may be placed anywhere between the laser beam LB irradiation area SA and the gas injection unit 20. It is preferable that the copper plate 22E is placed 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 Figure 8, the copper plates 22E are arranged on the two outer surfaces of the nozzle portion 21B in the transport direction C, taking into consideration the ease with which sputter LS adheres to them. As shown in Figure 9, the copper plates 22E can be detachably attached to the outer surface of the nozzle portion 21B by a fastener 23. The fastener 23 in Figure 8 is a mechanical device such as a screw. It is not essential that the copper plates are arranged on the outer surface of the nozzle portion 21B in the width direction (left-right direction in Figure 9). Furthermore, in this disclosure, a combination of elemental carbon and elemental copper may be used to form the adhesion inhibiting portion. For example, the material of the fastener 23 that joins the copper plates 22E in Figure 8 may be made of elemental carbon.

[0104] (Effects of the fourth modification) In the fourth modified example, similar to the second embodiment, the adhesion of sputtered material 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 laser beam LB irradiation area SA, can be suppressed. Furthermore, in the fourth modified example, the adhesion inhibiting portion is a plate-shaped member disposed on a part of the surface of the gas injection unit 20. That is, a copper plate 22E made of solid copper, which serves as the adhesion inhibiting portion, is disposed 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. In this disclosure, it is sufficient that the adhesion inhibiting portion made of solid copper is disposed on at least a part 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 the adhesion inhibiting part to an existing gas injection unit 20 that does not have an adhesion inhibiting part. Also, since the adhesion inhibiting part is a separate part from the gas injection unit 20, it is easy to replace when damaged. Other effects and advantages of the fourth modified example are the same as those of the second embodiment.

[0106] (Fifth variation) As shown in Figure 10, the laser processing apparatus 2B according to the fifth modified example differs from the fourth modified example in that, in addition to having a copper plate 22E arranged on the outer surface of the nozzle portion 21B of the fourth modified example, it is further equipped with a peeling mechanism 22F as an additional adhesion inhibiting part. In this disclosure, the peeling mechanism 22F is not limited to being used in combination with another adhesion inhibiting part such as the copper plate 22E, but can be used as an adhesion inhibiting part on its own.

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

[0108] The drive unit 22F1 causes the movable plate 22F2 to reciprocate along the inclined outer surface of the nozzle portion 21B. In Figure 10, the lower end of the movable plate 22F2 approaches and moves away from the nozzle portion 21B. The movable plate 22F2 extends along 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 opposite to the drive unit 22F1 slides on the outer surface of the nozzle portion 21B, and as a result, the deposit A3 on the outer surface can be peeled off.

[0109] (Effects of the fifth modified example) In the fifth modification, as in the second embodiment, the adhesion of sputter 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 laser beam LB irradiation area SA, can be suppressed. Furthermore, in the fifth modification, the movable plate 22F2 reciprocates along the inclined outer surface of the nozzle portion 21B due to the peeling mechanism 22F, which acts as an additional adhesion inhibitor. As a result, the adhesion of sputter LS to the outer surface of the nozzle portion 21B of the gas injection unit 20 can be further suppressed. Other effects of the fifth modification are the same as in the second embodiment.

[0110] (Sixth variation) As shown in Figure 10, the laser processing apparatus 2B according to the sixth modified example differs from the fourth modified example in that, in addition to having a copper plate 22E arranged on the outer surface of the nozzle portion 21B of the fourth modified example, it is further equipped with a vibration device 22G as an additional adhesion inhibiting part. In this disclosure, the use of the vibration device 22G is not limited to combination with another adhesion inhibiting part such as the copper plate 22E, but can be used as an adhesion inhibiting part on its own.

[0111] The vibration-applying device 22G can be configured using, for example, a known vibrator. The vibration-applying device 22G may apply vibration by, for example, striking. The vibration-applying device 22G is mounted on the outer surface of the base 21A of the gas injection unit 20. In this disclosure, the number of vibration-applying devices is arbitrary and can be one or more. The mounting position of the vibration-applying device can also be changed as appropriate. In this disclosure, it is not essential that the vibration-applying device is mounted in a state where it is constantly in contact with the gas injection unit 20. The vibration-applying device may be positioned around the gas injection unit 20 at a distance from the gas injection unit 20. Although not shown in the figures, the vibration-applying device may have a movable part that can contact the gas injection unit as needed from a distance, and may apply vibration to the nozzle by striking the movable part or the like.

[0112] (Effects of the sixth modification) In the sixth modified example, as in the second embodiment, the adhesion of sputtered 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 laser beam LB irradiation site SA, can be suppressed. Furthermore, in the sixth modified example, the adhesion of sputtered LS to the outer surface of the nozzle portion 21B of the gas injection unit 20 can be further suppressed by the vibration device 22G, which acts as an additional adhesion inhibitor. Other effects of the sixth modified example are the same as in the second embodiment.

[0113] (Example 2) Next, Example 2, in which the adhesion rate of sputtered LS was measured using the laser processing apparatus 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 sputtered LS in Figure 12 is the ratio of the number of sputtered LS particles that reached the outer surface of the nozzle portion 21B of the gas injection unit 20, calculated in the second embodiment and the fourth to sixth modified examples, with the number of sputtered LS particles that reached the outer surface of the nozzle portion 21B of the gas injection unit 20 in the second comparative example being set to 1.

[0115] The gas injection section of the laser processing apparatus in the second comparative example did not contain a sputter adhesion inhibiting section containing pure copper to inhibit sputter adhesion. Furthermore, the shape and dimensions of the laser processing apparatus in the second comparative example, the second embodiment, and the fourth to sixth modified examples were the same. In Example 2, the thickness of the copper plate 22E attached to the gas injection section 20 of the fourth to sixth modified examples was approximately 1 mm.

[0116] In Example 2, verification was conducted through laboratory testing. First, experimental models corresponding to the laser processing apparatus of the second comparative example, the second embodiment, and the fourth to sixth modified examples were set up. Then, using each of the set up experimental models, laser processing was performed by continuously irradiating a steel plate with laser light LB for approximately 100 hours. In each experimental model, the weight increase of each part 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 compared to the second comparative example. Furthermore, in the fourth modified example, the amount of sputter adhesion was reduced to the same level as in the second embodiment. Furthermore, in the fifth modified example, the amount of sputter adhesion was reduced to about 1 / 20 compared to the second comparative example. Furthermore, in the sixth modified example, the amount of sputter adhesion was reduced to about 1 / 20 compared to the second comparative example. Example 2 showed that when a copper adhesion inhibiting part is provided, the amount of sputter LS can be significantly reduced compared to when a copper adhesion inhibiting part is not provided.

[0118] Next, the third embodiment will be described. In the third embodiment and the seventh to nineth modifications of the third embodiment, the laser processing apparatus 2A according to the fourth modification of the second embodiment differs from the second embodiment in that the dust collection mechanism 30 has a separate adhesion inhibiting unit for inhibiting the adhesion of sputtered LS to the dust collection mechanism 30, in addition to the adhesion inhibiting unit for inhibiting the adhesion of sputtered LS to the gas injection unit 20. For this reason, redundant explanations of the same configuration as the fourth modification of the second embodiment in the third embodiment will be omitted.

[0119] In this disclosure, it is not essential that the adhesion inhibiting unit for inhibiting the adhesion of sputtered LS to the dust collection mechanism 30 be used in combination with the adhesion inhibiting unit of the gas injection unit 20. The adhesion inhibiting unit for inhibiting the adhesion of sputtered LS to the dust collection mechanism 30 may be used without an adhesion inhibiting unit for inhibiting the adhesion of sputtered LS to the gas injection unit 20.

[0120] <Third Embodiment> (Adhesion inhibiting part) As shown in Figure 13, the outer surface of the dust collection mechanism 30 of the laser processing apparatus 2A according to the third embodiment is provided with an adhesion inhibiting portion 33A containing solid copper to inhibit the adhesion of sputtered LS. The adhesion inhibiting portions provided in the dust collection mechanism 30 of the third embodiment and the modified version of the third embodiment correspond to the second adhesion inhibiting portion of this disclosure. Specifically, in the third embodiment, the entire dust collection mechanism 30 is formed as an adhesion inhibiting portion 33A using solid copper. "The entire dust collection mechanism 30" means, in other words, the main body of the dust collection nozzle as the dust collection mechanism 30.

[0121] In the dust collection mechanism 30, which is made of pure copper, the thermal conductivity is higher compared to a dust collection mechanism that does not contain pure copper and is made of, for example, metal such as steel or resin. Therefore, even if sputtered LS adheres to the inner surface and end faces of the dust collection mechanism 30, the temperature of the sputtered LS drops rapidly, and as a result, it is less likely to accumulate. The inner surface and end faces of the dust collection mechanism 30 in the third embodiment correspond to the "surface of the dust collection mechanism" in which the adhesion of sputtered LS is inhibited by the second adhesion inhibiting part of this disclosure.

[0122] (Effects of the third embodiment) In the third embodiment, adhesion inhibiting portions 33A containing copper particles are arranged on the inner surface and end faces of the dust collection mechanism 30 to inhibit the adhesion of sputter LS. Here, the Discloser has found that, as described in Embodiment 3 later, when adhesion inhibiting portions containing copper particles are arranged on the inner surface and end faces of the dust collection mechanism 30, the effect of suppressing the adhesion of sputter LS generated from the irradiation site SA to the inner surface and end faces of the dust collection mechanism 30 is higher than when no adhesion inhibiting portions are arranged. According to the third embodiment, the adhesion inhibiting portions 33A can suppress the adhesion of sputter LS to the inner surface and end faces of the dust collection mechanism 30. As a result, the burden of maintenance work to remove the adhering material can be reduced.

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

[0124] (Seventh variation) As shown in Figure 8, the seventh modified example differs from the third embodiment in that the copper plate 33B, which is made of a single piece of copper and serves as an adhesion inhibitor, is arranged in the dust collection mechanism 30 as a separate component from the dust collection mechanism 30.

[0125] Specifically, the dust collection mechanism 30 of the laser processing apparatus 2A according to the seventh modified example differs from the dust collection mechanism 30 of the third embodiment, which is made of a single piece of copper, in that it is made of a metal such as steel or a resin. Furthermore, the adhesion inhibiting part is a plate-shaped member arranged on a part of the surface of the dust collection mechanism 30. In this disclosure, the copper plate is not limited to being made of a single plate-shaped member. For example, the copper plate can be a single copper plate or an adhesion inhibiting part made of a laminate of two or more copper plates, and can be used as the copper plate in this disclosure.

[0126] The copper plate 33B is placed on both the inner surface and the end face of the dust collection mechanism 30. In this disclosure, the placement of the copper plate 33B is limited to at least one of the inner surface and the end face of the dust collection mechanism 30. As shown in Figure 14, the copper plate 33B is placed on the inner surface of the dust collection mechanism 30 where deposits A1 adhere, and on the end face of the dust collection mechanism 30 where deposits A2 adhere. In Figure 14, an example is shown 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, but this disclosure is not limited to this. It is also not ruled out that a step may be formed between the surface of the copper plate and the surface of the dust collection mechanism 30.

[0127] (Effects of the seventh modified example) In the seventh modified example, the adhesion inhibiting portion is a plate-shaped member arranged on a part of the surface of the dust collection mechanism 30. That is, a copper plate 33B, which is made of a single piece of copper and serves as the adhesion inhibiting portion, is arranged on both the inner surface and the end face of the dust collection mechanism 30 as a separate component from the dust collection mechanism 30. For this reason, it is easy to separately attach the adhesion inhibiting portion to an existing dust collection mechanism 30 that does not have one. Other effects and advantages of the seventh modified example are the same as in the third embodiment.

[0128] (Variation 8) As shown in Figure 15, the laser processing apparatus 2A according to the eighth modified example differs from the seventh modified example in that, in addition to having copper plates 33B arranged on the inner surface and end face of the dust collection mechanism 30, it further includes a first peeling mechanism 33C and a second peeling mechanism 33D as additional adhesion inhibiting parts. In this disclosure, the use of the first peeling mechanism 33C and the second peeling mechanism 33D is not limited to combination with other adhesion inhibiting parts such as copper plates 33B, but can each be used as an adhesion inhibiting part on its own.

[0129] (First peeling mechanism) As shown in Figures 16 and 17, the first peeling mechanism 33C comprises a drive unit 34A, a shaft 34B, a connecting unit 34C, a movable plate 34D, and a support unit 34E. As shown in Figure 17, the dust collection mechanism 30 is L-shaped. The suction airflow DF enters the inside of the dust collection mechanism 30 from the dust collection port 30A and then moves upward from the periphery of the left side wall 30B, which is opposite the right dust collection port 30A in Figure 17.

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

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

[0132] The drive unit 34A and shaft 34B can be composed of known linear motion mechanisms, 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 in Figure 17 of the dust collection mechanism 30 via the shaft 34B and the connecting portion 34C. The right end of the movable plate 34D in Figure 17 is movable outward, further to the right of the dust collection port 30A. In a standby state where no maintenance work to remove attached materials is performed, the right end of the movable plate 34D in Figure 17 is separated from the dust collection port 30A. The standby distance C1 of the movable plate 34D is illustrated in Figure 17.

[0133] As shown in Figure 19, when the drive unit 34A moves the shaft 34B to the right, the connecting part 34C moves to the right within the slit 31A in conjunction with the shaft 34B. As shown in Figure 20, in conjunction with the movement of the connecting part 34C, the right end of the movable plate 34D slides on the inner surface of the top 31 of the dust collection mechanism 30. The sliding pushes the deposits A1 on the inner surface outwards through the dust collection port 30A, thereby removing the deposits A1. Figure 20 illustrates the extrusion distance C2 of the movable plate 34D.

[0134] (Second peeling mechanism) As shown in Figures 21 and 22, the second peeling mechanism 33D comprises a drive unit 34A, a shaft 34B, a connecting 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 unit 30 in Figure 22. As shown in Figure 21, the movable plate 34D1 extends along the width direction. As shown in Figure 22, 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 34D1.

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

[0136] The drive unit 34A and shaft 34B can be composed of known linear motion mechanisms, 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 in Figure 22 of the dust collection mechanism 30 via the shaft 34B and the connecting part 34C. The right end of the movable plate 34D1 in Figure 22 is movable outward, further to the right of the dust collection port 30A. In the standby state when maintenance work to remove attached materials is not performed, the right end of the movable plate 34D1 in Figure 22 is away from the dust collection port 30A. The standby distance D1 of the movable plate 34D1 is illustrated in Figure 22.

[0137] As shown in Figure 24, when the drive unit 34A moves the shaft 34B to the right, the connecting part 34C moves to the right in conjunction with the shaft 34B. As shown in Figure 25, in conjunction with the movement of the connecting part 34C, the right end of the movable plate 34D1 protrudes outward from the end face of the bottom 32 of the dust collection mechanism 30. Due to the sliding, the deposits A2 on the end face are pushed outward from the position of the dust collection port 30A, and as a result, the deposits A2 can be removed. Figure 25 illustrates the extrusion distance D2 of the movable plate 34D1.

[0138] (Effects of the eighth modification) In the eighth modified example, the movable plate reciprocates along the surface of the dust collection mechanism 30 due to the first peeling mechanism 33C and the second peeling mechanism 33D acting as additional adhesion inhibitors. This further suppresses the adhesion of sputter LS to the inner surface and end face of the dust collection mechanism 30. Other effects of the eighth modified example are the same as those of the second embodiment.

[0139] (9th variation) As shown in Figure 26, the laser processing apparatus 2A according to the ninth modified example differs from the seventh modified example in that, in addition to having copper plates 33B arranged on the inner surface and end face of the dust collection mechanism 30, it further includes a vibration device 33E as an additional adhesion inhibiting part. In this disclosure, the use of the vibration device 33E is not limited to combination with another adhesion inhibiting part such as the copper plates 33B, but can be used as an adhesion inhibiting part on its own.

[0140] The vibration-applying device 33E can be configured using, for example, a known vibrator. The vibration-applying device 33E may apply vibration by, for example, striking. The vibration-applying device 33E is mounted on the outer surface of the top 31 of the dust collection mechanism 30. In this disclosure, the number of vibration-applying devices is arbitrary, one or more. The mounting position of the vibration-applying device can also be changed as appropriate. In this disclosure, it is not essential that the vibration-applying device is mounted in a state of constant contact with the dust collection mechanism 30. The vibration-applying device may be positioned around the dust collection mechanism 30 at a distance from the dust collection mechanism 30. Although not shown in the figures, the vibration-applying device may have a movable part that can contact the dust collection mechanism as needed from a distance, and may apply vibration to the nozzle by striking the movable part or the like.

[0141] (Effects of the 9th modification) In the ninth modified example, the vibration device 33E, which acts as an additional adhesion inhibitor, can further suppress the adhesion of sputter LS to the inner surface and end face of the dust collection mechanism 30. Other effects of the ninth modified example are the same as those of the third embodiment.

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

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

[0144] The dust collection mechanism of the laser processing apparatus in the third comparative example did not have an adhesion inhibiting part to inhibit sputter adhesion, which contained solid copper. Furthermore, the shape and dimensions of the laser processing apparatus in the third comparative example, the third embodiment, and the seventh to ninth modified examples were the same. In Example 3, the thickness of the copper plate 33B attached to the dust collection mechanism 30 of the seventh to ninth modified examples was approximately 1 mm.

[0145] In Example 3, verification was conducted through laboratory testing. First, experimental models corresponding to the laser processing apparatus of Comparative Example 3, Embodiment 3, and Modifications 7 to 9 were set up. Then, using each of the set up experimental models, laser processing was performed by continuously irradiating a steel plate with laser light LB for approximately 100 hours. In each experimental model, the weight increase of each part 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 compared to the third comparative example. Furthermore, in the seventh modified example, the amount of sputter adhesion was reduced to the same level as in the third embodiment. Furthermore, in the eighth modified example, the amount of sputter adhesion was reduced to about 1 / 20 compared to the third comparative example. Furthermore, in the ninth modified example, the amount of sputter adhesion was reduced to about 1 / 20 compared to the third comparative example. Example 3 showed that when a copper adhesion inhibiting part is provided, the amount of sputter LS can be significantly reduced compared to when a copper adhesion inhibiting part is not provided.

[0147] <Other Embodiments> Although this disclosure has been described by the embodiments disclosed above, the descriptions and drawings that constitute part of this disclosure should not be understood as limiting this disclosure. It should be expected that various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art from this disclosure.

[0148] For example, the present disclosure can be constructed by partially combining the configurations illustrated in the attached drawings. As described above, this disclosure includes various embodiments not described above, and the technical scope of this disclosure is determined solely by the inventive features of the claims that are reasonable from the above description.

[0149] ≪Note≫ The following embodiments are conceptualized herein.

[0150] Embodiment 1 is, A gas injection unit that injects gas from an opening toward the laser beam irradiation area on the surface of a steel plate, the nozzle unit having an outer surface that slopes toward the center of the opening from the outside of the opening in a direction parallel to the surface of the steel plate as it moves toward the opening from the opposite side of the opening in the injection direction, and a first adhesion inhibiting part for inhibiting the adhesion of laser sputter is disposed on at least a part of the outer surface of the nozzle unit. A laser processing device equipped with the following features.

[0151] Embodiment 2 is, The first adhesion inhibiting portion includes elemental carbon or elemental copper. A laser processing apparatus according to Embodiment 1.

[0152] Embodiment 3 is, The first adhesion inhibiting portion is configured such that the entire gas injection portion, including the nozzle portion, is formed from a single element of carbon or a single element of copper. A laser processing apparatus according to embodiment 2.

[0153] Appearance 4 is, The first adhesion inhibiting portion is a plate-shaped member disposed on at least a portion of the outer surface of the nozzle portion of the gas injection portion. A laser processing apparatus according to embodiment 2.

[0154] Embodiment 5 is, The first adhesion inhibiting unit includes a charge application device that applies a charge of the same polarity as the charge of the laser sputtering to the gas injection unit. A laser processing apparatus according to any one of embodiments 1 to 4.

[0155] Embodiment 6 is, The system includes a coating supply device that supplies a coating agent to cover the laser sputtered area. A laser processing apparatus according to any one of embodiments 1 to 5.

[0156] Embodiment 7 is, The gas injection unit injects the gas parallel to the optical axis direction of the laser beam. A laser processing apparatus according to any one of embodiments 1 to 6.

[0157] Embodiment 8 is, A conveying roll that conveys steel plates in a predetermined conveying direction, A laser light source unit that irradiates the surface of the steel plate being transported in the transport direction with the laser light, It also has, A laser processing apparatus according to any one of embodiments 1 to 7.

[0158] Embodiment 9 is, The device comprises a dust collection mechanism provided either upstream or downstream of the irradiation site in the aforementioned transport direction, which collects the laser sputter from a dust collection port. A laser processing apparatus as described in aspect 8.

[0159] Embodiment 10 is, The dust collection mechanism is provided with a second adhesion inhibiting part for inhibiting the adhesion of the laser sputter to the surface of the dust collection mechanism. A laser processing apparatus as described in aspect 9.

[0160] Embodiment 11 is, A laser beam is shone onto the surface of the steel plate, A gas injection unit is used to inject gas from the opening toward the irradiation site in such a way that the laser sputter generated from the irradiation site of the laser beam is lifted away from the surface of the steel plate, using a nozzle unit having an outer surface that slopes toward the center of the opening in a direction parallel to the surface of the steel plate, moving from the opposite side of the opening toward the side of the opening in the injection direction, and having an adhesion inhibiting part disposed on at least a part of the outer surface of the nozzle unit to inhibit the adhesion of laser sputter, and gas is injected from the opening toward the irradiation site in such a way that the laser sputter generated from the irradiation site of the laser beam is lifted away from the surface of the steel plate. Laser processing method.

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

[0162] Another embodiment 1 is: A laser light source unit that irradiates laser light onto the surface of a steel plate being transported in a predetermined transport direction, A gas injection unit that injects gas parallel to the optical axis direction of the laser beam toward the laser beam irradiation area, the gas injection unit having an adhesion inhibiting part on its surface that contains elemental carbon and inhibits the adhesion of laser sputtering, A laser processing device equipped with the following features.

[0163] Another embodiment 2 is, The adhesion inhibiting portion is constructed such that the entire gas injection portion is formed from carbon alone. A laser processing apparatus according to Embodiment 1.

[0164] Another embodiment 3 is, The adhesion inhibiting portion is a plate-shaped member arranged on a part of the surface of the gas injection portion. A laser processing apparatus according to Embodiment 1.

[0165] Another embodiment 4 is, The system includes a charge application device that applies a charge of the same polarity as the charge of the laser sputtering to the gas injection section. A laser processing apparatus according to any one of embodiments 1 to 3.

[0166] Another embodiment 5 is, The device includes a coating agent adding apparatus for adding a coating agent to cover the laser sputtered surface. A laser processing apparatus according to any one of embodiments 1 to 4.

[0167] Another embodiment 6 is, Using a laser light source, laser light is irradiated onto the surface of a steel plate being transported in a predetermined transport direction. Using a gas injection unit with an adhesion-inhibiting portion containing elemental carbon and positioned on its surface to inhibit the adhesion of laser sputter, the gas is injected parallel to the optical axis direction of the laser beam toward the laser beam irradiation area, thereby lifting the laser sputter generated from the irradiation area away from the surface of the steel plate. Laser processing method.

[0168] In another embodiment, the dust collection efficiency of laser sputtering can be increased, and the adhesion of laser sputtering can be prevented across the width of the plate.

[0169] The disclosure of Japanese Patent Application No. 2023-149623, filed on 14 September 2023, is incorporated herein by reference in its entirety. Furthermore, 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 had been specifically and individually indicated as being incorporated by reference.

[0170] 1.1A~1C Laser Processing Equipment 2.2A~2C Laser Processing Equipment 10 Laser light source unit 12. Ejection section 20 Gas injection unit 20A Gas 21A base 21B Nozzle section 21B1 Aperture 22A Adhesion inhibiting section (first adhesion inhibiting section) 22B Carbon plate (first adhesion inhibiting part) 22C charge (first adhesion inhibiting part) 22D Adhesion inhibiting portion (first adhesion inhibiting portion) 22E Copper plate (first adhesion inhibiting part) 23 Joints 24 Air supply duct 22F Peeling mechanism (first adhesion inhibition section) 22F1 Drive Unit 22F2 Movable plate 22G vibration Granting device (First adhesion inhibiting part) 33A Adhesion inhibiting section (second adhesion inhibiting section) 33B Copper plate (second adhesion inhibiting part) 33C First detachment mechanism (second adhesion inhibition part) 33D Second detachment mechanism (second adhesion inhibition part) 34A Drive Unit 34B shaft 34C connector 34D movable plate 34E Support part 30 Dust collection mechanism section 30A Dust Collection Port 30B side wall 31 Top 31A Slit 32 Bottom 33E Vibration Granting device (Second adhesion inhibiting part) 34 Dust collection duct 40 Charge application device 42 Power supply 44 Electric wire 50 Coating agent supply device 52 Coating agent source 54 Supply piping 56 Supply nozzle 90 Ceiling panels A1-A3 Adhering substances C Conveying direction C1 Standby distance C2 Extrusion distance D1 Waiting distance D2 Extrusion distance DF suction airflow G groove LB laser light LS sputtering (laser sputtering) P1 Air supply pump P2 Suction Pump R Conveyor 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 section of the gas injection unit

Claims

1. A laser processing apparatus for forming grooves with a depth of 10 μm to 50 μm on the surface of a conveyed grain-oriented electrical steel sheet, A gas injection unit that injects gas from an opening toward the laser beam irradiation area on the surface of the grain-oriented electrical steel sheet, It comprises a first adhesion inhibiting unit for inhibiting the adhesion of laser sputtering, The gas injection unit has a nozzle portion having an outer surface that is inclined in a direction parallel to the surface of the grain-oriented electrical steel sheet, moving from the opposite side of the opening in the injection direction toward the side of the opening, so as it moves toward the side of the opening, it moves toward the center of the opening from the outside of the opening. The first adhesion inhibiting portion is arranged on at least a part of the outer surface of the nozzle portion, The first adhesion-inhibiting portion is a plate-shaped member comprising elemental carbon or elemental copper, disposed on at least a portion of the outer surface of the nozzle portion of the gas injection portion, and the plate-shaped member is detachably attached to the outer surface of the nozzle portion by a fastener. Laser processing equipment.

2. The first adhesion inhibiting portion is configured such that the entire gas injection portion, including the nozzle portion, is formed from a single element of carbon or a single element of copper. The laser processing apparatus according to claim 1.

3. The first adhesion inhibiting unit includes a charge application device that applies a charge of the same polarity as the charge of the laser sputtering to the gas injection unit. The laser processing apparatus according to claim 1 or 2.

4. The system includes a coating supply device that supplies a coating agent to cover the laser sputtered area. The laser processing apparatus according to claim 1 or 2.

5. The gas injection unit injects the gas parallel to the optical axis direction of the laser beam. The laser processing apparatus according to claim 1 or 2.

6. A conveying roll that conveys grain-oriented electrical steel sheets in a predetermined conveying direction, A laser light source unit that irradiates the surface of the grain-oriented electrical steel sheet being transported in the transport direction with the laser light, It also has, The laser processing apparatus according to claim 1 or 2.

7. The device comprises a dust collection mechanism provided either upstream or downstream of the irradiation site in the aforementioned transport direction, which collects the laser sputter from a dust collection port. The laser processing apparatus according to claim 6.

8. The dust collection mechanism is provided with a second adhesion inhibiting part for inhibiting the adhesion of the laser sputter to the surface of the dust collection mechanism. The laser processing apparatus according to claim 7.

9. A laser processing method for forming grooves with a depth of 10 μm to 50 μm on the surface of a conveyed grain-oriented electrical steel sheet, The surface of the grain-oriented electrical steel sheet is irradiated with laser light, A gas injection unit is used which has a nozzle portion having 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 grain-oriented electrical steel sheet, with the nozzle portion having an outer surface that slopes toward the center of the opening in a direction parallel to the surface of the grain-oriented electrical steel sheet, and an adhesion inhibiting portion containing a single element of carbon or a single element of copper for inhibiting the adhesion of laser sputter is disposed on at least a part of the outer surface of the nozzle portion, and gas is injected from the opening toward the irradiation site so as to lift the laser sputter generated from the irradiation site of the laser beam away from the surface of the grain-oriented electrical steel sheet. The adhesion inhibiting portion is a plate-shaped member disposed on at least a portion of the outer surface of the nozzle portion of the gas injection portion, and the plate-shaped member is detachably attached to the outer surface of the nozzle portion by a fastener. Laser processing method.

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