Laser treatment method

Abstract

To prevent complication of a configuration of a laser irradiation unit due to measures against a scattering material generated during surface processing with laser light.SOLUTION: A collection device 20 for laser processing comprises: a collection case 21 that is a case formed separately from a laser radiation unit 32 for irradiating a surface to be processed 5 with laser light L, and separating the surface 5 to be processed and the laser radiation unit 32 from each other during surface processing on land, the collection case having an opening 13 formed on one side thereof, being provided with transparent panels 11, 12 facing the opening 13, and, in an installation state in which the opening 13 is closed and the surface 5 to be processed is covered, enabling surface processing in which the surface 5 to be processed is irradiated with the laser light L from the laser radiation unit 32 through the transparent panels 11, 12; and a suction device 22 that sucks air inside the collection case 21 in the installation state to thereby suck a scattering material generated during surface processing.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a recovery device for laser treatment used in surface treatment with laser light. [Background technology]

[0002] Some structures, such as bridges and tanks, have a paint film covering the surface of the base material, such as steel. This type of structure requires periodic repainting of the paint film. When repainting the paint film, the existing paint film must be removed. Methods for removing the paint film have been widely used, including cleaning with chemicals such as organic solvents and acids, high-pressure washing with water, and surface treatment methods such as sandblasting. However, environmental regulations have become stricter in recent years, making it difficult to clear these environmental regulations using these methods. In this context, laser cleaning has attracted attention as a new method for removing paint films.

[0003] Patent Document 1 describes a laser coating removal device. The laser head of this laser coating removal device includes an optical system that scans the irradiation point of the laser light, a shielding member that protects the optical system from debris generated from the surface of the structure, and an attachment that is configured to be able to abut against the surface of the structure. The laser head is provided with a suction means. Debris scattered by the irradiation of the laser light is collected through a suction port of the suction means, and some of the debris is attracted toward the optical system. In this laser head, the optical system is protected from debris by the shielding member. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5574354 Summary of the Invention [Problem to be solved by the invention]

[0005] In the conventional device, a shielding member is provided as a measure to prevent debris generated during surface treatment with laser light (laser cleaning, etc.) from adhering to the optical system of the laser irradiation unit. However, the configuration of the laser irradiation unit becomes more complicated by the provision of the shielding member.

[0006] The present invention has been made in consideration of the above circumstances, and aims to prevent the configuration of the laser irradiation unit from becoming complicated due to measures against scattered debris that occurs during surface treatment using laser light. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, the first invention is a recovery device for laser treatment that recovers scattered material generated during surface treatment with laser light, the recovery device being a case formed separately from a laser irradiation section for irradiating laser light onto the surface to be treated and separating the surface to be treated from the laser irradiation section during surface treatment on land, with an opening formed on one side and a transparent panel provided facing the opening, and in an installed state that blocks the opening and covers the surface to be treated, the recovery case is in a state where surface treatment can be performed by irradiating laser light from the laser irradiation section through the transparent panel onto the surface to be treated, and a suction device that sucks in air from inside the recovery case in the installed state, thereby sucking in scattered material generated during surface treatment, and adsorbs the recovery case to the blocking surface that blocks the opening.

[0008] In the second invention, in the first invention, the surface to be treated is a wall surface, and when the recovery case is installed with its opening blocked by the surface to be treated, the internal space is sealed, and when the air inside the recovery case in the installed state is sucked in by the suction device, the recovery case is fixed to the surface to be treated without falling, solely by the suction force that adsorbs the recovery case to the surface to be treated.

[0009] In a third aspect of the present invention, in the second aspect of the present invention, the recovery case has a magnet provided on the edge of the opening to assist the adsorptive force.

[0010] In a fourth aspect of the present invention, in the first aspect of the present invention, the recovery case has an air vent for introducing air from the outside into the internal space during surface treatment.

[0011] In the fifth invention, in the first invention, the collection case is formed into a flat box shape, and in addition to the main surface facing the opening, a transparent panel is also provided on the side extending from the periphery of the main surface toward the opening side.

[0012] In a sixth aspect of the present invention, in the first aspect of the present invention, the recovery case has a gas inlet connected to a gas supply device, and a gas outlet through which gas supplied from the gas supply device to the gas inlet is discharged toward the surface to be treated.

[0013] A seventh invention is a laser processing system comprising a recovery device for laser processing of any one of the first to sixth inventions, and a laser irradiation device having a laser irradiation unit and a laser oscillator that oscillates laser light toward the laser irradiation unit.

[0014] According to an eighth aspect of the present invention, in the seventh aspect of the present invention, the apparatus further comprises a liquid ejection device that ejects a liquid for wetting the treatment target surface before removing the coating as the surface treatment.

[0015] The ninth invention is a laser treatment method for performing surface treatment using laser light, which includes a step of installing a collection case that is formed separately from a laser irradiation section for irradiating laser light onto the surface to be treated, and has an opening formed on one side and a transparent panel facing the opening, and when performing surface treatment on land, the recovery case is installed in a state in which the opening is blocked and the surface to be treated is covered, thereby separating the surface to be treated and the laser irradiation section by the recovery case, making it possible to perform surface treatment by irradiating laser light from the laser irradiation section to the surface to be treated through the transparent panel, and a surface treatment step of performing surface treatment after the case installation step and sucking up any scattered material in the collection case by a suction device. Effect of the Invention

[0016] In the first invention, in the installed state where the opening is closed and the surface to be treated is covered, the surface to be treated can be irradiated with laser light from a laser irradiation unit separate from the collection case through a transparent panel for surface treatment. In addition, the air inside the collection case in the installed state is sucked in by a suction device, so that scattered objects generated during surface treatment are sucked in. Therefore, almost no scattered objects reach the laser irradiation unit outside the collection case. Therefore, it is possible to prevent the configuration of the laser irradiation unit from becoming complicated due to measures against scattered objects.

[0017] In the ninth invention, a case installation step is performed to close the opening and install the collection case in a state where it covers the surface to be treated, thereby separating the surface to be treated from the laser irradiation unit by the collection case, and enabling surface treatment in which the laser irradiation unit separate from the collection case irradiates the surface to be treated with laser light through a transparent panel. Then, in a surface treatment step after the case installation step, surface treatment is performed using laser light, and scattered matter in the collection case is sucked up by a suction device. Therefore, almost no scattered matter reaches the laser irradiation unit outside the collection case. Therefore, it is possible to prevent the configuration of the laser irradiation unit from becoming complicated due to measures against scattered matter. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a schematic configuration diagram of a laser processing system according to an embodiment. [Diagram 2] FIG. 2 is a perspective view of a recovery case of the laser processing system according to the embodiment. [Diagram 3] FIG. 3(a) is a top view of a recovery case of the laser processing system according to the embodiment (top view of the state of FIG. 2), and FIG. 3(b) is a bottom view of the recovery case. [Figure 4] 4(a) is a cross-sectional view of the recovery case of FIG. 3(a) taken along line AA, and FIG. 4(b) is a cross-sectional view of the recovery case of FIG. 3(a) taken along line BB. [Diagram 5] FIG. 5(a) is a diagram illustrating a case installation step of the laser processing method according to the embodiment, and FIG. 5(b) is a diagram illustrating a surface treatment step. [Figure 6] FIG. 6 is a diagram showing how surface treatment (laser cleaning) is performed on the surfaces of the members contained in the collection case 21. [Figure 7] Figure 7(a) is a top view of the recovery case of the laser processing system of the embodiment when a panel mounting portion is provided, Figure 7(b) is a CC cross-sectional view of the recovery case of Figure 7(a), and Figure 7(c) is an enlarged view for explaining the switching between the first and second states of the panel mounting portion. [Figure 8] FIG. 8(a) is a bottom view of a recovery case of a laser processing system according to a first modified example of the embodiment, and FIG. 8(b) is a DD cross-sectional view of the recovery case of FIG. 8(a). [Figure 9] FIG. 9(a) is a schematic diagram of a recovery case and other components of a laser processing system according to a second modified example of the embodiment, and FIG. 9(b) is a diagram showing a surface treatment step using the recovery case of FIG. 9(a). [Figure 10]FIG. 10 is a diagram showing a recovery case of a laser processing system according to a third modified example of the embodiment, seen from the side, illustrating a state of a liquid spraying step. [Figure 11] Figure 11 is a photograph confirming that wetting the surface to be treated before laser cleaning results in a clean base material after laser cleaning. [Figure 12] FIG. 12 is a top view of a laser processing system according to a fourth modified example of the embodiment, in which the recovery case is installed on a wall surface. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Note that the following embodiment is merely an example of the present invention, and is not intended to limit the scope of the present invention, its applications, or its uses.

[0020] [Laser processing system configuration] This embodiment is a laser processing system 10 used for laser cleaning (surface treatment by laser light) for removing coatings (paint, rust, asbestos, salt, etc.) on the surface of a base material in a structure or the like. As shown in FIG. 1, the laser processing system 10 includes a recovery device for laser processing 20 and a laser irradiation device 30. The recovery device for laser processing 20 includes a recovery case 21 that is installed so as to cover a surface 5 to be treated of a structure such as a bridge, a tank, an elevated railway / road, or a mechanical facility, and the laser irradiation device 30 includes a laser irradiation head 32 that is separate from the recovery case 21. In the laser processing system 10, the laser irradiation head 32 can be freely moved by an operator or a manipulator outside the recovery case 21 that covers the surface 5 to be treated, and the laser light L from the laser irradiation head 32 is irradiated onto the surface 5 to be treated through the transparent panels 11 and 12 of the recovery case 21. The laser processing system 10 can also be used for surface treatment by laser light (for example, laser welding) other than laser cleaning. The laser processing system 10 will now be described in detail.

[0021] <Configuration of the laser processing recovery device> 1, the recovery device 20 for laser processing includes a recovery case 21 having an opening 13 formed on one side and transparent panels 11, 12 provided to face the opening 13, and a suction device 22 connected to the recovery case 21 via a suction hose 23. The suction device 22 operates by receiving power from a power source (not shown) such as a generator. A vacuum pump can be used as the suction device 22.

[0022] The recovery case 21 is formed separately from the laser irradiation head (laser irradiation unit) 32 for irradiating the treatment surface 5 with laser light, and is a case that separates the treatment surface 5 from the laser irradiation head 32 during laser cleaning on land. As shown in Figs. 2 to 4, the recovery case 21 is formed in a substantially rectangular parallelepiped shape with an opening 13 on one side. In the recovery case 21, five sides other than the opening 13 side are composed of transparent panels 11 and 12. The recovery case 21 has a main panel 11 provided on the main surface facing the opening 13, and side panels 12 provided on four side surfaces extending from the periphery of the main surface to the opening 13 side. In the following, the main panel 11 side may be referred to as the "top side" and the opening 13 side may be referred to as the "bottom side" based on the installation state of the recovery case 21 shown in Fig. 2.

[0023] Regarding the more specific shape of the collection case 21, the collection case 21 is formed flat. Each side panel 12 extends approximately perpendicularly from each of the four sides of the main surface. The height of each side panel 12 is shorter than any side of the main panel 11, and the area of ​​the main panel 11 is the largest among the five transparent panels 11, 12. Regarding the dimensions of the main surface of the collection case 21, the length of each side can be 25 cm or more and 100 cm or less (preferably 50 cm or less). In addition, the shape of the main surface of the collection case 21 may be a square, a rectangle, or a shape other than a rectangle.

[0024] In the recovery case 21, the transparent panels 11, 12 are attached to rectangular portions of a frame 14 that is a substantially rectangular parallelepiped. In the recovery case 21, a flexible seal member 15 is provided on the opening side frame 14a that constitutes the edge portion 13e of the opening 13. The seal member 15 is provided around the entire periphery of the opening side frame 14a. The seal member 15 can be made of rubber or the like.

[0025] The recovery case 21 has an exhaust port 24 to which the suction hose 23 is connected. In this embodiment, the exhaust port 24 is formed in one of the side panels 12 of the recovery case 21. The exhaust port 24 may also be disposed in the main panel 11.

[0026] The collection case 21 has an air vent 25 for introducing air from the outside into the internal space 21s during laser cleaning. In this embodiment, a plurality of air vents 25 are provided in the side panel 12 facing the side panel 12 in which the exhaust port 24 is provided. The plurality of air vents 25 are arranged at intervals in the longitudinal direction of the side panel 12. Each air vent 25 is a small hole smaller than the exhaust port 24. No piping is connected to each air vent 25, and air near the outer surfaces of the transparent panels 11 and 12 is introduced through each air vent 25. The plurality of air vents 25 may be arranged separately in the plurality of side panels 12. The air vent 25 may be arranged in the main panel 11, or the seal member 15 may be partially omitted to form a gap as the air vent 25.

[0027] In the installation state where the recovery case 21 closes the opening 13 and covers the treatment target surface 5, the laser irradiation head 32 irradiates the treatment target surface 5 with laser light through the transparent panels 11 and 12, enabling surface treatment. For example, when the treatment target surface 5 is a substantially flat wall surface, the blocking surface that blocks the opening 13 is the treatment target surface 5. When the recovery case 21 is installed, the edge 13e of the opening 13 is placed against the treatment target surface 5, and the entire circumference of the seal member 15 is brought into close contact with the treatment target surface 5, thereby sealing the internal space 21s of the recovery case 21. In this specification, the "sealed state" includes a state in which a small amount of air flows between the inside and outside of the recovery case 21 through each of the small ventilation holes 25.

[0028] The suction device 22 is used to create a substantial vacuum in the internal space 21s of the collection case 21 when the collection case 21 is installed and fixed on the treatment target surface 5. The suction device 22 is also used to suck up scattered matter S inside the collection case 21 during laser cleaning.

[0029] For example, in the case where the surface to be treated 5 is a wall surface (e.g., a vertical surface) extending vertically, when the recovery case 21 is installed on the surface to be treated 5, the suction device 22 sucks the air in the recovery case 21 in the installed state in which the edge 13e of the opening 13 is in contact with the surface to be treated 5 so that the internal space 21s is in a sealed state, so that the recovery case 21 is fixed to the surface to be treated 5 blocking the opening 13 without falling due to gravity. This generates an adsorption force P that adsorbs the recovery case 21 to the surface to be treated 5. That is, when the air in the recovery case 21 is sucked by the suction device 22, the pressure in the internal space 21s of the recovery case 21 decreases, and the internal space 21s of the recovery case 21 becomes substantially in a vacuum state, and thus an adsorption force P sufficient to prevent the recovery case 21 from falling due to gravity is obtained. The recovery device 20 for laser processing is configured to be able to fix the recovery case 21 to a vertical wall surface only by this adsorption force P.

[0030] The recovery device for laser processing 20 according to this embodiment is used not only for a wall surface but also for a bottom surface or a slope as the surface 5 to be treated (see FIG. 6). In this case as well, the suction device 22 suctions air from within the recovery case 21, generating an adsorption force P that adsorbs the recovery case 21 to the surface 5 to be treated, and the recovery case 21 is fixed to the surface 5 to be treated.

[0031] <Configuration of laser irradiation device> As shown in Fig. 1, the laser irradiation device 30 includes a laser oscillator 31 that oscillates a laser beam, and a laser irradiation head 32 for emitting the laser beam L oscillated from the laser oscillator 31. The laser irradiation device 30 operates by receiving power from a power source (not shown) such as a generator. The laser oscillator 31 is a type of oscillator that performs pulse oscillation to oscillate a laser beam with a predetermined pulse width. The laser oscillator 31 is connected to the laser irradiation head 32 via a transmission line 33 such as a fiber cable for laser transmission.

[0032] The laser irradiation head 32 includes a casing 35 having a connection port 35a to which the transmission line 33 is connected and an exit window (e.g., a lens) 35b through which the laser light L supplied from the laser oscillator 31 via the transmission line 33 is emitted. The casing 35 incorporates a scanning optical system for scanning the laser light L, a focusing optical system for focusing the laser light L on the processing target surface 5, and the like (not shown). In addition, the outer surface of the casing 35 is provided with a handle 36 to be held by an operator, an operation switch (not shown), and the like.

[0033] [How to use the laser processing system] Next, a laser cleaning method (laser processing method for performing surface treatment by laser light) for removing coatings (paint film, rust, asbestos, salt, etc.) from a treatment target surface 5 will be described using the laser processing system 10. The planned treatment area for removing coatings is a metal surface that will become a magnetic body.

[0034] The laser processing system 10 is transported, for example, by a vehicle and carried into the construction site. First, in order to perform the laser cleaning on land, a case installation step is performed in which the opening 13 is closed and the collection case 21 is installed in a state in which the collection case 21 covers the surface 5 to be processed in the planned construction area. Before or during the case installation step, the suction hose 23 extending from the suction device 22 is connected to the exhaust port 24 of the collection case 21.

[0035] In the case installation step, the worker lifts the collection case 21 and faces the opening 13 side toward the processing target surface (wall surface, etc.) 5, and presses the edge 13e of the opening 13 against the processing target surface 5 so that the opening 13 is blocked by the processing target surface 5, as shown in FIG. 5(a). This pressing brings the internal space 21s of the collection case 21 into a sealed state. Then, in this state, the operation of the suction device 22 is started to suck the air inside the collection case 21. Then, the suction force P obtained by this suction brings the entire circumference of the seal member 15 into close contact with the processing target surface 5. The suction force P becomes a holding force that prevents the collection case 21 from falling due to gravity, and the collection case 21 is fixed to the processing target surface 5. In this state, even if the worker releases his / her hand from the collection case 21, the position of the collection case 21 is held above the ground. This completes the case installation step. When the case installation step is completed, the surface to be treated 5 and the laser irradiation head 32 are separated by the collection case 21, and the surface to be treated 5 can be irradiated with laser light from the laser irradiation head 32 through the transparent panels 11, 12.

[0036] Next, a surface treatment step is performed in which the surface 5 to be treated is irradiated with laser light L to remove the coating. In the surface treatment step, in addition to the laser irradiation device 30, the suction device 22 is also operated without stopping after the operation is started in the case installation step. In the surface treatment step, the laser light L is irradiated from the laser irradiation head 32 to the surface 5 to be treated through the transparent panels 11, 12, and the scattered material S in the recovery case 21 is sucked by the suction device 22. Note that the above-mentioned suction force P also acts in the surface treatment step, but is omitted from FIG. 5(b).

[0037] Specifically, in the surface treatment step, an operator starts the operation of the laser irradiation device 30 while directing the exit window 35b of the laser irradiation head 32 toward the surface 5 to be treated through the transparent panels 11 and 12 such as the main panel 11. Then, as shown in FIG. 5(b), the laser light L emitted from the exit window 35b of the laser irradiation head 32 is irradiated onto the surface 5 to be treated through the transparent panels 11 and 12. In the laser irradiation head 32, for example, the scanning optical system operates so that the laser light L is scanned linearly on the surface 5 to be treated. The scanning speed of the laser light L is high. Therefore, the laser light L emitted from the exit window 35b is visually recognized as a sheet-like laser light L. On the surface 5 to be treated, the coating is removed by the laser light L.

[0038] The removal of the covering generates flying matter S such as fumes. In the surface treatment step, the suction device 22 is operated, so that the flying matter S is sucked in from the exhaust port 24 by the suction device 22. At this time, outside air is introduced into the recovery case 21 through the ventilation port 25. Therefore, the airflow toward the exhaust port 24 increases in the recovery case 21, and the flying matter S can be effectively sucked in by the suction device 22. In particular, in this embodiment, the side panel 12 having the exhaust port 24 and the side panel 12 having the ventilation port 25 face each other, so that an airflow with a sufficient flow rate is generated in a wide range of the internal space 21s, and the flying matter S can be effectively sucked in by the suction device 22.

[0039] In the surface treatment step, the worker can change the irradiation position of the laser light L on the treatment target surface 5 by, for example, moving the exit window 35b of the laser irradiation head 32 along the outer surface of the main panel 11, thereby removing the coating from almost the entire surface of the treatment target surface 5 in the recovery case 21. Since the main panel 11 has a relatively large area, the coating can be removed from a wide range. Since almost the entire surface of the treatment target surface 5 in the recovery case 21 can be seen from outside the recovery case 21, the workability is also good.

[0040] When the removal of the covering material from inside the recovery case 21 is completed, a case removal step is performed to remove the recovery case 21 from the surface to be treated 5. Specifically, while the worker is supporting the recovery case 21, the suction device 22 stops sucking the air from inside the recovery case 21. Then, the pressure in the internal space 21s increases with the inflow of air from the ventilation hole 25, and the suction force P weakens. The worker pulls the recovery case 21 away from the surface to be treated 5. Thereafter, a case installation step is performed so as to cover another area in the planned processing area as the surface to be processed 5, and a surface treatment step is performed after the case installation step. At the processing site, the case installation step, surface treatment step, and case removal step are repeated in this order. The laser processing method can also be used for surface treatment other than laser cleaning (for example, laser welding, etc.).

[0041] The recovery device for laser treatment 20 can also be used to remove a coating (such as a coating film, rust, asbestos, or salt) covering the surface of a member (such as a part of an instrument or device) 6 that is large enough to be housed in the recovery case 21. In this case, as shown in FIG. 6, the recovery case 21 is installed so as to cover the member 6 with the opening 13 side facing downward. In this case, the blocking surface that blocks the opening 13 is the installation surface (such as a workbench or the ground) 7 on which the member 6 is installed. In this state, the laser light L emitted from the exit window 35b of the laser irradiation head 32 is irradiated onto the treatment target surface 5 through the main panel 11.

[0042] [Effects of the embodiment] In this embodiment, in an installation state in which the opening 13 is closed and the treatment target surface 5 is covered, a surface treatment can be performed by irradiating the treatment target surface 5 with laser light L from a laser irradiation head 32 separate from the collection case 21 through the transparent panels 11, 12. In addition, by sucking the air inside the collection case 21 in the installation state with the suction device 22, scattered matter S generated during laser cleaning in which the treatment target surface 5 is irradiated with laser light is sucked in. Therefore, almost no scattered matter S reaches the laser irradiation head 32 outside the collection case 21. Therefore, it is possible to prevent the configuration of the laser irradiation head 32 from becoming complicated due to measures against the scattered matter S.

[0043] In this embodiment, the side surface of the recovery case 21 is also formed of the transparent panel 12, so that the laser light L can be irradiated onto the treatment target surface 5 through the side panel 12. Therefore, if there is a protrusion such as a bolt on the treatment target surface 5 inside the recovery case 21, the coating on the side surface can be easily removed by irradiating the laser light L onto the side surface of the protrusion.

[0044] In addition, in this embodiment, since the laser irradiation head 32 separate from the collection case 21 is used, the focus of the laser light L on the surface of the processing target surface 5 can be easily adjusted by moving the laser irradiation head 32 closer to or farther away from the processing target surface 5. For example, if there is a protrusion such as a bolt on the processing target surface 5 inside the collection case 21, the focus of the laser light L can be easily adjusted to the surface of the protrusion. This can improve the cleaning quality.

[0045] Furthermore, in this embodiment, although the suction device 22 sucks up the scattered matter S, there is a risk that the scattered matter S will adhere to the transparent panels 11, 12. However, since the transparent panels 11, 12 have a large area, even if the scattered matter S adheres to and accumulates on the transparent panels 11, 12, the transmittance of the laser light L through the transparent panels 11, 12 is unlikely to decrease. Therefore, it is possible to suppress a decrease in the intensity of the laser light L reaching the treatment target surface 5 due to the accumulation of the scattered matter S.

[0046] Furthermore, in this embodiment, since the recovery case 21 has the ventilation hole 25, it is possible to prevent the pressure inside the recovery case 21 from dropping too much when the air inside the recovery case 21 whose internal space 21s is sealed is sucked in. This makes it possible to prevent the transparent panels 11, 12 (mainly the main panel 11) from bending significantly inward, or to prevent the transparent panels 11, 12 from being damaged by this bending. Furthermore, since the recovery case 21 has the ventilation hole 25, it becomes easier to remove the recovery case 21 during the case removal step.

[0047] In order to prevent the above-mentioned damage, a high-strength material can be used for the transparent panels 11 and 12. A material having a higher strength than that of the side panel 12 may be used for the main panel 11. In order to prevent the main panel 11 from bending inward, a support member (beam member) that crosses the main panel 11 and has both ends fixed to the frame 14 may be provided. The support member is provided so as to abut against the inner surface of the main panel 11. In this case, a transparent material may be used for the support member so that the worker can easily view the surface 5 to be treated.

[0048] In addition, since the laser light L emitted by the laser irradiation head 32 has high intensity, the laser light L passes through the transparent panels 11, 12, thereby increasing the temperature of the transparent panels 11, 12. For this reason, the transparent panels 11, 12 can be made of a material that has high laser light transmittance and high heat resistance.

[0049] In addition, the transparent panels 11, 12 may be provided with a panel mounting section 16 that can be switched between a first state in which the transparent panels 11, 12 can be attached and detached and a second state in which the transparent panels 11, 12 are held by rotating or sliding, so that the transparent panels 11, 12 can be replaced when they are deteriorated due to the above-mentioned bending or temperature rise, or when the transmittance of the laser light L is reduced due to the accumulation of scattered matter S. The panel mounting section 16 shown in FIG. 7 is provided for the main panel 11. The panel mounting section 16 is composed of a plurality of fasteners 17 that are rotatably provided on the main surface side claim 14b of the frame 14 that surrounds the main panel 11. The plurality of fasteners 17 are arranged at intervals in the circumferential direction of the main surface side claim 14b, as shown in FIG. 7(a). Each fastener 17 is a small plate-like piece and is rotatably attached to the main surface side claim 14b by a pin 18 (see FIG. 7(b)). In the main surface side claim 14b, the inner periphery side is recessed to form a mounting surface 14c for the main panel 11. When replacing the main panel 11, the fasteners 17 are rotated so that the fasteners 17 do not overlap the main panel 11 in a first state (the state shown in the left diagram of FIG. 7(c)). In this way, the used main panel 11 is removed and a new main panel 11 is placed on the mounting surface 14c. Then, the fasteners 17 are rotated so that the fasteners 17 overlap the main panel 11 in a second state (the state shown in the right diagram of FIG. 7(c)). In this way, the main panel 11 is held by each fastener 17. Note that the mounting surface 14c may be provided with an elastic member 19 such as rubber as shown in FIG. 7(b). In addition, the transparent panels 11, 12 may be detachably attached to the recovery case 21 by fasteners such as screws.

[0050] [First Modification of the Embodiment] 8, in this modification, the recovery case 21 is provided with a second fixing part that generates an adhesive force by a different method, as a component for fixing the recovery case 21 to the blocking surface that blocks the opening 13, in contrast to the first fixing part that is used for sucking the air inside the recovery case 21 by the suction device 22 that generates the adhesive force P. The second fixing part is, for example, a magnet 26 provided on the edge 13e of the opening 13 (opening-side frame 14a).

[0051] In this case, the magnet 26 may be, for example, rod-shaped. The magnet 26 is provided along each side of the opening-side frame 14a. In this case, although the magnet 26 is arranged outside the seal member 15 on the lower surface of the opening-side frame 14a in Fig. 8, the magnet 26 may be arranged inside the seal member 15. Also, a rubber magnet may be used for the seal member 15, so that the seal member 15 functions as the magnet 26.

[0052] In this modified example, as in the above-mentioned embodiment, the recovery device 20 for laser processing is configured to be able to fix the recovery case 21 to a vertical wall surface only by the above-mentioned suction force P, and the magnets 26 are provided as an auxiliary. The recovery case 21 is also able to be fixed to a vertical magnetic wall surface by the magnetic force of all the magnets 26 only so that the recovery case 21 does not fall. Therefore, when the suction device 22 stops due to a power outage or a malfunction, the recovery case 21 can be prevented from falling. An electromagnet may be used as the magnet 26. In this case, power may be supplied to the electromagnet from a power source separate from the suction device 22. A suction cup, a vacuum pad (suction pad), or the like may be used as the second fixing portion.

[0053] In addition, instead of securing the force for fixing the recovery case 21 to a vertical wall surface of a magnetic material by only one of the adhesive force P of the first fixing part and the adhesive force of the second fixing part (such as the magnetic force of the magnet 26, the adhesive force of a suction cup or vacuum pad), the adhesive force for fixing the recovery case 21 to a vertical wall surface may be secured by both the adhesive force P of the first fixing part and the adhesive force of the second fixing part.

[0054] [Second Modification of the Embodiment] 9(a), the recovery case 21 has a gas inlet 27 connected to a gas supply device 40 that supplies gas G (carbon dioxide, nitrogen, etc.) such as a cooling gas, a non-flammable gas, or an inert gas, and a gas outlet 28 that discharges the gas G supplied from the gas inlet 27 toward the treatment target surface 5. The gas outlet 28 is configured by a nozzle. In this modification, the vent 25 may be omitted.

[0055] For example, the opening-side frame 14a is formed in a tubular shape so that the inside serves as a flow path 29 for the gas G. A gas inlet 27 is provided on the outer surface of the opening-side frame 14a. A gas discharge port 28 is provided on the inner surface of the opening-side frame 14a. In this modification, a plurality of gas discharge ports 28 are provided in the opening-side frame 14a. In this case, as shown in FIG. 9(a), the gas discharge ports 28 may be provided on each side of the opening-side frame 14a, or the gas discharge ports 28 may be provided on only some of the sides.

[0056] In this modification, the gas supply device 40 is operated during the surface treatment step, and gas G is supplied from the gas supply device 40 to the gas introduction section 27. In the recovery case 21, the gas G supplied to the gas introduction section 27 flows through the flow path 29 in the opening side frame 14a, is discharged from each gas discharge port 28, and is supplied to the treatment target surface 5 (see FIG. 9(b)). This makes it possible to prevent ignition even in cases where ignition is likely to occur during surface treatment with laser light. Note that the operator is not shown in FIG. 9(b).

[0057] [Third Modification of the Embodiment] In this modification, as shown in Fig. 10, the laser processing system 10 further includes a liquid ejection device 50 that ejects liquid for wetting the processing target surface 5. For example, the liquid ejection device 50 includes a liquid ejection port 51 provided in the recovery case 21, and a liquid supply device 52 that supplies liquid (water, aqueous solution, etc.) to the liquid ejection port 51. The liquid ejection port 51 is configured by a spray nozzle, and liquid is sprayed from the liquid ejection port 51. The liquid ejection port 51 is connected to the liquid supply device 52 via a pipe 53. Note that the gas ejection port 28 of the second modification may also be used as a liquid ejection port, and the liquid ejection port 51 of this modification may also be used as an ejection port for a cooling gas, a non-flammable gas, or an inert gas.

[0058] Here, the inventor of the present application found that the base material after laser cleaning is cleaner when the surface 5 to be treated (surface of a coating such as a coating film, rust, asbestos, or salt) is wetted before laser cleaning than when the surface 5 to be treated is not wetted. The inventor of the present application conducted a comparative test on the surface 5 to be treated, which is covered with rust, as shown in the rightmost test piece in FIG. 11(a), between the case where the surface 5 is wetted with liquid (case 1) and the case where the surface 5 is not wetted with liquid (case 2). Water was used as the liquid for the comparative test. FIG. 11(a) shows, from the left, photographs of the test piece of the base material of case 1, in which the surface 5 to be treated is wetted and laser cleaning is performed, the test piece of the base material of case 2, in which the surface 5 to be treated is not wetted and laser cleaning is performed, and the test piece of the base material that has not been laser cleaned. FIG. 11(b) is an enlarged photograph of the test piece of case 1. FIG. 11(c) is an enlarged photograph of the test piece of case 2. 11(b) and 11(c), the former substrate is clearly cleaner, while the latter substrate has noticeable scratches. The inventors of the present application have also obtained similar results with aqueous solutions other than water.

[0059] In this modified example, after the case installation step and before the surface treatment step, a liquid spraying step is performed in which liquid is sprayed from the liquid discharge port 51 to wet the surface of the treatment target surface 5 in the recovery case 21. This makes the base material of the base material clean after laser cleaning, and therefore the grade of base material preparation can be improved.

[0060] The liquid spraying step may be performed using a liquid discharger 50 separate from the recovery case 21, without providing the liquid discharge port 51 of the liquid discharger 50 in the recovery case 21. In this case, the liquid spraying step is performed before the case installation step.

[0061] [Fourth Modification of the Embodiment] In this modification, the recovery case 21 has an L-shape when viewed from above, as shown in Fig. 12(a). The recovery case 21 is used when the treatment target surface 5 is a joint where two wall surfaces meet at a predetermined angle (such as 90°) or a rectangular column. Note that the illustration of the suction hose 23 is omitted in Fig. 12.

[0062] The recovery case 21 has a first case portion 21a whose opening 13 is blocked by the processing target surface 5 on one wall, a second case portion 21b whose opening 13 is blocked by the processing target surface 5 on the other wall, and a connecting portion 21c that connects the first case portion 21a and the second case portion 21b.

[0063] In Fig. 12(a), the opening 13 is provided on the inside of the L-shape, but as shown in Fig. 12(b), the opening 13 may be provided on the outside of the L-shape. Also, the recovery case 21 may be configured by providing transparent panels 11, 12 to a bellows-shaped case having an opening 13 on one side so that it can be deformed arbitrarily to fit the shape of the surface 5 to be treated. [Industrial Applicability]

[0064] The present invention can be applied to a recovery device for laser processing used for surface processing with laser light, etc. [Explanation of symbols]

[0065] 5 Surface to be processed 10 Laser Processing System 11 Main panel (transparent panel) 12 Side panel (transparent panel) 13 Opening 13e Edge of opening 20 Recovery device for laser processing 21 Collection Case 22 Suction device

Claims

[Claim 1] A laser processing method for performing surface treatment using laser light, comprising: Wetting the surface of the surface to be treated with a liquid; The laser processing method includes, after the wetting step, a surface processing step of irradiating the liquid-wetted surface to be processed with laser light to perform laser cleaning.

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