Mobile body, laser surface treatment system, and laser surface treatment method

Abstract

This mobile body moves along the surface of a wall of a ship while irradiating the surface with laser light to perform surface treatment, for example. The mobile body comprises: a moving mechanism including a plurality of rolling bodies that roll along the surface; a magnetic attraction mechanism that are provided separately from the rolling bodies, faces the surface at an interval, and presses the rolling bodies against the surface by generating a magnetic attraction force between the mechanism and the wall; and an optical head for irradiating the wall with laser light. In the mobile body, an opposing region of the surface facing the magnetic attraction mechanism may be positioned between a plurality of regions of contact with the rolling bodies on the surface. The mobile body may include: a support member that supports the moving mechanism and the magnetic attraction mechanism; and a position change mechanism that can change the position of the optical head with respect to the support member.

Description

Mobile body, laser surface treatment system, and laser surface treatment method

[0001] The present invention relates to a mobile body, a laser surface treatment system, and a laser surface treatment method.

[0002] 2. Description of the Related Art Conventionally, a method for removing coatings and deposits on the surface of a structure by irradiating the surface with laser light is known (for example, see Patent Document 1).

[0003] Patent No. 5574354

[0004] Patent Document 1 discloses a portable laser surface treatment device that irradiates a surface with laser light to remove a coating film on the surface.

[0005] When performing surface treatment using a portable laser surface treatment device, the worker needs to be relatively close to the surface to be treated, so in situations where it is difficult for the worker to approach the surface, the portable laser surface treatment device may not be usable in some locations. For example, such a situation may occur in repairs of ships or naval vessels.

[0006] Therefore, one of the objectives of the present invention is to provide a mobile body, a laser surface treatment system, and a laser surface treatment method that enable treatment to be performed on a surface even in situations where it is difficult for an operator to approach the surface to be treated.

[0007] The mobile body of the present invention is, for example, a mobile body that moves along the surface of a wall of a ship and processes the surface by irradiating the surface with laser light, and is equipped with a mobile mechanism including a plurality of rolling bodies that roll along the surface, a magnetic adsorption mechanism that is provided separately from the rolling bodies, faces the surface at a distance, and presses the rolling bodies against the surface by generating a magnetic attraction force between it and the wall, and an optical head that irradiates laser light toward the wall.

[0008] In the moving body, the opposing region of the surface facing the magnetic attraction mechanism may be located between a plurality of contact regions of the surface with the rolling elements.

[0009] The moving body may include a support member that supports the moving mechanism and the magnetic attraction mechanism, and a position changing mechanism that can change the position of the optical head relative to the support member.

[0010] In the moving body, the position change mechanism may be capable of changing the position of the optical head so that laser light can be irradiated to the contact area with the rolling body on the surface behind the rolling body in the direction of travel.

[0011] In the moving body, the position change mechanism may be capable of changing the position of the optical head so that laser light can be irradiated to a position that is off the contact area with the rolling body on the surface in a direction that intersects with the direction of travel of the rolling body.

[0012] In the movable body, the position change mechanism may be capable of changing the position of the optical head so that laser light can be irradiated to a position above the opposing area on the surface facing the magnetic adsorption mechanism.

[0013] The movable body may include a connecting portion provided on the support member to which a linear object for suspending the support member is connected.

[0014] In the moving body, the position changing mechanism may be capable of changing the position of the optical head so that the laser light passes between the coupling portion and the magnetic attraction mechanism and is irradiated onto the surface.

[0015] The movable body may include a cable holding portion provided on the support member for holding a cable in a bent state, the cable including at least one of an optical fiber for transmitting laser light toward the optical head and an electrical wiring for supplying power to drive the movable mechanism.

[0016] In the moving body, the position changing mechanism may be configured to be electrically operable.

[0017] In the movable body, the position changing mechanism may reciprocate the optical head between predetermined positions.

[0018] In the moving body, the optical head may have a diffractive optical element that splits a laser beam into a plurality of beams, and a rotation mechanism that rotates the diffractive optical element around the optical axis of the laser beam.

[0019] The moving body may include a nozzle that supplies fluid to the surface, the rolling body, or the optical head.

[0020] The movable body may include at least one of a foreign matter removal mechanism that removes foreign matter between the magnetic attraction mechanism and the surface and a cleaning mechanism that cleans the surface.

[0021] The movable body may include a distance varying mechanism that can change the distance between the optical head and the surface.

[0022] The laser surface treatment system of the present invention includes, for example, the moving body, a light source device that is optically connected to the optical head via an optical fiber and outputs laser light, and a power supply device that is electrically connected via an electric wire to an electric actuator that operates the moving mechanism.

[0023] The laser surface treatment system may further include a movable base on which the light source device and the power supply device are mounted.

[0024] The laser surface treatment method of the present invention comprises the steps of: placing a mobile body, which is a mobile body that moves along the surface of a wall of a ship and treats the surface by irradiating the surface with laser light, on the surface by activating the magnetic adsorption mechanism; and treating the surface by moving the mobile body along the surface while irradiating the surface with laser light. The mobile body includes a moving mechanism that includes a plurality of rolling bodies that roll along the surface; a magnetic adsorption mechanism that is provided separately from the rolling bodies, faces the surface at a distance, and presses the rolling bodies against the surface by generating a magnetic attraction force between the rolling bodies and the wall; and an optical head that irradiates the wall with laser light.

[0025] In the laser surface treatment method, the irradiation position of the laser light on the surface may be located behind the contact area with the rolling element on the surface in the direction of movement of the rolling element, or may be located away from the contact area with the rolling element on the surface in a direction intersecting the direction of travel of the rolling element.

[0026] In the laser surface treatment method, in the step of treating the surface, the power of the laser light may be feedback controlled so that the detected temperature of the surface falls within a predetermined temperature range.

[0027] According to the present invention, for example, a novel and improved moving body, a laser surface treatment system, and a laser surface treatment method can be obtained.

[0028] FIG. 1 is an exemplary and schematic front view of a mobile body included in the laser surface treatment system of the first embodiment. FIG. 2 is an exemplary and schematic side view of the mobile body of the first embodiment. FIG. 3 is a front view showing an example of the arrangement of suction areas and contact areas on a surface by the mobile body of the first embodiment. FIG. 4 is a schematic configuration diagram of a vehicle included in the laser surface treatment system of the embodiment. FIG. 5 is an exemplary explanatory diagram (perspective view) showing a mechanism for forming a rotating spot pattern in an optical head provided on the mobile body of the first embodiment. FIG. 6 is a schematic plan view showing an example of a rotating spot pattern formed on a virtual irradiation surface by the configuration of FIG. 5. FIG. 7 is an exemplary and schematic front view of the mobile body of the first embodiment, showing a state in which the position of the optical head is different from that of FIG. 1. FIG. 8 is an exemplary and schematic front view of the mobile body of the first embodiment, showing a state in which the position of the optical head is different from that of FIGS. 1 and 7. FIG. 9 is an exemplary and schematic front view of the mobile body of the first embodiment, showing a state in which the position of the optical head is different from that of FIGS. 1, 7, and 8. FIG. 10 is an exemplary and schematic front view of the moving body of the first embodiment, showing a state in which the position of the optical head is different from that shown in FIGS. 1 and 7-9. FIG. 11 is an exemplary and schematic front view of the moving body of the first embodiment, showing a state in which the position of the optical head is different from that shown in FIGS. 1 and 7-10. FIG. 12 is an exemplary flowchart of the laser surface treatment method of the first embodiment. FIG. 13 is an exemplary and schematic front view of the moving body of the second embodiment. FIG. 14 is an exemplary and schematic side view of the moving body of the second embodiment. FIG. 15 is an exemplary and schematic side view of the moving body of the third embodiment. FIG. 16 is an exemplary and schematic front view of the moving body of the fourth embodiment. FIG. 17 is a schematic plan view showing a modified example of a spot pattern formed on a virtual irradiation surface by laser light output from an optical head provided on the moving body of the embodiment. FIG. 18 is a schematic plan view showing another modified example of a spot pattern formed on a virtual irradiation surface by laser light output from an optical head provided on the moving body of the embodiment. Fig. 19 is an exemplary schematic front view of a moving body according to a fifth embodiment. Fig. 20 is an exemplary schematic front view of a moving body according to a sixth embodiment.Fig. 21 is an exemplary and schematic front view of a moving body according to a seventh embodiment. Fig. 22 is an exemplary and schematic front view of a moving body according to an eighth embodiment. Fig. 23 is an exemplary and schematic front view of a moving body according to a ninth embodiment. Fig. 24 is an exemplary and schematic front view of a moving body according to a tenth embodiment. Fig. 25 is an exemplary and schematic front view of a modified example of a magnetic adsorption mechanism included in the moving body according to the embodiment. Fig. 26 is an exemplary and schematic front view of a modified example of a magnetic adsorption mechanism included in the moving body according to the embodiment. Fig. 27 is an exemplary and schematic front view of a modified example of a magnetic adsorption mechanism included in the moving body according to the embodiment.

[0029] Exemplary embodiments and modifications of the present invention are disclosed below. The configurations of the embodiments and modifications shown below, as well as the actions and results (effects) brought about by these configurations, are merely examples. The present invention can also be realized by configurations other than those disclosed in the following embodiments and modifications. Furthermore, according to the present invention, it is possible to obtain at least one of the various effects (including derivative effects) obtained by the configurations.

[0030] The following embodiments and modifications have similar components, and in the following description, the same reference numerals will be used to designate the similar components, and redundant descriptions may be omitted.

[0031] In each figure, the X direction, Y direction, and Z direction intersect with each other and are perpendicular to each other. The Z direction is approximately vertically upward, and the X direction and Y direction are approximately horizontal. The X direction intersects with the surface Wa of the wall W and is approximately perpendicular to it, and the Y direction is approximately parallel to the surface Wa of the wall W. Note that the orientation of the moving body 10 with respect to the X direction, Y direction, and Z direction in each figure is an example, and the moving body 10 may take an orientation different from the orientation shown in each figure. Also, each figure is schematic, and the dimensions in the figure may differ from the actual dimensions.

[0032] First Embodiment FIG. 1 is a front view of a mobile object 10A (10) included in a laser surface treatment system 100 according to a first embodiment, and FIG. 2 is a side view of the mobile object 10A.

[0033] As shown in FIGS. 1 and 2 , a mobile body 10 included in a laser surface treatment system 100 has a magnetic attraction mechanism 13, and is attracted to a surface Wa of a wall W of a ship by the magnetic force generated by the magnetic attraction mechanism 13. The surface Wa is the object to be surface treated. The mobile body 10 also has a moving mechanism 12 including a rolling element 12a that rolls on the surface Wa, and moves over the surface Wa as the rolling element 12a rolls. The mobile body 10 also has an optical head 14 that outputs a laser beam L (see FIG. 2 ), and the optical head 14 outputs the laser beam L toward the surface Wa for surface treatment of the surface Wa. With this configuration, the mobile body 10 irradiates the surface Wa with the laser beam L while moving along the surface Wa to treat the surface Wa.

[0034] In this case, the main material of the wall W is a magnetic material such as an iron-based metal. By irradiating the laser beam L from the optical head 14 under appropriate conditions, the energy of the laser beam L causes laser ablation at the location on the surface Wa where the laser beam L is irradiated and in the vicinity thereof, thereby thinly removing the surface layer. In this process, dirt, rust, coatings, paint, deposits, etc. on the surface Wa are removed along with the base material of the wall W.

[0035] The moving body 10 includes a base 11 , a moving mechanism 12 , a magnetic attraction mechanism 13 , an optical head 14 , and a position changing mechanism 15 .

[0036] The base 11 functions as a support member for supporting other components. The base 11 includes an outer frame 11a, beams 11b, and a plate 11c. The outer frame 11a, beams 11b, and plate 11c all extend intersecting the X direction. The outer frame 11a is a hollow or solid rectangular member with rounded corners. The beams 11b are fixed to the outer frame 11a and extend rod-like within the outer frame 11a. The plate 11c is fixed to the outer frame 11a or the beams 11b and extends between multiple locations on the outer frame 11a or between the outer frame 11a and the beams 11b. The outer frame 11a, beams 11b, and plate 11c are each made of, for example, an iron-based material such as stainless steel or an aluminum-based material such as an aluminum alloy. The base 11 is not limited to the configuration shown in FIGS. 1 and 2 .

[0037] Furthermore, a coupling portion 11d for coupling a linear object 20 such as a wire is provided on the upper portion of the base 11, i.e., the upper end of the outer frame 11a in the example shown in FIGS. 1 and 2. The linear object 20 can suspend the mobile object 10. With this configuration, if the magnetic attraction mechanism 13 loses its attraction to the surface Wa for some reason and the mobile object 10 falls away from the surface Wa, the mobile object 10 can be suspended by the linear object 20, thereby preventing the mobile object 10 from falling to the ground, water, or the like and being damaged. The suspension device for suspending the linear object 20 may be configured to be movable in various directions on the vessel or other vessel to be treated, or may be configured to allow the suspension position to be moved. Furthermore, the linear object 20 is preferably bent between the suspension device and the mobile object 10 to reduce friction with the surface Wa. Furthermore, a buffer member or guide member may be appropriately interposed between the linear object 20 and the surface Wa.

[0038] Furthermore, the base 11 is provided with a cable holder 11e that holds the electric distribution cable 12d, the optical fiber cable 14a, the electric distribution cable 14d, the electric distribution cable 15f, or the cable 30 that houses these. The cable holder 11e can hold these cables in a bent state, thereby reducing the load on each cable.

[0039] The moving mechanism 12 includes two rolling elements 12a that roll on the surface Wa, two motors 12b that rotate the rolling elements 12a, and two casters 12c that are provided separately from the rolling elements 12a. The rolling elements 12a roll on the surface Wa by being driven to rotate by the motors 12b. The motors 12b are operated by power supplied from a power supply unit 42 (see FIG. 4) via an electrical wiring cable 12d, and rotate the rolling elements 12a. The casters 12c are attached to the base 11 so as to be rotatable around a rotation axis extending in the X direction. The rollers of the casters 12c roll on the surface Wa. The rollers are an example of rolling elements. The motors 12b generate a required torque to prevent the rolling elements 12a from rolling downward on the surface Wa due to gravity acting on the moving body 10. Furthermore, when the moving body 10 has multiple combinations of rolling elements 12a and motors 12b as in this embodiment, by controlling the rotation speed and rotation direction of each motor 12b, the moving body 10 can move not only along a straight path but also along a curved path and can turn. The movement mechanism 12 is not limited to the configuration shown in FIGS. 1 and 2 . The number and arrangement of the rollers of the rolling elements 12a and casters 12c can be changed as appropriate. The rolling elements 12a may be rolling elements other than wheels, such as crawlers.

[0040] The magnetic attraction mechanism 13 is provided separately from the moving mechanism 12 and faces the surface Wa with a gap g (gap) therebetween. The magnetic attraction mechanism 13 has, for example, a permanent magnet, and generates a magnetic attraction force between the permanent magnet and the wall, thereby pressing the rolling elements 12a of the moving mechanism 12 and the rollers of the casters 12c against the surface Wa. The permanent magnet is, for example, a rare earth magnet, and generates an attraction force of about 1000 to 200 kgf when the gap g is 0.5 to 1 cm.

[0041] Laser light is input to the optical head 14 from a laser unit 41 (see FIG. 4) serving as a light source device via an optical fiber in an optical fiber cable 14a. The optical head 14 has optical components such as a collimating lens, a magnifying lens, and a diffractive optical element (DOE), and outputs shaped laser light L toward the surface Wa of the wall W. The output laser light L will be described later.

[0042] The position change mechanism 15 can change the position of the optical head 14 relative to the base 11. The position change mechanism 15 has a fixed part 15a, a movable part 15b, an arm holder 15c, an arm 15d, and a head holder 15e. The fixed part 15a is fixed to the base 11. The movable part 15b is supported rotatably around an axis extending in the X direction relative to the fixed part 15a. The movable part 15b is rotatable relative to the fixed part 15a and can be stationary relative to the fixed part 15a at any one or more rotational positions. The arm holder 15c holds the arm 15d. The arm 15d extends in a rod shape intersecting the X direction. The arm holder 15c is configured to change the holding position of the arm 15d in the longitudinal direction. In other words, the arm 15d can move linearly (slide) relative to the arm holder 15c and can be stationary relative to the arm holder 15c at any one or more positions in the longitudinal direction. In this way, by changing the relative position of the movable part 15b with respect to the fixed part 15a and by changing the relative position of the arm 15d with respect to the arm holder 15c, it is possible to change the relative position of the optical head 14 with respect to the base 11. Note that the configuration of the position changing mechanism 15 is not limited to the examples shown in Figures 1 and 2. Furthermore, the position changing mechanism 15 may be configured so that the position of the optical head 14 can be changed in the X direction.

[0043] FIG. 3 illustrates the arrangement of the attraction areas As of the magnetic attraction mechanism 13 on the surface Wa and the contact areas Ac of the rollers (hereinafter simply referred to as rollers) of the rolling elements 12a and casters 12c. As shown in FIG. 3 , in this embodiment, the attraction areas As are positioned between and surrounded by multiple contact areas Ac. Specifically, for example, the attraction areas As are positioned inside a polygon connecting the centers of gravity (geometric centers) of the contact areas Ac. This arrangement allows the pressing force acting on the surface Wa from the moving element 10 due to the attraction force of the magnetic attraction mechanism 13 to be appropriately distributed to the multiple rolling elements 12a and rollers. If the pressing force from the rolling elements 12a or rollers on the surface Wa varies, the rolling elements 12a or rollers with a larger pressing force may have difficulty rolling, potentially hindering the movement of the moving element 10 on the surface Wa. In this regard, in the present embodiment, the attraction region As is positioned between and surrounded by the plurality of contact regions Ac, which reduces variation in the pressing force from the rolling element 12a or roller to the surface Wa, allowing the movable body 10 to move more smoothly on the surface Wa. The attraction region As is an example of a facing region on the surface Wa that faces the magnetic attraction mechanism 13. Note that the number, size, arrangement, etc. of the attraction regions As (facing regions) and the contact regions Ac are not limited to those shown in FIG. 3 .

[0044] 4 is a schematic diagram of a vehicle 40 included in the laser surface treatment system 100. As shown in FIG. 4, the vehicle 40 is equipped with a laser unit 41, a power supply device 42, a control circuit 43, and a laser cooling mechanism 44. The laser unit 41, the power supply device 42, the control circuit 43, and the laser cooling mechanism 44 are housed in a housing 48 mounted on the vehicle 40. The vehicle 40 is an example of a mobile base. Note that the laser surface treatment system 100 may also include a mobile base different from the vehicle 40, such as a ship other than the ship to be treated.

[0045] The laser unit 41 includes one or more laser light sources, such as a semiconductor laser, a solid-state laser using yttrium aluminum garnet, or a fiber laser, and multiple optical components for directing the laser light output from the laser light source to the optical fiber within the cable 30. Oscillator types include pulsed laser and continuous wave laser. Research by the inventors has confirmed that, as an example, processing was performed favorably in a configuration equipped with a fiber laser with an optical output of 6 kW and a continuous wave laser oscillator. The continuous wave method improves processing speed by continuously irradiating the laser light. Furthermore, compared to pulsed methods, it eliminates the need for a power supply with a capacity greater than the average output corresponding to the peak power. Furthermore, the higher the power density of the laser light emitted from the laser unit, the better the surface processing capability. Furthermore, the longer the length of the cable 30, the wider the processing range (movement range). Through research by the inventors, it was confirmed that, as an example, in a configuration in which the core diameter is 80 μm and the cable 30 distance is 100 m, processing can be performed effectively over the entire range that the cable 30 can reach by extending it long.

[0046] The power supply device 42 includes, for example, a battery, a generator, or the like, and supplies power to the motor 12b of the movement mechanism 12 to drive the motor 12b. When the position change mechanism 15 has a motor or the like and is electrically operated to change the position of the optical head 14 relative to the base 11, the power supply device 42 supplies power to the motor to drive the motor. The power is supplied to the motor via an electrical wiring cable 15f (see FIG. 2) that includes electrical wiring housed within the cable 30.

[0047] The control circuit 43 controls the operation of the laser unit 41 , the power supply device 42 , and the laser cooling mechanism 44 .

[0048] The laser cooling mechanism 44 includes, for example, a tank that stores a refrigerant such as a cooling liquid, a pump that discharges the refrigerant, and supplies the refrigerant to the laser unit 41 to cool each part thereof. The refrigerant is supplied to the laser unit 41 from the laser cooling mechanism 44 via tubes, piping, etc.

[0049] In this way, by mounting the laser unit 41, the power supply device 42, etc. on the vehicle 40 (mobile base), there is an advantage that the length of the cable 30 can be further shortened. The vehicle 40 may also be equipped with a gas delivery mechanism 45, a dry ice delivery mechanism 46, a dust collection mechanism 47, etc. These will be described later.

[0050] [Beam Shaping] The optical head 14 has a beam shaper such as a DOE. The beam shaper can split the laser light L into multiple beams. FIG. 5 is an explanatory diagram showing how a rotating spot pattern is formed in the optical head 14, and FIG. 6 is a diagram showing an example of a rotating spot pattern formed on a virtual irradiation plane P intersecting the X direction (axis Ax) by the configuration of FIG. 5. Note that the virtual irradiation plane P is a virtual plane introduced for the purpose of evaluating and comparing the spot patterns, and may be defined, for example, as a plane provided at a position spaced apart from the optical head 14 by the average value of the distance between the optical head 14 and the surface Wa, or as a plane provided at a position that partially overlaps the surface Wa.

[0051] The optical head 14 includes a DOE 14b and a lens 14c. The DOE 14b splits the laser light L into multiple beams B. The multiple beams B pass through the lens 14c and are irradiated onto the surface Wa. In this embodiment, the DOE 14b is configured to rotate about an axis Ax. The axis Ax is the optical axis of the laser light before it enters the DOE 14b, and the DOE 14b has a shape that is symmetrical with respect to the axis Ax. In this case, as the DOE 14b rotates about the axis Ax, the multiple beams B rotate about the axis Ax, as shown in FIGS. 5 and 6 .

[0052] As the DOE 14b rotates, the spots formed by the multiple beams B rotate on the surface Wa at a substantially constant angular velocity around the axis Ax over time. As a result, the spots formed by the multiple beams B, whose powers are appropriately adjusted by the DOE 14b, rotate on the surface Wa. This reduces the variation in power density across the surface Wa, and thus the variation in the processing state across the surface Wa, compared to, for example, when a single beam spot with a Gaussian intensity distribution is irradiated onto the surface Wa. Furthermore, adjusting the rotation speed also makes it possible to adjust the power density. This allows the laser beam to be irradiated with an appropriate power density only on the layer to be removed when removing paint or rust, and by rotating the laser beam spot at high speed, it is possible to perform processing effectively while suppressing thermal effects and the occurrence of black scale on steel materials. Furthermore, multi-point branching allows the processing speed to be increased depending on the number of branched spots, enabling faster processing than single-point irradiation and shortening the processing time. The DOE 14b is rotated by, for example, a motor and a speed reducer housed in the optical head 14. The motor is operated by power supplied from a power supply 42 (see FIG. 4) via an electrical wiring cable 14d (see FIG. 2) containing electrical wiring. Note that the spot pattern is not limited to the examples shown in FIGS. 5 and 6. The DOE 14b may also rotate in response to the rotation of an air motor.

[0053] 1 and 7 to 11 show different positions of the optical head 14 relative to the base 11. The positions shown in the figures are achieved by the operation of the position change mechanism 15 described above. The position change mechanism 15 may be operated electrically or by manual adjustment by the operator.

[0054] In the case of FIG. 1 , the optical head 14 is located at position P1. As shown in FIG. 2 , the optical head 14 located at position P1 irradiates the laser light L at a position on the surface Wa that is above the suction area As. Now, consider a situation where the laser light L is irradiated upside down, i.e., where the optical head 14 irradiates the laser light L at a position below the suction area As on the surface Wa. In this situation, if the suction area As is located near the top end of the surface Wa, the laser light L will be irradiated below the vicinity of the top end. If the moving body 10 attempts to move further above this position, the suction area As cannot be secured on the surface Wa. In other words, when the optical head 14 irradiates the laser light L at a position below the suction area As on the surface Wa, the optical head 14 cannot irradiate the laser light L onto the top end of the surface Wa. In this regard, in the case of FIG. 1, when the suction area As is positioned below the upper end portion of the surface Wa, the optical head 14 can irradiate the laser light L toward the upper end portion.

[0055] 2, the laser light L output from the optical head 14 passes between the connecting portion 11d and the magnetic attraction mechanism 13 and is irradiated onto the surface Wa. This prevents the laser light L from being irradiated onto the connecting portion 11d or the linear object 20.

[0056] In the example shown in Figure 7, the optical head 14 is located at position P2. The optical head 14 located at position P2 irradiates the laser light L at a position spaced apart in the opposite direction from the suction area As in the Z direction. In this case, if the traveling direction of the moving body 10 is the Z direction, the optical head 14 can irradiate the laser light L at or near the area on the surface Wa after the rolling body 12a and caster 12c have passed. In contrast, if the traveling direction of the moving body 10 is the Z direction, and the optical head 14 irradiates the laser light L at a position spaced apart in the Z direction from the suction area As as shown in Figure 1, the optical head 14 will irradiate the laser light L at or near the area on the surface Wa before the rolling body 12a and caster 12c have passed. In this case, the rolling element 12a and the caster 12c pass over the surface Wa, the temperature of which has risen due to irradiation with the laser light L, and there is a risk of thermal effects being caused to the rolling element 12a and the rollers of the caster 12c. In this regard, in the state shown in FIG. 7 , when the moving body 10 is traveling in the Z direction, the laser light L can be irradiated to a position behind the moving body 10's traveling direction (Z direction) relative to the contact area Ac between the rolling element 12a and the roller (rolling element) on the surface Wa, i.e., away from the moving body 10 in the opposite direction to the Z direction, thereby suppressing thermal effects on the rolling element 12a and the roller. Note that when the moving body 10 is traveling in the opposite direction to the Z direction, the state shown in FIG. 1 can be used. In this case, too, the optical head 14 can irradiate the laser light L to a position behind the moving body 10's traveling direction (opposite the Z direction) relative to the contact area Ac between the rolling element 12a and the roller on the surface Wa.

[0057] 8 and 9, the optical head 14 is located at position P3 or P4. When the optical head 14 is located at position P3 or P4, it irradiates the laser light L at a position on the surface Wa that is out of contact with the rollers of the rolling elements 12a and casters 12c in a direction intersecting the moving direction, both when the moving direction of the moving element 10 is the Z direction and when the moving direction is opposite to the Z direction. In this case, too, the thermal effect on the rolling elements 12a and the rollers of the casters 12c can be suppressed.

[0058] 10 and 11, by changing the holding position of the arm 15d by the arm holder 15c, the optical head 14 can irradiate the laser light L at positions P5 and P6 at a position farther away from the base 11. In this case, the thermal influence on the rollers of the rolling elements 12a and casters 12c can be further suppressed. Furthermore, the position of the optical head 14 relative to the base 11 can be changed in various ways, including as shown in FIGS. 1 and 7 to 11 and cases other than those shown in these figures.

[0059] Furthermore, the position changing mechanism 15 may move the optical head 14 back and forth between two distant positions P3 and P4, for example, position P3 (FIG. 8) → position P2 (FIG. 7) → position P4 (FIG. 9) → position P2 (FIG. 7) → position P3 (FIG. 8). In this case, there is an advantage that processing can be performed over a wider range of positions (movement path) of the moving body 10.

[0060] Fig. 12 is a flowchart of an example of a laser surface treatment method using the laser surface treatment system 100. As shown in Fig. 12, first, the movable body 10 is placed on the surface Wa (S11), and then the movable body 10 is moved over the surface Wa while irradiating the surface Wa with laser light L, thereby performing surface treatment over a relatively wide area on the surface Wa (S12).

[0061] As described above, this embodiment enables processing of the surface Wa, which is the processing target, even in situations where it is difficult for an operator to approach the surface Wa. Furthermore, in this embodiment, the mobile body 10 includes a magnetic attraction mechanism 13 separate from the rolling body 12a. If the magnetic attraction mechanism 13 is provided on the rolling body 12a, the size and placement of the magnetic attraction mechanism 13 are limited by the size and specifications of the rolling body 12a, making it difficult to obtain sufficient attraction force. Furthermore, the rolling body 12a, which includes a permanent magnet, may become hard, potentially making the surface Wa more susceptible to damage. In this regard, this embodiment provides the magnetic attraction mechanism 13 separate from the rolling body 12a, making it easier to configure the magnetic attraction mechanism 13 that generates the required attraction force. Furthermore, the increased flexibility in the material of the rolling body 12a provides advantages such as reduced wear on the rolling body 12a, reduced damage to the surface Wa, and improved durability of the rolling body 12a.

[0062] Second Embodiment FIG. 13 is a front view of a mobile body 10B (10) according to a second embodiment, and FIG. 14 is a side view of the mobile body 10B. As shown in FIGS. 13 and 14 , the mobile body 10B includes a nozzle 16 that ejects dry ice (DI) toward the surface Wa. According to this embodiment, supplying dry ice (DI) to the surface Wa effectively removes deposits from the surface Wa. Specifically, when dry ice (DI) at approximately −79°C is applied to the surface Wa, a sudden drop in temperature causes thermal contraction, weakening the adhesive strength of the deposits. Furthermore, the dry ice (DI) penetrates between the surface Wa and the deposits, causing the deposits to peel off. In this case, dry ice (DI) is an example of a fluid containing a solid phase. Dry ice (DI) is supplied to the nozzle 16 from the dry ice delivery mechanism 46 (see FIG. 4 ) via a tube housed within the cable 30 or via a tube routed separately from the cable 30. The nozzle 16 constitutes a dry ice supply mechanism (fluid supply mechanism).

[0063] The movable body 10B also includes a position change mechanism 17 that can change the position of the nozzle 16 relative to the base 11. The position change mechanism 17 can have, for example, the same configuration as the position change mechanism 15 that changes the position of the optical head 14 relative to the base 11.

[0064] The dry ice DI may be supplied to the position on the surface Wa that has been treated by the laser light L, or may be supplied to the position that is scheduled to be treated by the laser light L before that treatment, or may be supplied to a position other than the area that is to be treated by the laser light L.

[0065] Third Embodiment FIG. 15 is a side view of a movable body 10C (10) according to a third embodiment. As shown in FIG. 15 , the movable body 10C includes a nozzle 18 that ejects gas G toward the surface Wa, the rolling elements 12a, or the laser beam L emission end (window or lens) of the optical head 14. According to this embodiment, supplying gas G can reduce the temperature and remove dirt. The gas G is supplied to the nozzle 18 from a gas delivery mechanism 45 (see FIG. 4 ) via a tube housed within the cable 30 or a tube routed separately from the cable 30. The gas G is, for example, air or nitrogen gas, which is an example of a fluid. The nozzle 18 constitutes a gas supply mechanism (fluid supply mechanism). For example, air is effective as the gas G for removing coating residues during laser beam irradiation. Furthermore, an inert gas such as nitrogen gas or argon gas is effective for suppressing oxidation of the steel surface.

[0066] [Fourth Embodiment] Figure 16 is a front view of a movable body 10D (10) according to a fourth embodiment. As shown in Figure 16, in this embodiment, the movable body 10D includes a cover 19 that covers at least the vicinity of the laser beam L emission end of the optical head 14 and extends toward the surface Wa, and an exhaust duct 50 that communicates with the space inside the cover 19. The exhaust duct 50 is housed within the cable 30 or routed separately from the cable 30 and is connected to a dust collection mechanism 47 (see Figure 4). The dust collection mechanism 47 draws air from inside the cover 19 through the exhaust duct 50 and uses a filter to trap and collect fumes, removed materials, and the like contained in the air. This embodiment effectively prevents fumes and removed materials from scattering into the surrounding area and causing adverse effects.

[0067] [Modified Spot Pattern] FIGS. 17 and 18 are plan views showing modified spot patterns of beams B rotating around the axis Ax of the laser light L. As illustrated in FIGS. 17 and 18, the beams B can be arranged in various configurations. In FIG. 17, the spots of the beams B are arranged in a substantially cross shape. In the example of FIG. 18, the spots of the beams B are arranged in multiple circular rings around the axis Ax. In the example of FIG. 17, the power of each beam B is set to be smaller closer to the axis Ax and larger farther from the axis Ax. In the example of FIG. 18, the number of beams B in each ring is set to be smaller closer to the axis Ax and larger farther from the axis Ax. This setting can suppress variations in power density depending on the location. The arrangement of the beams B and the power of each beam B can be set in various ways.

[0068] Fifth Embodiment FIG. 19 is a front view of a movable body 10E (10) according to a fifth embodiment. As shown in FIG. 19 , the movable body 10E includes a suction mechanism 61 that sucks and collects foreign matter, such as dust and removed material, generated by irradiation of the surface Wa with the laser beam L to prevent the foreign matter from remaining between the magnetic attraction mechanism 13 and the surface Wa. The foreign matter collected by the suction mechanism 61 is discharged via an exhaust duct 50. This embodiment can prevent foreign matter from interfering with the operation of the magnetic attraction mechanism 13 due to foreign matter between the magnetic attraction mechanism 13 and the surface Wa. The suction mechanism 61 may be configured to be changeable in position, e.g., moved closer or farther from the magnetic attraction mechanism 13. The suction mechanism 61 may also perform suction on the area irradiated with the laser beam L. The suction mechanism 61 is an example of a foreign matter removal mechanism.

[0069] Sixth Embodiment FIG. 20 is a front view of a movable body 10F (10) according to a sixth embodiment. As shown in FIG. 20 , the movable body 10F is provided with a blower 62 that blows away foreign matter, such as dust and other removed materials, generated by irradiation of the surface Wa with the laser light L to prevent the foreign matter from remaining between the magnetic attraction mechanism 13 and the surface Wa. The blower 62 exhausts air sent via a delivery duct 62a. This embodiment also prevents foreign matter from interfering with the operation of the magnetic attraction mechanism 13 due to foreign matter between the magnetic attraction mechanism 13 and the surface Wa. The blower 62 may also blow air toward the area irradiated with the laser light L. The blower 62 is an example of a foreign matter removal mechanism.

[0070] Seventh Embodiment Figure 21 is a front view of a movable body 10G (10) according to a seventh embodiment. As shown in Figure 21, in this embodiment, the movable body 10G includes a cleaning mechanism 63 for cleaning the surface Wa, located at a position spaced apart from the rolling body 12a in the Z direction. The cleaning mechanism 63 may be, for example, a brush that rotates or moves back and forth, a grinder, a cloth, or a high-pressure cleaning nozzle that sprays cleaning fluid. This embodiment can prevent the rolling body 12a from leaving traces on the surface Wa. This configuration is effective when the movable body 10G primarily moves in the direction opposite the Z direction.

[0071] Eighth Embodiment Figure 22 is a front view of a movable body 10H (10) according to an eighth embodiment. As shown in Figure 22, in this embodiment, the movable body 10H has a cleaning mechanism 63 for cleaning the surface Wa, located at a position away from the rolling body 12a in the opposite direction of the Z direction. This embodiment can prevent traces of the rolling body 12a from remaining on the surface Wa. This configuration is effective when the movable body 10H moves mainly in the Z direction.

[0072] Ninth Embodiment FIG. 23 is a front view of a movable body 10I (10) according to a ninth embodiment. As shown in FIG. 23 , in this embodiment, the movable body 10I includes a distance-adjusting mechanism 64 that adjusts the distance between the optical head 14 and the surface Wa by changing the position of the optical head 14 in the X direction. This allows for adjusting the power density of the spot of the laser light L on the surface Wa or for moving the optical head 14 away from the surface Wa to enhance protection of the optical head 14. The distance-adjusting mechanism 64 may be configured to be manually adjustable. Alternatively, the distance-adjusting mechanism 64 may include an electric actuator or the like, allowing for remote, electrically adjustable distance adjustment. Furthermore, the movable body 10I may include a distance sensor (not shown), and the distance-adjusting mechanism 64 may be controlled by the control circuit 43 to maintain the distance within a predetermined distance range. In this case, even when the surface Wa has irregularities, changes in power density can be suppressed, thereby suppressing processing variations.

[0073] Tenth Embodiment FIG. 24 is a front view of a movable body 10J (10) according to a tenth embodiment. As shown in FIG. 24, in this embodiment, the movable body 10J includes a temperature sensor 65 for detecting the temperature of the surface Wa. In this case, the laser unit 41 (see FIG. 4) may have the control circuit 43 perform feedback control of the power of the laser beam output so that the detected temperature is maintained within a predetermined temperature range. Specifically, for example, the control circuit 43 controls the laser unit 41 to reduce the output power of the laser beam when the temperature of the surface Wa is higher than the predetermined temperature range. Furthermore, the control circuit 43 controls the laser unit 41 to increase the output power of the laser beam when the temperature of the surface Wa is lower than the predetermined temperature range. This configuration can prevent processing variations on the surface Wa. It can also prevent the rolling elements 12a from becoming too hot.

[0074] [Modifications of Magnetic Adsorption Mechanism] Figures 25 to 27 are front views showing modifications of the magnetic adsorption mechanism 13. As shown in Figures 25 to 27, the magnetic adsorption mechanism 13 can be configured to have multiple adsorption portions 13a as needed. With this configuration, arranging stronger adsorption portions 13a makes it easier to ensure a stronger attraction force. The shape and arrangement of the adsorption portions 13a can be modified in various ways.

[0075] While the above describes exemplary embodiments of the present invention, the above embodiments are merely examples and are not intended to limit the scope of the invention. The above embodiments can be implemented in various other forms, and various omissions, substitutions, combinations, and modifications can be made without departing from the spirit of the invention. Furthermore, the specifications of each configuration, shape, and the like (structure, type, direction, model, size, length, width, thickness, height, number, arrangement, position, material, etc.) can be appropriately modified and implemented.

[0076] For example, the magnetic attraction mechanism may include an electromagnet.

[0077] The present invention can be used in a moving body, a laser surface treatment system, and a laser surface treatment method.

[0078] DESCRIPTION OF SYMBOLS 10, 10A to 10J... Moving body 11... Base (support member) 11a... Outer frame 11b... Beam 11c... Plate 11d... Joint portion 11e... Cable holding portion 12... Moving mechanism 12a... Rolling body 12b... Motor 12c... Caster 12d... Electrical wiring cable 13... Magnetic adsorption mechanism 13a... Adsorption portion 14... Optical head 14a... Optical fiber cable 14b... DOE 14c... Lens 14d... Electrical wiring cable 15... Position change mechanism 15a... Fixed portion 15b... Movable portion 15c... Arm holder 15d... Arm 15e... Head holder 15f... Electrical wiring cable 16... Nozzle 17... Position change mechanism 18... Nozzle 19... Cover 20... Linear object 30... Cable 40... Vehicle 41... Laser unit (light source device) 42...Power supply unit 43...Control circuit 44...Laser cooling mechanism 45...Gas delivery mechanism 46...Dry ice delivery mechanism 47...Dust collection mechanism 48...Housing 50...Exhaust duct 61...Suction mechanism (foreign matter removal mechanism) 62...Blower (foreign matter removal mechanism) 62a...Delivery duct 63...Cleaning mechanism 64...Distance variable mechanism 65...Temperature sensor 100...Laser surface treatment system Ac...Contact area As...Suction area Ax...Axis B...Beam G...Gas g...Gap (distance) L...Laser light P...Virtual irradiation surface P1 to P6...Position W...Wall Wa...Surface X...Direction Y...Direction Z...Direction (movement direction, opposite direction to movement direction)

Claims

1. A mobile body that processes the surface of a ship's wall by irradiating the surface with laser light while moving along the surface, comprising: a moving mechanism including a plurality of rolling elements that roll along the surface; a magnetic attraction mechanism that is provided separately from the rolling elements, faces the surface at a distance, and presses the rolling elements against the surface by generating a magnetic attraction force between the rolling elements and the wall; and an optical head that irradiates the laser light toward the wall.

2. The moving body according to claim 1, wherein the opposing area of ​​the surface facing the magnetic attraction mechanism is located between a plurality of contact areas of the surface with the rolling element.

3. A moving body according to claim 1, comprising: a support member that supports said moving mechanism and said magnetic attraction mechanism; and a position changing mechanism that can change the position of said optical head relative to said support member.

4. A moving body as described in claim 3, wherein the position change mechanism is capable of changing the position of the optical head so that laser light can be irradiated to the contact area with the rolling body on the surface, behind the rolling body in the direction of travel.

5. A moving body as described in claim 3, wherein the position change mechanism is capable of changing the position of the optical head so that laser light can be irradiated to a position that is off the contact area with the rolling body on the surface in a direction that intersects with the direction of travel of the rolling body.

6. A moving body as described in claim 3, wherein the position change mechanism is capable of changing the position of the optical head so that laser light can be irradiated to a position above the opposing area on the surface facing the magnetic adsorption mechanism.

7. A moving body according to claim 3, further comprising a connecting portion provided on said support member to which a linear object for suspending said support member is connected.

8. A moving body according to claim 7, wherein said position changing mechanism is capable of changing the position of said optical head so that said laser light passes between said coupling portion and said magnetic attraction mechanism and is irradiated onto said surface.

9. A moving body as described in claim 3, comprising a cable holding section provided on the support member for holding in a flexible state a cable including at least one of an optical fiber for transmitting laser light toward the optical head and an electrical wiring for supplying power to drive the moving mechanism.

10. The moving body according to claim 3, wherein the position changing mechanism is configured to be electrically operable.

11. The moving body according to claim 10, wherein the position changing mechanism moves the optical head back and forth between predetermined positions.

12. The moving body according to claim 1, wherein the optical head comprises a diffractive optical element that splits the laser light into a plurality of beams, and a rotation mechanism that rotates the diffractive optical element around the optical axis of the laser light.

13. The moving body according to claim 1, further comprising a nozzle for supplying a fluid to the surface, the rolling body, or the optical head.

14. A moving body according to claim 1, further comprising at least one of a foreign matter removal mechanism for removing foreign matter between said magnetic attraction mechanism and said surface and a cleaning mechanism for cleaning said surface.

15. A moving body according to claim 1, comprising a distance varying mechanism that can change the distance between said optical head and said surface.

16. A laser surface treatment system comprising: a moving body according to any one of claims 1 to 15; a light source device optically connected to the optical head via an optical fiber and emitting laser light; and a power supply device electrically connected via an electric wire to an electric actuator that operates the moving mechanism.

17. The laser surface treatment system according to claim 16, further comprising a movable base on which the light source device and the power supply device are mounted and which is movable.

18. A laser surface treatment method comprising: a mobile body that treats the surface of a ship's wall by irradiating the surface with laser light while moving along the surface, the mobile body comprising: a moving mechanism including a plurality of rolling bodies that roll along the surface; a magnetic attraction mechanism that is provided separately from the rolling bodies, faces the surface at a distance, and presses the rolling bodies against the surface by generating a magnetic attraction force between it and the wall; and an optical head that irradiates the wall with laser light, the mobile body being placed on the surface by operating the magnetic attraction mechanism; and a process of treating the surface by moving the mobile body along the surface while irradiating the surface with laser light.

19. A laser surface treatment method according to claim 18, wherein the irradiation position of the laser light on the surface is located behind the contact area with the rolling element in the direction of movement of the rolling element, or is located away from the contact area with the rolling element in a direction intersecting the direction of travel of the rolling element.

20. A laser surface treatment method according to claim 18, wherein in the step of treating the surface, the power of the laser beam is feedback-controlled so that the detected temperature of the surface falls within a predetermined temperature range.

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