Portable laser surface treatment device

Abstract

This portable laser surface treatment device for outputting a laser beam toward the surface of an object to treat said surface includes, e.g., a housing, a beam shaper that is accommodated within the housing and is supported by the housing so as to be capable of rotating or moving in a reciprocal manner, an optical component that is fixed to the housing, and an operation mechanism for rotating or reciprocally moving the beam shaper. The laser beam that is introduced into the housing and passes through the optical component and the beam shaper is outputted, and a spot of the outputted laser beam is capable of rotating or reciprocally moving on the surface. The beam shaper may be a diffractive optical element.

Description

Portable Laser Surface Treatment Device

[0001] The present invention relates to a portable laser surface treatment device.

[0002] Conventionally, a method of removing a coating film or an adherent on the surface of a structure by irradiating laser light is known (for example, Patent Document 1).

[0003] Japanese Patent No. 5574354

[0004] In the method of Patent Document 1, the irradiation point of the laser light is rotationally scanned in a circular shape to remove the coating film on the surface.

[0005] In this type of portable laser surface treatment device, it would be beneficial to obtain a portable laser surface treatment device that can further reduce variations and unevenness in the treatment state depending on the location.

[0006] Therefore, one of the problems of the present invention is to obtain an improved and novel portable laser surface treatment device that can further reduce variations and unevenness in the treatment state depending on the location, for example.

[0007] The portable laser surface treatment device of the present invention is, for example, a portable laser surface treatment device that outputs laser light toward the surface of an object to perform treatment on the surface, and includes a housing, a beam shaper housed in the housing and supported by the housing so as to be rotatable or reciprocally movable, an optical component fixed to the housing, and an operating mechanism for rotating or reciprocally moving the beam shaper. The laser light introduced into the housing and passing through the optical component and the beam shaper is output, and the spot of the output laser light can be rotated or reciprocated on the surface.

[0008] In the portable laser surface treatment device, the beam shaper may be a diffractive optical element.

[0009] The portable laser surface treatment device may include a shielding structure that is housed in the housing and forms a wall intervening between the optical path of the laser light and the operating mechanism.

[0010] In the portable laser surface treatment device, the shielding structure may have a cylindrical portion surrounding the optical path of the laser light.

[0011] In the portable laser surface treatment apparatus, the shielding structure may have a plate-shaped, annular disc portion that faces the axial end of the cylindrical portion and intersects with the axial direction.

[0012] In the portable laser surface treatment apparatus, the beam shaper may be rotatably supported in the housing around a rotation axis substantially parallel to the axial direction, and the disc portion may be separated from the cylindrical portion with a gap in the axial direction and configured to rotate in conjunction with the rotation of the beam shaper.

[0013] In the portable laser surface treatment apparatus, the beam shaper is rotatably supported in the housing, the operating mechanism includes a motor having a shaft, a ring gear integrated with the beam shaper and configured in an annular shape with external teeth surrounding the optical path of the laser beam, and a rotational transmission mechanism that transmits rotational power from the shaft to the external teeth, and the shielding structure may have a cylindrical portion that surrounds the optical path of the laser beam and is interposed between the optical path and the motor.

[0014] In the portable laser surface processing apparatus, the shielding structure may have a disc portion that is separated from the cylindrical portion by a gap in the axial direction of the rotation axis of the beam shaper, and is configured as a plate-like and annular shape intersecting the axial direction, and rotates in conjunction with the rotation of the beam shaper.

[0015] The portable laser surface treatment apparatus may include a light-emitting unit fixed to the housing and outputting inspection light toward a detection position on the disc away from the rotation axis of the beam shaper; a detection unit provided on the disc and configured such that the transmission or reflection state of the inspection light at the detection position switches as the disc rotates; and a sensor that receives transmitted or reflected light from the detection unit, and may also include a rotation speed detection mechanism that detects the rotation speed of the beam shaper based on the time interval of light reception by the sensor.

[0016] In the portable laser surface processing apparatus, the detected position may be further away from the rotation axis than the cylindrical portion of the disc portion.

[0017] The portable laser surface treatment apparatus comprises a cylindrical holder to which the beam shaper and the ring gear are fixed, and the ring gear may be fixed to the outer circumference of the holder.

[0018] In the portable laser surface treatment apparatus, the fixing position of the beam shaper in the holder and the fixing position of the ring gear may be offset in the axial direction of the rotation axis of the beam shaper.

[0019] In the aforementioned portable laser surface treatment apparatus, the operating mechanism may have a power transmission part made of synthetic resin that transmits rotational power.

[0020] According to the present invention, for example, a novel, more improved portable laser surface treatment apparatus can be obtained.

[0021] Figure 1 is an exemplary schematic configuration diagram of the laser surface treatment system of the embodiment. Figure 2 is an exemplary and schematic side view of the portable laser surface treatment apparatus of the embodiment. Figure 3 is an exemplary and schematic rear view of the portable laser surface treatment apparatus of the embodiment. Figure 4 is an exemplary and schematic perspective view showing the internal configuration of the portable laser surface treatment apparatus of the embodiment. Figure 5 is an exemplary and schematic perspective view showing the internal configuration of the portable laser surface treatment apparatus of the embodiment, viewed from a different direction than Figure 4. Figure 6 is an exemplary and schematic cross-sectional view of a part of the portable laser surface treatment apparatus of the embodiment. Figure 7 is an explanatory diagram illustrating the concept of the principle of the diffractive optical element included in the portable laser surface treatment apparatus of the embodiment. Figure 8 is a schematic plan view showing an example of a spot pattern formed on a virtual irradiation surface by the portable laser surface treatment apparatus of the embodiment. Figure 9 is a schematic plan view showing an example of a spot pattern formed on a virtual irradiation surface by the portable laser surface treatment apparatus of the embodiment. Figure 10 is a schematic plan view showing an example of a spot pattern formed on a virtual irradiation surface by the portable laser surface treatment apparatus of the embodiment. Figure 11 is an illustrative diagram showing part of the circuit configuration of a portable laser surface treatment apparatus according to an embodiment. Figure 12 is an exemplary and schematic perspective view showing the internal configuration of the grip of a portable laser surface treatment apparatus according to an embodiment. Figure 13 is an exemplary and schematic cross-sectional view of part of a portable laser surface treatment apparatus according to another embodiment.

[0022] Illustrative embodiments of the present invention are disclosed below. The configurations of the embodiments shown below, as well as the actions and results (effects) brought about by such configurations, are examples only. The present invention can also be realized by configurations other than those disclosed in the following embodiments. Furthermore, according to the present invention, it is possible to obtain at least one of the various effects (including derived effects) that can be obtained by the configuration.

[0023] Furthermore, in this specification, ordinal numbers are assigned for convenience to distinguish directions, spots, the radius of the circle around which those spots are located, the position of those spots, etc., and do not indicate priority or order, nor do they limit the number of elements.

[0024] Furthermore, in the following explanation, in patterns containing multiple spots, unless otherwise specified, the power densities of the multiple spots are assumed to be approximately the same. Also, in each plan view showing the pattern on the virtual illumination surface, the arrangement of the multiple spots is shown in an unrotated state.

[0025] [Laser Surface Treatment System] Figure 1 is a diagram showing the schematic configuration of the laser surface treatment system 100 according to the embodiment. As shown in Figure 1, the laser surface treatment system 100 comprises a portable laser surface treatment device 200, a mounting device 300, and a cable 400.

[0026] The portable laser surface treatment apparatus 200 irradiates the surface 1a of the object 1 to be treated with laser light L. By irradiating with laser light L under appropriate conditions, laser ablation occurs on the surface 1a at the location irradiated with laser light L and in its vicinity, and a thin layer of the surface is removed. At this time, along with the material constituting the body (base material) including the surface 1a of the object 1, dirt, rust, coatings, paints, and other coatings on the surface 1a are removed. In other words, the portable laser surface treatment apparatus 200 can remove the surface layer of the surface 1a and perform cleaning. Object 1 is an example of an object to be surface treated.

[0027] Object 1 encompasses a wide range of items, such as buildings, structures, architectural materials, steel plates, bridge girders, concrete, and the products, parts, and objects that make them up. Furthermore, the materials that constitute Object 1 are, for example, metal, concrete, mortar, etc., but are not limited to these.

[0028] Operator W uses the portable laser surface treatment device 200 by gripping it. Operator W can change the position of the portable laser surface treatment device 200 by changing their own position. Operator W can also change the output direction of the laser beam L from the portable laser surface treatment device 200 by changing the orientation of the portable laser surface treatment device 200. In other words, by changing the position and orientation of the portable laser surface treatment device 200, operator W can change the position on the surface 1a where the laser beam L is irradiated and the surface layer is removed, and perform the work of removing the surface layer over a wide area of ​​the surface 1a.

[0029] The mounted device 300 includes various components such as a light source 301, a power supply 302, and a cooling system 303. These components are bulky and heavy, making them difficult to mount on the portable laser surface treatment device 200. Therefore, the laser surface treatment system 100 separates the components mounted on the mounted device 300 from the portable laser surface treatment device 200, and connects the mounted device 300 and the portable laser surface treatment device 200 with a cable 400, thereby reducing the weight and size of the portable laser surface treatment device 200. Furthermore, the cable 400 is made relatively long so that surface 1a can be treated over a relatively wide area away from the mounted device 300.

[0030] Furthermore, the mounted device 300 is a mobile body configured to be movable, such as a truck (automobile, vehicle). Because the mounted device 300 is movable, the location where the surface removal process by the laser surface treatment system 100 is performed can be easily changed. Note that the mounted device 300 is not limited to automobiles, but may be other vehicles such as trains, or ships, etc. Also, the mounted device 300 does not need to have its own power source, such as a trailer.

[0031] The light source device 301 is equipped with a laser oscillator and is configured to output laser light with a power of 6000 [W], for example. The laser oscillator is an example of a laser device. The wavelength of the laser light output by the laser oscillator is, for example, 400 [nm] or more and 1200 [nm] or less. The laser oscillator is typically a fiber laser oscillator with a wavelength of 1070 [nm]. However, the laser oscillator may also be a semiconductor laser oscillator with a wavelength of 940 [nm], a semiconductor laser oscillator with a wavelength of 450 [nm], or a disk laser or solid-state laser with a wavelength of 1064 [nm].

[0032] The light source device 301 and the portable laser surface treatment device 200 are optically connected via an optical fiber cable 401. The optical fiber cable 401 has an optical fiber (not shown) having a core and a cladding surrounding the core. The optical fiber transmits the laser light output from the light source device 301 to the portable laser surface treatment device 200.

[0033] For application to relatively large objects 1 such as buildings, structures, and architectural structures, the length of the optical fiber cable 401 and, by extension, the cable 400 is set to, for example, 5 [m] or more and 300 [m] or less, so that a relatively long distance can be secured between the light source device 301 and the portable laser surface treatment device 200. Because there is a trade-off relationship between light density and the transmittable cable length due to the energy shift caused by stimulated Raman scattering, in order to realize the transmission of laser light over such long distances, the diameter of the optical fiber core is preferably 50 [μm] or more, more preferably 80 [μm] or more, and even more preferably 100 [μm] or more.

[0034] Furthermore, in order to obtain a high-quality processed surface (surface layer removal surface) with less processing unevenness and high shape accuracy, it is essential to maintain high quality laser light output from the optical fiber to the portable laser surface processing device 200. From this perspective, the optical fiber, with the above-mentioned length and diameter specifications, has a high M laser light output from the optical fiber. ２ The beam quality is set to below a predetermined value. ２ Beam quality is M ２It can also be called a factor.

[0035] If the optical fiber is a single-mode optical fiber, M ２ The beam quality is set to 1.5 or less, in which case the laser output is set to between 300 [W] and 5000 [W].

[0036] Furthermore, if the optical fiber is a multimode optical fiber, M ２ The beam quality is set to 10 or less, in which case the laser output is set to between 500 [W] and 20,000 [W].

[0037] The power supply unit 302 includes, for example, a battery or a generator, and supplies the portable laser surface treatment device 200 with the power necessary for each part of it to operate. Power is supplied to the portable laser surface treatment device 200 from the power supply unit 302 via the electrical cable 402.

[0038] Furthermore, the cooling device 303 includes, for example, a tank for storing a refrigerant such as a cooling liquid, and a pump for discharging the refrigerant, and supplies the refrigerant to the portable laser surface treatment apparatus 200 to cool its various parts. The portable laser surface treatment apparatus 200 is supplied with refrigerant from the cooling device 303 via the refrigerant tube 403.

[0039] [Portable Laser Surface Processing Device] The portable laser surface processing device 200 is an optical device that outputs laser light input from the light source device 301 via an optical fiber cable 401, through a plurality of built-in optical components 202 (see Figure 4), and irradiates the target object 1 in an appropriate state. The laser light output from the portable laser surface processing device 200 is a continuous wave.

[0040] Figure 2 is a side view of the portable laser surface treatment apparatus 200, and Figure 3 is a rear view of the portable laser surface treatment apparatus 200. As shown in Figures 2 and 3, the portable laser surface treatment apparatus 200 comprises a housing 201 and a grip 230.

[0041] As shown in FIG. 2, the housing 201 has a connector 203LR. A connector 203LP fixed to the optical fiber cable 401 is detachably attached to the connector 203LR. In a state where the connector 203LP is attached to the connector 203LR, laser light is introduced into the housing 201 from the optical fiber cable 401.

[0042] The laser light L is transmitted in the substantially X direction via a plurality of optical components 202 in the housing 201 and is output in the substantially X direction outside the housing 201. The housing 201 has a cylindrical structure extending in the X direction.

[0043] The grip 230 protrudes from the housing 201 in a direction intersecting the X direction, in the example of FIGS. 2 and 3, in the opposite direction of the Z direction. An operator W who performs laser surface treatment irradiates the laser light L toward a predetermined target on the surface 1a of the object 1 separated from the housing 201 in the X direction as shown in FIG. 1 while gripping the grip 230. As shown in FIG. 2, a lock lever 230a is provided on the grip 230 or the housing 201 as an operation unit for switching the irradiation enable / disable state. When emitting the laser light L, the operator W first moves the lock lever 230a from the prohibited position Pd where the trigger 230b cannot be operated to the allowable position Pe where the trigger 230b can be operated (see FIG. 12). Thereby, the lock of the trigger 230b is released, and the laser light L can be emitted. In that state, the grip 230 is gripped and both the trigger 230b and the push button 230c are pressed. Thereby, the laser light L is output from the housing 201. The laser surface treatment system 100 is configured such that when either the trigger 230b or the push button 230c is released, the output of the laser light L stops.

[0044] As shown in FIG. 3, the housing 201 has an inner housing 201I, an outer housing 201O, and a shaft 201S. The laser beam L passes through the inner housing 201I, and the outer housing 201O covers the inner housing 201I with a gap therebetween. The shaft 201S is a rod-shaped member extending in the Y direction and connects the inner housing 201I and the outer housing 201O. The inner housing 201I, the outer housing 201O, and the shaft 201S are made of a metal material having relatively high thermal conductivity, such as an aluminum-based material or an iron-based material, for example.

[0045] The outer housing 201O has various effects. For example, if there were no outer housing 201O, when the operator W accidentally drops the portable laser surface treatment apparatus 200 onto the ground, the housing (inner housing 201I) in which the optical component 202 is housed would be directly impacted, and there is a risk that not only the housing but also the optical component 202 housed in the housing would be damaged or broken. That is, in the present embodiment, the outer housing 201O functions as a protective member or a shock-absorbing member that surrounds the inner housing 201I. Further, on the outer surfaces of the outer housing 201O and the grip 230, buffer members 201a and 230d, such as silicone rubber, are provided, for example, to further improve protection and shock absorption.

[0046] Further, since the laser beam L is transmitted inside the inner housing 201I, the temperature may become relatively high. In this regard, according to the present embodiment, even if the inner housing 201I becomes high temperature, the outer housing 201O can prevent the operator W from directly contacting the high-temperature inner housing 201I.

[0047] Further, the outer housing 201O is thermally connected to the inner housing 201I via the shaft 201S. And, as shown in FIG. 2, a number of holes are provided in the outer housing 201O to improve heat dissipation. That is, the outer housing 201O also contributes to improving the heat dissipation from the housing 201.

[0048] Furthermore, as shown in Figure 3, the inner housing 201I is provided with an electrical wiring connector 203ER. The electrical wiring inside the inner housing 201I or grip 230 is electrically connected to the electrical wiring inside the electrical cable 402 via the connector of the electrical cable 402, which is detachably attached to the connector 203ER.

[0049] [Internal Structure] Figures 4 and 5 are perspective views showing the internal structure of the portable laser surface treatment apparatus 200. The inner housing 201I has a first housing 201I1 (see Figure 4) and a second housing 201I2 (see Figure 5).

[0050] The first housing 201I1 is made of, for example, a metal material and has a box-like shape with a predetermined thickness for housing the components. The first housing 201I1 houses a plurality of optical components 202, a motor 204, a pinion gear 205, a cover 206, a rotation speed detection mechanism 220, and the like.

[0051] In this embodiment, the first housing 201I1 is, as an example, constructed by integrating two parts that are divided in the center in the Y direction. Figures 4 and 5 show a state in which the part in front of the center in the Y direction in the Y direction has been removed, leaving only the part in the rear in the Y direction.

[0052] A sealing member 208 is interposed at the boundary between the two parts constituting the first housing 201I1. The sealing member 208 ensures airtightness and liquid tightness at the boundary.

[0053] As shown in Figure 5, the second housing 201I2 is provided so as to cover the opening 201b located at the X-direction end of the first housing 201I1. A sealing member 208 is interposed at the boundary between the first housing 201I1 and the second housing 201I2 around the opening 201b, thereby ensuring airtightness and liquid tightness at the boundary.

[0054] As shown in Figure 4, a cover 206 is housed inside the first housing 201I1. The cover 206 has a cylindrical shape extending in the X direction and is fixed to the first housing 201I1 via a screw-like coupling. Inside the cover 206 are collimating lenses 202a and 202b, which serve as optical components 202, collimating the laser beam L traveling in the X direction in both the fast and slow axes. The collimating lenses 202a and 202b are examples of optical components fixed to the housing 201 via the cover 206. In Figures 4 to 6, Ax is the central axis of the cylindrical portion of the cover 206 and approximately coincides with the optical axis of the laser beam L passing through the cover 206. Furthermore, the central axis Ax is also the rotation center of the rotating assembly 210 (see Figure 6), which will be described later, i.e., the rotation center of the bearing 215. However, it is not essential that these central axes coincide. The cover 206 is an example of a cylindrical portion that surrounds the optical path of the laser beam L, and the X direction is the axial direction of the cover 206.

[0055] Figure 6 is a cross-sectional view including the second housing 201I2 and the rotating assembly 210. The second housing 201I2 has a stepped cylindrical shape with multiple sections of different diameters. The second housing 201I2 houses the rotating assembly 210 within its cylinder and supports the rotating assembly 210 so as to be rotatable around its central axis Ax via a bearing 215.

[0056] The rotating assembly 210 includes a holder 211, a ring gear 212, a DOE assembly 213, and a pressing plate 214. The rotating assembly 210 is a structure for rotating the c (DOE: diffractive optical element) included in the DOE assembly 213 around the central axis Ax. The effects of rotating the DOE 202c will be described later.

[0057] The holder 211 has a cylindrical and rotating shape, and the laser beam L passes through the inside of the cylinder in the X direction. A ring gear 212 is fixed to the end of the holder 211 opposite to the X direction. The ring gear 212 has external teeth 212a on its outer circumference that face outward in the circumferential direction. The ring gear 212 surrounds the end of the holder 211 opposite to the X direction and is fixed to the holder 211 by means of press-fitting, bonding, or joining with a joint.

[0058] The DOE assembly 213 has a generally cylindrical shape and includes two protective members 213a located at both ends in the X direction, a DOE 202c as an optical component 202 located between the two protective members 213a, and a ring member 213b located between the protective members 213a and the DOE 202c. These protective members 213a, DOE 202c, and ring member 213b are integrated by means of adhesive, for example. The protective member 213a is made of a transparent material such as glass that transmits laser light L. The ring member 213b may also be called a spacer.

[0059] Figure 7 is an explanatory diagram illustrating the concept of the DOE202c principle. As conceptually illustrated in Figure 7, the DOE202c has a configuration in which, for example, multiple diffraction gratings 202c1 with different periods are superimposed. The DOE202c can shape the beam by bending or superimposing parallel light in the direction influenced by each diffraction grating 202c1.

[0060] By having a beam shaper such as the DOE202c, the portable laser surface treatment apparatus 200 divides the laser light into multiple beams, each with appropriately adjusted power. From the portable laser surface treatment apparatus 200, the laser light L, which has multiple beams, is output in the X direction toward the surface 1a, and multiple spots (spot patterns) are formed on the surface 1a by these multiple beams. The spots may be spaced apart from each other or connected.

[0061] The DOE assembly 213 is housed in the inner circumferential surface 211a of the holder 211 from the opposite direction of the X direction. The inner circumferential surface 211a has a multi-stage stepped shape in which the diameter decreases as it moves toward the opposite direction of the X direction. The DOE assembly 213 is housed in a state where it abuts against a stepped surface facing the X direction, which is located in the middle part of the inner circumferential surface 211a in the X direction.

[0062] An internal thread 211b is provided at the X-direction end of the inner circumferential surface 211a, having an internal diameter larger than the external diameter of the DOE assembly 213. An external thread 214a that engages with the internal thread 211b is provided on the outer circumferential surface of the pressing plate 214. By rotating the pressing plate 214 with the external thread 214a engaged with the internal thread 211b and fitting it onto the inner circumferential surface 211a, the DOE assembly 213 can be fixed to the holder 211 by pressing the DOE assembly 213 in the opposite direction of the X-direction. The rotating assembly 210 may be provided with a loosening prevention structure to prevent loosening of the engagement between the internal thread 211b and the external thread 214a. Furthermore, by removing the pressing plate 214, the DOE assembly 213 including the DOE 202c can be replaced with a different DOE assembly 213 including a different DOE 202c that forms a different spot pattern.

[0063] As is clear from Figure 6, in the rotary assembly 210, the fixing position of the ring gear 212 relative to the holder 211 and the fixing position of the DOE assembly 213 are offset from each other in the X direction. This makes it possible to suppress the application of greater forces to the DOE assembly 213 depending on the pressing force when mounting or fixing the ring gear 212 to the holder 211, or the rotational power acting on the ring gear 212.

[0064] The bearing 215 is, for example, a radial ball bearing. In this case, the outer race is mounted on the second housing 201I2, and the inner race is mounted on the holder 211.

[0065] As shown in Figure 4, a pinion gear 205 is fixed to the shaft 204a of the motor 204. The pinion gear 205 rotates together with the shaft 204a. The pinion gear 205 also meshes with the external teeth 212a of the ring gear 212. Therefore, the rotational power of the shaft 204a of the motor 204 is transmitted to the pinion gear 205 and the external teeth 212a of the ring gear 212, causing the rotating assembly 210 having the ring gear 212 to rotate. In other words, the motor 204, pinion gear 205, and ring gear 212 are an example of an operating mechanism. Furthermore, the pinion gear 205 and ring gear 212 are an example of a rotation transmission mechanism.

[0066] In this structure, the peripheral wall of the cover 206 is interposed between the inside of the cover 206 and the motor 204. The peripheral wall of the cover 206 suppresses stray light from the laser beam L passing through the inside of the cylinder from being directed toward the motor 204. If stray light were to irradiate the motor 204, there is a risk that the motor 204 would overheat. In this regard, according to this structure, the peripheral wall of the cover 206 can suppress stray light from the laser beam L from irradiating the motor 204. The peripheral wall constitutes a wall interposed between the optical path of the laser beam L and the motor 204, and the cover 206 is an example of a shielding structure.

[0067] Furthermore, as shown in Figures 4 and 5, an annular disc portion 222 is fixed to the end of the ring gear 212 opposite to the X direction, having a substantially constant thickness in the X direction and extending in a direction intersecting the X direction. The disc portion 222 faces the end of the cylindrical portion of the cover 206 in the X direction, and is separated from that end with a small gap. The disc portion 222 also protrudes radially inward from the position facing the end of the cover 206 in the central axis Ax direction. That is, at the end in the X direction, the disc portion 222 covers the portion of the cover 206 that is close to the peripheral wall inside the cylinder from the opposite side of the connector 203LR. With this configuration, it is possible to suppress stray light of the laser beam L from leaking out of the cylinder of the cover 206 at the end of the cover 206 in the X direction, and prevent the stray light from adversely affecting components inside the inner housing 201I. The disc portion 222 is an example of a shielding structure.

[0068] Furthermore, as shown in Figures 4 and 5, the disc portion 222 is also a component of the rotational speed detection mechanism 220. The rotational speed detection mechanism 220 includes a light-emitting unit 221, a disc portion 222, and a sensor 223. The light-emitting unit 221 is located away from the central axis Ax and outputs inspection light substantially parallel to the central axis Ax, i.e., along the X direction. The disc portion 222 is provided with a plurality of apertures 222o that transmit the inspection light emitted from the light-emitting unit 221 at the location where the light reaches, i.e., at a location away from the central axis Ax. Therefore, depending on the rotation of the disc portion 222, the inspection light from the light-emitting unit 221 switches between a state in which it passes through the apertures 222o and a state in which it does not pass through the disc portion 222 or is reflected by the disc portion 222. The sensor 223 is a sensor that can detect the inspection light, and is, for example, a photodiode. In this embodiment, the sensor 223 is positioned in the X direction, aligned with the light-emitting unit 221 and the aperture 222o, and on the opposite side of the disc portion 222 from the light-emitting unit 221, so as to be able to detect the inspection light transmitted through the aperture 222o. Therefore, the sensor 223 can detect the inspection light when the disc portion 222 is positioned at an angle in which the inspection light passes through the aperture 222o, but cannot detect the inspection light when the angle in which the inspection light is blocked or reflected by the disc portion 222. The multiple apertures 222o are provided at predetermined angular intervals around the central axis Ax, for example, at approximately constant angular intervals. Therefore, the rotational speed of the disc portion 222, i.e., DOE 202c, can be measured based on the time interval in which the inspection light is detected by the sensor 223. In this embodiment, the sensor 223 detects the inspection light transmitted through the aperture 222o, but is not limited to this, and may also detect the reflected light reflected by the disc portion 222. In this case, the sensor 223 is provided on the same side as the light-emitting unit 221. Furthermore, in this case, the sensor 223 may be configured as a single unit housed in the same housing as the light-emitting unit 221. In the rotational speed detection mechanism 220, the disc portion 222 provided with a plurality of openings 222o is an example of the part to be detected, and the openings 222o of the disc portion 222, and the portion of the disc portion 222 aligned in the circumferential direction with respect to the openings 222o and the central axis Ax, are examples of the position to be detected.

[0069] In this embodiment, the detection position of the disc portion 222 is located further from the central axis Ax than the peripheral wall of the cover 206. If the opening 222o, which is the detection position, were located closer to the central axis Ax than the peripheral wall, there would be a risk of stray light leaking out of the opening 222o. In this embodiment, however, since the detection position is located further from the central axis Ax than the peripheral wall, stray light does not leak out of the cover 206 through the opening 222o.

[0070] Furthermore, in this structure, at least the external teeth of the pinion gear 205 and at least the external teeth 212a of the ring gear 212 are made of synthetic resin material. These external teeth are an example of a power transmission part. Metal gears can generate wear particles. Therefore, if the gears (teeth) of these power transmission parts were made of metal material and wear particles were generated, these wear particles could adhere to the optical component 202, reducing the transmission efficiency of the laser light L, or adhere to the components of the rotational speed detection mechanism 220, hindering the transmission and detection of the detection light. In this embodiment, however, the power transmission parts are made of synthetic resin material, which generates less wear particles compared to when they are made of metal material, thus making such undesirable phenomena less likely to occur.

[0071] Furthermore, the shielding structure, including the cover 206 and the disc portion 222, also suppresses stray light from the laser beam L from reaching the power transmission part. If stray light is irradiated onto a power transmission part made of synthetic resin material, there is a risk that the power transmission part will deteriorate. In this embodiment, since the shielding structure can suppress stray light from reaching the power transmission part, the probability of deterioration of the power transmission part due to irradiation with stray light can be reduced, and consequently, it becomes easier to use synthetic resin material for the power transmission part, thereby making it easier to obtain the advantage of suppressing the generation of wear particles.

[0072] Furthermore, as shown in Figure 4, a lens 202d is fixed to the housing 201 via a holder 207 at a position away from the rotating assembly 210 in the X direction. The holder 207 may be supported in an inner housing 201I, for example, a second housing 201I2, so as to be able to change its position in the X direction. The lens 202d is an example of an optical component fixed to the housing 201 via the holder 207.

[0073] [Spot Pattern] Due to the rotation of the DOE 202c accompanying the rotation of the rotating assembly 210 described above, the spot of the laser beam L rotates around the rotation center C on the surface 1a and on a virtual irradiation surface Pv that is separated from the portable laser surface processing device 200 in the Z direction and intersects and is orthogonal to the Z direction (see Figure 8).

[0074] Here, the actual surface 1a of object 1 is not necessarily planar, nor is it necessarily perpendicular to the Z direction. For this reason, it can be difficult to determine the configuration and arrangement of spots on surface 1a. Therefore, in this embodiment, the shape and arrangement of the laser beam L spots are determined on a virtual irradiation surface Pv that is perpendicular to the Z direction, i.e., the output direction of the laser beam L, and is located away from the portable laser surface processing device 200. In other words, the virtual irradiation surface Pv is a virtual plane for determining the configuration and arrangement of the laser beam L spots, and can also be called an identification plane or a detection plane. In this way, by comparing the configuration and arrangement of spots formed by the laser beam L on the virtual irradiation surface Pv, it is possible to determine the agreement or disagreement between the configuration and arrangement of spots between the portable laser surface processing device of this embodiment and another portable laser surface processing device. The virtual irradiation surface Pv may be defined, for example, as a surface located at a distance from the portable laser surface processing apparatus 200 that is the center of the design range of the distance between the portable laser surface processing apparatus 200 and the surface 1a, or as a surface located at a position that partially overlaps with the surface 1a.

[0075] According to this embodiment, the DOE202c, acting as a beam shaper, splits the laser beam into multiple beams. By further rotating the DOE202c, spots corresponding to multiple beams can be rotated on the surface 1a, thereby increasing the area of ​​the surface 1a that can be processed simultaneously. In addition, the energy density at each position on the surface 1a can be set lower, which has the advantage of mitigating the thermal effects on areas deeper than the surface to be processed. When the target object is metal, the formation of a surface oxide film due to thermal effects can be suppressed simultaneously with the removal of the coating, resulting in the ability to achieve both the required processing speed and quality for coating and rust removal. Furthermore, in a pattern containing multiple spots by appropriately setting the DOE202c, the arrangement of the multiple spots and the power of each spot can be appropriately set, thereby suppressing variations in the power density distribution on the surface 1a, and thus suppressing variations and uneven processing on the processed surface. Note that if only a single spot with a single beam is rotated without splitting the beam, it becomes difficult to suppress uneven processing.

[0076] Figure 8 is a plan view illustrating a pattern P1 of spots S formed on a virtual irradiation surface Pv. The pattern P1 shown in Figure 8 rotates at a constant angular velocity around the rotation center C. In this example, the laser beam L forms multiple spots S on the virtual irradiation surface Pv, away from the rotation center C, and does not form any spots that overlap with the rotation center C. In the case of pattern P1, at each position in the region away from the rotation center C on the surface 1a, the spots S pass intermittently as the pattern P1 rotates around the rotation center C, and the laser beam L is irradiated intermittently. In contrast, the spots S remain near the rotation center C, and the laser beam L is irradiated continuously there. Therefore, on the surface 1a, the region where the rotation center C is located will be more processed than the region away from the rotation center C, and consequently, there is a risk that the difference in processing state depending on the location on the surface 1a will be large. In this regard, as shown in pattern P1 in Figure 8, when there is no spot S that coincides with the rotation center C, it is possible to suppress the continuous irradiation of the laser beam L in the vicinity of the rotation center C, and consequently, to suppress large differences in the processing state depending on the location on the surface 1a. In reality, however, it is unlikely that the rotation center C will remain completely still, so in the case of pattern P1, there will be virtually no areas where the laser beam L is not irradiated locally and therefore the surface is not treated.

[0077] Figure 9 is a plan view illustrating a pattern P2 of spots S formed on a virtual irradiation surface Pv. As shown in Figure 9, pattern P2 includes multiple spots S of multiple beams of laser light L, each at a different distance from the rotation center C. In a plan view with respect to the virtual irradiation surface Pv, the multiple spots S are arranged in two rows at predetermined intervals and staggered, substantially along the radial direction with respect to the rotation center C. The power and size of the multiple spots S are the same. In this case as well, the multiple spots S rotate on the virtual irradiation surface Pv around the rotation center C at a substantially constant angular velocity over time as the DOE202c rotates as described above.

[0078] Figure 10 is a plan view illustrating a pattern P3 of spots S formed on a virtual irradiation surface Pv. Pattern P3 also includes multiple spots S that rotate around a rotation center C, as well as multiple spots S at different distances from the rotation center C. However, in pattern P3, adjacent spots S are arranged such that the distance i between them is greater than or equal to a predetermined distance (first distance), and the difference in distance dr (i.e., difference in radius) from the rotation center C is less than the predetermined distance. The distance i is the distance between the centers (geometric centers) of the spots S. If the distance i between adjacent spots S in multiple spots S arranged along the radial direction of the rotation center C is too short, the power density may become excessively high, potentially causing melting or damage to areas deeper than the surface layer being treated. If the distance i is increased as a countermeasure, variations in the power density distribution in the radial direction may occur, potentially resulting in a situation where sufficiently treated areas and insufficiently treated areas alternate in a concentric pattern. Another approach is to reduce the power of each spot S without changing the spacing i between adjacent spots S. However, this may result in insufficient power for surface treatment or an increased time required to complete the required surface treatment. In this regard, pattern P3 is designed such that adjacent spots S are arranged such that the spacing i between them is greater than a predetermined distance, and the difference in distance dr from the rotation center C is smaller than the spacing i. This suppresses excessive energy density between adjacent spots S and allows for setting an appropriate power density while suppressing variations in the radial power density distribution. In other words, pattern P3 reduces uneven processing and shortens the time required for processing. Furthermore, in the example shown in Figure 10, since the spacing i between adjacent spots S is set to a constant (approximately the same) distance, the multiple spots S are arranged approximately along a spiral curve Cs where the angular difference with respect to the radial direction increases as the radial direction moves outward. In this embodiment, only three spot patterns are given as examples, but the examples of spot patterns are not limited to these.

[0079] [Electrical System] Figure 11 is an explanatory diagram showing a part of the circuit configuration of the portable laser surface treatment apparatus 200. As shown in Figure 11, the portable laser surface treatment apparatus 200 is provided with wiring 402a to 402d. Wiring 402a is a signal wire for switching the output of the laser light L on or off. Wiring 402b is a power supply wire that supplies power to drive the motor 204. Wiring 402c is a power supply wire that supplies power to operate the light-emitting part 221 of the rotation speed detection mechanism 220. Wiring 402d is a signal wire that transmits the detection signal from the sensor 223 of the rotation speed detection mechanism 220. These wirings 402a to 402d are introduced into the housing 201 from inside the electrical cable 402, through the connector 203EP fixed to the electrical cable 402, and through the connector 203ER provided on the housing 201. Connector 203EP is detachably connected to connector 203ER.

[0080] The wiring 402a for switching the output of the laser beam L includes two switches 231 and 232 connected in series. The laser surface treatment system 100 is configured such that the laser beam L is not output unless both the movable elements 231a and 232a of these two switches 231 and 232 are pressed, that is, the light source device 301 does not output the laser beam L.

[0081] Figure 12 is a perspective view showing the internal structure of the grip 230. As shown in Figure 12, the trigger 230b is supported on the grip 230 so as to be rotatable around a central axis Ax2 extending, for example, in the Y direction. The trigger 230b also has a lever 230b1 that presses the movable element 231a of the switch 231. The trigger 230b is configured such that the lever 230b1 presses the movable element 231a in response to an inward pushing operation of the grip 230 by the operator W.

[0082] Furthermore, the push button 230c is supported on the grip 230 so as to be rotatable around a central axis Ax3 extending, for example, in the Y direction. The push button 230c also has a lever 230c1 that presses the movable element 232a of the switch 232. The push button 230c is configured such that the lever 230c1 presses the movable element 232a in response to an inward pushing operation of the grip 230 by the operator W.

[0083] With this configuration, for example, if worker W loses their balance or falls and is unable to grasp the grip 230 in the correct posture, and is unable to press at least one of the trigger 230b and the pressure button 230c, the wiring 402a can be cut off by at least one of the switches 231 and 232. In this way, according to this embodiment, the trigger 230b and the pressure button 230c can more reliably prevent unintended output of laser light L from the portable laser surface treatment device 200.

[0084] Furthermore, in this embodiment, the lock lever 230a is supported on the grip 230 so as to be rotatable around a central axis Ax1 extending, for example, in the Y direction. The lock lever 230a is configured to be able to switch between a prohibited position Pd, which prevents the trigger 230b from moving inward from the grip 230, and a permitted position Pe, which allows the trigger 230b to move inward from the grip 230. In this configuration, the direction in which the trigger 230b moves inward from the grip and the direction in which the lock lever 230a moves from the prohibited position Pd to the permitted position Pe intersect (for example, are orthogonal). Therefore, even if the trigger 230b is pushed inward from the grip 230 by the operator W while the lock lever 230a is in the prohibited position Pd, the lock lever 230a will not move from the prohibited position Pd to the permitted position Pe due to the trigger 230b. Thus, according to this embodiment, the lock lever 230a can more reliably prevent unintended output of laser light L from the portable laser surface treatment apparatus 200.

[0085] [Another Embodiment] Figure 13 is a cross-sectional view of a portable laser surface treatment apparatus 200A of another embodiment, including a second housing 201I2 and a rotating assembly 210. As shown in Figure 13, in this other embodiment, the rotating assembly 210 has a deflection member 216 that deflects the laser light that has passed through the DOE 202c. The deflection member 216 is, for example, a wedge prism, but is not limited thereto, and may be a lens or the like. The deflection member 216 can deflect the laser light, for example, in a direction away from the central axis Ax as it moves toward the X direction.

[0086] In this configuration, multiple deflection members 216 with different deflection angles are prepared, and by removing the pressing plate 214 and replacing the deflection members 216, the distance of the spot pattern formed on the surface 1a from the rotation center C can be changed. In other words, by replacing the deflection members 216, different spot patterns can be formed on the surface 1a. Therefore, it becomes easier to obtain a spot pattern that is more suitable for the process. Generally, the deflection members 216 can be constructed at a lower cost than the DOE 202c. Therefore, with this configuration, the spot pattern can be changed at a lower cost compared to replacing the DOE 202c.

[0087] Furthermore, if a spot pattern shifted to one side of the rotation center C, as illustrated in Figures 9 and 10, is formed using only the DOE 202c, the angular difference between the zero-order light, which is roughly aligned with the optical axis, and the beams forming each spot tends to become large. In this case, there is a risk that the noise component in the DOE 202c will increase. In this respect, with the configuration that includes the deflection member 216, the direction of the zero-order light itself can be deflected, and the angular difference between the zero-order light and the beams forming each spot can be made smaller, thus suppressing the increase in the noise component in the DOE 202c. In other words, advantages such as being able to form beams with greater precision and achieving higher energy efficiency can also be obtained.

[0088] As described above, according to this embodiment, an improved and novel portable laser surface treatment apparatus 200 can be obtained that provides various effects, such as further reducing variations and unevenness in processing conditions depending on the location, suppressing adverse effects due to stray light of the laser beam L, and preventing unintended output of the laser beam L.

[0089] Although embodiments of the present invention have been illustrated above, these 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, each configuration, shape, and other specifications (structure, type, orientation, model, size, length, width, thickness, height, number, arrangement, position, material, etc.) can be modified as appropriate.

[0090] For example, the portable laser surface treatment apparatus is equipped with a mechanism for rotating the beam shaper as an operating mechanism, but instead, it may be equipped with an operating mechanism for reciprocating the beam shaper, such as a linear actuator or a mechanism having a rotational drive mechanism and a motion conversion mechanism that converts rotational motion into reciprocating motion. In this case, the portable laser surface treatment apparatus may be equipped with an actuator that generates power for reciprocating movement and a power transmission mechanism that transmits power from the actuator to the beam shaper as an operating mechanism, and may also be equipped with a shielding structure having a wall to block stray light between the operating transmission mechanism and the optical path of the laser beam.

[0091] Furthermore, the portable laser surface processing device may include a laser scanner, such as a galvanometer scanner, which scans the laser light after it has passed through a beam shaper.

[0092] This invention can be used in a portable laser surface treatment apparatus.

[0093] 1...Object (Personal object) 1a...Surface 100...Laser surface treatment system 200, 200A...Portable laser surface treatment device 201...Housing 201I...Inner housing 201I1...First housing 201I2...Second housing 201O...Outer housing 201S...Shaft 201a...Cushioning member 201b...Aperture 202...Optical component 202a, 202b...Collimating lens 202c...DOE (Beam shaper) 202c1...Diffraction grating 202d...Lens 203LR, 203LP, 203ER, 203EP...Connector 204...Motor (Operating mechanism) 204a...Shaft 205...Pinion gear (Rotation transmission mechanism, Operating mechanism) 206...Cover (Shielding structure, Wall, Cylindrical part) 207...Holder 208...Sealing member 210...Rotation assembly 211...Holder 211a...Inner circumferential surface 211b...Female thread 212...Ring gear (rotation transmission mechanism, operating mechanism) 212a...External teeth 213...DOE assembly 213a...Protective member 213b...Ring member 214...Pressing plate 214a...Male thread 215...Bearing 216...Delection member 220...Rotation speed detection mechanism 221...Light-emitting part 222...Disc part 222o...Opening (detected part) 223...Sensor 230...Grip 230a...Lock lever 230b...Trigger 230b1...Lever 230c...Pressing button 230c1...Lever 230d...Cushioning member 231...Switch 231a...Modular part 232...Switch 232a...Modular part 300...Mounting device 301...Light source device 302...Power supply device 303...Cooling device (cooling mechanism) 400...Cable 401...Optical fiber cable 402...Electrical cable 402a-402d...Wiring 403...Refrigerant tube (cooling mechanism) Ax...Central axis Ax1-Ax3...Central axis C...Center of rotation Cs...Curve dr...Difference i...Spacing L...Laser beam P1-P3...Pattern Pe...Allowable position Pd...Forbidden position Pv...Virtual irradiation surface S...Spot W...Worker X...Direction (axial direction) Y...Direction Z...Direction (first direction)

Claims

1. A portable laser surface processing apparatus for processing an object by outputting laser light toward the surface of the object, comprising: a housing; a beam shaper housed within the housing and supported by the housing so as to be rotatable or reciprocating; an optical component fixed to the housing; and an operating mechanism for rotating or reciprocating the beam shaper, wherein the laser light introduced into the housing and passing through the optical component and the beam shaper is output, and the spot of the output laser light is rotatable or reciprocating on the surface.

2. The portable laser surface processing apparatus according to claim 1, wherein the beam shaper is a diffractive optical element.

3. The portable laser surface processing apparatus according to claim 1, comprising a shielding structure housed within the housing and forming a wall interposed between the optical path of the laser beam and the operating mechanism.

4. The portable laser surface processing apparatus according to claim 3, wherein the shielding structure has a cylindrical portion surrounding the optical path of the laser light.

5. The portable laser surface processing apparatus according to claim 4, wherein the shielding structure has a plate-shaped and annular disc portion that faces the axial end of the cylindrical portion and intersects with the axial direction.

6. The portable laser surface processing apparatus according to claim 5, wherein the beam shaper is supported in the housing so as to be rotatable about a rotation axis substantially parallel to the axial direction, and the disc portion is separated from the cylindrical portion with a gap in the axial direction and configured to be rotatable in conjunction with the rotation of the beam shaper.

7. The portable laser surface treatment apparatus according to claim 3, wherein the beam shaper is rotatably supported in the housing, the operating mechanism comprises a motor having a shaft, a ring gear integrated with the beam shaper and configured in an annular shape with external teeth surrounding the optical path of the laser beam, and a rotational transmission mechanism that transmits rotational power from the shaft to the external teeth, and the shielding structure comprises a cylindrical portion that surrounds the optical path of the laser beam and is interposed between the optical path and the motor.

8. The portable laser surface processing apparatus according to claim 7, wherein the shielding structure is separated from the cylindrical portion by a gap in the axial direction of the rotation axis of the beam shaper, and has a plate-like and annular structure that intersects the axial direction, and has a disc portion that rotates in conjunction with the rotation of the beam shaper.

9. A portable laser surface processing apparatus according to claim 8, comprising: a light-emitting unit fixed to the housing and outputting inspection light toward a detection position on the disc portion away from the rotation axis of the beam shaper; a detection unit provided on the disc portion and configured such that the transmission state or reflection state of the inspection light at the detection position switches as the disc portion rotates; and a sensor that receives transmitted or reflected light from the detection unit, wherein the apparatus is further equipped with a rotation speed detection mechanism that detects the rotation speed of the beam shaper based on the time interval of light reception by the sensor.

10. The portable laser surface processing apparatus according to claim 9, wherein the detected position is further from the axis of rotation than the cylindrical portion of the disc portion.

11. The portable laser surface treatment apparatus according to claim 7, comprising a cylindrical holder to which the beam shaper and the ring gear are fixed, wherein the ring gear is fixed to the outer circumference of the holder.

12. The portable laser surface processing apparatus according to claim 11, wherein the fixing position of the beam shaper in the holder and the fixing position of the ring gear are offset in the axial direction of the rotation axis of the beam shaper.

13. The portable laser surface treatment apparatus according to claim 7, wherein the operating mechanism is made of synthetic resin and has a power transmission part that transmits rotational power.

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