Laser cleaning apparatus and laser cleaning method

Abstract

The application discloses a laser cleaning device and a laser cleaning method, and relates to the technical field of laser cleaning. The laser cleaning device is used for cleaning foreign matters to be cleaned on a base material. The laser cleaning device comprises a plurality of laser output devices and a focusing lens. The laser output device comprises a laser and a light transmission module. The light transmission module is used for transmitting a laser beam output by the laser. The focusing lens is used for receiving and converging the laser beams emitted from the plurality of light transmission modules and is arranged towards the base material. The light spots formed by the plurality of laser beams on the base material are distributed along a first direction. The plurality of laser output devices are crossed to form a plurality of laser output groups. The plurality of laser output groups are used for matching the types of the foreign matters to be cleaned.

Description

Technical Field

[0001] This invention relates to the field of laser cleaning technology, and in particular to a laser cleaning device and a laser cleaning method. Background Technology

[0002] For a long time, the shipbuilding industry has mainly relied on traditional sandblasting or chemical cleaning methods. These traditional methods have many limitations: for example, sandblasting cleaning easily generates a lot of dust and waste, which can easily lead to pneumoconiosis among workers, and the consumption of sand is large and cleaning is difficult; chemical cleaning waste liquid treatment is costly and can easily cause soil and water pollution; mechanical cleaning is inefficient, labor-intensive, and may cause mechanical damage to the hull surface and weaken the steel thickness.

[0003] Currently, laser cleaning technology, with its unique advantages of being non-contact, non-destructive, environmentally friendly, and highly efficient, is gradually becoming an ideal solution in the shipbuilding and maintenance fields. However, laser cleaning technology still has some shortcomings in practical applications, mainly that the applicable scenarios of current laser cleaning equipment are relatively limited, and it is difficult to guarantee cleaning efficiency when faced with various types of foreign objects to be cleaned. Summary of the Invention

[0004] The main objective of this invention is to propose a laser cleaning device and a laser cleaning method, aiming to improve the problem that current laser cleaning devices have limited applicable scenarios and are difficult to guarantee cleaning efficiency when faced with various types of foreign objects to be cleaned.

[0005] In a first aspect, the laser cleaning equipment provided by the present invention is used for cleaning foreign objects to be cleaned on a substrate, the laser cleaning equipment comprising: Multiple laser output devices, each laser output device including a laser and an optical transmission module, wherein the optical transmission module is used to transmit the laser beams output by the laser, and the multiple laser beams have different energy distributions; A focusing lens is used to receive and converge laser beams emitted from multiple optical transmission modules and is positioned toward the substrate, wherein the light spots formed by the multiple laser beams on the substrate are distributed along a first direction; The laser output devices are arranged in pairs to form multiple laser output groups, which are used to match the type of foreign object to be cleaned.

[0006] In one embodiment, the lasers of the plurality of laser output devices include continuous lasers, flat-top pulsed lasers, and Gaussian pulsed lasers.

[0007] In one embodiment, the plurality of laser output groups includes a first laser output group, which is matched to the loose rust in the foreign matter to be cleaned, and the first laser output group includes a continuous laser and a flat-top pulsed laser; and / or, The plurality of laser output groups include a second laser output group, the second laser output group being matched with the oxide scale in the foreign matter to be cleaned, the second laser output group comprising a continuous laser and a Gaussian pulsed laser; and / or, The plurality of laser output groups includes a third laser output group that is matched to the multiple coatings in the foreign matter to be cleaned, and the third laser output group includes a flat-top pulsed laser and a Gaussian pulsed laser.

[0008] In one embodiment, the laser output device further includes a deflecting mirror disposed between the output end of the optical transmission module and the focusing lens. The deflecting mirror is used to reflect the laser beam transmitted by the optical transmission module to the focusing lens, and the deflecting mirror oscillates around the axis of the first direction so that the reflected laser beam oscillates along the second direction. Wherein, the first direction intersects with the second direction.

[0009] In one embodiment, the laser output device further includes an adjustable reflector disposed between the output end of the optical transmission module and the deflection mirror, so as to reflect the laser beam transmitted by the optical transmission module to the deflection mirror. The adjustable reflector has an adjustable reflection angle, so that the position of the laser spot formed on the substrate in the first direction is adjustable.

[0010] In one embodiment, the plurality of lasers include a continuous laser, a flat-top pulsed laser, and a Gaussian pulsed laser; Multiple optical transmission modules include a first transmission structure, a second transmission structure, and a third transmission structure. The input end of the first transmission structure is connected to the continuous laser, the input end of the second transmission structure is connected to the flat-top pulsed laser, and the input end of the third transmission structure is connected to the Gaussian pulsed laser. The first transmission structure and the second transmission structure each include a laser collimator.

[0011] Secondly, the laser cleaning method provided by the present invention is based on the aforementioned laser cleaning equipment, and the laser cleaning method includes: Identify the type of foreign object to be cleaned; The corresponding laser output group is determined according to the type of foreign object to be cleaned, and multiple lasers in the corresponding laser output group are turned on so that the multiple lasers output laser beams according to preset operating parameters.

[0012] In one embodiment, the plurality of laser output groups includes a first laser output group, which includes a continuous laser and a flat-top pulsed laser, and the type of foreign matter to be cleaned includes loose rust; The step of determining the corresponding laser output group based on the type of foreign object to be cleaned, and activating multiple lasers in the corresponding laser output group so that the multiple lasers output laser beams according to preset operating parameters, includes: The first laser output group is determined based on the surface rust. Turn on the continuous laser and the flat-top pulsed laser in the first laser output group so that the continuous laser and the flat-top pulsed laser output laser beams according to preset operating parameters.

[0013] In one embodiment, the plurality of laser output groups includes a second laser output group, the second laser output group including a continuous laser and a Gaussian pulse laser, and the type of foreign matter to be cleaned includes oxide scale; The step of determining the corresponding laser output group based on the type of foreign object to be cleaned, and activating multiple lasers in the corresponding laser output group so that the multiple lasers output laser beams according to preset operating parameters, includes: The second laser output group is determined based on the oxide layer; Turn on the continuous laser and the Gaussian pulse laser in the second laser output group so that the continuous laser and the Gaussian pulse laser output laser beams according to preset operating parameters.

[0014] In one embodiment, the plurality of laser output groups includes a third laser output group, which includes a flat-top pulsed laser and a Gaussian pulsed laser, and the type of foreign matter to be cleaned includes multiple coatings; The step of determining the corresponding laser output group based on the type of foreign object to be cleaned, and activating multiple lasers in the corresponding laser output group so that the multiple lasers output laser beams according to preset operating parameters, includes: The third laser output group is determined based on the multi-coating; Turn on the flat-top pulse laser and the Gaussian pulse laser in the third laser output group so that the flat-top pulse laser and the Gaussian pulse laser output laser beams according to preset operating parameters.

[0015] The technical solution provided by this invention involves setting up multiple laser output devices of different types and combining them in pairs at the control level to form multiple laser output groups, so that each laser output group corresponds to a type of foreign object to be cleaned. In specific operations, the type of foreign object to be cleaned on the substrate surface is first identified, and then the corresponding laser output group is selected and its laser output device is activated based on the identification result, thereby achieving differentiated and precise cleaning for different types of foreign objects. Furthermore, since different laser output groups may share laser output devices, multiple combination schemes can be formed without increasing the number of laser output devices, significantly improving the utilization rate of the laser output devices and simplifying the overall structure of the laser cleaning equipment. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of an embodiment of the laser cleaning equipment (excluding the first laser and the second laser) proposed in this invention; Figure 2 This is a flowchart of the first embodiment of the laser cleaning method proposed in this invention; Figure 3 This is a flowchart of a second embodiment of the laser cleaning method proposed in this invention.

[0018] Explanation of icon numbers: 100. Laser cleaning equipment; 1. Laser output device; 1a. First laser output device; 1b. Second laser output device; 1c. Third laser output device; 11. Optical transmission module; 111. Laser collimator; 112. Adjustable reflector; 113. Deflecting mirror; 2. Focus the lens; X, first direction; Y, second direction; Z, third direction.

[0019] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] It should be noted that if the embodiments of the present invention involve directional indication, the directional indication is only used to explain the relative positional relationship and movement of the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0022] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0023] Currently, laser cleaning technology, with its unique advantages of being non-contact, non-destructive, environmentally friendly, and highly efficient, is gradually becoming an ideal solution in the shipbuilding and maintenance fields. However, laser cleaning technology still has some shortcomings in practical applications. The main issue is that current laser cleaning equipment can usually only effectively clean a single type of foreign object. When faced with cleaning scenarios involving multiple types of foreign objects, laser cleaning equipment struggles to guarantee cleaning efficiency.

[0024] In view of this, the present invention proposes a laser cleaning device and a laser cleaning method, which can at least improve the problem that the current laser cleaning devices have a relatively limited range of applicable scenarios and are difficult to guarantee cleaning efficiency when faced with various types of foreign objects to be cleaned.

[0025] To facilitate understanding of the laser cleaning equipment provided by this invention, the following description is provided in conjunction with the accompanying drawings, wherein... Figure 1 This is a schematic diagram of an embodiment of the laser cleaning equipment (excluding the first laser and the second laser) proposed in this invention.

[0026] Please see Figure 1In one embodiment, the laser cleaning equipment 100 is used to clean foreign objects on a substrate. The laser cleaning equipment 100 includes multiple laser output devices 1 and a focusing lens 2. The laser output device 1 includes a laser and an optical transmission module 11. The optical transmission module 11 is used to transmit the laser beams output by the laser, and the multiple laser beams have different energy distributions. The focusing lens 2 is used to receive and converge the laser beams emitted from the multiple optical transmission modules 11 and is positioned towards the substrate. The light spots formed by the multiple laser beams on the substrate are distributed along a first direction X. The multiple laser output devices 1 are intersected in pairs to form multiple laser output groups, and the multiple laser output groups are used to match the type of foreign object to be cleaned.

[0027] "Substrate" typically includes, but is not limited to, metal components involved in shipbuilding and maintenance, such as hull steel plates, bulkhead steel structures, deck components, etc.; "Foreign matter to be cleaned" refers to non-target substances that are attached to, bonded to, or deposited on the surface of the substrate and need to be removed, including but not limited to rust, scale, and various coatings. The laser output device 1, as the execution unit of this equipment, is composed of a laser and an optical transmission module 11: the laser is the source of the laser beam, and the optical transmission module 11 is responsible for guiding the laser beam output by the laser from the output end of the laser to the downstream optical path; the focusing lens 2 is located downstream of the optical transmission module 11, and its function is to receive and converge multiple laser beams to the area of ​​the substrate to be cleaned. Its setting direction is towards the substrate, thereby ensuring that the laser energy is accurately applied to the surface of the foreign matter to be cleaned.

[0028] The number of "multiple laser output devices 1" is usually no less than three, but this invention does not limit this; the specific form of the optical transmission module 11 can be a transmission optical fiber or a reflective optical path structure, which can be reasonably selected by those skilled in the art according to the optical path design and equipment layout. "First direction X" refers to the arrangement direction of multiple light spots formed on the surface of the substrate after multiple laser beams are converged by the focusing lens 2, which is usually also the direction of movement of the substrate relative to the focusing lens 2; the focusing lens 2 is usually set along the third direction Z toward the substrate. It should be noted that the laser output group is not a physically independent combination of laser output devices 1, but a logical combination defined by the laser cleaning equipment 100 at the control level. That is, multiple laser output devices 1 can be cross-combined in pairs under the scheduling of the control system to form multiple laser output groups. The same laser output device 1 can belong to multiple laser output groups at the same time. For example, if the numbers of multiple laser output devices 1 are 1, 2 and 3, then these three laser output devices 1 can be combined into laser output group (1,2), laser output group (1,3) and laser output group (2,3). "Energy distribution" includes the temporal distribution (pulse waveform) and the spatial distribution (spot shape). Laser beams with different energy distributions can perform different cleaning tasks, such as preheating the substrate and peeling off foreign objects to be cleaned.

[0029] Traditional cleaning methods such as sandblasting and chemical cleaning suffer from drawbacks such as severe pollution, low efficiency, and easy damage to the substrate. Existing laser cleaning equipment (100) often uses a single laser or a combination of fixed lasers, making it difficult to balance cleaning efficiency and quality when dealing with various types of foreign matter commonly found on substrate surfaces, such as surface rust, oxide scale, and multiple coatings. This invention addresses these problems by setting up multiple different types of laser output devices 1, which are then cross-combined in pairs at the control level to form multiple laser output groups. Each laser output group corresponds to a specific type of foreign matter to be cleaned. In practice, the type of foreign matter to be cleaned on the substrate surface is first identified, and then the corresponding laser output group is selected and its laser output device 1 is activated based on the identification result. This achieves differentiated and precise cleaning for different types of foreign matter. Furthermore, since different laser output groups share laser output devices 1, multiple combination schemes can be formed without increasing the number of laser output devices 1, significantly improving the utilization rate of the laser output devices 1 and simplifying the overall structure of the laser cleaning equipment 100.

[0030] In one embodiment, the lasers of the plurality of laser output devices 1 include continuous lasers, flat-top pulsed lasers, and Gaussian pulsed lasers.

[0031] A "continuous laser" refers to a laser that can output a laser beam with continuous timing and stable power. Its output laser has no pulse interval and is in a continuous emission state. A "flat-top pulsed laser" refers to a pulsed laser whose output laser beam has an energy distribution that is approximately flat-topped during the pulse duration and whose energy distribution is uniform across the cross-section of the laser spot. A "Gaussian pulsed laser" refers to a pulsed laser whose output laser beam has a typical Gaussian curve energy distribution across the cross-section of the laser spot, that is, the energy density is highest at the center of the spot and gradually decreases towards the edge.

[0032] For ease of combination Figure 1 To understand this, we define the laser output device 1 corresponding to the continuous laser as the first laser output device 1a, the laser output device 1 corresponding to the flat-top pulse laser as the second laser output device 1b, and the laser output device 1 corresponding to the Gaussian pulse laser as the third laser output device 1c.

[0033] The naming of the above three types of lasers is based on the timing characteristics and spatial energy distribution characteristics of their output laser beams. This application does not impose restrictive requirements on the specific wavelength, power rating, or other parameters of the laser. As long as the energy distribution and timing of its output laser beams meet the above characteristics, it falls within the protection scope claimed by this invention.

[0034] The removal of foreign matter from substrate surfaces is not a single physical process, but rather involves the combined effects of multiple mechanisms such as contaminant softening, peeling, and vaporization. Continuous lasers provide stable and continuous energy output, primarily serving as preheaters and auxiliary cleaners when applied to the substrate surface. This allows contaminants to soften by absorbing heat, thereby reducing the bonding strength between the contaminants and the substrate, facilitating efficient subsequent pulsed laser peeling. Flat-top pulsed lasers exhibit significantly uniform energy distribution, applying approximately consistent energy to contaminants over a large scanning area, avoiding uneven cleaning depths caused by uneven energy distribution. This is particularly suitable for applications requiring large-area uniform treatment. Gaussian pulsed lasers have extremely high peak energy in their central region, inducing micro-shock waves at the contaminant interface upon pulse application. These shock waves, through mechanical force, disrupt the molecular bonds between the adhering layer and the substrate, demonstrating significant peeling effects on firmly bonded oxide scale and coatings. This invention introduces these three types of lasers as optional light-emitting devices. Through flexible combinations in different laser output groups, the cleaning needs of most common foreign matter on ship substrate surfaces can be covered.

[0035] In one embodiment, the plurality of laser output groups includes a first laser output group that is matched with floating rust in the foreign matter to be cleaned. The first laser output group includes a continuous laser and a flat-top pulsed laser.

[0036] In another embodiment, the plurality of laser output groups includes a second laser output group that is matched with oxide scale in the foreign matter to be cleaned, the second laser output group including a continuous laser and a Gaussian pulsed laser.

[0037] In another embodiment, the plurality of laser output groups includes a third laser output group that is matched with multiple coatings in the foreign matter to be cleaned. The third laser output group includes a flat-top pulsed laser and a Gaussian pulsed laser.

[0038] It should be noted that the above three parallel technical features, "first laser output group", "second laser output group" and "third laser output group", can be set as one, two, or simultaneously.

[0039] "Surface rust" refers to the loosely bonded initial oxidation products that adhere to the surface of a metal substrate. Its bonding strength with the substrate is relatively weak, and it covers a wide area. "Oxide scale" refers to the oxide layer that forms on a metal substrate under long-term oxidation or high temperature and has formed a tight bond with the substrate surface. Its bonding strength is significantly higher than that of surface rust, and it usually has a certain hardness and thickness. "Multi-coating" refers to the coating structure formed on the substrate surface by multiple coating operations, which consists of different materials or multiple layers of the same material. It is commonly seen in the anti-corrosion coating layer of ship hulls.

[0040] While "floating rust, scale, and multiple coatings" are all common contaminants on ship substrate surfaces, their physicochemical properties and bonding methods with the substrate differ significantly. Therefore, differentiated laser energy input strategies are required for efficient cleaning. Specifically: For floating rust, due to its weak adhesion to the substrate and wide coverage, it is advisable to first preheat the rust area with a continuous laser to further loosen the rust layer and reduce its weak adhesion to the substrate. Then, a flat-top pulsed laser is used to apply uniform energy over a large area to peel off the loosened rust as a whole, thus achieving high-efficiency, large-area cleaning. Therefore, this application uses a continuous laser and a flat-top pulsed laser to form the first laser output group, matched with the floating rust. For scale, due to its tight adhesion and high hardness, it is difficult to peel off simply by relying on a flat-top pulsed laser with uniform energy distribution. Therefore, it is necessary to first preheat and soften the scale with a continuous laser, and then use a Gaussian pulsed laser with high energy in the central area. Peak energy instantaneously impacts the interface between the oxide layer and the substrate, breaking and peeling off the oxide layer as a whole. Therefore, this application uses a continuous laser and a Gaussian pulse laser to form a second laser output group to match the oxide layer. For multi-layer coatings, the interlayer structure is complex and the materials of each layer may differ. If a continuous laser is introduced for continuous preheating, heat is likely to accumulate inside the coating and cause thermal impact on the substrate. Therefore, it is advisable to use a flat-top pulse laser to uniformly etch and thin the surface of the multi-layer coating layer by layer, and then use the instantaneous impact of the Gaussian pulse laser to destroy the interface between the deep coating and the substrate. The two work together to achieve the overall peeling off of the multi-layer coating. Therefore, this application uses a flat-top pulse laser and a Gaussian pulse laser to form a third laser output group to match the multi-layer coating.

[0041] In one embodiment, the laser output device 1 further includes a deflection mirror 113, which is disposed between the output end of the optical transmission module 11 and the focusing lens 2. The deflection mirror 113 is used to reflect the laser beam transmitted by the optical transmission module 11 to the focusing lens 2, and the deflection mirror 113 swings around the axis of the first direction X so that the reflected laser beam swings along the second direction Y; wherein the first direction X and the second direction Y intersect.

[0042] "Deflection mirror 113" refers to an optical component consisting of a swing drive mechanism and a reflecting mirror, which can change the reflection direction of the incident laser beam by slightly swinging the reflecting mirror around a fixed axis, thereby realizing the scanning of the laser beam in a specified direction; "second direction Y" refers to the scanning direction of the light spot formed by the reflected laser beam on the substrate surface, which intersects with the first direction X. The swing axis of the deflection mirror 113 is parallel or coincident with the axis of the first direction X, and the specific setting can be adjusted according to the optical path layout; the intersection angle between the second direction Y and the first direction X can be perpendicular or any non-perpendicular angle, and this application does not make a specific limitation, as long as the two are not parallel and the light spot can cover a predetermined two-dimensional area on the substrate surface.

[0043] Laser cleaning operations typically require covering a certain area of ​​the substrate. Relying solely on the fixed spot distribution of multiple laser output devices 1 arranged in the first direction X, cleaning can only be achieved in a single line segment direction, resulting in a limited coverage area. Therefore, this application introduces a deflecting mirror 113 between the output end of the optical transmission module 11 and the focusing lens 2. The laser beam emitted from the optical transmission module 11 is reflected by the deflecting mirror 113 before entering the focusing lens 2. The high-frequency oscillation of the deflecting mirror 113 allows the reflected laser beam to reciprocate along the second direction Y. The fixed arrangement of multiple spots in the first direction X, combined with the scanning motion in the second direction Y, allows the laser spots to form a two-dimensional coverage area on the substrate surface, achieving large-area scanning cleaning without relying on mechanical movement of the entire machine along the second direction Y. Simultaneously, the deflecting mirror 113 is electrically driven, resulting in high response speed and fast scanning frequency, ensuring the efficiency and stability of the cleaning process. In this embodiment, the first direction Z, the second direction Y, and the third direction Z are arranged in pairs.

[0044] In one specific embodiment, the average power of the continuous laser is not less than 6000W, the average power of the flat-top pulsed laser is not less than 1000W, and the average power of the Gaussian pulsed laser is not less than 500W. The repetition frequency of the flat-top pulsed laser is in the range of 10-50kHz, the single pulse energy is not less than 50mJ, and the pulse width is in the range of 20-100ns. The repetition frequency of the Gaussian pulsed laser is in the range of 10-4000kHz, the single pulse energy is not less than 2mJ, and the pulse width is in the range of 10-500ns. The size of the focused spot output by the three types of lasers is not less than 0.1mm. The swing radius of the deflection mirror 113 is 100-200mm. The scanning speed of the deflection mirror 113 corresponding to the continuous laser and the flat-top pulse laser is 1000-10000mm / s. The scanning speed of the deflection mirror 113 corresponding to the Gaussian pulse laser is 1000-40000mm / s. The moving speed of the substrate relative to the focusing lens 2 is adjusted according to the on-site rhythm.

[0045] In one embodiment, the laser output device 1 further includes an adjustable reflector 112, which is disposed between the output end of the optical transmission module 11 and the deflection mirror 113 to reflect the laser beam transmitted by the optical transmission module 11 to the deflection mirror 113; wherein the reflection angle of the adjustable reflector 112 is adjustable so that the position of the light spot formed by the laser beam on the substrate in the first direction X is adjustable.

[0046] "Adjustable reflector 112" refers to a reflective optical element whose angle relative to the incident light path can be adjusted manually or mechanically. The adjustment method may include, but is not limited to, fine-tuning the attitude of the reflector surface by means of adjusting bolts, micro-motion mechanisms, etc. The angle adjustment of the adjustable reflector 112 usually occurs during the equipment debugging stage before the start of the cleaning operation. After the debugging is completed, the set attitude is maintained for subsequent cleaning operations.

[0047] The optimal spacing between multiple laser spots is not fixed, depending on the substrate material and the type of foreign object to be cleaned. If the distance between two spots is too close, heat may accumulate in the area of ​​action of adjacent spots, potentially causing localized overheating and damage to the substrate. If the distance between two spots is too far, the energy connection between the areas covered by adjacent spots will be insufficient. In this application, an adjustable reflector 112 is provided between the output end of the optical transmission module 11 and the deflection mirror 113. By adjusting the reflection angle of the adjustable reflector 112, the incident posture of the laser beam entering the deflection mirror 113 can be changed, thereby adjusting the position of the laser beam formed on the substrate along the first direction X after being focused by the focusing lens 2. This allows the spacing between multiple spots along the first direction X to be flexibly adjusted to meet the differentiated requirements of different substrate materials and different types of foreign objects for the spacing of the laser spots.

[0048] In one specific embodiment, the adjustable reflector 112 can be composed of a reflective lens, a lens bracket, and an angle adjustment bolt. The reflective lens is installed on the downstream optical path of the output end of the optical transmission module 11 via the lens bracket. The operator can make the reflective lens rotate slightly around a set pivot by rotating the angle adjustment bolt. When cleaning large areas of floating rust on the surface of ship hull steel plates, the spacing of each light spot along the first direction X can be adjusted to a larger value to obtain a larger coverage width. When dealing with substrates with fast heat diffusion, the spacing can be appropriately increased to avoid heat accumulation. For cleaning foreign matter requiring dense coordination, such as multiple coatings, the spacing can be adjusted to a smaller value to ensure sufficient energy connection between the two light spots.

[0049] In one embodiment, the plurality of lasers include a continuous laser, a flat-top pulsed laser, and a Gaussian pulsed laser; the plurality of optical transmission modules 11 include a first transmission structure, a second transmission structure, and a third transmission structure, wherein the input end of the first transmission structure is connected to the continuous laser, the input end of the second transmission structure is connected to the flat-top pulsed laser, and the input end of the third transmission structure is connected to the Gaussian pulsed laser; wherein the first transmission structure and the second transmission structure each include a laser collimator 111.

[0050] "Laser collimator 111" refers to an optical component that shapes the incident laser beam to reduce its divergence angle and make the laser beam more parallel. It is usually composed of a collimating lens and its supporting structure. Its function is to convert the laser beam with a certain divergence angle emitted from the laser or transmission fiber into a laser beam with a smaller divergence angle and approximately parallel, so as to improve the transmission quality of the laser beam in the subsequent optical path.

[0051] The inclusion of a laser collimator 111 in both the first and second transmission structures does not preclude the possibility of including a laser collimator 111 in the third transmission structure. When the output laser beam of the Gaussian pulse laser already possesses good directionality, the laser collimator 111 can be omitted from the third transmission structure to simplify the structure. In addition to the laser collimator 111, the specific optical path structures of the first and second transmission structures may also include transmission optical fibers and corresponding input / output coupling interfaces.

[0052] Continuous laser beams from continuous-wave lasers and flat-top pulsed laser beams from flat-top pulsed lasers typically have a certain divergence angle after being transmitted through optical fibers. If they directly enter the focusing lens 2, the energy distribution of the focused spot will be diffused due to the divergence angle, affecting the cleaning accuracy and effect. This application provides laser collimators 111 in both the first and second transmission structures, which can effectively compress the divergence angle of the corresponding laser beams, allowing them to enter the subsequent optical path as approximately parallel light, thus improving the focusing accuracy of the focusing lens 2.

[0053] Based on this, the laser collimator 111 can be further equipped with a rotating sleeve and an adjustable lens. The rotating sleeve is connected to the adjustable lens. The rotation of the rotating sleeve can drive the adjustable lens to move along the optical axis, thereby adjusting the distance between the adjustable lens and the output end of the transmission fiber to adapt to the output beam characteristics of different lasers and achieve fine adjustment of the collimation effect.

[0054] To facilitate understanding of the laser cleaning method provided by this invention, the following description is provided in conjunction with the accompanying drawings, wherein... Figure 2 This is a flowchart of the first embodiment of the laser cleaning method proposed in this invention; Figure 3 This is a flowchart of a second embodiment of the laser cleaning method proposed in this invention.

[0055] The laser cleaning method provided by this invention is based on the laser cleaning equipment 100 described above, and the laser cleaning method includes: S10. Identify the type of foreign object to be cleaned; Among them, the methods for determining which type of foreign matter to be cleaned on the substrate surface belongs to, such as floating rust, oxide scale, or multiple coatings, are predetermined. These methods include, but are not limited to, visual judgment by operators based on experience, or automatic judgment by image recognition systems, spectral recognition systems, etc. configured in the equipment.

[0056] S20. Determine the corresponding laser output group according to the type of foreign object to be cleaned, and turn on multiple lasers in the corresponding laser output group so that multiple lasers output laser beams according to preset operating parameters.

[0057] "Preset operating parameters" refers to the pre-set values ​​of technical parameters such as power, pulse width, repetition frequency, and scanning rate that the laser needs to perform during operation.

[0058] The above steps, through the process of pre-identifying the type of foreign object, determining the corresponding laser output group, and finally activating the corresponding laser and making it work according to preset parameters, ensure the targeting of subsequent cleaning strategies and avoid ineffective cleaning using mismatched laser parameters. Furthermore, the operation according to preset parameters ensures the coordinated stability between the activated lasers. This cleaning process fully utilizes the hardware structure advantage of the cross-grouping of over 100 lasers in the laser cleaning equipment, and ensures the efficiency and stability of the cleaning operation through parameter presets. Simultaneously, because the lasers are reused in different laser output groups, compared to the solution of configuring independent hardware for each type of foreign object, this application significantly improves the utilization rate of the laser output device 1 and simplifies the overall structure of the laser cleaning equipment 100.

[0059] In one embodiment, the plurality of laser output groups include a first laser output group, which includes a continuous laser and a flat-top pulsed laser, and the type of foreign matter to be cleaned includes loose rust; Step S20, which involves determining the corresponding laser output group based on the type of foreign object to be cleaned and activating multiple lasers within the corresponding laser output group so that the multiple lasers output laser beams according to preset operating parameters, includes: S21. Determine the first laser output group based on the surface rust; S22. Turn on the continuous laser and the flat-top pulsed laser in the first laser output group so that the continuous laser and the flat-top pulsed laser output laser beams according to the preset operating parameters.

[0060] As a type of early-stage oxide with weak adhesion and wide distribution, the challenge in removing surface rust lies in balancing cleaning efficiency for large areas with avoiding damage to the substrate. In the above steps, when surface rust is identified as the foreign matter to be cleaned, the first laser output group is activated. The continuous laser in this group outputs continuous and stable laser energy to preheat the surface rust area, further softening the rust layer and reducing its weak adhesion to the substrate. The flat-top pulsed laser then applies uniformly distributed pulsed energy to the weakened surface rust layer, evenly peeling away the entire softened layer. Both lasers work synergistically according to preset power and pulse frequency parameters, leveraging the preheating and softening effect of the continuous laser and the uniform abrasion effect of the flat-top pulsed laser. This significantly improves the cleaning efficiency and consistency of surface rust-like foreign matter while effectively preventing excessive thermal damage to the substrate.

[0061] In one embodiment, the preset operating parameters for the continuous laser and the flat-top pulsed laser in the first laser output group are as follows: Laser power: 6000W for continuous laser, 1000W for flat-top pulsed laser; Pulse frequency: 10-50kHz; Scanning speed: 1000-10000 mm / s; Cleaning width: 100-200mm; Pulse width: 20-100ns; For surface rust with a thickness of 100μm on the base material of ship plate, a combination of continuous and flat-top pulse cleaning mode is used. After cleaning, the surface roughness is 5Ra and the rust removal rate reaches 99%.

[0062] In one embodiment, the plurality of laser output groups includes a second laser output group, which includes a continuous laser and a Gaussian pulse laser, and the type of foreign matter to be cleaned includes oxide scale; Step S20, which involves determining the corresponding laser output group based on the type of foreign object to be cleaned and activating multiple lasers within the corresponding laser output group so that the multiple lasers output laser beams according to preset operating parameters, includes: S23. Determine the second laser output group based on the oxide scale; S24. Turn on the continuous laser and Gaussian pulse laser in the second laser output group so that the continuous laser and Gaussian pulse laser output laser beams according to the preset operating parameters.

[0063] Oxide scale is a tightly bonded layer formed on the substrate under long-term oxidation or high temperature. It has strong adhesion to the substrate, a certain thickness, and hardness, making it difficult to effectively remove with simple uniform pulse ablation. In the above steps, when the foreign object to be cleaned is identified as oxide scale, a second laser output group is activated. The continuous laser preheats the oxide scale, raising its temperature and changing its internal stress, thereby weakening its bond strength with the substrate. The Gaussian pulse laser, using the high peak energy at its spot center, induces instantaneous micro-shock waves on the oxide scale surface. The mechanical force transmitted from these shock waves to the interface between the oxide scale and the substrate breaks down the molecular bonds, causing the oxide scale to break apart and peel off. Both lasers work together according to preset parameters, efficiently removing oxide scale while ensuring the integrity of the substrate. Compared to purely mechanical or purely chemical methods, there is no consumable consumption, no waste liquid discharge, and a lower risk of damage to the substrate.

[0064] In one embodiment, the plurality of laser output groups includes a third laser output group, which includes a flat-top pulsed laser and a Gaussian pulsed laser, and the type of foreign matter to be cleaned includes multiple coatings; Step S20, which involves determining the corresponding laser output group based on the type of foreign object to be cleaned and activating multiple lasers within the corresponding laser output group so that the multiple lasers output laser beams according to preset operating parameters, includes: S25. Determine the third laser output group based on the multiple coatings; S26. Turn on the flat-top pulse laser and Gaussian pulse laser in the third laser output group so that the flat-top pulse laser and Gaussian pulse laser output laser beams according to the preset operating parameters.

[0065] Multi-coat hull plates are multi-layered structures formed through multiple coating processes. The materials between layers may differ, and the overall thickness is typically substantial. Continuous laser heating can easily accumulate heat within the coatings, causing thermal impact damage to the substrate. In the above steps, when the foreign object to be cleaned is identified as oxide scale, a third laser output group is activated. The flat-top pulsed laser in this group applies large-area, uniform pulse energy to the multi-coat layers, ablating them layer by layer. Once the outer coating is ablated down to the remaining thin layer near the substrate, the high peak energy in the central region of the Gaussian pulsed laser instantaneously impacts and destroys the interface between the deeper coating and the substrate, peeling off the remaining coating entirely. Both processes work collaboratively according to preset parameters, achieving layer-by-layer, overall removal of multi-coat layers without introducing a continuous heat source. This avoids thermal impact damage to the substrate and improves upon the thickness reduction problem caused by traditional mechanical cleaning methods that result in the substrate beneath the coating.

[0066] In one embodiment, the preset operating parameters for the flat-top pulse laser and the Gaussian pulse laser in the third laser output group are as follows: Laser power: 1000W for flat-top pulsed laser, 500W for Gaussian pulsed laser; Flat-top pulse frequency: 10-50kHz; Gaussian pulse frequency: 10-4000kHz; Scanning speed: 1000-10000 mm / s; Cleaning width: 100-200mm; Flat-top pulse width: 20-100ns; Gaussian pulse width: 10-500ns; For a 50μm thick multi-coated substrate, a combination of flat-top pulse and Gaussian pulse cleaning mode was used. After cleaning, the surface roughness was 5Ra and the paint removal rate reached 99%.

[0067] The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention specification and drawings under the concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A laser cleaning device for cleaning foreign objects on a substrate, characterized in that, The laser cleaning equipment includes: Multiple laser output devices, each laser output device including a laser and an optical transmission module, wherein the optical transmission module is used to transmit the laser beams output by the laser, and the multiple laser beams have different energy distributions; A focusing lens is used to receive and converge laser beams emitted from multiple optical transmission modules and is positioned toward the substrate, wherein the light spots formed by the multiple laser beams on the substrate are distributed along a first direction; The laser output devices are arranged in pairs to form multiple laser output groups, which are used to match the type of foreign object to be cleaned.

2. The laser cleaning equipment as described in claim 1, characterized in that, The lasers in the plurality of laser output devices include continuous lasers, flat-top pulsed lasers, and Gaussian pulsed lasers.

3. The laser cleaning equipment as described in claim 2, characterized in that, The plurality of laser output groups include a first laser output group, which is matched to the loose rust in the foreign matter to be cleaned, the first laser output group including a continuous laser and a flat-top pulsed laser; and / or, The plurality of laser output groups include a second laser output group, the second laser output group being matched with the oxide scale in the foreign matter to be cleaned, the second laser output group comprising a continuous laser and a Gaussian pulsed laser; and / or, The plurality of laser output groups includes a third laser output group that is matched to the multiple coatings in the foreign matter to be cleaned, and the third laser output group includes a flat-top pulsed laser and a Gaussian pulsed laser.

4. The laser cleaning equipment as described in claim 1, characterized in that, The laser output device further includes a deflecting mirror, which is disposed between the output end of the optical transmission module and the focusing lens. The deflecting mirror is used to reflect the laser beam transmitted by the optical transmission module to the focusing lens, and the deflecting mirror swings around the axis of the first direction so that the reflected laser beam swings along the second direction. Wherein, the first direction intersects with the second direction.

5. The laser cleaning equipment as described in claim 4, characterized in that, The laser output device also includes an adjustable reflector, which is disposed between the output end of the optical transmission module and the deflection mirror to reflect the laser beam transmitted by the optical transmission module to the deflection mirror. The adjustable reflector has an adjustable reflection angle, so that the position of the laser spot formed on the substrate in the first direction is adjustable.

6. The laser cleaning equipment as described in claim 1, characterized in that, The plurality of lasers include continuous lasers, flat-top pulsed lasers, and Gaussian pulsed lasers; Multiple optical transmission modules include a first transmission structure, a second transmission structure, and a third transmission structure. The input end of the first transmission structure is connected to the continuous laser, the input end of the second transmission structure is connected to the flat-top pulsed laser, and the input end of the third transmission structure is connected to the Gaussian pulsed laser. The first transmission structure and the second transmission structure each include a laser collimator.

7. A laser cleaning method, based on the laser cleaning equipment as described in any one of claims 1 to 6, characterized in that, The laser cleaning method includes: Identify the type of foreign object to be cleaned; The corresponding laser output group is determined according to the type of foreign object to be cleaned, and multiple lasers in the corresponding laser output group are turned on so that the multiple lasers output laser beams according to preset operating parameters.

8. The laser cleaning method as described in claim 7, characterized in that, The plurality of laser output groups include a first laser output group, which includes a continuous laser and a flat-top pulsed laser, and the type of foreign matter to be cleaned includes loose rust; The step of determining the corresponding laser output group based on the type of foreign object to be cleaned, and activating multiple lasers in the corresponding laser output group so that the multiple lasers output laser beams according to preset operating parameters, includes: The first laser output group is determined based on the surface rust. Turn on the continuous laser and the flat-top pulsed laser in the first laser output group so that the continuous laser and the flat-top pulsed laser output laser beams according to preset operating parameters.

9. The laser cleaning method as described in claim 7, characterized in that, The plurality of laser output groups include a second laser output group, the second laser output group including a continuous laser and a Gaussian pulse laser, and the type of foreign matter to be cleaned includes oxide scale; The step of determining the corresponding laser output group based on the type of foreign object to be cleaned, and activating multiple lasers in the corresponding laser output group so that the multiple lasers output laser beams according to preset operating parameters, includes: The second laser output group is determined based on the oxide layer; Turn on the continuous laser and the Gaussian pulse laser in the second laser output group so that the continuous laser and the Gaussian pulse laser output laser beams according to preset operating parameters.

10. The laser cleaning method as described in claim 7, characterized in that, The plurality of laser output groups include a third laser output group, which includes a flat-top pulse laser and a Gaussian pulse laser, and the type of foreign matter to be cleaned includes multiple coatings; The step of determining the corresponding laser output group based on the type of foreign object to be cleaned, and activating multiple lasers in the corresponding laser output group so that the multiple lasers output laser beams according to preset operating parameters, includes: The third laser output group is determined based on the multi-coating; Turn on the flat-top pulse laser and the Gaussian pulse laser in the third laser output group so that the flat-top pulse laser and the Gaussian pulse laser output laser beams according to preset operating parameters.

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