Intelligent laser-dry ice composite cleaning method and device

Abstract

The invention discloses an intelligent laser-dry ice composite cleaning method and device, belongs to the field of stain cleaning, and aims to solve the problem that the cleaning effect on large-thickness stains is not ideal in the prior art. The method comprises the following steps: performing visual scanning on a to-be-cleaned workpiece, obtaining surface stain thickness distribution of the to-be-cleaned workpiece through three-dimensional surface topography reconstruction, and dividing the surface of the to-be-cleaned workpiece into a plurality of sub-regions according to the stain thickness; the sub-regions comprise three types: an ultra-thin sub-region, a medium-thickness sub-region and a large-thickness sub-region; performing cleaning path planning to form three cleaning paths; the cleaning process of the ultra-thin sub-region cleaning path comprises the following steps: laser cleaning; the cleaning process of the medium-thickness sub-region cleaning path is laser-dry ice composite cleaning; the cleaning process of the large-thickness subarea cleaning path is laser-dry ice composite cleaning. The cleaning device comprises a ground rail gantry movement system, a first mechanical arm, a second mechanical arm, a dry ice cleaning system, a visual recognition system and a pulse laser cleaning system.

Description

Technical Field

[0001] The invention relates to a steel plate stain cleaning technology and belongs to the field of stain cleaning. Background Art

[0002] Traditional methods for cleaning coatings and surface stains vary, mainly relying on chemical agents and mechanical means. Mechanical means are usually contact-based, and remove stains by applying mechanical force to the surface of the object, which may damage the surface or cause residual cleaning media that cannot be completely removed, resulting in secondary pollution. Chemical cleaning requires a large amount of chemicals. With the increasingly stringent environmental protection laws and regulations in my country, and the enhancement of people's environmental protection and safety awareness, the types of chemicals that can be used in industrial production will gradually decrease.

[0003] In the prior art, laser cleaning technology uses a high-energy laser beam to irradiate the surface of the workpiece, causing the surface stains, rust spots or coatings to evaporate or peel off instantly, quickly and efficiently removing surface attachments or coatings, thereby achieving cleaning. Laser cleaning is based on the interaction between laser and matter. Unlike traditional mechanical, chemical and ultrasonic cleaning methods, it does not require the use of CFC organic solvents that damage the ozone layer. It is pollution-free, noise-free, harmless to the human body and the environment, and is a "green" cleaning technology. Although laser cleaning technology performs well in many applications, its cleaning effect is not ideal for thick organic adhesive residues. Laser cleaning mainly relies on the instantaneous evaporation or peeling effect of high-energy laser beams, but thick organic adhesives are difficult to achieve good cleaning effects due to the inability to be completely penetrated by the laser, poor heat transfer, and carbonization of organic matter.

[0004] Another "green" cleaning technology is dry ice cleaning, which uses high-pressure air to spray dry ice particles onto the surface of the object to be cleaned to cool it down, and uses the temperature difference to make different substances separate at different shrinkage speeds. Dry ice cleaning will not cause any damage to the surface of the object being cleaned, especially the metal surface. Similarly, its disadvantages are that the cleaning thickness is limited, and dry ice cleaning is more effective in cleaning organic adhesive residues on the surface, but the cleaning effect on oil stains, rust and the like on the surface is very limited.

[0005] In view of the advantages and disadvantages of laser cleaning and dry ice cleaning, the existing technology combines the two to achieve better cleaning effects. For example, patent CN215997900U provides a cleaning device that transports the parts to be cleaned to different process points for multiple cleanings, and performs one dry ice cleaning and two laser cleanings in sequence. This cleaning method can meet most stain cleaning tasks, but the same processing steps are used regardless of the thickness of the stain, and its defects are also obvious: it is not energy-saving. Moreover, this cleaning method is still not ideal for cleaning thick organic adhesive residues. Summary of the invention

[0006] In view of the problem that the prior art has unsatisfactory cleaning effect on thick stains, the present invention provides an intelligent laser-dry ice composite cleaning method and device.

[0007] In one aspect, the present invention provides an intelligent laser-dry ice composite cleaning method, which comprises the following steps:

[0008] S1. Visually scan the workpiece to be cleaned, obtain the thickness distribution of stains on the surface of the workpiece to be cleaned by three-dimensional surface topography reconstruction, and divide the surface of the workpiece to be cleaned into multiple sub-areas according to the thickness of the stains;

[0009] The sub-regions include three categories: extremely thin sub-regions, medium-thickness sub-regions and large-thickness sub-regions;

[0010] S2, planning the cleaning path, dividing the sub-areas of the same type into the same cleaning path, and forming three cleaning paths for the three types of sub-areas, namely, the cleaning path for the extremely thin sub-areas, the cleaning path for the medium-thickness sub-areas, and the cleaning path for the thicker sub-areas, and the three cleaning paths are connected in series;

[0011] S3, cleaning each extremely thin sub-region on the path in turn along the extremely thin sub-region cleaning path, the cleaning process being: laser cleaning;

[0012] S4, cleaning each of the medium-thickness sub-areas in turn along the medium-thickness sub-area cleaning path, the cleaning process is: laser-dry ice composite cleaning, specifically: firstly performing dry ice cleaning to remove surface pollutants, and then using laser cleaning to perform secondary cleaning on the surface residual oil and coating;

[0013] S5. Clean each thick sub-region in turn along the thick sub-region cleaning path. The cleaning process is: laser-dry ice composite cleaning, specifically: first use laser to preheat for 1 to 3 seconds, then use dry ice cleaning to remove surface pollutants, and then use laser cleaning to clean the residual surface oil and coating again.

[0014] Preferably, the method further comprises the following steps:

[0015] S6. Perform visual scanning on the workpiece to be cleaned again to determine whether the surface of the workpiece to be cleaned is clean. If it is clean, the workpiece is removed; if it is not clean, repeat steps S1 to S5.

[0016] Preferably, the division criteria of the three types of sub-areas are:

[0017] Areas with stain thickness less than 0.5 mm are classified as very thin sub-areas;

[0018] The area with stain thickness between 0.5mm-5mm is classified as medium thickness sub-area;

[0019] Areas with stain thickness greater than 5 mm are classified as high-thickness sub-areas.

[0020] In another aspect, the present invention provides an intelligent laser-dry ice composite cleaning device for implementing the aforementioned method, wherein the cleaning device comprises a ground rail gantry motion system 1, a No. 1 robotic arm 2, a No. 2 robotic arm 6, a dry ice cleaning system 3, a visual recognition system 4 and a pulse laser cleaning system 5;

[0021] The visual recognition system 4 is fixed to the center of the gantry of the ground rail gantry motion system 1, and the bases of the No. 1 robot arm 2 and the No. 2 robot arm 6 are mounted on the gantry of the ground rail gantry motion system 1 in parallel and are located on both sides of the visual recognition system 4. The dry ice cleaning system 3 is connected to the tool head position of the No. 1 robot arm 2, and the pulse laser cleaning system 5 is connected to the tool head position of the No. 2 robot arm 6. The workpiece 7 to be cleaned is located directly below the gantry of the ground rail gantry motion system 1;

[0022] The visual recognition system 4 is used to perform visual scanning on the workpiece 7 to be cleaned, and obtain the thickness distribution of stains on the surface of the workpiece to be cleaned through three-dimensional surface topography reconstruction in the computer system;

[0023] The first robot arm 2 drives the dry ice cleaning system 3 to perform dry ice cleaning on the workpiece 7 to be cleaned, and the second robot arm 6 drives the laser cleaning system 5 to perform laser cleaning on the workpiece 7 to be cleaned.

[0024] Preferably, the laser light source of the pulse laser cleaning system 5 is a fiber laser, a disk laser, a YAG laser or a CO2 laser.

[0025] Preferably, the No. 1 robotic arm 2 and the No. 2 robotic arm 6 have the same structure and are implemented using a six-axis robot system or a three-axis linkage machining machine.

[0026] Beneficial effects of the present invention:

[0027] 1. The present invention utilizes the synergistic effect of laser and dry ice to achieve a greater temperature difference, further enhancing the application effect of the two methods on the difference in thermal physical properties of different materials, breaking through the limit of the existing method for cleaning thick organic pollutants. At the same time, in view of the insufficient effect of laser cleaning on thick organic pollutants, and the disadvantage that dry ice cleaning is difficult to remove pollutants such as oil, the two methods can be used in synergy to achieve good complementarity, and can achieve good cleaning effects on workpieces with pollutants of different forms and thicknesses.

[0028] 2. The laser-dry ice composite cleaning system used in the present invention can intelligently select different cleaning method combinations according to the thickness and form of the pollutants through the visual recognition system and path planning to ensure the cleaning effect, realize the automation of the cleaning process, and improve the cleaning efficiency and accuracy. At the same time, the highly integrated system is simple to operate and intelligently controlled, and the labor cost and time cost required are reduced, which helps to reduce production costs and promote efficient and intelligent production. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a structural schematic diagram of an intelligent laser-dry ice composite cleaning device described in the present invention. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0032] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0033] Specific implementation method 1: The following is combined Figure 1 This embodiment describes an intelligent laser-dry ice composite cleaning method, which includes the following steps:

[0034] S1. Visually scan the workpiece to be cleaned, obtain the thickness distribution of stains on the surface of the workpiece to be cleaned by three-dimensional surface topography reconstruction, and divide the surface of the workpiece to be cleaned into multiple sub-areas according to the thickness of the stains;

[0035] The sub-regions include three categories: extremely thin sub-regions, medium-thickness sub-regions and large-thickness sub-regions;

[0036] The criteria for dividing the three sub-areas are as follows:

[0037] Areas with stain thickness less than 0.5 mm are classified as very thin sub-areas;

[0038] The area with stain thickness between 0.5mm-5mm is classified as medium thickness sub-area;

[0039] Areas with stain thickness greater than 5 mm are classified as high-thickness sub-areas.

[0040] S2, planning the cleaning path, dividing the sub-areas of the same type into the same cleaning path, and forming three cleaning paths for the three types of sub-areas, namely, the cleaning path for the extremely thin sub-areas, the cleaning path for the medium-thickness sub-areas, and the cleaning path for the thicker sub-areas, and the three cleaning paths are connected in series;

[0041] S3, cleaning each extremely thin sub-region on the path in turn along the extremely thin sub-region cleaning path, the cleaning process being: laser cleaning;

[0042] S4, cleaning each of the medium-thickness sub-areas in turn along the medium-thickness sub-area cleaning path, the cleaning process is: laser-dry ice composite cleaning, specifically: firstly performing dry ice cleaning to remove surface pollutants, and then using laser cleaning to perform secondary cleaning on the surface residual oil and coating;

[0043] S5. Clean each thick sub-region in turn along the thick sub-region cleaning path. The cleaning process is: laser-dry ice composite cleaning, specifically: first use laser to preheat for 1 to 3 seconds, then use dry ice cleaning to remove surface pollutants, and then use laser cleaning to clean the residual surface oil and coating again.

[0044] S6. Perform visual scanning on the workpiece to be cleaned again to determine whether the surface of the workpiece to be cleaned is clean. If it is clean, the workpiece is removed; if it is not clean, repeat steps S1 to S5.

[0045] Specific implementation method 2: The following is combined Figure 1 This embodiment is described. This embodiment further describes the first embodiment. The cleaning device includes a ground rail gantry motion system 1, a first robotic arm 2, a second robotic arm 6, a dry ice cleaning system 3, a visual recognition system 4 and a pulse laser cleaning system 5;

[0046] The visual recognition system 4 is fixed to the center of the gantry of the ground rail gantry motion system 1, and the bases of the No. 1 robot arm 2 and the No. 2 robot arm 6 are mounted on the gantry of the ground rail gantry motion system 1 in parallel and are located on both sides of the visual recognition system 4. The dry ice cleaning system 3 is connected to the tool head position of the No. 1 robot arm 2, and the pulse laser cleaning system 5 is connected to the tool head position of the No. 2 robot arm 6. The workpiece 7 to be cleaned is located directly below the gantry of the ground rail gantry motion system 1;

[0047] The visual recognition system 4 is used to perform visual scanning on the workpiece 7 to be cleaned, and obtain the thickness distribution of stains on the surface of the workpiece to be cleaned through three-dimensional surface topography reconstruction in the computer system;

[0048] Robot arm No. 1 2 drives the dry ice cleaning system 3 to perform dry ice cleaning on the workpiece 7 to be cleaned. In the dry ice cleaning system 3, a high-pressure air flow mixed with dry ice particles is emitted by the dry ice cleaning machine and transmitted to the dry ice cleaning gun head through a hose. The execution unit of the equipment is robot arm No. 1 2.

[0049] The second robot arm 6 drives the laser cleaning system 5 to perform laser cleaning on the workpiece 7 to be cleaned. In the pulse laser cleaning system 5, the laser is generated by a fiber laser and transmitted to the welding gun head via an operating optical fiber. The execution unit of the equipment is the second robot arm 6.

[0050] The No. 1 robot arm 2 and the No. 2 robot arm 6 have the same structure and are implemented using a six-axis robot system or a three-axis linkage processing machine tool.

[0051] The workpiece 7 to be cleaned is a stainless steel plate, and oil, plating and resin coating residues of varying thickness are attached to the surface. In addition, the device is suitable for workpieces to be cleaned of any size and any material within the allowable size range.

[0052] Before welding, the workpiece 7 to be cleaned is first fixed in the internal space of the ground rail gantry motion system 1. The gantry is moved, and the workpiece 7 to be cleaned is scanned using the visual recognition system 4, and the three-dimensional surface morphology is reconstructed in the computer system. The three-dimensional reconstructed surface morphology is compared with the digital model of the stain-free standard shape and the path planning is performed. Different cleaning methods are used according to different thicknesses and different forms of contaminants. The digital model of the stain-free standard shape mentioned here is a three-dimensional digital model of the stain-free standard part made by modeling software in the computer system.

[0053] For extremely thin (less than 0.5mm) pollutants, laser cleaning is used, using pulsed lasers to scan and heat the surface to be cleaned, and cleaning is achieved based on the instantaneous evaporation or stripping effect of high-energy laser beams. For medium-thickness (less than 5mm) pollutants, laser-dry ice composite cleaning is used, through high-pressure air purging mixed with dry ice particles, surface pollutants are stripped by using the difference in shrinkage rates of different substances during cooling, and then laser cleaning is used for secondary cleaning of residual oil stains, coatings, etc. on the surface. For thick (more than 5mm) pollutants, laser-dry ice composite cleaning is used, first using laser for preheating, then using dry ice cleaning for purging, using a larger instantaneous temperature difference to enhance the surface stripping effect, thereby achieving the cleaning of thicker pollutants, and then laser cleaning is used for secondary cleaning of residual oil stains, coatings, etc. on the surface.

[0054] After completing the path planning, the dry ice cleaning system 3 emits high-pressure air mixed with dry ice particles, and the pulse laser cleaning system 5 emits high-power pulse laser to clean different sub-areas of the workpiece 7 according to the above-mentioned different processes. After the cleaning is completed, scanning and reconstruction are performed again, and the workpiece is exited after verifying the cleaning effect.

[0055] The laser light source of the pulse laser cleaning system 5 of the present invention can be but not limited to fiber laser, disk laser, YAG laser and CO2 laser. The execution unit of the dry ice cleaning system 3 and the pulse laser cleaning system 5 can be but not limited to a six-axis robot and a three-axis linkage processing machine. The cleaning gun head of the pulse laser cleaning system 5 is a laser alignment system, a focusing system and a galvanometer system, and the focusing focal length is greater than the height of the sealed cavity space. The cleaning gun head includes but is not limited to a water cooling module, a lateral air curtain, a protective gas path, a protective window, a CCD, a guide red light system, etc.

[0056] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the present invention. It should therefore be understood that many modifications may be made to the exemplary embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in a manner different from that described in the original claims. It should also be understood that the features described in conjunction with a single embodiment may be used in other described embodiments.

Claims

1. An intelligent laser-dry ice composite cleaning method, characterized in that: The method comprises the following steps: S1. Visually scan the workpiece to be cleaned, obtain the thickness distribution of stains on the surface of the workpiece to be cleaned by three-dimensional surface topography reconstruction, and divide the surface of the workpiece to be cleaned into multiple sub-areas according to the thickness of the stains; The sub-regions include three categories: extremely thin sub-regions, medium-thickness sub-regions and large-thickness sub-regions; S2, planning the cleaning path, dividing the sub-areas of the same type into the same cleaning path, and forming three cleaning paths for the three types of sub-areas, namely, the cleaning path for the extremely thin sub-areas, the cleaning path for the medium-thickness sub-areas, and the cleaning path for the thicker sub-areas, and the three cleaning paths are connected in series; S3, cleaning each extremely thin sub-region on the path in turn along the extremely thin sub-region cleaning path, the cleaning process being: laser cleaning; S4, cleaning each of the medium-thickness sub-areas in turn along the medium-thickness sub-area cleaning path, the cleaning process is: laser-dry ice composite cleaning, specifically: firstly performing dry ice cleaning to remove surface pollutants, and then using laser cleaning to perform secondary cleaning on the surface residual oil and coating; S5. Clean each thick sub-region in turn along the thick sub-region cleaning path. The cleaning process is: laser-dry ice composite cleaning, specifically: first use laser to preheat for 1 to 3 seconds, then use dry ice cleaning to remove surface pollutants, and then use laser cleaning to clean the residual surface oil and coating again.

2. The intelligent laser-dry ice composite cleaning method according to claim 1, characterized in that: The following steps are also included: S6, visually scanning the workpiece to be cleaned again to determine whether the surface of the workpiece to be cleaned is clean, and if it is clean, the workpiece is removed; If the cleaning is not complete, repeat steps S1 to S5.

3. The intelligent laser-dry ice composite cleaning method according to claim 1, characterized in that: The criteria for dividing the three sub-areas are as follows: Areas with stain thickness less than 0.5 mm are classified as very thin sub-areas; The area with stain thickness between 0.5mm-5mm is classified as medium thickness sub-area; Areas with stain thickness greater than 5 mm are classified as large thickness sub-areas.

4. An intelligent laser-dry ice composite cleaning device, used to implement the intelligent laser-dry ice composite cleaning method according to claim 1 or 2, characterized in that: The cleaning device includes a ground rail gantry motion system (1), a No. 1 robotic arm (2), a No. 2 robotic arm (6), a dry ice cleaning system (3), a visual recognition system (4) and a pulse laser cleaning system (5); The visual recognition system (4) is fixed at the center of the gantry of the ground rail gantry motion system (1); the bases of the first robot arm (2) and the second robot arm (6) are mounted on the gantry of the ground rail gantry motion system (1) in parallel and are located on both sides of the visual recognition system (4); the dry ice cleaning system (3) is connected to the tool head position of the first robot arm (2); the pulse laser cleaning system (5) is connected to the tool head position of the second robot arm (6); and the workpiece (7) to be cleaned is located directly below the gantry of the ground rail gantry motion system (1); The visual recognition system (4) is used to perform visual scanning on the workpiece to be cleaned (7), and obtain the thickness distribution of stains on the surface of the workpiece to be cleaned by reconstructing the three-dimensional surface morphology in a computer system; The first robot arm (2) drives the dry ice cleaning system (3) to perform dry ice cleaning on the workpiece to be cleaned (7), and the second robot arm (6) drives the laser cleaning system 5 to perform laser cleaning on the workpiece to be cleaned (7).

5. The intelligent laser-dry ice composite cleaning device according to claim 4, characterized in that: The laser light source of the pulse laser cleaning system (5) adopts a fiber laser, a disk laser, a YAG laser or a CO2 laser.

6. The intelligent laser-dry ice composite cleaning device according to claim 4, characterized in that: The first mechanical arm (2) and the second mechanical arm (6) have the same structure and are implemented by using a six-axis robot system or a three-axis linkage processing machine tool.

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