A dry-wet combined laser cutting system and method

Abstract

The application provides a dry-wet composite laser cutting system and method, and belongs to the technical field of laser cutting.The system comprises a dry laser processing unit, a water guide laser processing unit and a water guide laser water supply unit.The dry laser output by the dry laser processing unit forms a preset cutting seam and a heat affected zone in a preset processing area.The output end of the water guide laser water supply unit is connected to the output end of the water guide laser processing unit and outputs high-pressure fluid.The water guide laser output by the water guide laser processing unit is injected into the surface of the preset processing area after multiple total reflections in the high-pressure fluid to realize trimming and removal of the heat affected zone.The organic combination of the dry laser processing unit and the water guide laser processing unit not only improves the processing speed, but also improves the processing quality of the workpiece, effectively solving the contradiction between the laser cutting speed, thickness and quality of the composite material.

Description

Technical Field

[0001] This invention belongs to the field of laser cutting technology, and relates to a laser cutting system, particularly a dry-wet composite laser cutting system and method. Background Technology

[0002] Composite materials have wide applications in aircraft, ships, vehicles, and other fields. In engineering, after prefabrication, composite materials generally require precision cutting and machining before they can be used in the assembly of these macroscopic and precision systems. Due to their non-uniform material properties and multi-layered structure, composite materials are difficult to process using mechanical cutting tools, abrasive waterjet machining, and other methods that can easily lead to interlayer tearing. While laser processing has a much smaller reaction force compared to mechanical processing, its application to composite material processing requires addressing issues such as heat-affected zones.

[0003] Laser cutting is generally a dry cutting process. The principle involves focusing laser energy onto a designated location on the workpiece material, applying an auxiliary gas, and moving the gas at a controlled speed. The material being processed absorbs the laser energy and rapidly heats up, completing the cutting process. Furthermore, laser cutting has minimal mechanical impact on the workpiece, making it easy to automate and intelligently control the cutting process. It has been widely used for cutting various types of sheet metal, such as metals and wood, and the lasers used are typically kilowatt or megawatt-level continuous lasers.

[0004] During continuous laser cutting, a heat-affected zone (HAZ) is generated in the workpiece due to ablation. For low-melting-point materials, such as carbon fiber reinforced resin (CFRP) composites, while dry laser cutting can achieve high speeds, defects such as microcracks and carbonization affect processing accuracy and quality. Short-pulse lasers, such as nanosecond, picosecond, and femtosecond lasers, can perform high-quality cutting of composite materials; however, because the power of these pulsed lasers is generally much lower than that of continuous lasers, their processing efficiency is difficult to compare with that of high-power continuous lasers. Summary of the Invention

[0005] The purpose of this invention is to address the aforementioned problems in existing technologies by proposing a dry-wet composite laser cutting system that improves processing quality while ensuring processing efficiency.

[0006] The objective of this invention can be achieved through the following technical solution: a dry-wet composite laser cutting system, comprising:

[0007] The system comprises a dry laser processing unit, a water-guided laser processing unit, and a water-guided laser water supply unit. The dry laser processing unit outputs a dry laser beam, which processes the workpiece within a preset processing area, forming a preset kerf and a heat-affected zone. The heat-affected zone is distributed around the preset kerf. Within the same cross-section, the sum of the cross-sectional areas of the preset kerf and the heat-affected zone is not greater than the cross-sectional area of ​​the preset processing area. The water-guided laser water supply unit is connected to the output of the water-guided laser processing unit, causing a high-pressure fluid to be generated at the output of the water-guided laser processing unit. The water-guided laser outputs a water-guided laser beam, which enters the high-pressure fluid at a first preset angle and undergoes multiple total reflections within the high-pressure fluid along its output direction before entering the surface of the preset processing area at a second preset angle. The heat-affected zone is removed by the water-guided laser, forming a trimmed area. Within the same cross-section, the sum of the cross-sectional areas of the preset kerf and the trimmed area is equal to the cross-sectional area of ​​the preset processing area.

[0008] In the aforementioned wet-dry composite laser cutting system, the dry laser is injected into the preset processing area perpendicular to the workpiece surface. The side of the heat-affected zone that is adjacent to the preset kerf is flat, while the side of the heat-affected zone that is opposite to the preset kerf is wavy. When the preset processing area is required to be processed into a vertical cross-section, the water-guided laser uses the cut surface of the deepest peak of the wavy cross-section in the heat-affected zone as the vertical reference plane to gradually trim and remove the heat-affected zone. When the preset processing area is required to be processed into a conical cross-section, the water-guided laser uses the plane of the line connecting the shallowest and deepest peaks of the wavy cross-section in the heat-affected zone as the inclined reference plane to gradually trim and remove the heat-affected zone.

[0009] In the aforementioned dry-wet composite laser cutting system, the dry laser processing unit is sequentially equipped with a dry laser, a first optical transmission structure, and a dry laser cutting head along the output direction of the dry laser. The dry laser is generated by the dry laser and then enters the dry laser cutting head through the first optical transmission structure.

[0010] In the aforementioned dry-wet composite laser cutting system, the water-guided laser processing unit is sequentially equipped with a water-guided laser, a second optical transmission structure, and a water-guided laser cutting head along the output direction of the water-guided laser. The water-guided laser generated by the water-guided laser is transmitted into the water-guided laser cutting head through the second optical transmission structure. The output end of the water-guided laser water supply unit is connected to the water-guided laser cutting head, and the high-pressure fluid generated by the water-guided laser water supply unit is input into the water-guided laser cutting head.

[0011] In the aforementioned wet-dry composite laser cutting system, the wet-dry composite laser cutting system further includes a dry laser auxiliary gas supply unit, which is connected to the dry laser cutting head. The dry laser auxiliary gas supply unit is used to output high-pressure inert auxiliary gas and input it into the dry laser cutting head.

[0012] In the aforementioned wet-dry composite laser cutting system, the wet-dry composite laser cutting system also includes a water-guided laser auxiliary gas supply unit, which is connected to the water-guided laser cutting head. The water-guided laser auxiliary gas supply unit is used to output high-pressure inert auxiliary gas and input it into the water-guided laser cutting head.

[0013] In the aforementioned dry-wet composite laser cutting system, the dry-wet composite laser cutting system also includes a detection unit, a motion control unit, and a central control system. The detection unit, motion control unit, dry laser processing unit, dry laser auxiliary gas supply unit, water-guided laser processing unit, water-guided laser water supply unit, and water-guided laser auxiliary gas supply unit are all electrically connected to the central control system. The dry laser cutting head and the water-guided laser cutting head are connected to the motion control unit.

[0014] In the aforementioned dry-wet composite laser cutting system, the motion control unit includes a base, on which a workpiece mounting platform is provided. The workpiece mounting platform is used to clamp and support the workpiece, and works in conjunction with the dry laser processing unit and the water-guided laser processing unit to complete the precise laser cutting of the workpiece. A gantry spans both sides of the base and can move along the length of the base, and a crossbeam is provided on the gantry. Two linear guides are mounted on the crossbeam, and a laser cutting head mounting seat is slidably connected to each linear guide. One laser cutting head mounting seat is used to connect the dry laser cutting head, and the other laser cutting head mounting seat is used to connect the water-guided laser cutting head.

[0015] The present invention also includes a laser cutting method based on the aforementioned wet-dry composite laser cutting system, comprising the following steps:

[0016] S1: Applying or attaching a protective layer to the surface of the workpiece;

[0017] S2: Clamp the workpiece onto the workpiece mounting platform and input the original coordinates of the workpiece into the central control system;

[0018] S3: The detection unit generates the workpiece's processing file;

[0019] S4: Perform dry laser processing on the preset processing area of ​​the workpiece;

[0020] S5: Detect the damaged area on the workpiece surface and the damaged area on the cross section after step S4, and generate the water-guided laser processing path;

[0021] S6: Perform water-guided laser processing on the preset processing area of ​​the workpiece;

[0022] S7: Perform a quality assessment on the workpiece after step S6. If the quality is qualified, the cutting process is completed; if the quality is unqualified, return to step S6 to continue water-guided laser processing until the quality is met.

[0023] In the laser cutting method described above, step S3 includes the following steps:

[0024] S31: At least three marking points are set on the workpiece, and the height and surface normal are measured by the detection unit, and the obtained measurement information is transmitted to the central control system;

[0025] S32: Based on the measurement information obtained in step S31, the original coordinate parameters of the workpiece in step S2 are converted into the actual coordinate parameters of the workpiece in the current system, and the machining file of the workpiece is generated based on the actual coordinate parameters.

[0026] In the laser cutting method described above, step S4 includes the following steps:

[0027] S41: Turn on the dry laser and the dry laser auxiliary gas supply unit to output dry laser and high-pressure inert auxiliary gas respectively;

[0028] S42: Dry laser is input into the dry laser cutting head through the first optical transmission structure. High-pressure inert auxiliary gas is input into the dry laser cutting head through the gas pipe to perform dry laser cutting on the preset processing area of ​​the workpiece and quickly cut through the preset processing area to form a preset kerf.

[0029] In the laser cutting method described above, after completing dry laser cutting in step S5, the detection unit detects the damaged area on the workpiece surface and the cross-sectional damaged area after step S4, thereby determining the processing path of the water-guided laser, and determining the tilt angle when the water-guided laser is incident on the workpiece surface by the processing taper.

[0030] In the laser cutting method described above, step S6 includes the following steps:

[0031] S61: Turn on the water-guided laser, the water-guided laser auxiliary gas supply unit, and the water-guided laser water supply unit to output the water-guided laser, high-pressure inert auxiliary gas, and high-pressure fluid, respectively.

[0032] S62: The water-guided laser is input into the water-guided laser cutting head through the second optical transmission structure. High-pressure inert auxiliary gas is input into the water-guided laser cutting head through the gas pipe. High-pressure fluid is input into the water-guided laser cutting head through the water pipe. Then, the heat-affected area generated by the dry laser is trimmed and removed by the water-guided laser.

[0033] In the laser cutting method described above, for step S7, after the water-guided laser processing in step S6 is completed, the processing surface and cross-section of the workpiece are inspected again by the detection unit to obtain the processing surface damage, cross-section damage and processing taper data. When the processing surface damage, cross-section damage and processing taper data all meet the preset corresponding data, the water-guided laser processing is stopped; otherwise, the water-guided laser processing continues.

[0034] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0035] (1) The dry-wet composite laser cutting system provided by the present invention, through the organic combination of dry laser processing unit and water-guided laser processing unit, not only improves the processing speed, but also improves the processing quality of workpiece, effectively solving the contradiction between speed, thickness and quality of composite material laser cutting;

[0036] (2) By coating or attaching a protective layer to the workpiece surface, on the one hand, it can absorb or block the low-density energy of the processing surface from reaching the material area around the preset kerf, protecting the material surface from or reducing thermal damage. On the other hand, the spatter is isolated from the workpiece surface, making it convenient to remove after processing, i.e., the protective layer can be directly peeled off the workpiece surface. In addition, by coating or attaching a protective layer to the workpiece surface, the processing taper can be reduced, making the side of the heat-affected zone that meets the preset kerf relatively straight, which is beneficial to the quality control of subsequent water-guided laser processing and finishing, and improves the processing accuracy.

[0037] (3) The protective layer has a certain conductivity and a distance sensor is provided at the end of the dry laser cutting head and the water-guided laser cutting head, so that the dry laser cutting head and the water-guided laser cutting head can use the distance sensor to sense and correct the relative distance between the workpiece in real time. That is, the vertical distance between the laser processing focus and the workpiece processing surface will not change with the change of the curved surface, and will always maintain a constant distance, which is conducive to the consistent control of processing quality and thus improves processing quality. Attached Figure Description

[0038] Figure 1 This is a structural block diagram of a dry-wet composite laser cutting system according to the present invention.

[0039] Figure 2 This is a schematic diagram of the water-guided laser processing unit of the present invention eliminating the heat-affected zone.

[0040] Figure 3 This is a time series diagram of dry-wet composite laser processing and water-guided laser processing when cutting thin composite materials.

[0041] Figure 4This is a time series diagram of dry-wet composite laser processing and water-guided laser processing when cutting thick composite materials.

[0042] Figure 5 This is a schematic diagram of water-guided laser processing in existing technology.

[0043] Figure 6 It is a cross-sectional view of a workpiece formed after dry laser processing when the workpiece surface is not coated with a protective layer in the existing technology.

[0044] Figure 7 This is a cross-sectional view of the workpiece formed after dry laser processing when a protective layer is coated on the workpiece surface according to the present invention.

[0045] Figure 8 This is a schematic diagram of the incident angle of the water-guided laser when processing straight holes and tapered holes according to the present invention.

[0046] Figure 9 This is a schematic diagram of the motion control unit in a preferred embodiment of the present invention.

[0047] Figure 10 This is a process flow diagram of a laser cutting method based on a dry-wet composite laser cutting system according to the present invention.

[0048] In the picture,

[0049] 10. Dry laser processing unit; 11. Dry laser; 12. First optical transmission structure; 13. Dry laser cutting head;

[0050] 20. Water-guided laser processing unit; 21. Water-guided laser; 22. Second optical transmission structure; 23. Water-guided laser cutting head;

[0051] 30. Water-guided laser water supply unit;

[0052] 40. Dry laser-assisted gas supply unit;

[0053] 50. Water-guided laser-assisted gas supply unit;

[0054] 60. Detection unit;

[0055] 70. Motion control unit; 71. Base; 72. Workpiece mounting platform; 73. Gantry frame; 74. Crossbeam; 75. Linear guide rail; 76. Laser cutting head mounting base;

[0056] 80. Central control system;

[0057] 90. Auxiliary Unit. Detailed Implementation

[0058] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0059] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0060] like Figures 1 to 9 As shown, the present invention provides a wet-dry composite laser cutting system for processing within a preset processing area on a workpiece, comprising:

[0061] The system comprises a dry laser processing unit 10, a water-guided laser processing unit 20, and a water-guided laser water supply unit 30. The dry laser processing unit 10 outputs a dry laser, which processes the workpiece within a preset processing area to form a preset kerf and a heat-affected zone. The heat-affected zone is distributed around the preset kerf. Within the same cross-section, the sum of the cross-sectional area of ​​the preset kerf and the cross-sectional area of ​​the heat-affected zone is not greater than the cross-sectional area of ​​the preset processing area. The output of the water-guided laser water supply unit 30 is connected to the output of the water-guided laser processing unit 20, causing the output of the water-guided laser processing unit 20 to form a high-pressure fluid. The output of the water-guided laser processing unit 20 outputs a water-guided laser, which enters the high-pressure fluid at a first preset angle and undergoes multiple total reflections within the high-pressure fluid along the output direction before entering the surface of the preset processing area at a second preset angle. The heat-affected zone is removed by the water-guided laser trimming, forming a trimmed area. Within the same cross-section, the sum of the cross-sectional area of ​​the preset kerf and the cross-sectional area of ​​the trimmed area is equal to the cross-sectional area of ​​the preset processing area.

[0062] It is worth mentioning that the dry laser processing unit 10 can quickly form a preset kerf in the preset processing area. The preset kerf runs through the preset processing area, and the maximum diameter of the cross-section of the heat-affected zone generated by the dry laser processing unit 10 after processing will not spread to the range covered by the diameter of the same horizontal cross-section in the preset processing area. Then, the water-guided laser processing unit 20 is injected into the workpiece surface after total reflection in high-pressure fluid. This not only eliminates the heat-affected zone formed by the dry laser processing unit 10, making the processed size reach the preset processing size, but also solves the problem of the water-guided laser processing unit 20 generating a heat-affected zone during processing due to the presence of high-pressure fluid, thereby improving the processing quality.

[0063] The present invention provides a dry-wet composite laser cutting system, which, through the organic combination of dry laser processing unit 10 and water-guided laser processing unit 20, not only improves the processing speed but also improves the processing quality of the workpiece, effectively solving the contradiction between the laser cutting speed, thickness and quality of composite materials.

[0064] It is worth mentioning that in the experiment of dry laser cutting of flat composite materials, the analysis of the experimental results shows that the thickness of the heat-affected zone generated during dry laser cutting of CFRP composite materials is approximately 87 μm. Therefore, when selecting a laser for water-guided laser trimming and cleaning, a kilowatt-level fiber laser with a fiber core diameter of Φ20 μm–200 μm is preferred. Figure 2 As can be seen, selecting a water-guided laser with a diameter not smaller than the diameter of the heat-affected zone helps the water-guided laser to quickly trim and remove the pre-set kerf after high-speed dry laser cutting, eliminating the heat-affected zone, improving the surface quality of the composite material kerf section, and increasing the surface roughness of the product. High-speed dry laser cutting of the composite material kerf lays the foundation for subsequent water-guided laser trimming and removal, ensuring that the water flow velocity reaching the bottom of the kerf remains high, and that sufficiently high laser energy can reach the top of the kerf, facilitating the cutting of thick composite materials. The processing efficiency is significantly improved compared to simple water-guided laser cutting.

[0065] Furthermore, it was pointed out that, from Figure 3 From this, we can see that L th1 This represents the maximum thickness that a water-guided laser can cut. When cutting relatively thin composite materials (L < 2 mm), [the following is a description of the process]. Figure 3 It can be seen that the cutting time of the wet-dry composite cutting is significantly shorter than that of the water-guided laser cutting time, i.e., t A =t1 + t2 < t3 (t1 is the processing time for dry laser high-speed cutting, t2 is the processing time for water-guided laser trimming and removal, and t3 is the processing time for water-guided laser alone). According to the formula... It can be seen that v 干湿复合 Much greater than v 水导 Therefore, the present invention is used to cut composite materials with small thickness, and the processing efficiency can be significantly higher than that of the existing technology of simple water-guided laser processing.

[0066] Furthermore, it was pointed out that, from Figure 4 From this, we can see that L th1 L is the maximum thickness that a water-guided laser can cut. th2 This represents the maximum thickness that a dry laser can cut. When cutting composite materials with the same large thickness (e.g., >2-20mm), the... Figure 4 and Figure 5It is known that wet-dry composite processing can complete the cutting quickly, while water-guided laser processing requires repeated operations and increases in kerf width to possibly complete the cutting task, or even fail to cut through at all. Therefore, wet-dry composite processing time is shorter than water-guided laser processing time, i.e., t A = t1 + t2 < t3 (t1 is the processing time for dry laser high-speed cutting, and t2 is the processing time for water-guided laser trimming and removal) (This refers to the processing time for water-guided lasers). According to the formula... It can be seen that... 干湿复合 Much greater than v 水导 Therefore, the method of the present invention is used for cutting large-sized and thick composite materials, which can improve the thickness limit, increase the cutting speed, and ensure the cutting quality, thus better meeting engineering requirements. Preferably, the dry laser is injected into the preset processing area along the surface of the workpiece perpendicularly, and the side of the heat-affected zone that is in contact with the preset cut is a plane, while the side of the heat-affected zone that is opposite to the preset cut is wavy. When the preset processing area is required to be processed into a vertical cross section, the water-guided laser uses the cut surface of the deepest peak of the wavy cross section in the heat-affected zone as the vertical reference plane to gradually trim and remove the heat-affected zone; when the preset processing area is required to be processed into a conical cross section, the water-guided laser uses the plane where the line connecting the shallowest and deepest peaks of the wavy cross section in the heat-affected zone is located as the inclined reference plane to gradually trim and remove the heat-affected zone.

[0067] In this embodiment, depending on the different aperture cross-sections within the preset processing area, the incident angle of the water-guided laser when incident on the workpiece surface will also change. If a straight hole is being processed, the cross-section of the deepest peak in the heat-affected zone is used as the vertical reference plane, and then the water-guided laser is incident on the workpiece surface in a manner parallel to this vertical reference plane, gradually trimming and removing the heat-affected zone, and finally completing the processing of the preset processing area. If a tapered hole is being processed, the plane connecting the shallowest and deepest peaks in the heat-affected zone is used as the inclined reference plane, and then the water-guided laser is incident on the workpiece surface in a manner parallel to this inclined reference plane, gradually trimming and removing the heat-affected zone, and finally completing the processing of the preset processing area, thereby ensuring the processing quality of the hole within the preset processing area.

[0068] Preferably, the dry laser processing unit 10 is provided with a dry laser 11, a first optical transmission structure 12 and a dry laser cutting head 13 arranged sequentially along the output direction of the dry laser. The dry laser is generated by the dry laser 11 and enters the dry laser cutting head 13 through the first optical transmission structure 12.

[0069] It is worth mentioning that the dry laser 11 in this embodiment is preferably a high-power quality kilowatt-level or higher single-mode laser, including but not limited to fiber lasers, CO2 lasers, solid-state lasers, etc., and especially preferably a fiber laser that is easy to transmit flexibly. The kerf width of the dry laser cutting is preferably <200μm, more preferably <100μm.

[0070] Preferably, the water-guided laser processing unit 20 is provided with a water-guided laser 21, a second optical transmission structure 22 and a water-guided laser cutting head 23 in sequence along the output direction of the water-guided laser. The water-guided laser generated by the water-guided laser 21 is injected into the water-guided laser cutting head 23 through the second optical transmission structure 22. The output end of the water-guided laser water supply unit 30 is connected to the water-guided laser cutting head 23, and the high-pressure fluid generated by the water-guided laser water supply unit 30 is input into the water-guided laser cutting head 23.

[0071] It is worth mentioning that in this embodiment, the water-guided laser cutting head 23 emits a laminar water column, and the water-guided laser is coupled into the laminar water column and transmitted to the surface of the preset processing area through total internal reflection. The water-guided laser generated by the water-guided laser 21 will cause energy attenuation when it undergoes total internal reflection in the water column, but the attenuated energy can still meet the processing requirements. Moreover, the water-guided laser is not limited to green light and near-infrared light.

[0072] In addition, the water-guided laser is preferably a high-power laser, including but not limited to fiber lasers, solid-state lasers, etc.

[0073] More preferably, when the single-line cutting width of the water-guided laser is greater than or equal to the maximum cross-sectional width of the heat-affected zone, the water-guided laser can trim and remove the heat-affected zone in a single pass; when the single-line cutting width of the water-guided laser is less than the maximum cross-sectional width of the heat-affected zone, the water-guided laser can trim and remove the heat-affected zone in multiple passes, wherein the angle at which the water-guided laser incident on the workpiece surface is consistent each time.

[0074] Preferably, the dry-wet composite laser cutting system further includes a dry laser auxiliary gas supply unit 40, which is connected to the dry laser cutting head 13. The dry laser auxiliary gas supply unit 40 is used to output high-pressure inert auxiliary gas and input it into the dry laser cutting head 13.

[0075] It is worth mentioning that the high-pressure inert auxiliary gas is an inert gas with a pressure higher than that of conventional dry laser cutting, used to solve problems such as easy ignition, carbonization, and oxidation of composite materials during dry laser cutting. The auxiliary gas is preferably nitrogen, but includes, but is not limited to, helium and argon. The pressure is preferably 20% or more higher than that of conventional dry laser cutting, and more preferably greater than 40%.

[0076] Preferably, the dry-wet composite laser cutting system further includes a water-guided laser auxiliary gas supply unit 50, which is connected to the water-guided laser cutting head 23. The water-guided laser auxiliary gas supply unit 50 is used to output high-pressure inert auxiliary gas and input it into the water-guided laser cutting head 23.

[0077] It is worth mentioning that the high-pressure inert auxiliary gas is a high-intensity inert gas used to avoid the influence of sputtering on the laser beam during the water-guided laser trimming and cleaning process. The auxiliary gas is preferably helium, but includes, but is not limited to, nitrogen, argon, etc.

[0078] Preferably, the dry-wet composite laser cutting system further includes a detection unit 60, a motion control unit 70, and a central control system 80. The detection unit 60, motion control unit 70, dry laser processing unit 10, dry laser auxiliary gas supply unit 40, water-guided laser processing unit 20, water-guided laser water supply unit 30, and water-guided laser auxiliary gas supply unit 50 are all electrically connected to the central control system 80. The dry laser cutting head 13 and the water-guided laser cutting head 23 are connected to the motion control unit 70.

[0079] In this embodiment, the detection unit 60 is used to collect the actual position information of the workpiece and transmit it to the central control system 80. The detection unit 60 includes at least an imaging structure and a ranging structure.

[0080] It is worth mentioning that the imaging structure is preferably a CCD image sensor, used for image recognition, edge alignment, and workpiece positioning. Positioning includes automatic positioning and manual positioning. The ranging structure is used to acquire the real-time processing height between the dry laser cutting head 13 and the water-guided laser cutting head 23 and the workpiece surface, including but not limited to the use of ultrasonic ranging sensors, laser ranging sensors, electromagnetic induction sensors, etc.

[0081] In this embodiment, the motion control unit 70 is used to adjust the laser energy and the motion cutting positions of the dry laser cutting head 13 and the water-guided laser cutting head 23 according to the control information of the central control system 80, so as to achieve precise cutting of the workpiece. The laser energy adjustment includes the use of pulse modulation function of high-power laser, preferably using a duty cycle of less than 50%, more preferably using a duty cycle of less than 20%, so that the laser that usually runs continuously becomes a laser with a pulse width of microsecond to millisecond, thereby reducing the thermal impact of dry laser processing.

[0082] In this embodiment, the central control system 80 is an industrial control computer, an embedded industrial control system, or a remote control system connected via a network, used to control the completion of large-scale laser cutting of composite material dry and wet composite workpieces.

[0083] More preferably, the motion control unit 70 includes a base 71, on which a workpiece mounting platform 72 is provided. The workpiece mounting platform 72 is used to clamp and support the workpiece, and cooperates with the dry laser processing unit 10 and the water-guided laser processing unit 20 to complete the precise laser cutting of the workpiece. A gantry 73 spans both sides of the base 71 and can move along the length of the base 71. A crossbeam 74 is provided on the gantry 73. Two linear guides 75 are mounted on the crossbeam 74, and a laser cutting head mounting seat 76 is slidably connected to each linear guide 75. One laser cutting head mounting seat 76 is used to connect the dry laser cutting head 13, and the other laser cutting head mounting seat 76 is used to connect the water-guided laser cutting head 23.

[0084] More preferably, the two linear guide rails 75 are installed on both sides of the crossbeam 74, or on the same side of the crossbeam 74. When the two linear guide rails 75 are installed on both sides of the crossbeam 74, the two linear guide rails 75 are arranged on both sides of the crossbeam 74 along the moving direction of the gantry frame 73.

[0085] Preferably, the dry-wet composite laser cutting system further includes an auxiliary unit 90, which is electrically connected to the main control system 80. The auxiliary unit 90 is used to collect waste gas, smoke, wastewater and waste residue after workpiece processing, thereby protecting the environment and the health of operators.

[0086] like Figure 10 As shown, the present invention also provides a method based on a wet-dry composite laser cutting system, comprising the following steps:

[0087] S1: Applying or attaching a protective layer to the surface of the workpiece;

[0088] S2: Clamp the workpiece onto the workpiece mounting platform 72 and input the original coordinates of the workpiece into the central control system 80;

[0089] S3: The detection unit 60 generates a machining file for the workpiece;

[0090] S4: Perform dry laser processing on the preset processing area of ​​the workpiece;

[0091] S5: Detect the damaged area on the workpiece surface and the damaged area on the cross section after step S4, and generate the water-guided laser processing path;

[0092] S6: Perform water-guided laser processing on the preset processing area of ​​the workpiece;

[0093] S7: Perform a quality assessment on the workpiece after step S6. If the quality is qualified, the cutting process is completed; if the quality is unqualified, return to step S6 to continue water-guided laser processing until the quality is met.

[0094] It is worth mentioning that the protective layer in step S1 is a medium with a certain conductivity, such as graphite powder, aluminum foil, copper foil, including but not limited to conductive tape, conductive paste and other conductive materials.

[0095] In existing technologies, during continuous laser composite material processing, the high energy can cut through tens of millimeters of material in a single pass. However, this results in severe thermal damage to the processed surface and cross-section, creating a significant heat-affected zone and noticeable taper. Furthermore, high-temperature spatter can accumulate near the cut area or undergo secondary adhesion, thus affecting the surface quality of the workpiece.

[0096] In this embodiment, by coating or attaching a protective layer to the workpiece surface, on the one hand, it can absorb or block the low-density energy of the processing surface from reaching the material area around the preset cut, protecting the material surface from or reducing thermal damage; on the other hand, the spatter is isolated from the workpiece surface, making it convenient to remove after processing, that is, the protective layer can be directly peeled off the workpiece surface.

[0097] In addition, by coating or attaching a protective layer to the workpiece surface, the machining taper can be reduced, making the side of the heat-affected zone that meets the preset cut relatively straight. This is beneficial for quality control in subsequent water-guided laser machining and finishing, and improves machining accuracy.

[0098] More preferably, the protective layer has a certain conductivity, and a distance sensor is provided at the end of the dry laser cutting head 13 and the water-guided laser cutting head 23, so that the dry laser cutting head 13 and the water-guided laser cutting head 23 can use the distance sensor to sense and correct the relative distance with the workpiece in real time. That is, the vertical distance between the laser processing focus and the workpiece processing surface will not change with the curvature of the surface, and will always maintain a constant distance, which is conducive to the consistent control of processing quality and thus improves processing quality.

[0099] More preferably, step S3 includes the following steps:

[0100] S31: At least three marking points are set on the workpiece, and the height and surface normal are measured by the detection unit 60, and the obtained measurement information is transmitted to the main control system 80;

[0101] S32: Based on the measurement information obtained in step S31, the original coordinate parameters of the workpiece in step S2 are converted into the actual coordinate parameters of the workpiece in the current system, and the machining file of the workpiece is generated based on the actual coordinate parameters.

[0102] More preferably, for step S4, adjusting the dry laser processing parameters according to the processing file formed in step S3 includes the following steps:

[0103] S41: Turn on the dry laser and the dry laser auxiliary gas supply unit 40 to output dry laser and high-pressure inert auxiliary gas respectively;

[0104] S42: Dry laser is input into dry laser cutting head 13 through first optical transmission structure 12, and high-pressure inert auxiliary gas is input into dry laser cutting head 13 through gas pipe to dry laser cut the preset processing area of ​​workpiece and quickly cut through the preset processing area to form preset kerf.

[0105] More preferably, in step S5, after dry laser cutting is completed, the detection unit 60 detects the damaged area on the workpiece surface and the cross-sectional damaged area after step S4, thereby determining the processing path of the water-guided laser, and determining the tilt angle when the water-guided laser is incident on the workpiece surface by the processing taper. Preferably, the tilt angle is the angle between the incident direction of the water-guided laser and the normal of the workpiece surface, and the angle is generally less than 10°.

[0106] More preferably, for step S6, based on the water-guided laser processing path generated in step S5, the processing parameters for water-guided laser trimming and removal are adjusted, including the following steps:

[0107] S61: Turn on the water-guided laser. The water-guided laser auxiliary gas supply unit 50 and the water-guided laser water supply unit 30 output water-guided laser, high-pressure inert auxiliary gas and high-pressure fluid respectively.

[0108] S62: The water-guided laser is input into the water-guided laser cutting head 23 through the second optical transmission structure 22. High-pressure inert auxiliary gas is input into the water-guided laser cutting head 23 through the gas pipe. High-pressure fluid is input into the water-guided laser cutting head 23 through the water pipe. Then, the heat-affected area generated by the dry laser is trimmed and removed by the water-guided laser.

[0109] More preferably, for step S7, after the water-guided laser processing of step S6 is completed, the processing surface and cross-section of the workpiece are inspected again by the detection unit 60 to obtain the processing surface damage, cross-section damage and processing taper data. When the processing surface damage, cross-section damage and processing taper data all meet the preset corresponding data, the water-guided laser processing is stopped; otherwise, the water-guided laser processing continues.

[0110] It should be noted that in this invention, the use of terms such as "first," "second," and "a" is 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 as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified. The terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two elements or the interaction between two elements, unless otherwise explicitly specified. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0111] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0112] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. A dry-wet composite laser cutting system, characterized in that, include: The system comprises a dry laser processing unit, a water-guided laser processing unit, and a water-guided laser water supply unit. The dry laser processing unit outputs a dry laser beam, which processes the workpiece within a preset processing area to form a preset kerf and a heat-affected zone. The heat-affected zone is distributed around the preset kerf. Within the same cross-section, the sum of the cross-sectional areas of the preset kerf and the heat-affected zone is not greater than the cross-sectional area of ​​the preset processing area. The water-guided laser water supply unit is connected to the output of the water-guided laser processing unit, causing the output of the water-guided laser processing unit to form a high-pressure fluid. The output of the water-guided laser processing unit outputs a water-guided laser beam, which enters the high-pressure fluid at a first preset angle and undergoes multiple total reflections within the high-pressure fluid along its output direction before entering the surface of the preset processing area at a second preset angle. The water-guided laser trims and removes the heat-affected zone, forming a trimmed area. Within the same cross-section, the sum of the cross-sectional areas of the preset kerf and the trimmed area is equal to the cross-sectional area of ​​the preset processing area. A dry laser is directed into a pre-defined processing area perpendicular to the workpiece surface. The side of the heat-affected zone that meets the pre-defined cut is flat, while the side that does not meet the pre-defined cut is wavy. When the pre-defined processing area is required to be processed into a vertical cross-section, the water-guided laser uses the cut surface of the deepest peak of the wavy cross-section in the heat-affected zone as the vertical reference plane to gradually trim and remove the heat-affected zone. When the pre-defined processing area is required to be processed into a tapered cross-section, the water-guided laser uses the plane of the line connecting the shallowest and deepest peaks of the wavy cross-section in the heat-affected zone as the inclined reference plane to gradually trim and remove the heat-affected zone. When machining a straight hole, the cut surface of the deepest peak in the heat-affected zone is used as the vertical reference plane. Then, the water-guided laser is incident on the workpiece surface in a manner parallel to this vertical reference plane, gradually trimming and removing the heat-affected zone to complete the machining of the preset machining area. When machining a tapered hole, the plane where the connection between the shallowest and deepest peaks in the heat-affected zone is located is used as the inclined reference plane. Then, the water-guided laser is incident on the workpiece surface in a manner parallel to this inclined reference plane, gradually trimming and removing the heat-affected zone to complete the machining of the preset machining area.

2. The dry-wet composite laser cutting system according to claim 1, characterized in that, The dry laser processing unit is provided with a dry laser, a first optical transmission structure and a dry laser cutting head arranged sequentially along the output direction of the dry laser. The dry laser is generated by the dry laser and enters the dry laser cutting head through the first optical transmission structure.

3. The dry-wet composite laser cutting system according to claim 2, characterized in that, The water-guided laser processing unit is provided with a water-guided laser, a second optical transmission structure, and a water-guided laser cutting head in sequence along the output direction of the water-guided laser. The water-guided laser generated by the water-guided laser is injected into the water-guided laser cutting head through the second optical transmission structure. The output end of the water-guided laser water supply unit is connected to the water-guided laser cutting head, and the high-pressure fluid generated by the water-guided laser water supply unit is input into the water-guided laser cutting head.

4. The dry-wet composite laser cutting system according to claim 3, characterized in that, The dry-wet composite laser cutting system also includes a dry laser auxiliary gas supply unit, which is connected to the dry laser cutting head. The dry laser auxiliary gas supply unit is used to output high-pressure inert auxiliary gas and input it into the dry laser cutting head.

5. The dry-wet composite laser cutting system according to claim 4, characterized in that, The dry-wet composite laser cutting system also includes a water-guided laser auxiliary gas supply unit, which is connected to the water-guided laser cutting head. The water-guided laser auxiliary gas supply unit is used to output high-pressure inert auxiliary gas and input it into the water-guided laser cutting head.

6. The dry-wet composite laser cutting system according to claim 5, characterized in that, The dry-wet composite laser cutting system further includes a detection unit, a motion control unit, and a central control system. The detection unit, the motion control unit, the dry laser processing unit, the dry laser auxiliary gas supply unit, the water-guided laser processing unit, the water-guided laser water supply unit, and the water-guided laser auxiliary gas supply unit are all electrically connected to the central control system. The dry laser cutting head and the water-guided laser cutting head are connected to the motion control unit.

7. The dry-wet composite laser cutting system according to claim 6, characterized in that, The motion control unit includes a base, on which a workpiece mounting platform is provided. The workpiece mounting platform is used to clamp and support the workpiece, and works in conjunction with the dry laser processing unit and the water-guided laser processing unit to complete the laser cutting of the workpiece. A gantry spans both sides of the base and can move along the length of the base, and a crossbeam is provided on the gantry. Two linear guides are mounted on the crossbeam, and a laser cutting head mounting seat is slidably connected to each linear guide. One laser cutting head mounting seat is used to connect the dry laser cutting head, and the other laser cutting head mounting seat is used to connect the water-guided laser cutting head.

8. A laser cutting method based on the dry-wet composite laser cutting system of claim 6, characterized in that, Including the following steps: S1: Applying or attaching a protective layer to the surface of the workpiece; S2: Clamp the workpiece onto the workpiece mounting platform and input the original coordinates of the workpiece into the central control system; S3: The detection unit generates the workpiece's processing file; S4: Perform dry laser processing on the preset processing area of ​​the workpiece; S5: Detect the damaged area on the workpiece surface and the damaged area on the cross section after step S4, and generate the processing path of the water-guided laser. S6: Perform water-guided laser processing on the preset processing area of ​​the workpiece; S7: Perform a quality assessment on the workpiece after step S6. If the quality is qualified, the cutting process is completed; if the quality is unqualified, return to step S6 to continue water-guided laser processing until the quality is met.

9. The laser cutting method according to claim 8, characterized in that, For step S3, the steps include: S31: At least three marking points are set on the workpiece, and the height and surface normal are measured by the detection unit, and the obtained measurement information is transmitted to the central control system; S32: Based on the measurement information obtained in step S31, the original coordinate parameters of the workpiece in step S2 are converted into the actual coordinate parameters of the workpiece in the current system, and the machining file of the workpiece is generated based on the actual coordinate parameters.

10. The laser cutting method according to claim 8, characterized in that, For step S4, the steps include: S41: Turn on the dry laser and the dry laser auxiliary gas supply unit to output dry laser and high-pressure inert auxiliary gas respectively; S42: Dry laser is input into the dry laser cutting head through the first optical transmission structure. High-pressure inert auxiliary gas is input into the dry laser cutting head through the gas pipe to perform dry laser cutting on the preset processing area of ​​the workpiece and quickly cut through the preset processing area to form a preset kerf.

11. The laser cutting method according to claim 8, characterized in that, For step S5, after dry laser cutting is completed, the detection unit is used to detect the damaged area on the workpiece surface and the damaged area on the cross section after step S4, so as to determine the processing path of the water-guided laser, and the tilt angle when the water-guided laser is incident on the workpiece surface is determined by the processing taper.

12. The laser cutting method according to claim 8, characterized in that, For step S6, the steps include: S61: Turn on the water-guided laser, the water-guided laser auxiliary gas supply unit, and the water-guided laser water supply unit to output the water-guided laser, high-pressure inert auxiliary gas, and high-pressure fluid, respectively. S62: The water-guided laser is input into the water-guided laser cutting head through the second optical transmission structure. High-pressure inert auxiliary gas is input into the water-guided laser cutting head through the gas pipe. High-pressure fluid is input into the water-guided laser cutting head through the water pipe. Then, the heat-affected area generated by the dry laser is trimmed and removed by the water-guided laser.

13. The laser cutting method according to claim 8, characterized in that, Regarding step S7, after the water-guided laser processing in step S6 is completed, the processing surface and cross-section of the workpiece are inspected again by the detection unit to obtain data on surface damage, cross-section damage, and processing taper. If the surface damage, cross-section damage, and processing taper data all meet the preset corresponding data, the water-guided laser processing is stopped; otherwise, the water-guided laser processing continues.

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