An underwater laser processing device based on water guide laser

Abstract

The utility model discloses a kind of underwater laser processing equipment based on water guide laser, belong to laser processing technical field, including laser generating device, water flow generating device, laser processing head and displacement module, the integrated setting of laser transmission lens group in laser processing head, water chamber, water guide laser pipe fitting, so that high-energy laser beam can be guided to the machining area of underwater workpiece accurately under the guidance of high-pressure water column, and then accurately realize the laser processing of underwater workpiece.The underwater laser processing equipment based on water guide laser in the utility model, it is simple in structure, control is convenient, can accurately realize the coaxial coupling of laser beam and high-pressure water column, accurately realize the guidance processing of water column to high-energy laser beam, ensure the accuracy and reliability of underwater laser processing, avoid the loss of laser energy, expand the application range of laser underwater processing technology, reduce the application cost of laser underwater processing technology, with excellent application value and popularization prospect.

Description

Technical Field

[0001] This utility model belongs to the field of laser processing technology, specifically relating to an underwater laser processing device based on a water-guided laser. Background Technology

[0002] With the increasing development of marine resources and the growing number of underwater engineering activities, the application of underwater operation technologies is becoming more widespread, and the demand for underwater processing operations is becoming increasingly diversified. Consequently, higher performance requirements are being placed on traditional underwater laser processing equipment.

[0003] Taking underwater welding technology as an example, traditional underwater welding methods mainly rely on electric arc welding. However, this method has disadvantages in underwater operations, such as shielding gas failure, unstable electric arc, poor underwater operation accuracy, and processing equipment being limited by space / waterproofing. In addition, traditional underwater welding equipment has poor flexibility and cannot meet the welding requirements under high-speed movement, resulting in certain limitations in the quality and efficiency of underwater welding.

[0004] In recent years, the engineering applications of water-guided lasers have developed rapidly. By combining high-energy lasers with high-pressure water jets, they possess both high energy density and low thermal impact, and have already been applied in some scenarios. However, existing water-guided laser processing technologies still face a series of application problems, such as high requirements for water quality in the processing area, low laser energy utilization, and low processing efficiency. These issues prevent the full realization of the potential of water-guided laser processing technology and limit its application. Utility Model Content

[0005] In response to one or more of the above-mentioned defects or improvement needs of the existing technology, this utility model provides an underwater laser processing device based on water-guided laser, which can reliably combine a high-energy laser beam with a high-pressure water jet, ensuring the energy density of underwater laser processing and improving the stability and processing efficiency of underwater laser processing.

[0006] To achieve the above objectives, this utility model provides an underwater laser processing device based on a water-guided laser, comprising: A laser generator used to produce a laser beam; A water flow generating device used to produce a high-pressure water jet; A laser processing head; the laser processing head includes a laser transmission mirror assembly, a water chamber, and a water-guided laser tube; wherein, the laser transmission mirror assembly is connected to a laser generating device via a transmission optical fiber; the water chamber includes a sealed cavity connected to a water flow generating device via a transmission water pipe, and a laser incident window and a water flow nozzle are coaxially arranged on the sealed cavity; the light outlet of the laser transmission mirror assembly is directly opposite the laser incident window for transmitting the laser beam into the sealed cavity; and The water-guided laser tube is used to couple a laser beam into a high-pressure water jet and guide it to the underwater processing area. One end of the tube is connected to a water chamber and coaxially communicated with the water jet nozzle, while the other end extends underwater and aligns with the underwater workpiece. The water-guided laser tube includes a heat-conducting tube for rapid heat conduction and a structural support tube sleeved around the heat-conducting tube. The structural support tube provides strength to the water-guided laser tube. The heat-conducting tube has a central through-hole for jetting the high-pressure water jet, and a total reflection surface is formed on the inner wall of the central through-hole. Displacement device; the laser processing head is mounted on the displacement device and can be moved under the drive of the displacement device to irradiate the part of the underwater workpiece to be processed with laser transmitted through the high-pressure water jet.

[0007] As a further improvement of this utility model, the length of the water-guided laser tube is not less than the distance between the underwater workpiece and the horizontal plane, and the end of the water-guided laser tube away from the water chamber can be spaced 0.5mm~5mm from the surface of the underwater workpiece during equipment processing.

[0008] As a further improvement of this utility model, the water-guided laser tube is detachably connected to the water chamber, and the water-guided laser tube is available in a variety of length specifications. and / or The thermal conductivity of the heat pipe is 300~500 W / (m·K); and / or The tensile strength of the structural support tube is not less than 500 MPa, and the yield strength is not less than 200 MPa.

[0009] As a further improvement of this utility model, the surface roughness of the total reflection surface is not greater than 100 Å; and / or The total reflective surface is obtained by grinding and polishing, or the total reflective surface is formed by a hard gold plating layer with a thickness of not less than 0.1 μm.

[0010] As a further improvement of this utility model, the inner diameter of the central through hole is larger than the spot diameter of the laser beam at the beam waist after focusing, and the inner diameter of the central through hole is 0.2~3mm. and / or The outlet end face of the water-guided laser tube is a slope, and the slope forms an angle of 30° to 70° with the surface of the underwater workpiece.

[0011] As a further improvement of this utility model, the structural support tube is a stainless steel tube and the heat-conducting tube is a copper tube; and / or The structural support tube and the heat-conducting tube are assembled by a threaded connection. and / or The outer periphery of the structural support tube is provided with an anti-corrosion layer of a certain thickness. As a further improvement of this utility model, the water source pressure provided by the water flow generating device is continuously adjustable in the range of 0~500 bar, and the water pressure in the water-guided laser tube is 1.05 times to 3 times the water pressure at the depth where the underwater workpiece is located.

[0012] As a further improvement of this utility model, the water flow generating device includes a water treatment device and a high-pressure water jet device; The water treatment equipment is used to treat the water that forms the high-pressure water jet column to ensure the purity of the high-pressure water jet column; the high-pressure water jet equipment is connected to the water chamber via a transmission water pipe to generate a high-pressure water jet column with corresponding pressure.

[0013] As a further improvement of this utility model, the laser processing head also includes an underwater searchlight and an industrial camera; The industrial camera is connected to the laser transmission mirror assembly and is used to photograph the processing area of ​​the underwater workpiece; the underwater searchlight is used to provide illumination to the processing area of ​​the underwater workpiece.

[0014] As a further improvement of this utility model, a central control device is also included; The central control device is electrically connected to the laser generator, the water flow generator, the laser processing head, and the displacement device, respectively, to realize the automated control of each device.

[0015] The aforementioned improved technical features can be combined with each other as long as they do not conflict with each other.

[0016] In summary, the beneficial effects of the above-described technical solutions conceived by this utility model compared with the prior art include: This utility model relates to an underwater laser processing device based on water-guided lasers. It includes a laser generator, a water flow generator, a laser processing head, and a displacement module. By integrating the laser transmission mirror group, water chamber, and water-guided laser tube in the laser processing head, a high-energy laser beam can be accurately guided to the processing area of ​​the underwater workpiece under the guidance of a high-pressure water flow column. This ensures the accuracy of high-energy laser beam transmission and processing, improves the processing efficiency and quality of underwater workpieces, meets the underwater processing needs of more application scenarios, and expands the application scope of underwater laser processing technology.

[0017] The underwater laser processing equipment based on water-guided laser of this invention has a simple structure and convenient control. It can accurately achieve coaxial coupling between the laser beam and the high-pressure water column, accurately guide the high-energy laser beam through the water column, ensure the accuracy and reliability of underwater laser processing, avoid laser energy loss, expand the application range of underwater laser processing technology, reduce the application cost of underwater laser processing technology, and improve the efficiency and quality of underwater laser processing of workpieces. It has excellent application value and promotion prospects. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the overall structure of the underwater laser processing equipment based on water-guided laser in this embodiment of the present invention; In all the accompanying drawings, the same reference numerals denote the same technical features, specifically: 1. Laser generator; 2. Water flow generator; 3. Laser processing head; 4. Displacement device; 5. Underwater workpiece; 6. Central control device; 101. Laser; 102. Laser water chiller; 103. Transmission optical fiber; 201. High-pressure water jet equipment; 202. Water transmission pipe; 301. Laser transmission mirror assembly; 302. Water chamber; 3021. Laser entrance window; 3022. Water flow nozzle; 303. Water-guided laser tube; 3031. Total reflection surface; 3032. Heat pipe; 3033. Structural support tube; 304. Industrial camera; 305. Underwater searchlight; 401. Displacement actuator; 402. Displacement control mechanism. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the present utility model and are not intended to limit the present utility model. Furthermore, the technical features involved in the various embodiments of the present utility model described below can be combined with each other as long as they do not conflict with each other.

[0021] In the description of this utility model, it should be understood that, unless otherwise explicitly specified and limited, the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0022] Furthermore, unless otherwise expressly defined, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise expressly and specifically defined.

[0023] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0024] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0025] Below, for reference Figure 1 This invention describes an underwater laser processing device based on a water-guided laser according to a preferred embodiment of the present invention.

[0026] like Figure 1As shown in the preferred embodiment, the underwater laser processing equipment based on water-guided laser includes a laser generating device 1, a water flow generating device 2, a laser processing head 3, and a displacement device 4.

[0027] The laser generator 1 generates a laser beam of corresponding power; the water flow generator 2 generates a high-pressure water jet of corresponding pressure. The laser processing head 3 is mounted on the displacement device 4 and can be moved under the drive of the displacement device 4 to irradiate the part of the underwater workpiece 5 to be processed with the laser transmitted through the high-pressure water jet.

[0028] Meanwhile, in the preferred embodiment, the laser processing head 3 is used to couple the laser beam in the high-pressure water jet and to perform laser processing on the underwater workpiece 5.

[0029] Specifically, in the preferred embodiment, the laser processing head 3 includes a laser transmission mirror group 301, a water chamber 302, and a water-guided laser tube 303; wherein, the laser transmission mirror group 301 is connected to the laser generating device 1 via a transmission optical fiber 103; the water chamber 302 includes a sealed cavity connected to the water flow generating device 2 via a transmission water pipe 202, and a laser incident window 3021 and a water flow nozzle 3022 are coaxially arranged on the sealed cavity, and the light outlet of the laser transmission mirror group 301 is directly opposite the laser incident window 3021 for transmitting the laser beam into the sealed cavity.

[0030] More specifically, the water-guided laser tube 303 is used to couple the laser beam into a high-pressure water jet and guide it to the underwater processing area. One end of the tube is connected to the water chamber 302 and coaxially communicated with the water jet nozzle 3022, so that the high-pressure water in the sealed cavity is sprayed into the water-guided laser tube 303 through the water jet nozzle 3022. The other end of the water-guided laser tube 303 is used to extend underwater and align with the underwater workpiece 5, so that the high-pressure water jet is accurately sprayed into the processing area of ​​the underwater workpiece 5 through the water-guided laser tube 303, and the water-guided transmission of the laser beam is completed simultaneously with the spraying of the high-pressure water jet.

[0031] In addition, the water-guided laser tube 303 includes a heat-conducting tube 3032 and a structural support tube 3033 sleeved on the outer periphery of the heat-conducting tube 3032. The heat-conducting tube 3032 has a central through hole for spraying a high-pressure water jet column, and a total reflection surface 3031 is formed on the inner wall surface of the central through hole.

[0032] By utilizing the total reflection surface 3031 for total reflection transmission of the laser beam, the water-guided transmission of the laser beam can be accurately realized, ensuring the accuracy and reliability of the water-guided transmission of the laser beam.

[0033] However, precisely because the laser beam needs to undergo total internal reflection water conduction transmission within the water-guided laser tube 303, the water temperature in the high-pressure water column within the tube 303 will rise rapidly. When the water temperature in the high-pressure water column rises to a certain level, a "water explosion" phenomenon will occur, thus affecting the water conduction transmission of the laser. Therefore, in actual installation, it is preferable to use a heat pipe 3032 on the inner side of the water-guided laser tube 303 to quickly conduct the high temperature in the high-pressure water column, preventing the water temperature in the high-pressure water column from becoming too high.

[0034] In a preferred embodiment, the thermal conductivity of the heat pipe 3032 is preferably 300 to 500 W / (m·K), and it is further preferably made of copper.

[0035] Meanwhile, since the water-guided laser tube 303 needs to be moved by the displacement device 4 during equipment operation, and its bottom end remains underwater throughout the underwater laser processing, it is constantly affected by underwater resistance during displacement control. Therefore, if the overall strength of the water-guided laser tube 303 is insufficient, it is prone to bending or deformation. Thus, in the preferred embodiment, the water-guided laser tube 303 is provided with a structural support tube 3033 on its outermost side to provide structural strength.

[0036] In a preferred embodiment, the tensile strength of the structural support tube 3033 is preferably not less than 500 MPa, and the yield strength is preferably not less than 200 MPa. Simultaneously, the structural support tube 3033 is preferably made of metal, and its thermal conductivity is preferably not less than 15 W / (m·K). By coupling the structural support tube 3033 and the heat-conducting tube 3032, the rapid conduction and release of the water temperature after coupling the high-energy laser beam with the high-pressure water column (absorbed by the ambient water) can be achieved, ensuring the stable conduction of the high-pressure water column and the operational stability of the water-guided laser tube 303, thus preventing tube bursting or explosion.

[0037] As a specific example, the structural support tube 3033 is preferably a stainless steel tube made of stainless steel. Furthermore, the connection between the structural support tube 3033 and the heat-conducting tube 3032 is more preferably a threaded connection. In addition, to withstand the high corrosiveness of underwater operations, the outer periphery of the structural support tube 3033 in the preferred embodiment is preferably coated with a corrosion-resistant layer of a certain thickness.

[0038] Furthermore, in the preferred embodiment, the heat pipe 3032 has an axially penetrating through hole in its middle part, and a total reflection surface 3031 is formed on the inner wall surface of the middle through hole to ensure that the laser beam is transmitted by total reflection coupling in the high-pressure water column.

[0039] In actual installation, the inner diameter of the through-hole in the middle of the heat pipe 3032 is larger than the spot diameter of the laser beam at the beam waist after focusing, to ensure that the laser beam can enter the high-pressure water jet column through the corresponding incident angle. In a preferred embodiment, the inner diameter of the through-hole in the middle of the heat pipe 3032 is 0.2mm to 3mm.

[0040] Furthermore, in order to ensure the quality of total internal reflection transmission of the laser beam in the water-guided laser tube 303, the total internal reflection surface 3031 in the preferred embodiment needs to ensure a certain smoothness. In the preferred embodiment, the surface roughness of the total internal reflection surface 3031 is not greater than 100 Å.

[0041] As a feasible example, the total reflective surface 3031 is obtained by grinding and polishing, or the total reflective surface 3031 is formed by a hard gold plating layer with a thickness of not less than 0.1 μm.

[0042] More specifically, in a preferred embodiment, the length of the water-guided laser tube 303 is not less than the distance between the underwater workpiece 5 and the horizontal plane (i.e., the water depth where the underwater workpiece 5 is located), and the end of the water-guided laser tube 303 facing away from the water chamber 302 can be spaced 0.5mm to 5mm from the surface of the underwater workpiece 5 during equipment processing.

[0043] As a preferred design, the water-guided laser tube 303 is detachably connected to the water chamber 302, for example, by a threaded connection, or by a clamping component located below the water chamber 302. After the water-guided laser tube 303 is aligned with the water flow nozzle 3022, the clamping component completes the end connection of the water-guided laser tube 303. Furthermore, to meet the operational needs at different water depths, the water-guided laser tube 303 is available in various length specifications during actual installation.

[0044] Of course, depending on the actual processing needs, a sufficiently long water-guided laser tube 303 can be directly set, and the distance between the water outlet of the water-guided laser tube 303 and the surface of the underwater workpiece 5 can be adjusted by controlling the distance between the laser processing head 3 and the water surface.

[0045] It should be noted that the distance between the water outlet of the water-guided laser tube 303 and the processing surface of the underwater workpiece 5 is controlled within the aforementioned range because if the distance between the outlet and the processing surface is too small, impurities generated during processing may not be able to be discharged between the outlet and the surface, affecting the processing quality. If the distance is too large, the high-pressure water jet will have a long contact area with the underwater environment after exiting the tube. This is not conducive to maintaining the cleanliness of the water in the high-pressure water jet, nor is it conducive to maintaining the column shape of the high-pressure water jet, which is at risk of being dispersed and deformed by the ambient water. This will affect the end transmission of the laser beam and prevent the accurate completion of the corresponding processing process. Therefore, in actual processing, the distance between the outlet of the water-guided laser tube 303 and the processing surface needs to be controlled between 0.5mm and 5mm, and further controlled within the range of 1.0mm to 3.0mm.

[0046] In addition, in actual setup, the outlet end face of the water-guided laser tube 303 is a slope, and the slope forms an angle of 30° to 70° with the surface of the underwater workpiece.

[0047] Furthermore, in the preferred embodiment, the water pressure provided by the water flow generating device 2 is continuously adjustable in the range of 0 to 500 bar, and the water pressure in the water-guided laser tube 303 is 1.05 to 3 times the water pressure at the depth where the underwater workpiece 5 is located.

[0048] Specifically, in the preferred embodiment, the water flow generating device 2 preferably includes a water treatment device and a high-pressure water jet device 201; wherein, the water treatment device is used to treat the water liquid forming the high-pressure water jet column to ensure the purity of the high-pressure water jet column; the high-pressure water jet device 201 is connected to the water chamber 302 via a transmission water pipe 202 and is used to generate a high-pressure water jet column with corresponding pressure.

[0049] As a specific example, the water treatment process of the water treatment equipment preferably includes: Activated carbon is used for initial filtration, followed by reverse osmosis using a semi-permeable membrane to remove a large amount of sodium. + Cl - Ions, organic matter, and microorganisms are removed, and residual ions are further removed using anion and cation exchange membranes. Vacuum degassing is then performed to ensure that the dissolved gas content in the water is <0.1 mg / L. Finally, the water is sterilized with ultraviolet light.

[0050] By utilizing water treatment equipment, the cleanliness of the water used to form the high-pressure water jet can be fully guaranteed. At the same time, based on the high-pressure characteristics of the high-pressure water jet, ambient water can be effectively prevented from entering the water-guided laser tube 303, thereby ensuring the cleanliness of the high-pressure water jet system and meeting the water-guided transmission requirements of the laser beam.

[0051] Furthermore, to ensure the accuracy of underwater laser processing, the laser processing head 3 in the preferred embodiment also includes an underwater searchlight 305 and an industrial camera 304. The industrial camera 304 is positioned on the side of the laser transmission mirror assembly 301 facing away from the water chamber 302 and is connected to the laser transmission mirror assembly 301. It is used to photograph the processing area of ​​the underwater workpiece, accurately determine the area directly opposite the water-guided laser tube 303, and provide conditions for the laser processing head 3 to continuously process according to the processing path. Simultaneously, the underwater searchlight 305 in the preferred embodiment is preferably located on one side of the water outlet end of the water-guided laser tube 303 to provide illumination to the area of ​​the underwater workpiece 5 to be processed.

[0052] It is understandable that, in actual setup, the composition and power selection of the laser generating device 1 system can be optimized as needed, including a laser 101 and a laser water chiller 102. The laser 101 is used to generate a laser beam of corresponding power, and its performance parameters can be selected according to different material absorption characteristics and process parameter adjustment requirements. The laser water chiller 102 is used to provide cooling for the laser 101 and the laser processing head 3, ensuring that the devices operate at normal temperatures and extending the service life of the equipment.

[0053] As an example, the wavelength of the laser 101 is preferably 1064nm (infrared laser), the core diameter of the transmission fiber 103 is preferably selectable in the range of 50~1000μm, and the power of the laser is preferably controllable in the range of 500~20000W.

[0054] As another example, the wavelength of the laser 101 is preferably 532nm (green laser), the core diameter of the transmission fiber 103 is preferably selectable in the range of 100~400um, and the power of the laser is preferably controllable in the range of 200~2000W.

[0055] In addition, for the displacement device 4 in the preferred embodiment, its configuration can be selected from various displacement mechanisms in the prior art, such as slide rail displacement mechanism, multi-axis robotic arm, etc., as long as it can meet the precise displacement control of laser processing head 3.

[0056] In a preferred embodiment, the displacement device 4 includes a displacement actuator 401 and a displacement control mechanism 402 electrically connected thereto. The displacement actuator 401 is preferably a multi-axis robotic arm, with its front end connected to the laser processing head 3. Meanwhile, the displacement control mechanism 402 is preferably a processing device with trajectory planning capabilities, capable of generating precise displacement control commands, thereby driving the laser processing head 3 to accurately move along the processing path.

[0057] To ensure automated control of the equipment, in the preferred embodiment, a central control device 6 is also provided for each device, such as... Figure 1As shown, it is electrically connected to the laser generator 1, the water flow generator 2, the laser processing head 3, and the displacement device 4, respectively, enabling unified management of the operation of each device and thus achieving automated control of the entire equipment. Of course, based on the central control device 6, it can also accurately acquire the position information of the underwater workpiece 5 and plan and adjust the processing path.

[0058] For the underwater laser processing equipment in the preferred embodiment, the preferred operation process during actual underwater laser processing is as follows: Before actual operation begins, the various components of the equipment should be assembled according to design requirements. For example, the laser processing head 3 is connected to the flange at the end of the industrial robot (displacement actuator 401) to establish a connection between the laser processing head 3 and the displacement device 4. Simultaneously, the high-pressure water jet device 201 is connected to the inlet of the water chamber 302 via a water transmission pipe 202, and the laser 101 is connected to the laser processing head 3 via a transmission optical fiber 103. A water-guided laser tube 303 is selected and verified based on the position of the underwater workpiece 5, and connected to the bottom of the water chamber 302. Of course, the electrical connections between the components can be completed according to conventional practices in existing technologies, and will not be elaborated upon here.

[0059] For an assembled underwater laser processing equipment, the preferred steps for underwater laser processing are as follows: S1: Obtain the position parameter information of underwater workpiece 5, determine the underwater laser processing path, and calculate the absolute pressure at each point along the processing path. ;in, , Atmospheric pressure; The water depth at which the underwater workpiece is located; The density of water; This is the acceleration due to gravity.

[0060] Specifically, the acquisition of position parameter information of underwater workpiece 5 can preferably be accomplished by using a depth measuring device, or by setting up a sensing device in the processing area of ​​underwater workpiece 5 and using the sensing device to acquire the water depth of underwater workpiece 5 and its processing path, so as to provide accurate basis for the control of subsequent displacement device 4.

[0061] It is understandable that during actual processing, the processing path of underwater workpiece 5 may not be on the same horizontal plane. In this case, the absolute pressure calculated for each part of the processing path... The pressure value will change, and at this point, the pressure value used in subsequent designs will be the maximum value among them. .

[0062] S2: Determine the operating parameters of laser generator 1 and water flow generator 2; the operating parameters should include at least the power of the laser beam and the (control) water pressure of the high-pressure water flow column. ;in, .

[0063] Specifically, the selection of the operating parameters of the laser generator 1 can be based on the type of workpiece being processed and the type of processing operation. This is the conventional selection method, which will change according to the changes in processing requirements, and will not be elaborated here.

[0064] The selection of the high-pressure water jet is usually related to the control distance between the water outlet of the water-guided laser tube 303 and the processing surface of the underwater workpiece 5. When the distance between the two is large (e.g., 4mm), a larger multiple is usually selected, such as 2 or 2.5 times; when the distance between the two is small (e.g., 1mm), a smaller multiple is usually selected, such as 1.2 or 1.5 times. And so on, without specific limitations.

[0065] Of course, the above options can be adjusted flexibly according to the processing quality, which will not be elaborated here.

[0066] S3: Control the operation of water flow generating device 2 to generate water pressure of A high-pressure water jet is generated and stably ejected from the outlet of the water-guided laser tube 303; In actual processing, it is preferable to first control the stable ejection of the high-pressure water jet, and then adjust the coupling of the laser beam and control the displacement of the laser processing head 3. At this time, the entire equipment is above the water surface.

[0067] This design is intended to ensure the stability of the high-pressure water jet formation and to prevent external water from entering the water-conducting system, thus avoiding contamination of the laser beam's coupling and transmission path by water from the processing environment entering the water-conducting laser tube 303.

[0068] S4: Control the laser generator 1 to operate, generate a laser beam of corresponding power, and adjust the laser beam and the high-pressure water jet to be coaxially coupled in the laser processing head 3; In actual operation, the laser processing head 3 focuses the laser beam and adjusts the beam direction through the laser transmission mirror group 301, so that the incident angle of the laser beam is less than the critical angle of total internal reflection at the water-air interface, thereby ensuring that the laser is transmitted along the high-pressure water column by total internal reflection.

[0069] S5: Control the displacement device 4 to work, drive the laser processing head 3 to move, and move the water outlet of the water-guided laser tube 303 to the starting position of the processing path of the underwater workpiece 5 to be processed, so that the water outlet of the water-guided laser tube 303 and the surface to be processed are spaced at the corresponding size (0.5mm~5mm) and form a certain angle with the processing surface. The control of the displacement device 4 can be accomplished using existing mature technologies. During the operation of the equipment, except for the middle and lower sections of the water-guided laser tube 303, all other components of the equipment are located above the water surface. Thus, only appropriate waterproof sealing design is needed for the laser processing head 3 to avoid the problems caused by the waterproofing of optical components. The waterproofing problem is solved with the simplest and most reliable structure, while improving the control flexibility of the processing process.

[0070] During the control of the displacement device 4, it is preferable to use the cooperation between the underwater searchlight 305 and the industrial camera 304 to complete the alignment of the water-guided laser tube 303 and the verification of the processing path.

[0071] In addition, before processing with the laser beam, it is recommended to pre-treat the processing area. For example, when performing underwater laser welding, the weld seam is first manually ground with sandpaper to improve the working conditions of the processing area.

[0072] S6: Continue to control the operation of the displacement device 4, drive the laser processing head 3 to move along the processing path of the underwater workpiece 5, and complete the scanning processing of each processing position of the underwater workpiece 5.

[0073] Based on the actual processing area and path planning of the underwater workpiece 5, the displacement device 4 drives the laser processing head 3 to perform displacement adjustment (planar displacement and vertical displacement) in three-dimensional space, ensuring that the water outlet of the water-guided laser tube 303 moves along the processing path, and that the water outlet of the water-guided laser tube 303 is always kept within the expected size interval range (0.5mm~5mm) with the surface of each processing area, thereby ensuring the accurate execution of underwater laser processing operations.

[0074] S7: Turn off the laser generator 1, and after the water outlet of the water-guided laser tube 303 is raised above the water surface, turn off the water flow generator 2. After that, the equipment is reset, and the underwater laser processing of the underwater workpiece 5 is completed.

[0075] Similar to the case where the water flow generating device 2 enters a stable working state before the water-guided laser tube 303 enters the water, after the underwater laser processing is completed, the water flow generating device 2 continues to work until the water-guided laser tube 303 is lifted above the water surface by the displacement device 4. In this way, the backflow of environmental water and its contamination of the internal pipeline of the water-guided laser tube 303 can be fully avoided.

[0076] The technical solution of the preferred embodiment of this utility model will be described below through a specific example.

[0077] In this embodiment, the underwater laser processing scenario is underwater laser welding. The underwater workpiece 5 is a 3mm stainless steel plate, which needs to be butt-welded. The size of the steel plate is 100mm*100mm*3mm, and the welding material is located 60mm underwater.

[0078] For the aforementioned underwater welding scenario, the specific operation process in this embodiment is as follows: S1: Based on the location of the weld joints of the underwater stainless steel plates, determine the underwater welding processing trajectory and calculate the absolute pressure at each point along the processing path. ; S2: Determine the operating parameters of the laser generator 1 based on the underwater operation requirements of stainless steel plates; specifically, a dot-ring laser is selected, with a center power of 6000W, an outer ring power of 6000W, a center core diameter of 100μm, and an outer ring core diameter of 600μm. Simultaneously, the laser processing head 3 has a focusing focal length of 200mm and a collimating focal length of 100mm. The laser processing head 3 is equipped with a CCD camera and a waterproof 5W blue light searchlight.

[0079] At the same time, the working parameters of the water flow generating device 2 are determined, and the water flow pressure of the high-pressure water column is specifically controlled to 2.0 bar.

[0080] Furthermore, in this embodiment, the inner layer of the water-guided laser tube 303 is a copper tube with a wall thickness of 10 mm, and the inner wall surface is provided with a hard gold plating layer with a thickness of 0.15 μm and a surface roughness of Ra 100 Å. The outer layer of the water-guided laser tube 303 is a 3.0 mm thick stainless steel tube, and a 0.5 mm thick anti-corrosion layer is laser-coated around its outer periphery. Meanwhile, the total length of the water-guided laser tube 303 is 200 mm. To match the focused laser beam, the inner diameter of the central through-hole is approximately 1.4 mm to achieve coaxial coupling of the laser beam and the water flow beam.

[0081] Furthermore, the displacement actuator 401 in this embodiment is preferably an industrial robot of model KUKA (KR 180 R3200 PA), with a load capacity of 180kg and an arm span of 3195mm. The end of the robot is connected to the laser processing head 3 via a flange.

[0082] S3: At the front end of the water flow generating device 2, the water used to form the high-pressure water jet is pre-treated by a water treatment device to ensure the cleanliness of the water used to form the high-pressure water jet. The specific treatment process is as follows: Activated carbon is used for initial filtration, followed by reverse osmosis using a semi-permeable membrane to remove a large amount of sodium. + Cl -Ions, organic matter, and microorganisms are removed, and residual ions are further removed using anion and cation exchange membranes. Vacuum degassing is then performed to ensure that the dissolved gas content in the water is <0.1 mg / L. Finally, the water is sterilized with ultraviolet light.

[0083] At the same time, the water flow generating device 2 is controlled to operate, keeping the water pressure of the high-pressure water jet at a predetermined value, and ensuring that the water outlet of the water-guided laser tube 303 stably ejects the high-pressure water jet.

[0084] S4: Control the operation of the laser generator 1, control its center power to be 4300W and the outer ring power to be 2800W, and adjust the laser beam and the high-pressure water jet to be coaxially coupled in the laser processing head 3.

[0085] S5: The displacement control mechanism 402 controls the displacement actuator 401 to work, driving the water-guided laser tube 303 and extending it underwater until the outlet of the water-guided laser tube 303 is located on one side of the starting position of the processing path in the underwater workpiece 5 to be processed area.

[0086] S6: Displace along the welding trajectory at a welding speed of 8 mm / s, so that the water-guided laser tube 303 completes the welding operation of the underwater workpiece 5 along the welding processing path.

[0087] S7: Turn off the laser generator 1 and continue to operate the water flow generator 2 until the water-guided laser tube 303 is lifted above the water surface by the displacement device 4. Then turn off the water flow generator 2, reset the equipment, and complete the underwater welding operation of the underwater workpiece 5.

[0088] It is understood that, in addition to the underwater welding operation scenario mentioned above, the technical solution in the preferred embodiment is also applicable to other underwater laser operation scenarios, such as underwater laser cutting and underwater laser cleaning. In various operation scenarios, only the control details of the aforementioned steps need to be fine-tuned, which will not be elaborated here.

[0089] The underwater laser processing equipment based on water-guided laser of this invention has a simple structure and convenient control. It can accurately achieve coaxial coupling between the laser beam and the high-pressure water column, accurately guide the high-energy laser beam through the water column, ensure the accuracy and reliability of underwater laser processing, avoid laser energy loss, expand the application range of underwater laser processing technology, reduce the application cost of underwater laser processing technology, and improve the efficiency and quality of underwater laser processing of workpieces. It has excellent application value and promotion prospects.

[0090] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An underwater laser processing device based on a water-guided laser, characterized in that, include: A laser generator used to produce a laser beam; A water flow generating device used to produce a high-pressure water jet; A laser processing head; the laser processing head includes a laser transmission mirror assembly, a water chamber, and a water-guided laser tube; wherein, the laser transmission mirror assembly is connected to a laser generating device via a transmission optical fiber; the water chamber includes a sealed cavity connected to a water flow generating device via a transmission water pipe, and a laser incident window and a water flow nozzle are coaxially arranged on the sealed cavity; the light outlet of the laser transmission mirror assembly is directly opposite the laser incident window for transmitting the laser beam into the sealed cavity; and The water-guided laser tube is used to couple a laser beam into a high-pressure water jet and guide it to the underwater processing area. One end of the tube is connected to a water chamber and coaxially communicated with the water jet nozzle, while the other end extends underwater and aligns with the underwater workpiece. The water-guided laser tube includes a heat-conducting tube for rapid heat conduction and a structural support tube sleeved around the heat-conducting tube. The structural support tube provides strength to the water-guided laser tube. The heat-conducting tube has a central through-hole for jetting the high-pressure water jet, and a total reflection surface is formed on the inner wall of the central through-hole. Displacement device; the laser processing head is mounted on the displacement device and can be moved under the drive of the displacement device to irradiate the part of the underwater workpiece to be processed with laser transmitted through the high-pressure water jet.

2. The underwater laser processing equipment based on water-guided laser according to claim 1, characterized in that, The length of the water-guided laser tube is not less than the distance between the underwater workpiece and the horizontal plane, and the end of the water-guided laser tube away from the water chamber can be spaced 0.5mm to 5mm from the surface of the underwater workpiece during equipment processing.

3. The underwater laser processing equipment based on water-guided laser according to claim 2, characterized in that, The water-guided laser tube is detachably connected to the water chamber, and the water-guided laser tube is available in various length specifications. and / or The thermal conductivity of the heat pipe is 300~500 W / (m·K); and / or The tensile strength of the structural support tube is not less than 500 MPa, and the yield strength is not less than 200 MPa.

4. The underwater laser processing equipment based on water-guided laser according to any one of claims 1 to 3, characterized in that, The surface roughness of the total reflection surface is no greater than 100 Å; and / or The total reflective surface is obtained by grinding and polishing, or the total reflective surface is formed by a hard gold plating layer with a thickness of not less than 0.1 μm.

5. The underwater laser processing equipment based on water-guided laser according to any one of claims 1 to 3, characterized in that, The inner diameter of the central through hole is larger than the spot diameter of the laser beam at the beam waist after focusing, and the inner diameter of the central through hole is 0.2~3mm; and / or The outlet end face of the water-guided laser tube is a slope, and the slope forms an angle of 30° to 70° with the surface of the underwater workpiece.

6. The underwater laser processing equipment based on water-guided laser according to any one of claims 1 to 3, characterized in that, The structural support tube is made of stainless steel, and the heat-conducting tube is made of copper. and / or The structural support tube and the heat-conducting tube are assembled by a threaded connection. and / or The outer periphery of the structural support tube is provided with an anti-corrosion layer of a certain thickness.

7. The underwater laser processing equipment based on water-guided laser according to any one of claims 1 to 3, characterized in that, The water pressure provided by the water flow generating device is continuously adjustable within the range of 0~500 bar, and the water pressure in the water-guided laser tube is 1.05 to 3 times the water pressure at the depth where the underwater workpiece is located.

8. The underwater laser processing equipment based on water-guided laser according to any one of claims 1 to 3, characterized in that, The water flow generating device includes water treatment equipment and high-pressure water jet equipment; The water treatment equipment is used to treat the water that forms the high-pressure water jet column to ensure the purity of the high-pressure water jet column; the high-pressure water jet equipment is connected to the water chamber via a transmission water pipe to generate a high-pressure water jet column with corresponding pressure.

9. The underwater laser processing equipment based on water-guided laser according to any one of claims 1 to 3, characterized in that, The laser processing head also includes an underwater searchlight and an industrial camera; The industrial camera is connected to the laser transmission mirror assembly and is used to photograph the processing area of ​​the underwater workpiece; the underwater searchlight is used to provide illumination to the processing area of ​​the underwater workpiece.

10. The underwater laser processing equipment based on water-guided laser according to any one of claims 1 to 3, characterized in that, It also includes a central control unit; The central control device is electrically connected to the laser generator, the water flow generator, the laser processing head, and the displacement device, respectively, to realize the automated control of each device.

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