Laser processing system with atmosphere auxiliary protection and processing method

Abstract

The invention relates to a laser processing system and method with atmosphere auxiliary protection, and the processing system comprises a laser head which is used for generating and transmitting a laser beam to the downstream, and the side part of the laser head is provided with a gas inlet interface for introducing protective gas; the upstream end of the atmosphere protection cover is connected with the lower part of the laser head, the atmosphere protection cover comprises a cover body and an axial adjustable gas cover capable of axially displacing relative to the cover body, and an adjustable gas-light coaxial nozzle is arranged at the tail end of the axial adjustable gas cover; the atmosphere protection cabin is arranged below the atmosphere protection cover and comprises a working table, an observation window and a flexible sealing telescopic cover, the observation window, the working table and the flexible sealing telescopic cover jointly form a closed laser processing cavity, the working table is located at the bottom of the laser processing cavity, and the flexible sealing telescopic cover is located at the bottom of the working table. A first end of the flexible sealing telescopic cover is connected with the bottom of a cover body of the atmosphere protection cover in a sealing manner, and a second end of the flexible sealing telescopic cover is connected with the top of the observation window in a sealing manner, so that a dynamically-sealed channel which is telescopic along with the movement of the laser head is formed between the atmosphere protection cover and the atmosphere protection cabin; the gas supply unit is used for independently supplying protective gas to the gas inlet interface of the laser head and the gas inlet control valve of the atmosphere protection cabin; and the laser smoke dust purification unit is connected to a gas outlet control valve of the atmosphere protection cabin and is used for pumping, discharging and purifying gas in the atmosphere protection cabin and smoke dust generated in the machining process.

Description

Technical Field

[0001] This invention relates to the field of laser processing, and more specifically, to a laser processing system and method with atmosphere-assisted protection. Background Technology

[0002] Currently, laser processing technology (including laser welding, laser cutting, laser cladding, etc.) is increasingly widely used in fields such as new energy vehicles, aerospace, and precision manufacturing due to its advantages such as high energy density, fast processing speed, and small heat-affected zone. However, when processing highly reactive metals or easily oxidized materials such as aluminum alloys, titanium alloys, and high-temperature alloys, this technology faces a core common challenge: the processing area is extremely chemically reactive at high temperatures, and the molten pool or cutting edge is very likely to react chemically with oxygen, water vapor, etc. in the surrounding environment.

[0003] This interaction leads to a series of processing defects and quality problems: First, for laser welding, a high-melting-point oxide film is generated (such as Al2O3 in aluminum alloys), which not only increases laser reflectivity and decreases energy absorption, but also causes defects such as weld porosity, lack of fusion, and inclusions, severely degrading the mechanical properties of the joint. Second, for laser cutting, the oxidation reaction changes the energy coupling mechanism at the cutting front, leading to increased surface roughness, slag buildup, burrs, and potentially causing the cutting contour to deviate from the preset path, affecting dimensional accuracy. Furthermore, for laser cladding, atmospheric contamination can cause oxidation of the cladding material, forming oxide inclusions that reduce the density, bonding strength, and corrosion resistance of the cladding.

[0004] For laser processing, the control of the protective gas flow is one of the key factors to ensure processing quality. However, a common technical challenge is that if the protective gas flow becomes turbulent or the gas curtain is unstable, it will draw in surrounding air into the processing area, causing a sudden increase in local oxygen concentration, which will exacerbate the oxidation problem. Most existing protective devices have problems such as uneven gas distribution, mismatch between the gas curtain coverage and the dynamic processing path, and lag response. They cannot provide a continuous, stable and full-coverage gas protection effect for deep penetration welding, precision cutting or three-dimensional dynamic processing, and are particularly difficult to deal with the interference of ambient gas during complex trajectories or long-term processing.

[0005] Therefore, there is an urgent need in this field to develop a universal laser processing atmosphere-assisted protection system that can effectively isolate air and form and maintain a local, stable low-oxygen environment (inert gas atmosphere) in and around the laser point of action and surrounding high-temperature areas, so as to meet the requirements of laser processing technology for high-quality, low-oxidation finished products. Summary of the Invention

[0006] Based on this, and to address the aforementioned problems, the present invention provides a laser processing system with atmosphere-assisted protection, which has a stable and adjustable protective gas curtain to ensure that a stable and uniform protective gas curtain can be formed under any working condition, completely isolating the workpiece processing area from the air, and meeting the requirements of laser processing technology for high-quality, low-oxidation finished products.

[0007] To achieve the above objectives, the present invention provides a laser processing system with atmosphere-assisted protection, comprising: a laser head for generating and transmitting a laser beam downstream, the laser head having an inlet port on its side for receiving a protective gas; an atmosphere protection hood, the upstream end of which is connected to the lower part of the laser head, including a hood body and an axially adjustable gas hood capable of axial displacement relative to the hood body, the end of the axially adjustable gas hood having an adjustable gas-optic coaxial nozzle; and an atmosphere protection chamber disposed below the atmosphere protection hood, including a worktable, an observation window, and a flexible sealing telescopic cover, the observation window being enclosed by the worktable and the flexible sealing telescopic cover. The system is assembled into a sealed laser processing chamber. The worktable is located at the bottom of the laser processing chamber. The first end of the flexible sealing telescopic cover is sealed to the bottom of the atmosphere protection cover, and the second end is sealed to the top of the observation window, thereby forming a dynamically sealed channel between the atmosphere protection cover and the atmosphere protection chamber that expands and contracts with the movement of the laser head. A gas supply unit is used to independently supply protective gas to the air inlet of the laser head and the air inlet control valve of the atmosphere protection chamber. A laser fume purification unit is connected to the air outlet control valve of the atmosphere protection chamber and is used to extract and purify the gas and fume generated during the processing in the atmosphere protection chamber.

[0008] In one specific embodiment, the axially adjustable air shroud is made of copper.

[0009] In one specific embodiment, the air inlet of the laser head adopts a venturi tube structure.

[0010] In one specific embodiment, the axially adjustable air cover is connected to the cover body by a thread or by a gear and rack meshing mechanism. The meshing mechanism includes: a rack, which is fixedly installed axially on the inner or outer wall of the axially adjustable protective cover; a gear, which meshes with the rack; and a drive mechanism, which is connected to the shaft of the gear.

[0011] In one specific embodiment, a limiter is provided on the cover to limit the displacement range of the axially adjustable air cover.

[0012] In one specific embodiment, the adjustable coaxial air nozzle is threadedly connected to an axially adjustable air cover, and rotating the adjustable coaxial air nozzle can change its angular position relative to the workpiece.

[0013] In one specific embodiment, the surface of the workbench is anodized and blackened.

[0014] In one specific embodiment, the observation window is made of high-temperature resistant glass and is fixedly installed by a surrounding aluminum alloy frame; the flexible sealing telescopic cover is made of high-temperature resistant transparent PVC material.

[0015] In one specific embodiment, the gas supply unit includes a high-purity argon gas source connected to the gas inlet of the laser head, wherein the purity of the high-purity argon gas source is ≥99.999%; and a pure argon gas source connected to the gas inlet control valve of the atmosphere protection chamber, wherein the purity of the pure argon gas source is 99.99% ≤ 99.999%.

[0016] In one specific embodiment, a laser processing system with atmosphere-assisted protection further includes: an oxygen content sensor disposed in an atmosphere protection chamber for real-time monitoring of the oxygen concentration within the atmosphere protection chamber; a pressure sensor disposed in the atmosphere protection chamber for real-time monitoring of the gas pressure within the atmosphere protection chamber; a flow controller disposed in the inlet and outlet channels of the atmosphere protection chamber for regulating the flow rate of the protective gas; and a system controller, signal-connected to the oxygen content analyzer, pressure sensor, and flow controller, configured to: control the operating state of the flow controller based on feedback signals from the oxygen content sensor and the pressure sensor, so as to maintain the oxygen concentration and gas pressure of the laser processing chamber within a preset range.

[0017] In one specific embodiment, the system is used for laser welding of aluminum alloys.

[0018] In one specific embodiment, a laser processing method with atmosphere-assisted protection is provided, employing any of the aforementioned laser processing systems with atmosphere-assisted protection, comprising the following steps: fixing the workpiece to be processed on the worktable; activating the gas supply unit and the laser fume purification unit, inputting protective gas into the laser head and the atmosphere protection chamber, and extracting gas from the atmosphere protection chamber to create a low-oxygen environment and maintain a slight positive pressure within the laser processing chamber; according to process requirements, adjusting the axial position of the axially adjustable gas hood and / or adjusting the adjustable gas-optic coaxial nozzle to axially adjust the axial position of the adjustable gas-optic coaxial nozzle, thereby obtaining the required protective gas flow pattern; activating the laser head to output and transmit a laser beam to process the workpiece, the fume purification unit extracting the fumes generated during processing, the flexible sealing telescopic cover extending and retracting with the movement of the laser head to maintain the sealing of the dynamic sealing channel; after the workpiece processing is completed, first stopping the laser beam output, keeping the gas supply unit and the fume purification unit running, allowing the workpiece to cool to a predetermined temperature under the protective atmosphere, then stopping the supply of protective gas and shutting down the fume purification unit.

[0019] In one specific embodiment, a laser processing method with atmosphere-assisted protection further includes the step of: rotating an axially adjustable gas shroud by a screw thread, thereby changing the axial position of the adjustable gas shroud and simultaneously changing the distance and angular position of the adjustable coaxial gas-optic nozzle relative to the workpiece surface, thereby obtaining the desired protective airflow pattern.

[0020] In one specific embodiment, a laser processing method with atmosphere-assisted protection further includes the steps of: driving a gear to rotate, thereby driving an axially adjustable protective cover to move axially relative to the cover body, and the axially adjustable protective cover causing the axial position of an adjustable gas-optic coaxial nozzle to change, thereby adjusting the state of the protective atmosphere.

[0021] In one specific embodiment, a laser processing method with atmosphere-assisted protection further includes the step of: rotating an adjustable gas-optic coaxial nozzle to change its angular position relative to the workpiece.

[0022] In one specific embodiment, a laser processing method with atmosphere-assisted protection further includes the step of: the system controller controlling the working state of the flow controller based on the feedback signals of the oxygen content sensor and the pressure sensor, so as to maintain the oxygen concentration and gas pressure of the laser processing chamber within a preset range.

[0023] Compared with the prior art, the beneficial effects of the present invention are: This invention proposes a laser processing system and method with atmosphere-assisted protection. On one hand, the axial adjustment function of the axially adjustable gas hood, combined with the adjustable coaxial gas-optic nozzle design, allows operators to precisely adjust the outflow state of the protective gas according to process parameters such as laser power and welding speed. This includes the outflow position, flow rate, and coverage area of ​​the protective gas, forming a stable and tunable protective gas curtain. This ensures a stable and uniform protective gas curtain under any working condition, completely isolating the workpiece processing area from the air, significantly reducing weld porosity, improving weld density, and enhancing weld surface formation and color. On the other hand, the near-end atmosphere protection hood and the far-end atmosphere protection hood... The dual-stage design of the protective chamber, in conjunction with the gas supply unit, establishes a multi-level, full-coverage atmosphere protection around the laser beam's point of impact and throughout the entire workpiece operating environment. This effectively prevents highly reactive metal parts from coming into contact with air during the entire laser welding or laser cutting process, thus avoiding defects such as workpiece oxidation and nitriding. Furthermore, a flexible, telescopic sealing cover forms a dynamically retractable sealing channel between the laser head and the atmosphere protection chamber, resolving the contradiction between moving processing and static sealing. This allows the entire system to maintain a reliable seal even when the laser processing head is executing complex two-dimensional or three-dimensional processing paths, without affecting processing flexibility while maintaining the stability of the protective atmosphere within the laser processing chamber. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of a laser processing system with atmosphere-assisted protection according to the present invention. Figure 1 .

[0025] Figure 2 This is a schematic diagram of the structure of a laser processing system with atmosphere-assisted protection according to the present invention. Figure 2 .

[0026] Figure 3 This is a schematic diagram of the air intake interface in one embodiment of the present invention.

[0027] Figure 4 This is a schematic diagram of the structure of an axially adjustable air cover connected to the cover body via a gear and rack meshing mechanism in one embodiment of the present invention.

[0028] Figure 5 This is a schematic flowchart of a laser processing method with atmosphere-assisted protection according to the present invention. Detailed Implementation

[0029] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0030] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "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 invention 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 invention.

[0031] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," 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 invention according to the specific circumstances.

[0032] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0033] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] like Figures 1-2As shown, this embodiment provides a laser processing system with atmosphere-assisted protection, including: a laser head 100 for generating and transmitting a laser beam downstream, with an inlet 101 for receiving a protective gas on its side; an atmosphere protection hood 200, the upstream end of which is connected to the lower part of the laser head 100, including a hood body 201 and an axially adjustable gas hood 202 that can be axially displaced relative to the hood body 201, the end of the axially adjustable gas hood 202 being provided with an adjustable gas-optic coaxial nozzle 203; the laser head 100, the hood body 201, the axially adjustable gas hood 202 and the adjustable gas-optic coaxial nozzle 203 are provided with a coaxial laser transmission channel that is interconnected, and the laser beam passes sequentially from the laser head 100 through the hood body 201 and the axially adjustable gas hood 202. The laser beam from laser head 100 is transmitted to workpiece 102 via adjustable gas-optic coaxial nozzle 203, where it is used for laser cutting or laser welding. The laser head 100, cover 201, axially adjustable gas cover 202, and adjustable gas-optic coaxial nozzle 203 have interconnected gas channels. Protective gas flows into these channels from inlet 101 and exits coaxially with the laser beam within the adjustable gas-optic coaxial nozzle 203, surrounding the laser beam. An atmosphere protection chamber 300, located below the atmosphere protection cover 200, includes a worktable 301 for supporting workpiece 102, an observation window 302, and a flexible sealed telescopic cover 303. The observation window 302 is connected to the worktable 301 and the flexible sealed telescopic cover 303. The shroud 303 together form a sealed laser processing chamber. During processing, the operator can observe the workpiece processing status in real time and clearly through the observation window, facilitating timely detection of processing abnormalities and improving processing efficiency and operational safety. For example, the observation window 302 forms the four sides of the laser processing chamber, together with the bottom worktable 301 and the top flexible sealing telescopic shroud 303, forming a sealed laser processing chamber. The worktable 301 is located at the bottom of the laser processing chamber. The first end of the flexible sealing telescopic shroud 303 is sealed to the bottom of the cover 201 of the atmosphere protection shroud 200, and the second end is sealed to the top of the observation window 302, thereby ensuring a sealed connection between the atmosphere protection shroud 200 and the atmosphere protection... A dynamically sealed channel that expands and contracts with the movement of the laser head is formed between the chambers 300; the gas supply unit 400 is used to independently supply protective gas to the gas inlet 101 of the laser head 100 and the gas inlet control valve 304 of the atmosphere protection chamber 300 respectively. The gas supply unit uses independent gas paths to supply protective gas of different purities to the atmosphere protection shroud 200 and the atmosphere protection chamber 300 respectively. For example, higher purity argon is supplied to the atmosphere protection shroud 200 to directly protect the molten pool, and slightly lower purity argon is supplied to the atmosphere protection chamber 300 to maintain the processing environment. This staged gas supply strategy saves expensive high-purity gas consumption and reduces operating costs while ensuring the best protection effect, and realizes efficient and staged utilization of protective gas.A laser fume purification unit 500 is connected to the exhaust control valve 305 of the atmosphere protection chamber 300, used to extract and purify the gas and fumes generated during processing in the atmosphere protection chamber 30. This specific embodiment provides a laser processing system with atmosphere-assisted protection, which has the following technical effects: On the one hand, the axial adjustment function of the axially adjustable gas hood 202, combined with the adjustable coaxial gas-optic nozzle 203 design, allows operators to precisely adjust the outflow state of the protective gas according to process parameters such as laser power and welding speed, including the outflow position, flow rate, and coverage area of ​​the protective gas. This forms a stable and adjustable protective gas curtain, ensuring a stable and uniform protective gas curtain can be formed under any working condition, completely isolating the workpiece processing area from the air, significantly reducing weld porosity, improving weld density, and enhancing weld surface formation and color. On the other hand, the atmosphere protection hood 200 for near-end atmosphere protection and the atmosphere protection chamber for far-end atmosphere protection... The dual-stage design of the 300, in conjunction with the gas supply unit 400, establishes a multi-stage, full-coverage atmosphere protection around the laser beam's point of impact and throughout the entire workpiece operating environment. This effectively prevents active metal parts such as aluminum alloys from coming into contact with air during the entire laser welding or cutting process, thus avoiding defects such as workpiece oxidation and nitriding. Furthermore, the flexible, telescopic sealing cover 303 forms a dynamically retractable sealing channel between the laser head 100 and the atmosphere protection chamber 300, resolving the conflict between mobile processing and static sealing. This allows the entire system to maintain a reliable seal even when the laser processing head 100 is executing complex two-dimensional or three-dimensional processing paths, ensuring both processing flexibility and maintaining a stable protective atmosphere within the laser processing chamber.

[0035] In one specific embodiment, the axially adjustable gas cover 202 is made of copper, which has an extremely high melting point and high thermal conductivity. It can effectively resist the spatter and high-temperature heat radiation generated during laser processing, preventing the axially adjustable gas cover 202 from deforming or being damaged due to overheating. This ensures the long service life and reliability of the component. At the same time, the good thermal conductivity of copper helps to quickly dissipate the absorbed heat, avoiding local overheating that could cause turbulence in the protective gas flow field, and is conducive to maintaining a stable and uniform laminar protective gas curtain.

[0036] like Figure 3 As shown, in one specific embodiment, the air inlet 101 of the laser head 100 adopts a Venturi tube structure. Utilizing Bernoulli's principle, when high-pressure gas flows through a narrow throat, the flow velocity increases and the pressure decreases, forming a stable, concentrated, and uniform protective gas curtain at the outlet. This effectively avoids turbulence, ensuring that the protective gas can accurately and stably cover the molten pool area, resulting in better air isolation.

[0037] In one specific embodiment, the axially adjustable gas shroud 202 is threadedly connected to the shroud body 201. This threaded connection is a precise mechanical transmission method, allowing the axially adjustable gas shroud 202 to be converted into precise axial displacement. This enables the operator to make fine and continuous adjustments to the outlet position, flexibly adapting to different welding process requirements. For example, it allows adjustment of the defocusing amount and protection range of the shielding gas and laser beam. When the axially adjustable gas shroud 202 moves axially upwards, the distance between the adjustable gas-laser coaxial nozzle 203 and the workpiece increases, resulting in a wider range of action for the shielding gas and laser beam, a gentler airflow, and a larger coverage area, making it suitable for heat transfer welding. This is suitable for sensitive processes or processes requiring wide weld formation. Conversely, when the axially adjustable gas hood 202 moves axially downward, the distance between the adjustable gas-optic coaxial nozzle 203 and the workpiece decreases, making the flow of protective gas and laser beam more concentrated, increasing airflow speed, enhancing impact force, and improving energy density. This is suitable for deep penetration welding, high-speed welding, or conditions requiring greater penetration. At the same time, as the axially adjustable gas hood 202 rotates, the angular position of the adjustable gas-optic coaxial nozzle 203 relative to the workpiece also changes. This change in angular position directly adjusts the dominant direction of the protective gas ejection, thereby achieving precise calibration of the protective gas flow pattern, such as the airflow impact point and coverage area.

[0038] like Figure 4 As shown, in one specific embodiment, the axially adjustable air cover 202 is connected to the cover body 201 via a gear 2021 and rack 2022 meshing mechanism. The meshing mechanism includes: a rack 2022, axially fixedly installed on the inner or outer wall of the axially adjustable protective cover 202; a gear 2021 meshing with the rack 2022; and a drive mechanism (not shown) connected to the shaft of the gear 2021. When the axial position of the axially adjustable protective cover 202 needs to be adjusted, the drive mechanism is activated, generating rotational torque (either by manually rotating a handle or starting a motor). The output is sent to the shaft of the gear 2021. The gear 2021 rotates under torque. Because it meshes with the fixed rack 2022, the rotational motion of the gear is converted into linear motion of the rack along its length. Since the rack 2022 is fixedly mounted on the axially adjustable protective cover 202, the linear motion of the rack drives the entire axially adjustable protective cover 202 to undergo precise axial displacement (i.e., lifting) relative to the cover body 201. The axially adjustable protective cover 202 causes a change in the axial position of the adjustable coaxial gas nozzle 203, thereby adjusting the state of the protective atmosphere. Furthermore, a limiter 2011 is provided on the cover body 201 to limit the displacement range of the axially adjustable gas cover 202.

[0039] In one specific embodiment, the adjustable coaxial gas nozzle 203 is threadedly connected to the axially adjustable gas cover. Rotating the adjustable coaxial gas nozzle 203 can change the angular position relative to the workpiece. This change in angular position directly adjusts the dominant direction of the protective gas ejection, thereby achieving fine calibration of the protective gas flow pattern, such as the airflow impact point and coverage area.

[0040] In one specific embodiment, the surface of the worktable 301 is anodized and blackened, which can effectively absorb stray laser light, prevent reflected light from damaging optical components or interfering with the processing, and ensure processing efficiency and equipment safety.

[0041] In one specific embodiment, the observation window 302 is made of high-temperature resistant glass and is fixedly installed by the surrounding aluminum alloy frame 3021. The high-temperature resistant glass observation window has excellent light transmittance and heat resistance, allowing operators to safely and clearly observe the molten pool morphology, weld formation, and internal spatter in real time during the welding process, which is convenient for process debugging and quality control. The flexible sealing telescopic cover 303 is made of high-temperature resistant transparent PVC material, which has excellent flexibility, sealing, and heat resistance. It can expand and deform with the laser head as it moves, always maintaining the sealing of the protective chamber, without restricting the processing freedom of the laser head. It is the key to realizing complex trajectory laser processing.

[0042] In one specific embodiment, the gas supply unit 400 includes a high-purity argon gas source connected to the gas inlet 101 of the laser head 100, wherein the purity of the high-purity argon gas source is ≥99.999%; and a pure argon gas source connected to the gas inlet control valve 304 of the atmosphere protection chamber 300, wherein the purity of the pure argon gas source is 99.99% ≤ 99.999%.

[0043] In one specific embodiment, the system further includes: an oxygen content sensor (not shown) disposed in the atmosphere protection chamber 300 for real-time monitoring of the oxygen concentration in the atmosphere protection chamber 300; a pressure sensor (not shown) disposed in the atmosphere protection chamber 300 for real-time monitoring of the gas pressure in the atmosphere protection chamber 300; a flow controller (not shown) disposed in the inlet and outlet channels of the atmosphere protection chamber 300 for regulating the flow rate of the protective gas; and a system controller (not shown), signal-connected to the oxygen content analyzer, pressure sensor, and flow controller, configured to: control the working state of the flow controller based on the feedback signals from the oxygen content sensor and the pressure sensor, so as to maintain the oxygen concentration and gas pressure in the laser processing chamber within a preset range. Regardless of changes in the external environment, the system can ensure that every welding is performed in the exact same optimal protective environment, greatly improving product yield and production efficiency.

[0044] In one specific embodiment, the laser processing system with atmosphere-assisted protection is used for laser welding of aluminum alloys. This system can precisely solve the core difficulties of aluminum alloys, such as their susceptibility to oxidation and their high requirements for the welding environment. By applying this system to weld aluminum alloys, defects such as oxidation, porosity, and lack of fusion in the weld seam can be effectively eliminated, resulting in a beautifully formed welded joint with excellent mechanical properties, thus effectively improving the quality of aluminum alloy welded parts.

[0045] like Figure 5 As shown, in one specific embodiment, a laser processing method with atmosphere-assisted protection is also provided, employing the laser processing system described above, including the following steps: fixing the workpiece to be processed on the worktable 301; starting the gas supply unit 400 and the laser fume purification unit 500, inputting protective gas into the air inlet 101 of the laser head 100 and the air inlet control valve 304 of the atmosphere protection chamber 300 respectively at set flow rates, and extracting gas from the atmosphere protection chamber 300 through the air outlet control valve 305, continuously flushing the laser processing chamber with gas and monitoring it until the oxygen concentration in the laser processing chamber drops below a preset threshold and is maintained at a slightly positive pressure, wherein the preset oxygen concentration threshold is less than 50 ppm; adjusting the axial position of the axially adjustable gas hood 201 according to process requirements, so that the adjustable... The axial position of the gas-photonic coaxial nozzle 203 changes simultaneously, and the distance between the adjustable gas-photonic coaxial nozzle 203 and the workpiece surface also changes accordingly, thereby obtaining the required protective airflow pattern; the laser head 100 is activated to output and transmit a laser beam to process the workpiece, and the fume purification unit 500 extracts the fume generated during processing. The flexible sealing telescopic cover 303 extends and retracts with the movement of the laser head 100 to maintain the sealing of the dynamic sealing channel; after the workpiece is processed, the laser beam output is stopped first, and the gas supply unit 400 and the fume purification unit 500 continue to operate, allowing the workpiece to cool to a predetermined temperature under the protective atmosphere. The preset temperature should be lower than the oxidation critical temperature of the workpiece. For example, when aluminum alloy is used as the workpiece, the preset temperature is lower than 250°C. Then, the supply of protective gas is stopped and the fume purification unit 500 is turned off.

[0046] In one specific embodiment, the step further includes: by rotating the axially adjustable air cover 203 by thread, the axial position of the adjustable air cover 201 is changed, so that the distance and angular position of the adjustable air-optic coaxial nozzle 203 relative to the workpiece surface and the workpiece surface change simultaneously, thereby obtaining the required protective airflow state.

[0047] In one specific embodiment, the method further includes the step of: driving the gear to rotate, thereby driving the axially adjustable protective cover to move axially relative to the cover body, and the axially adjustable protective cover 202 causing the axial position of the adjustable coaxial gas-light nozzle to change, thereby adjusting the state of the protective atmosphere.

[0048] In one specific embodiment, the method further includes the step of rotating the adjustable coaxial gas nozzle 203 to change its angular position relative to the workpiece. This change in angular position directly adjusts the dominant direction of the protective gas ejection, thereby achieving fine calibration of the protective gas flow pattern, such as the airflow impact point and coverage area.

[0049] In one specific embodiment, the method further includes the step of: the system controller comparing the feedback signals from the oxygen content sensor and the pressure sensor with preset oxygen concentration and pressure values, and controlling the working state of the flow controller to dynamically adjust the inlet flow rate and / or outlet flow rate of the protective gas, so as to maintain the oxygen concentration and gas pressure of the laser processing chamber within a preset range.

[0050] It should be noted that, for those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention, and no reference numerals in the claims should be construed as limiting the scope of the claims.

[0051] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A laser processing system with atmosphere-assisted protection, characterized in that: include: The laser head is used to generate and transmit a laser beam downstream, and its side is provided with an inlet for connecting to protective gas. An atmosphere protection hood, the upstream end of which is connected to the lower part of the laser head, includes a hood body and an axially adjustable gas hood that can be axially displaced relative to the hood body. The end of the axially adjustable gas hood is provided with an adjustable gas-optic coaxial nozzle. An atmosphere protection chamber, located below an atmosphere protection shield, includes a worktable, an observation window, and a flexible sealing telescopic shield. The observation window, worktable, and flexible sealing telescopic shield together form a sealed laser processing chamber. The worktable is located at the bottom of the laser processing chamber. The first end of the flexible sealing telescopic shield is sealed to the bottom of the atmosphere protection shield, and the second end is sealed to the top of the observation window, thereby forming a dynamically sealed channel between the atmosphere protection shield and the atmosphere protection chamber that expands and contracts with the movement of the laser head. A gas supply unit is used to independently supply protective gas to the gas inlet of the laser head and the gas inlet control valve of the atmosphere protection chamber, respectively. The laser fume purification unit is connected to the exhaust control valve of the atmosphere protection chamber and is used to extract and purify the gas and fumes generated during the processing in the atmosphere protection chamber.

2. The laser processing system with atmosphere-assisted protection according to claim 1, characterized in that: The axially adjustable air shroud is made of copper.

3. The laser processing system with atmosphere-assisted protection according to claim 1, characterized in that: The air inlet of the laser head adopts a venturi tube structure.

4. The laser processing system with atmosphere-assisted protection according to claim 1, characterized in that: The axially adjustable air cover is connected to the cover body by a thread or by a gear and rack meshing mechanism. The meshing mechanism includes: a rack, which is fixedly installed axially on the inner or outer wall of the axially adjustable protective cover; a gear, which meshes with the rack; and a drive mechanism, which is connected to the shaft of the gear.

5. A laser processing system with atmosphere-assisted protection according to claim 1 or 4, characterized in that: The cover is equipped with a limiter to limit the displacement range of the axially adjustable air cover.

6. The laser processing system with atmosphere-assisted protection according to claim 1, characterized in that: The adjustable coaxial air nozzle is connected to the axially adjustable air cover by a thread. Rotating the adjustable coaxial air nozzle can change its angular position relative to the workpiece.

7. A laser processing system with atmosphere-assisted protection according to claim 1, characterized in that: The surface of the workbench has undergone anodizing and blackening treatment.

8. A laser processing system with atmosphere-assisted protection according to claim 1, characterized in that: The observation window is made of high-temperature resistant glass and is fixedly installed by a surrounding aluminum alloy frame; the flexible sealing telescopic cover is made of high-temperature resistant transparent PVC material.

9. A laser processing system with atmosphere-assisted protection according to claim 1, characterized in that: The gas supply unit includes a high-purity argon gas source connected to the gas inlet of the laser head, wherein the purity of the high-purity argon gas source is ≥99.999%; and a pure argon gas source connected to the gas inlet control valve of the atmosphere protection chamber, wherein the purity of the pure argon gas source is 99.99% ≤ 99.999%.

10. A laser processing system with atmosphere-assisted protection according to claim 1, characterized in that: Also includes: An oxygen content sensor installed in the atmosphere protection chamber is used to monitor the oxygen concentration in the atmosphere protection chamber in real time. The pressure sensor installed in the atmosphere protection chamber is used to monitor the gas pressure inside the atmosphere protection chamber in real time. The flow controllers installed in the air inlet and outlet passages of the atmosphere protection chamber are used to regulate the flow rate of the protective gas. The system controller, which is connected to the oxygen content analyzer, pressure sensor, and flow controller, is configured to control the operating state of the flow controller based on the feedback signals from the oxygen content sensor and the pressure sensor, so as to maintain the oxygen concentration and gas pressure in the laser processing chamber within a preset range.

11. A laser processing system with atmosphere-assisted protection according to any one of claims 1-10, characterized in that: The system is used for laser welding of aluminum alloys.

12. A laser processing method with atmosphere-assisted protection, characterized in that: The laser processing system according to any one of claims 1-11 includes the following steps: The workpiece to be processed is fixed on the worktable; The gas supply unit and the laser fume purification unit are activated to input protective gas into the laser head and the atmosphere protection chamber, and to extract gas from the atmosphere protection chamber, so that a low-oxygen environment is formed in the laser processing chamber and a slight positive pressure is maintained. According to process requirements, the axial position of the adjustable air hood and / or the adjustable air-photonic coaxial nozzle is adjusted to adjust the axial position of the adjustable air-photonic coaxial nozzle, thereby obtaining the required protective airflow pattern. The laser head is activated to output and transmit a laser beam to process the workpiece. The dust purification unit extracts the dust generated during the processing. The flexible sealing telescopic cover extends and retracts with the movement of the laser head to maintain the sealing of the dynamic sealing channel. After the workpiece is processed, the laser beam output is stopped first, while the gas supply unit and the dust purification unit continue to operate. After the workpiece is cooled to the predetermined temperature under the protective atmosphere, the supply of protective gas is stopped and the dust purification unit is turned off.

13. A laser processing method with atmosphere-assisted protection according to claim 12, characterized in that: The method also includes the step of rotating the axially adjustable air cover by screws, thereby changing the axial position of the adjustable air cover and simultaneously changing the distance and angular position of the adjustable coaxial air nozzle relative to the workpiece surface, so as to obtain the required protective airflow pattern.

14. A laser processing method with atmosphere-assisted protection according to claim 12, characterized in that: The method also includes the following steps: the drive mechanism drives the gear to rotate, thereby driving the axially adjustable protective cover to move axially relative to the cover body. The axially adjustable protective cover drives the axial position of the adjustable coaxial gas-light nozzle to change, thereby adjusting the state of the protective atmosphere.

15. A laser processing method with atmosphere-assisted protection according to claim 12, characterized in that: It also includes the step of rotating the adjustable coaxial air nozzle to change its angular position relative to the workpiece.

16. A laser processing method with atmosphere-assisted protection according to claim 12, characterized in that: The method also includes the step of: the system controller controlling the working state of the flow controller based on the feedback signals from the oxygen content sensor and the pressure sensor, so as to maintain the oxygen concentration and gas pressure in the laser processing chamber within a preset range.

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