Double-laser double-swing auxiliary MIG electric arc thick plate narrow gap welding method and device

Abstract

The invention relates to the technical field of welding, in particular to a double-laser double-swing auxiliary MIG electric arc thick plate narrow gap welding method and device, and the welding method specifically comprises the following steps that S1, initial positioning is conducted; s2, performing double-laser cross scanning preheating; s3, MIG electric arc auxiliary fusion is conducted, specifically, MIG electric arc is introduced on the basis of a molten pool formed by laser, so that the molten pool is stably combusted under laser induction, the common molten pool effect is achieved, and complete fusion of the side wall and the root of the groove is promoted; s4, real-time monitoring and adjustment in the welding process are conducted, specifically, in the welding process, the state of a molten pool and the welding quality are monitored in real time, and the laser power, the electric arc parameters and the welding speed are dynamically adjusted; and S5, welding seam quality detection. The double-laser-assisted MIG electric arc is used, the stability of the MIG electric arc is remarkably enhanced, the advantage of MIG filling efficiency is brought into play, and the welding efficiency and the welding quality are effectively improved.

Description

Technical Field

[0001] The present invention relates to the field of welding technology, and particularly relates to a double-laser double-oscillation assisted MIG arc thick plate narrow-gap welding method and device. Background Art

[0002] In the field of thick plate welding, narrow-gap welding technology is widely used due to its high efficiency, low deformation and high quality. Taking the aerospace field as an example, the welding of key components such as large aircraft wing panels and rocket fuel tanks requires the use of narrow-gap welding technology. However, traditional MIG welding has many technical problems in thick plate narrow-gap welding: firstly, due to the narrow welding gap (usually 8-15mm), it is difficult for the arc energy to penetrate deep into the bottom of the weld, resulting in insufficient penetration; secondly, during multi-layer multi-pass welding, defects such as lack of fusion and slag inclusion are likely to occur, seriously affecting the welding quality; furthermore, it is difficult to precisely control the welding heat input, which is likely to cause welding deformation and excessive residual stress.

[0003] Although laser welding has the advantages of high energy density (up to 106W / cm 2 ), and large penetration depth (up to more than 10mm), it is vulnerable to laser shielding effects in narrow-gap welding. For example, when the welding depth exceeds 20mm, multiple reflections of the laser beam in the narrow gap will cause energy loss, the welding process is unstable, and defects such as pores and cracks are likely to occur. In addition, it is difficult to achieve good control of weld formation with single laser welding, especially when welding thick materials, surface quality problems such as weld depression or protrusion are likely to occur.

[0004] In response to the above technical problems, researchers at home and abroad have proposed various solutions. For example, the traditional laser-MIG hybrid welding method, by arranging the laser beam and the MIG arc coaxially, improves the welding efficiency to a certain extent. However, this method still has problems such as uneven energy distribution and unstable welding process in thick plate narrow-gap welding. In addition, the oscillating laser welding technology improves the fluidity of the molten pool through the periodic oscillation of the laser beam, but fails to fundamentally solve the energy transfer problem in narrow-gap welding. Therefore, effectively combining the advantages of laser and MIG welding and developing a new welding method that can adapt to thick plate narrow-gap welding has become an important direction in current welding technology research.

[0005] Publication No.: CN118789114B A narrow-gap laser-GMAW hybrid welding method with molten pool coupling. During welding, the spot of the laser beam swings along a predetermined trajectory inside the narrow-gap groove, melting the side walls of the narrow-gap groove and forming a laser molten pool; the GMAW arc remains stationary at the center position of the narrow-gap groove and directly acts on the laser molten pool. The liquid metal formed by the GMAW arc spreads and flows along the surface of the laser molten pool under the action of surface tension, and forms a composite molten pool after coupling with the laser molten pool, and finally cools and solidifies into a weld. However, this solution has the following problems: (1) Using a single laser, the adjustable action angle is small, and the adaptability to grooves of different widths is poor; (2) Swinging along a predetermined trajectory, it cannot act on both sides at the same time, and there is still a risk of incomplete fusion on the side walls; (3) When the laser swings, it acts on the center of the molten pool, and it is easy to produce welding defects caused by unstable keyholes.

[0006] Therefore, it is urgent to propose a new welding method and device to solve the problems of laser occlusion, incomplete fusion defects, welding oxidation, etc. existing in the prior art. Summary of the Invention

[0007] In view of this, the present invention aims to propose a double-laser double-swing assisted MIG arc thick-plate narrow-gap welding method and device to solve the problems of laser occlusion, incomplete fusion defects, welding oxidation, etc. existing in the prior art.

[0008] The present invention proposes an innovative double-laser double-swing assisted MIG arc welding method. Through unique energy distribution and motion control strategies, and innovative designs such as double-laser cross-scanning, MIG arc and laser co-molten pool, and laser-arc hybrid welding copper heads, high-quality and high-efficiency narrow-gap welding of thick plates is achieved.

[0009] The technical solution of the present invention is realized as follows:

[0010] The present invention discloses a double-laser double-swing assisted MIG arc thick-plate narrow-gap welding method, which specifically includes the following steps:

[0011] S1: Initial positioning: Fix the workpiece to be welded, ensure that the center of the workpiece groove is accurately aligned with the welding torch, and set the welding path and parameters;

[0012] S2: Double-laser cross-scanning preheating: Adopt a cross-scanning mode to preheat and preliminarily fuse the root of the groove. The laser beam acts on the root of the groove to generate a molten pool, and the range of the molten pool is expanded by swinging;

[0013] S3: MIG arc assisted fusion: Introduce the MIG arc on the basis of the molten pool formed by the laser, and make it burn stably under the induction of the laser to achieve the effect of a co-molten pool and promote complete fusion of the side walls and the root of the groove;

[0014] S4: Real-time monitoring and adjustment during welding: During the welding process, the molten pool state and welding quality are monitored in real time, and the laser power, arc parameters, and welding speed are dynamically adjusted.

[0015] S5: Weld quality inspection: After welding is completed, ultrasonic flaw detection or X-ray inspection is used to check the weld quality to confirm that there are no lack of fusion or crack defects.

[0016] Furthermore, in step S1, the groove angle of the workpiece is 5 - 20°, ensuring that the groove angle can avoid the interference between the laser beam and the side wall. The groove gap width is 8 - 12 mm, and the width above the groove is ≥ 14 mm, ensuring that the laser and arc can fully cover the root of the groove.

[0017] Furthermore, in step S2, the first welding torch is a high-precision MIG welding torch, equipped with a wire feeding mechanism and an arc control system. The wire feeding speed is set to 6 - 10 m / min, and the distance between the arc and the laser molten pool is 3 - 10 mm.

[0018] Furthermore, in step S2, the second welding torch is a high-power fiber laser. Laser power: 1 - 6 KW per unit. Laser scanning mode: double-swing circular or figure-eight scanning, amplitude 2 - 6 mm, frequency 50 - 200 Hz. The laser incident angle ensures that the laser beam can cover the root of the groove. The laser head incident angle can be rotated and adjusted around the R axis to adapt to different groove angles.

[0019] Furthermore, in step S3, the relationship between the laser center distance d1, the laser swing amplitude h, and the minimum distance d3 between the narrow-gap groove side wall is:

[0020] d1 + 2*h ≈ d4;

[0021] d4 > d3.

[0022] Furthermore, in step S3, the welding speed is set to 100 - 400 mm / min to ensure that the single-layer filling welding thickness reaches 5 - 8 mm.

[0023] Furthermore, in step S4, a CCD image monitoring system can be used to make adjustments according to real-time data.

[0024] Another object of the present invention is to disclose a double-laser double-swing assisted MIG arc thick plate narrow-gap welding device, which is applied to the double-laser double-swing assisted MIG arc thick plate narrow-gap welding method described in any one of the above, and includes:

[0025] A welding motion platform for achieving precise alignment and stable movement during the welding process;

[0026] The welding torch system includes: a first adjustment mechanism, a first welding torch, a second adjustment mechanism, and at least two second welding torches. The first welding torch is a MIG welding torch, and the second welding torch is a laser welding torch. Two ends of the first adjustment mechanism are respectively connected to the first welding torch and the welding motion platform, and two ends of the second adjustment mechanism are respectively connected to the second welding torch and the welding motion platform;

[0027] The welding workpiece fixture is arranged on the welding motion platform and is used for fixing the workpiece to be welded. The workpiece is processed with a narrow-gap groove;

[0028] The protective cover is used for cooling the laser and arc heat and suppressing the laser reflection from burning the upper components;

[0029] The image monitoring system is used for real-time monitoring of the molten pool state and welding quality;

[0030] The control system is used for controlling the coordinated movement of the welding motion platform and the welding torch system, and dynamically adjusting the welding parameters according to the data fed back by the image monitoring system.

[0031] Further, the welding motion platform includes a base and a motion component. The welding workpiece fixture is arranged on the base. The motion component is an XYZ three-axis motion device driven by a high-precision servo motor. The motion component is used for controlling the precise positioning and stable movement of the welding torch system. A rotating shaft is installed at the end of the motion component, and the rotating shaft is used for controlling the adjustment of the welding torch system in the plane rotation direction.

[0032] Further, the first adjustment mechanism and the second adjustment mechanism are mechanical structures or systems capable of realizing the position adjustment of the X-axis, Y-axis, and Z-axis. The first adjustment mechanism is used for adjusting the position and angle of the first welding torch, and the second adjustment mechanism is used for adjusting the position and angle of the second welding torch.

[0033] Compared with the prior art, a double-laser double-oscillation assisted MIG arc thick-plate narrow-gap welding method and device of the present invention have the following advantages:

[0034] 1. By using the double-laser assisted MIG arc, the stability of the MIG arc is significantly enhanced, the advantage of the MIG filling efficiency is exerted, and the welding efficiency and welding quality are effectively improved.

[0035] 2. By using the laser double-oscillation assisted MIG arc, the defect of unfused side walls in thick-plate narrow-gap welding is effectively solved, and the stability of welding quality is improved.

[0036] 3. By using the double-laser cross scanning, the problem of laser occlusion in laser welding is effectively solved, the energy distribution is promoted to be uniform, and the incidence of welding defects is reduced. Description of the Drawings

[0037] The accompanying drawings that form a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0038] Figure 1 is a schematic structural diagram of the welding device of the present invention;

[0039] Figure 2 is a schematic structural diagram of the dual-laser MIG welding of the present invention;

[0040] Figure 3 is a schematic diagram of the dual-laser MIG welding principle in the present invention;

[0041] Figure 4 is a schematic diagram of the positional relationship between the laser molten pool and the arc molten pool in the present invention;

[0042] Figure 5 is a physical diagram of the welding effect of the large-thickness test plate in Embodiment 1 of the present invention;

[0043] Figure 6 is the radiographic film of the weld in Embodiment 1 of the present invention.

[0044] 1. Welding motion platform; 101. Base; 102. Motion component; 103. Rotation shaft; 2. Welding torch system; 201. First adjustment mechanism; 202. First welding torch; 203. Second adjustment mechanism; 204. Second welding torch; 3. Welding workpiece fixture; 4. Workpiece; 401. Narrow-gap groove; 5. Protective cover. Detailed implementation manners

[0045] In order to make the technical means, achieved objectives and effects of the present invention easy to understand, the embodiments of the present invention will be described in detail below with reference to specific drawings.

[0046] It should be noted that all the terms indicating directions and positions in the present invention, such as: "upper", "lower", "left", "right", "front", "rear", "vertical", "horizontal", "inner", "outer", "top", "bottom", "lateral", "longitudinal", "center", etc., are only used to explain the relative positional relationship and connection situation between components in a certain specific state, and are only for the convenience of describing the present invention, rather than requiring the present invention to be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation of the present invention. In addition, the descriptions involving "first", "second", etc. in the present invention are only for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features.

[0047] In the description of the present invention, unless otherwise clearly specified and defined, the terms "installation", "connection", and "coupling" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection; it may be a direct connection, or an indirect connection through an intermediate medium, and it may be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0049] MIG welding torch and laser welding torch are common terms in the field of welding technology. A MIG welding torch is a tool used for metal inert gas shielded welding, also known as GMAW. It uses a continuously fed welding wire as an electrode and an inert gas to protect the molten pool from atmospheric pollution. A laser welding torch refers to the head assembly of the equipment used for laser welding, which uses a laser beam with a high energy density as a heat source for welding. Laser welding can achieve very fine welding, with characteristics such as concentrated heat input and small deformation.

[0050] As Figures 1-6 shown, the first object of the present invention is to disclose a double - laser double - swing assisted MIG arc thick - plate narrow - gap welding method, which specifically includes the following steps:

[0051] S1: Initial positioning: Fix the workpiece 4 to be welded, ensure that the center of the groove of the workpiece 4 is precisely aligned with the welding torch, and set the welding path and parameters;

[0052] Fix the workpiece 4 to be welded on the welding motion platform 1, ensure that the center of the groove of the workpiece 4 is precisely aligned with the welding torch, and set the welding path and parameters through the control system to ensure the accuracy of the welding starting point, providing a stable physical basis for the subsequent welding process. This setting improves the welding accuracy and reduces quality problems caused by position deviation.

[0053] S2: Double - laser cross - scanning preheating: Adopt a cross - scanning mode to preheat and preliminarily fuse the root of the groove. The laser beam acts on the root of the groove to generate a molten pool, and the range of the molten pool is expanded by swinging;

[0054] Preheat the material to reduce the risk of thermal stress cracks; and the formed molten pool provides a good foundation for the subsequent MIG arc. This setting enhances the weldability of the material and improves the welding quality and efficiency.

[0055] S3: MIG arc-assisted fusion: Introduce the MIG arc on the basis of the molten pool formed by the laser, and make it burn stably under the induction of the laser to achieve the effect of a common molten pool, and promote the complete fusion of the side wall and root of the groove;

[0056] Utilize the arc energy to further melt the metal, and act together with the laser to increase the penetration depth and width, ensuring the welding quality. This setting combines the high precision of laser welding and the good filling performance of MIG arc welding to optimize the welding effect.

[0057] S4: Real-time monitoring and adjustment during the welding process: During the welding process, monitor the state of the molten pool and the welding quality in real time, and dynamically adjust the laser power, arc parameters, and welding speed;

[0058] Timely detect and correct abnormal conditions during the welding process, such as defects like lack of fusion or porosity, to ensure the stability of the welding process. This setting improves the consistency and reliability of welding and reduces the scrap rate.

[0059] S5: Weld quality inspection: After welding, use ultrasonic flaw detection or X-ray inspection to check the weld quality and confirm that there are no defects such as lack of fusion or cracks;

[0060] Verify the welding quality to ensure that the final product meets the standard requirements. This setting guarantees the product quality through non-destructive testing methods and provides a basis for subsequent improvement.

[0061] This setting solves problems such as laser occlusion, lack of fusion defects, and welding oxidation existing in the prior art through innovative designs such as double-laser cross scanning, MIG arc and laser common molten pool, and laser-arc composite welding of copper heads, realizing efficient and high-quality narrow-gap welding of thick plates.

[0062] Specifically, in step S2, the scanning amplitude of the laser beam is 2 - 5 mm, and the frequency is 50 - 200 Hz.

[0063] By adjusting the scanning amplitude and frequency of the laser beam, the heating degree of the root of the groove of the workpiece 4 can be precisely controlled. A smaller scanning amplitude and a higher frequency allow for more refined control of the heat input, which helps to achieve a more uniform preheating effect, can effectively promote the melting and mixing of the material at the root of the groove, thereby forming a stable and good-quality initial molten pool, expanding the range of the molten pool and heating it evenly, can effectively relieve the phenomenon of local overheating, reduce the temperature gradient, and avoid thermal stress concentration.

[0064] This setting can ensure the efficiency and accuracy of the preheating process, improve the physical properties of the materials to be welded, increase the success rate and stability of welding, and contribute to improving the overall welding quality and efficiency.

[0065] Specifically, in step S2, the first welding torch 202 is a high-precision MIG welding torch, equipped with a wire feeding mechanism and an arc control system. The wire feeding speed is set at 6 - 10 m / min to ensure that the distance between the arc and the laser molten pool is controlled within a reasonable range, usually 3 - 10 mm.

[0066] By setting the wire feeding speed at 6 - 10 m / min, it can ensure that the filler material enters the molten pool at an appropriate rate, guarantee the quality of the welded joint, reduce the occurrence probability of defects such as lack of fusion and porosity, form a more uniform and complete weld seam, and keep the distance between the arc and the laser molten pool within the range of 3 - 10 mm, which helps to optimize the energy distribution and avoid overheating caused by too close a distance or energy loss caused by too far a distance.

[0067] Specifically, in step S2, the second welding torch 204 is a high-power fiber laser. The laser head is fixed on the welding torch bracket through an XYZR three-dimensional adjustment mechanism. Laser power: 1 - 6 KW per unit. The laser head is equipped with a swinging mechanism to achieve double laser cross scanning and circular swinging scanning functions. Usually, the laser scanning mode: double swinging circular or figure-eight scanning, amplitude 2 - 6 mm, frequency adjustable. Laser incident angle: adjusted according to the groove angle to ensure that the laser beam can cover the root of the groove. The incident angle of the laser head can be rotated and adjusted around the R axis to adapt to different groove angles.

[0068] Flexibly adjust the angle of the laser head according to the actual welding requirements, so that the laser beam can effectively act on grooves of different shapes and sizes. Through different scanning modes, such as double swinging circular or figure-eight scanning, the root of the groove can be heated more evenly, promoting the preliminary fusion of materials, achieving double laser cross scanning and circular swinging scanning, which helps to expand the range of the molten pool, improve the material fluidity in the molten pool, and reduce the occurrence probability of lack of fusion defects.

[0069] Specifically, the groove angle of the workpiece 4 is usually 5 - 20°, ensuring that the groove angle can avoid the interference between the laser beam and the side wall. The groove gap width is 8 - 12 mm, and the width above the groove is ≥14 mm, ensuring that the laser and the arc can fully cover the root of the groove.

[0070] An appropriate groove angle can ensure that the laser beam can shine smoothly on the root of the groove without being blocked or reflected by the side wall, thus ensuring the effective utilization of laser energy, helping the molten material to better fill the weld seam, forming a uniform molten pool, reducing defects such as lack of fusion, etc. A suitable groove gap width allows the laser beam and the MIG arc to fully contact and heat the root of the groove, promoting good fusion of the materials. The wider area above the groove helps to improve the fluidity of the molten pool, making the welding process more stable and improving the quality of the welded joint.

[0071] This setting reduces the possibility of interference between the laser beam and the side wall, ensures that the laser energy can accurately act on the root of the groove, improves the welding precision, and reduces the occurrence of welding defects such as lack of fusion and porosity.

[0072] Specifically, in step S3, the distance d2 between the double lasers and the arc is d2 ≤ 8 mm.

[0073] By controlling the distance between the double lasers and the MIG arc within 8 mm, it can ensure that the molten pool induced by the laser is closely connected to the arc action area, which is conducive to forming a stable common molten pool, helping to achieve complete fusion of the side wall and the root of the groove. The smaller distance helps to improve the fluidity of the materials in the molten pool, making the molten metal easier to fill the weld seam, reducing the occurrence probability of defects such as lack of fusion and porosity, and ensuring the efficient utilization of the energy of the laser and the arc, reducing energy loss. The synergistic effect between the two can achieve a better welding effect while reducing the total input energy.

[0074] This setting can make the welding process more stable by optimizing the relative position of the double lasers and the arc, thereby improving the quality of the final weld seam, including improving the surface formation of the weld seam, increasing the weld strength, etc., and reducing the risk of material property changes caused by overheating, such as a decrease in hardness or the generation of cracks.

[0075] Specifically, in step S3, the relationship between the laser center distance d1, the laser swing amplitude h, and the minimum distance d3 from the side wall of the narrow-gap groove 401:

[0076] d1 + 2*h ≈ d4;

[0077] d4 > d3.

[0078] The sum of the laser center distance d1 and twice the laser swing amplitude h is d4. d4 can be understood as the effective action range or the molten pool coverage width, that is, the maximum width that can be affected by the double laser beams and their swing. d4 > d3 ensures that the laser treatment area can completely cover the weld seam and leave a certain margin, avoiding direct action on the side wall of the groove and reducing the thermal damage to the side wall material. d3 represents the minimum safety distance from the side wall of the narrow-gap groove 401 to the edge of the laser action area.

[0079] This setting can evenly distribute the laser energy in the area to be welded, ensuring sufficient heat input to form a good molten pool while avoiding a decrease in material properties or other defects caused by overheating. It can maximize the effective action range of the laser without damaging the sidewalls of the groove, contribute to forming a more uniform and complete weld seam, and reduce the occurrence probability of defects such as lack of fusion and porosity.

[0080] Specifically, in step S3, the welding speed is set to 100 - 400 mm / min to ensure that the single-layer filling welding thickness reaches 5 - 8 mm.

[0081] By adjusting the welding speed to 100 - 400 mm / min, the heat transferred to the workpiece 4 per unit time can be precisely controlled, which helps to maintain the stability of the molten pool, avoid overheating or insufficient heating. Setting the single-layer filling welding thickness to 5 - 8 mm ensures that each layer of welding material can be fully melted and form a uniform and dense weld seam, contributing to reducing defects that may occur during multi-layer welding.

[0082] Specifically, in step S4, a CCD image monitoring system can be used to make adjustments according to real-time data.

[0083] Through the CCD image monitoring system, the image information of the molten pool can be obtained in real time, including key parameters such as size, shape, and fluidity. Welding defects such as lack of fusion and porosity can be detected in a timely manner, and by analyzing the characteristics of these defects, it can guide the operator or the automatic control system to make corresponding adjustments to ensure the best welding effect.

[0084] This setting makes real-time adjustments using the precise data provided by the CCD image monitoring system, which helps to maintain a high degree of consistency and stability in the welding process and reduce quality fluctuations caused by human factors.

[0085] The second object of the present invention is to disclose a double-laser double-swing-assisted MIG arc thick-plate narrow-gap welding device, which is applied to any of the above welding methods and includes:

[0086] A welding motion platform 1 for achieving precise alignment and stable movement during the welding process;

[0087] A welding torch system 2, including: a first adjustment mechanism 201, a first welding torch 202, a second adjustment mechanism 203, and at least two second welding torches 204. The first welding torch 202 is a MIG welding torch, the second welding torch 204 is a laser welding torch. Two ends of the first adjustment mechanism 201 are respectively connected to the first welding torch 202 and the welding motion platform 1, and two ends of the second adjustment mechanism 203 are respectively connected to the second welding torch 204 and the welding motion platform 1.

[0088] The welding workpiece fixture 3 is arranged on the welding motion platform 1 and is used to fix the workpiece 4 to be welded. The workpiece 4 is machined with a narrow-gap groove 401.

[0089] The protective cover 5 is used to cool the laser and arc heat and suppress the laser reflection from burning the upper components.

[0090] The image monitoring system is used to monitor the molten pool state and welding quality in real time.

[0091] The control system is used to control the coordinated movement of the welding motion platform 1 and the welding torch system 2, and dynamically adjust the welding parameters according to the data fed back by the image monitoring system.

[0092] The welding motion platform 1 provides a stable welding environment to ensure that the workpiece 4 does not move during the welding process. The welding torch system 2 can move along the set route, ensuring the welding accuracy. The first welding torch 202 and the first adjustment mechanism 201 perform the MIG arc welding task and make precise position and angle adjustments through the first adjustment mechanism 201, achieving precise control of the welding parameters, which helps to improve the welding quality and efficiency. The second welding torch 204 and the second adjustment mechanism 203 perform the laser welding torch welding task. At least two laser welding torches are used to preheat the root of the groove and form a preliminary molten pool. The second adjustment mechanism 203 is used to adjust the position and angle of the laser welding torch, enhancing the weldability of the material and reducing the risk of thermal stress cracks. In addition to cooling the laser and arc heat, the protective cover 5 can also suppress the laser reflection, protect the welding area from external interference, improve the safety and stability of welding, avoid unnecessary energy loss. The image monitoring system monitors the molten pool state and welding quality in real time, discovers and corrects abnormal situations in the welding process in a timely manner, increases the consistency and reliability of the welding process, reduces the scrap rate, and improves the production efficiency. The control system controls the coordinated movement of the first welding torch 202 and the second welding torch 204, monitors the welding process in real time to dynamically adjust the welding parameters, ensuring the automation and intelligence of the entire welding process, and improving the welding quality and consistency.

[0093] This setting, by integrating a variety of advanced technologies and equipment, can not only complete the double-laser double-oscillation assisted MIG arc thick-plate narrow-gap welding method efficiently and with high quality, but also has high flexibility and adaptability, suitable for the welding requirements of workpieces 4 with different materials and thicknesses.

[0094] Specifically, the welding motion platform 1 includes a base 101 and a motion component 102. The welding workpiece fixture 3 is arranged on the base 101. The motion component 102 is an XYZ three-axis motion device driven by a high-precision servo motor. The motion component 102 is used for the precise positioning and stable movement of the welding torch system 2. At the same time, a rotating shaft 103 is added to the end of the motion component 102, and the rotating shaft 103 is used to control the adjustment of the welding torch system 2 in the plane rotation direction.

[0095] The motion component 102 adopts an XYZ three-axis motion device driven by a high-precision servo motor to ensure that the welding torch system 2 can accurately move to a predetermined position, achieve precise control of the welding path. By installing a rotating shaft 103 at the end of the motion component 102, the rotation direction of the welding torch system 2 in the plane can be further controlled to adapt to the welding seam requirements of different trajectories, increasing the flexibility of welding operations. The base 101 not only provides a stable foundation support but also integrates a welding workpiece fixture 3 for fixing the workpiece 4 to be welded, ensuring the stability of the position of the workpiece 4 during the welding process. The entire motion platform can be programmed and set through a control system to achieve automated operation of the welding path and real-time monitoring of the platform position and motion state, thereby improving production efficiency and the consistency of welding quality.

[0096] This setting enables the welding torch system 2 to perform fine adjustments in three-dimensional space, greatly improving the accuracy and repeatability of welding, enhancing the device's ability to handle complex weld seam structures, and being applicable to various welding tasks. The automated control system reduces the need for manual intervention, speeds up the welding speed, while ensuring welding quality and consistency, helping to reduce production costs, optimize welding parameters, and reduce the occurrence probability of welding defects such as lack of fusion and porosity, thereby improving the quality of the final product.

[0097] Preferably, the motion component 102 may include an X-axis motion component, a Y-axis motion component, and a Z-axis motion component. The Y-axis motion component is fixed to the ground. The Y-axis motion component includes a Y-axis track and a Y-axis driving device. A Y-axis connecting plate is provided on the Y-axis driving device, and the connecting plate connects the X-axis motion component, enabling the X-axis motion component to move along the Y-axis direction. The X-axis motion component includes an X-axis track and an X-axis driving device. An X-axis connecting plate is provided on the X-axis driving device, and the X-axis connecting plate connects the Z-axis motion component, enabling the Z-axis motion component to move within the XY plane. The Z-axis motion component is connected to the rotating shaft 103 to achieve precise positioning of the welding torch system 2 and adjustment of the plane rotation direction.

[0098] Preferably, the motion component 102 can also be a manipulator.

[0099] Specifically, the first adjustment mechanism 201 and the second adjustment mechanism 203 are mechanical structures or systems capable of achieving position adjustments in the X-axis, Y-axis, and Z-axis. The first adjustment mechanism 201 is used to adjust the position and angle of the first welding torch 202, and the second adjustment mechanism 203 is used to adjust the position and angle of the second welding torch 204.

[0100] The first adjustment mechanism 201 is used to adjust the position of the first welding torch 202 in the X, Y, and Z directions to ensure that it can accurately align with the weld position during the welding process. The second adjustment mechanism 203: is used to adjust the position of the second welding torch 204 in the X, Y, and Z directions to ensure that the laser beam can accurately cover the area to be welded, which is particularly important for welding of complex shapes or narrow gaps. In addition to position adjustment, the first adjustment mechanism 201 can also adjust the angle of the MIG welding torch to adapt to different welding groove angles and welding process requirements. The second adjustment mechanism 203 also supports angle adjustment, enabling the laser welding torch to flexibly meet various welding needs, such as welding of grooves with different inclination angles, making the entire welding system highly adaptable and flexible, capable of handling workpieces 4 of different types, thicknesses, and shapes, and greatly expanding the application range of the equipment.

[0101] This precise position and angle adjustment ability ensures that the welding head can accurately align with the weld, reducing quality problems caused by inaccurate positioning, such as defects like lack of fusion or porosity, helping to optimize welding parameters, making the welding process more stable, improving the quality and consistency of the weld, reducing the need for manual intervention, accelerating the welding speed, while ensuring welding quality and consistency, and helping to reduce production costs.

[0102] The mechanical structures of the first adjustment mechanism 201 and the second adjustment mechanism 203 are prior arts and will not be described in detail here.

[0103] Specifically, the laser head of the second welding torch 204 can perform precise position adjustment in the XYZ space and achieve rotational R adjustment of the incident angle.

[0104] Allowing the laser head to move precisely in the X, Y, and Z directions ensures that the laser beam can accurately act on the specified position of the workpiece 4 to be welded. By rotating and adjusting the R axis, the incident angle of the laser beam relative to the surface of the workpiece 4 can be changed, enabling the laser head to not only move freely on the plane but also adjust the irradiation angle according to actual needs to adapt to different groove shapes and welding requirements.

[0105] This setting reduces quality problems caused by inaccurate positioning, such as defects like lack of fusion or porosity, reduces the size of the heat-affected zone, reduces the risk of crack generation, and improves the overall strength of the weld.

[0106] Specifically, the protective cover 5 is a water-cooled copper head. The protective cover 5 is arranged above the narrow-gap groove 401. The protective cover 5 is provided with a through hole 501, and the through hole 501 is used for the welding torch system 2 to pass through the protective cover 5 to perform welding.

[0107] The protective cover 5 adopts water-cooling technology. Through the internal circulating water flow, it effectively absorbs and takes away a large amount of heat generated during the welding process, helps maintain the temperature stability of the welding area, prevents overheating from damaging the equipment or workpiece 4. The water-cooled copper head can suppress laser reflection, avoid the laser beam reflecting to places where it should not shine, thereby protecting the upper components from being burned out.

[0108] This setting reduces the working temperature of the welding equipment, reduces the wear of key components in a high-temperature environment, thereby extending the service life of the equipment, effectively controls the temperature of the welding area, reduces the risk of material deformation or performance degradation caused by overheating, and improves the quality and consistency of the welded joints.

[0109] Specifically, the image monitoring system is a CCD image monitoring system.

[0110] The CCD charge-coupled device image monitoring system can capture and analyze the image data of the welding molten pool and the surrounding area in real time, including dimensions, shapes, positions, and their dynamic changes, etc. It can identify and record the characteristics of common welding defects such as lack of fusion, porosity, cracks, etc., discover potential problems in a timely manner, and make corresponding adjustment or correction measures accordingly.

[0111] This setting makes real-time adjustments using the precise data provided by the high-resolution CCD camera, helps maintain a high degree of consistency and stability in the welding process, reduces quality fluctuations caused by human factors, realizes highly automated operation, reduces the dependence on manual experience, improves production efficiency, and reduces the scrap rate of products.

[0112] Embodiment 1

[0113] 1. Welding motion platform 1

[0114] Select an XYZ three-axis motion platform driven by a high-precision servo motor. At the same time, install a rotating shaft 103 above the composite welding torch to ensure the precise positioning of the welded workpiece 4 and the adjustment of the plane rotation direction to adapt to welding of different trajectory welds. Configure a control system to realize the programming and automated operation of the welding path, and real-time monitor the platform position and motion state. The welding speed is set at 100 - 400 mm / min to ensure that the single-layer filling welding thickness reaches 5 - 8 mm.

[0115] 2. Dual-laser-assisted MIG welding torch system 2:

[0116] Dual laser welding torch: Two high-power fiber lasers are installed, and the laser heads are fixed on the welding torch bracket through the XYZR three-dimensional adjustment mechanism. Among them, the laser power is 1 - 6 KW per unit, and the laser heads are equipped with a swinging mechanism to achieve the functions of dual-laser cross scanning and circular swinging scanning. Usually, the laser scanning mode is dual-swing circular or figure-eight scanning, with an amplitude of 2 - 6 mm and adjustable frequency. The laser incident angle is adjusted according to the groove angle to ensure that the laser beam can cover the root of the groove. The incident angle of the laser head can be rotated and adjusted around the R axis to adapt to different groove angles. MIG welding torch: A high-precision MIG welding torch is selected, equipped with a wire feeding mechanism and an arc control system, and the wire feeding speed is set at 6 - 10 m / min. The MIG welding torch can be flexibly adjusted in terms of the front-back distance and angle through the adjustment mechanism to ensure that the distance between the arc and the laser molten pool is controlled within a reasonable range, usually 3 - 10 mm.

[0117] The workpiece 4 is a large-thickness titanium alloy test plate, and a narrow-gap groove 401 is machined. The groove angle and gap width are designed according to the welding requirements. The groove design should avoid the interference between the dual lasers and the groove side walls to ensure that the laser can effectively scan the root of the groove. The groove angle is designed according to the welding material and thickness, usually 5 - 20°, to ensure that the groove angle can avoid the interference between the laser beam and the side walls. The groove gap width is designed according to the welding requirements, usually 8 - 12 mm, and the width above the groove is ≥14 mm to ensure that the laser and the arc can fully cover the root of the groove.

[0118] The protective cover 5 is a composite welding torch cooling copper head: A water-cooled copper head is designed, integrating the cooling channels for the laser and the arc, to ensure the stable operation of the laser head and the MIG welding torch in a high-temperature environment.

[0119] 3. Welding process

[0120] 1. Initial positioning:

[0121] Fix the welding workpiece 4 on the XYZ motion platform, and adjust the position of the workpiece 4 to align the center of the groove with the welding torch. Set the welding path and parameters through the control system.

[0122] 2. Dual-laser cross scanning:

[0123] Start the dual-laser system, and the laser heads preheat and fuse the root of the groove in a cross-scanning mode. The laser beam forms a molten pool at the root of the groove, and at the same time, the molten pool range is expanded through swinging scanning, with a scanning amplitude of 2 - 5 mm and a scanning frequency of 50 - 200 Hz.

[0124] 3. MIG arc starting:

[0125] After the laser molten pool is formed, start the MIG arc, and the arc burns stably under the induction of the laser molten pool. The distance d2 between the two lasers and the arc is ≤ 8 mm to ensure that the arc and the laser molten pool share the same molten pool, effectively ensuring full fusion of the side wall and root of the groove.

[0126] 4. Welding process control:

[0127] During the welding process, monitor the molten pool state and welding quality in real time, and adjust the laser power, arc parameters and welding speed through the control system. Ensure the stability of the welding process and avoid defects such as lack of fusion and porosity. In addition, a real-time CCD image monitoring system can be installed to achieve adjustment and optimization during the welding process, and adjust the laser and arc parameters according to the monitoring data to ensure that the molten pool size and temperature meet the requirements.

[0128] 5. Weld quality inspection:

[0129] After welding is completed, use ultrasonic flaw detection or X-ray to detect the weld quality to ensure that there are no defects such as lack of fusion and cracks. Analyze the test results and optimize the welding parameters and processes.

[0130] Through the above specific implementation manners, the present invention can achieve high-efficiency and high-quality narrow-gap welding of thick titanium alloys, solve the technical problems in traditional welding methods, and has a wide application prospect.

[0131] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A dual laser dual swing assisted MIG arc thick plate narrow gap welding method, characterized in that: The specific steps include: S1: Initial positioning: fix the workpiece (4) to be welded, ensure that the center of the groove of the workpiece (4) is accurately aligned with the welding gun, and set the welding path and parameters; S2: Dual laser cross scanning preheating: The cross scanning mode is used to preheat and initially fuse the root of the groove. The laser beam acts on the root of the groove to generate a molten pool, and the molten pool range is expanded by swinging; S3: MIG arc assisted fusion: MIG arc is introduced on the basis of the molten pool formed by laser, so that it burns stably under the induction of laser to achieve the eutectic pool effect and promote complete fusion of the groove side wall and root; S4: Real-time monitoring and adjustment of welding process: During the welding process, the molten pool status and welding quality are monitored in real time, and the laser power, arc parameters and welding speed are dynamically adjusted; S5: Weld quality inspection: After welding is completed, use ultrasonic testing or X-ray to check the weld quality to confirm that there are no defects such as lack of fusion and cracks.

2. The dual laser dual swing assisted MIG arc thick plate narrow gap welding method according to claim 1 is characterized in that: In step S1, the groove angle of the workpiece (4) is 5-20°, ensuring that the groove angle can avoid interference between the laser beam and the side wall, the groove gap width is 8-12 mm, and the width above the groove is ≥14 mm, ensuring that the laser and the arc can fully cover the groove root.

3. The dual laser dual swing assisted MIG arc thick plate narrow gap welding method according to claim 2 is characterized in that: In step S2, the first welding gun (202) is a high-precision MIG welding gun equipped with a wire feeding mechanism and an arc control system. The wire feeding speed is set to 6-10 m / min, and the distance between the arc and the laser molten pool is 3-10 mm.

4. The dual laser dual swing assisted MIG arc thick plate narrow gap welding method according to claim 2, characterized in that: In step S2, the second welding gun (204) is a high-power fiber laser, with a laser power of 1-6KW per unit, a laser scanning mode of double-swing circular or figure-8 scanning, an amplitude of 2-6mm, a frequency of 50-200Hz, and a laser incident angle that ensures that the laser beam can cover the root of the groove. The laser head incident angle can be rotated to adjust the R axis to adapt to different groove angles.

5. The dual laser dual swing assisted MIG arc thick plate narrow gap welding method according to claim 2, characterized in that: In step S3, the relationship between the laser center distance d1, the laser swing amplitude h and the minimum distance d3 of the narrow gap groove side wall is: d1+2*h≈d4; d4>d3.

6. The dual laser dual swing assisted MIG arc thick plate narrow gap welding method according to claim 5, characterized in that: In step S3, the welding speed is set to 100-400 mm / min to ensure that the single-layer filling welding thickness reaches 5-8 mm.

7. The dual laser dual swing assisted MIG arc thick plate narrow gap welding method according to claim 1, characterized in that: In step S4, a CCD image monitoring system may be used to make adjustments based on real-time data.

8. A dual laser dual swing assisted MIG arc thick plate narrow gap welding device, characterized in that: The dual laser dual swing assisted MIG arc thick plate narrow gap welding method applied to any one of claims 1 to 7 comprises: A welding motion platform (1) for achieving precise positioning and stable motion during the welding process; A welding gun system (2) comprises: a first adjustment mechanism (201), a first welding gun (202), a second adjustment mechanism (203) and at least two second welding guns (204), wherein the first welding gun (202) is a MIG welding gun, and the second welding gun (204) is a laser welding gun; two sections of the first adjustment mechanism (201) are respectively connected to the first welding gun (202) and the welding motion platform (1); and two ends of the second adjustment mechanism (203) are respectively connected to the second welding gun (204) and the welding motion platform (1); A welding workpiece fixture (3) is arranged on the welding motion platform (1) and is used to fix a workpiece (4) to be welded, wherein the workpiece (4) is processed with a narrow gap groove (401); A protective cover (5) is used to cool the heat of the laser and the arc and to prevent the laser from reflecting and burning the upper parts; Image monitoring system for real-time monitoring of molten pool status and welding quality; A control system is used to control the coordinated movement of the welding motion platform (1) and the welding gun system (2), and dynamically adjust welding parameters according to data fed back by an image monitoring system.

9. The dual laser dual swing assisted MIG arc thick plate narrow gap welding device according to claim 8, characterized in that: The welding motion platform (1) comprises a base (101) and a motion component (102); the welding workpiece fixture (3) is arranged on the base (101); the motion component (102) is an XYZ three-axis motion device driven by a high-precision servo motor; the motion component (102) is used to control the precise positioning and stable movement of the welding gun system (2); a rotating shaft (103) is installed at the end of the motion component (102); the rotating shaft (103) is used to control the adjustment of the welding gun system (2) in a plane rotation direction.

10. The dual laser dual swing assisted MIG arc thick plate narrow gap welding device according to claim 8, characterized in that: The first adjustment mechanism (201) and the second adjustment mechanism (203) are mechanical structures or systems capable of achieving position adjustment on the X-axis, Y-axis, and Z-axis; the first adjustment mechanism (201) is used to adjust the position and angle of the first welding gun (202); and the second adjustment mechanism (203) is used to adjust the position and angle of the second welding gun (204).

Images