A dual-beam laser welding device and method

Abstract

The present invention relates to a dual-beam laser welding device and method, belonging to the field of material processing engineering, and comprising a structured light sensor, a front-side laser control system, a rear-side laser control system, a front-side laser, a rear-side laser, and a galvanometer system; the structured light sensor is arranged at the starting position of the welding joint of the base body, and the front-side laser control system is respectively connected to the structured light sensor and the front-side laser; the rear-side laser control system is respectively connected to the structured light sensor and the rear-side laser; the galvanometer system is arranged on the output optical paths of the front-side laser and the rear-side laser; the rear-side laser and the front-side laser are sequentially arranged along the welding direction; the present invention can achieve high-quality connection of complex structural parts that are difficult to weld by conventional lasers, and achieve the comprehensive control purpose of simultaneously reducing the porosity of the weld seam, improving the working condition adaptability, and improving the weld seam forming quality.

Description

Technical Field

[0001] The present invention relates to the field of material processing engineering, and particularly to a dual-beam laser welding device and method. Background Art

[0002] As a type of high-energy beam welding, laser welding has technical characteristics such as concentrated energy density and precise control of welding energy, and is widely used in the precision welding of thin-walled structural parts. However, this method has extremely high requirements for the assembly of workpieces, which is a technical bottleneck restricting the engineering application of this technology under complex working conditions. In recent years, with the continuous increase in the output power of lasers, it has become possible to apply this technology in the field of medium and thick plates. However, the assembly accuracy of large medium and thick plate structural parts is a more demanding challenge for laser welding, which is also a technical problem that urgently needs to be solved in the application of high-power laser welding in the field of medium and thick plates. Summary of the Invention

[0003] The object of the present invention is to provide a dual-beam laser welding device and method to achieve high-quality connection of complex structural parts that are difficult to weld by conventional lasers, and to achieve the comprehensive regulation purpose of simultaneously reducing the porosity of the weld seam, improving the working condition adaptability, and improving the weld formation quality.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] A dual-beam laser welding device includes: a structured light sensor, a front-side laser control system, a rear-side laser control system, a front-side laser, a rear-side laser, and a galvanometer system;

[0006] The structured light sensor is arranged at the starting position of the welding joint of the base body, and the structured light sensor is used to detect the gap and misalignment information at the starting position of the welding joint; the front-side laser control system is respectively connected to the structured light sensor and the front-side laser; the front-side laser control system is used to adjust the welding parameters of the front-side laser according to the gap and misalignment information detected by the structured light sensor; the rear-side laser control system is respectively connected to the structured light sensor and the rear-side laser; the rear-side laser control system is used to adjust the welding parameters of the rear-side laser according to the gap and misalignment information detected by the structured light sensor;

[0007] The galvanometer system is arranged on the output optical paths of the front-side laser and the rear-side laser, and the galvanometer system is used to adjust the swing of the output laser of the front-side laser and the rear-side laser; the rear-side laser and the front-side laser are arranged in sequence along the welding direction; the front-side laser and the rear-side laser are both used to melt the base body.

[0008] Optionally, the galvanometer system includes a front-side laser galvanometer system and a rear-side laser galvanometer system; the front-side laser galvanometer system includes a front-side laser X galvanometer system and a front-side laser Y galvanometer system; the front-side laser X galvanometer system and the front-side laser Y galvanometer system are sequentially arranged on the laser output optical path of the front-side laser; the rear-side laser galvanometer system includes a rear-side laser X galvanometer system and a rear-side laser Y galvanometer system; the rear-side laser X galvanometer system and the rear-side laser Y galvanometer system are sequentially arranged on the laser output optical path of the rear-side laser.

[0009] Optionally, the front-side laser X galvanometer system includes a front-side laser X swinging lens and a front-side laser X motor arranged on the front-side laser X swinging lens; the front-side laser Y galvanometer system includes a front-side laser Y swinging lens and a front-side laser Y motor arranged on the front-side laser Y swinging lens.

[0010] Optionally, the rear-side laser X galvanometer system includes a rear-side laser X swinging lens and a rear-side laser X motor arranged on the rear-side laser X swinging lens; the rear-side laser Y galvanometer system includes a rear-side laser Y swinging lens and a rear-side laser Y motor arranged on the rear-side laser Y swinging lens.

[0011] Optionally, the dual-beam laser welding device further includes a front-side laser reflecting lens and a rear-side laser reflecting lens;

[0012] The front-side laser reflecting lens is arranged between the front-side laser and the front-side laser X galvanometer system; the rear-side laser reflecting lens is arranged between the rear-side laser and the rear-side laser X galvanometer system.

[0013] Optionally, the dual-beam laser welding device further includes a front-side laser focusing lens and a rear-side laser focusing lens;

[0014] The front-side laser focusing lens is arranged between the front-side laser Y galvanometer system and the substrate; the rear-side laser focusing lens is arranged between the rear-side laser Y galvanometer system and the substrate.

[0015] Optionally, the dual-beam laser welding device further includes a front-side laser protection air pipe and a rear-side laser protection air pipe;

[0016] The front-side laser protection air pipe is arranged at the contact position between the laser focused by the front-side laser focusing lens and the substrate; the rear-side laser protection air pipe is arranged at the contact position between the laser focused by the rear-side laser focusing lens and the substrate.

[0017] A dual-beam laser welding method provided by the present invention, the dual-beam laser welding method uses the dual-beam laser welding device described in any one of the above, and the dual-beam laser welding method includes:

[0018] Obtain the gap information and misalignment information at the starting position of the welded joint detected by the structured light sensor;

[0019] Determine process parameters according to the gap information and misalignment information by using a process matching model;

[0020] Control the front laser, rear laser and galvanometer system to perform fusion welding on the substrate respectively according to the welding parameters in the process parameters.

[0021] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0022] The present invention includes: a structured light sensor, a front laser control system, a rear laser control system, a front laser, a rear laser and a galvanometer system; the structured light sensor is arranged at the starting position of the welded joint of the substrate, and the structured light sensor is used to detect the gap information and misalignment information at the starting position of the welded joint; the front laser control system is respectively connected with the structured light sensor and the front laser; the front laser control system is used to adjust the welding parameters of the front laser according to the gap information and misalignment information detected by the structured light sensor; the rear laser control system is respectively connected with the structured light sensor and the rear laser; the rear laser control system is used to adjust the welding parameters of the rear laser according to the gap information and misalignment information detected by the structured light sensor; the galvanometer system is arranged on the output optical paths of the front laser and the rear laser, and the galvanometer system is used to adjust the swing of the output laser of the front laser and the rear laser; the rear laser and the front laser are arranged in sequence along the welding direction; both the front laser and the rear laser are used to melt the substrate. The present invention realizes high-quality connection of complex structural parts that are difficult to weld by conventional lasers through the independent cooperative control of the process parameters of two light beams by the front laser control system and the rear laser control system, and achieves the comprehensive control purpose of simultaneously reducing the porosity of the weld seam, improving the working condition adaptability and improving the weld forming quality. Description of the Drawings

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0024] Figure 1 It is a schematic structural diagram of the dual-beam laser welding device provided by the present invention.

[0025] Symbolic Explanation:

[0026] 1 - Front - side laser, 2 - Rear - side laser, 3 - Front - side laser reflection lens, 4 - Rear - side laser reflection lens, 5 - Front - side laser X - axis motor, 6 - Rear - side laser X - axis motor, 7 - Front - side laser Y - axis motor, 8 - Rear - side laser Y - axis motor, 9 - Front - side laser X - axis swing lens, 10 - Rear - side laser X - axis swing lens, 11 - Front - side laser Y - axis swing lens, 12 - Rear - side laser Y - axis swing lens, 13 - Front - side laser focusing lens, 14 - Rear - side laser focusing lens, 15 - Substrate, 16 - Front - side laser protection air pipe, 17 - Rear - side laser protection air pipe, 18 - Structured light. Detailed Implementation Manner

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0028] The object of the present invention is to provide a dual - beam laser welding device and method to achieve high - quality connection of complex structural parts that are difficult to weld by conventional lasers, and to achieve the comprehensive control objectives of simultaneously reducing the porosity of the weld seam, improving the working condition adaptability, and improving the weld formation quality.

[0029] To make the above - mentioned objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific implementation manners.

[0030] As Figure 1 shown, a dual - beam laser welding device provided by the present invention includes: a structured light sensor, a front - side laser control system, a rear - side laser control system, a front - side laser, a rear - side laser, and a galvanometer system.

[0031] The structured light sensor is arranged at the starting position of the welding joint of the substrate 15. The structured light sensor is used to detect the gap and misalignment information at the starting position of the welding joint. The front - side laser control system is respectively connected to the structured light sensor and the front - side laser. The front - side laser control system is used to adjust the welding parameters of the front - side laser according to the gap and misalignment information detected by the structured light sensor. The rear - side laser control system is respectively connected to the structured light sensor and the rear - side laser. The rear - side laser control system is used to adjust the welding parameters of the rear - side laser according to the gap and misalignment information detected by the structured light sensor. The structured light sensor obtains the gap and misalignment information by acquiring the structured light 18.

[0032] The galvanometer system is arranged on the output optical paths of the front laser and the rear laser. The galvanometer system is used to adjust the swing of the output laser of the front laser and the rear laser. The rear laser and the front laser are arranged in sequence along the welding direction. Both the front laser and the rear laser are used to melt the substrate 15. The front laser is used to generate the front laser 1, and the rear laser is used to generate the rear laser 2.

[0033] The galvanometer system includes a front laser galvanometer system and a rear laser galvanometer system. The front laser galvanometer system includes a front laser X galvanometer system and a front laser Y galvanometer system. The front laser X galvanometer system and the front laser Y galvanometer system are arranged in sequence on the laser output optical path of the front laser. The rear laser galvanometer system includes a rear laser X galvanometer system and a rear laser Y galvanometer system. The rear laser X galvanometer system and the rear laser Y galvanometer system are arranged in sequence on the laser output optical path of the rear laser.

[0034] The front laser X galvanometer system includes a front laser X swing lens 9 and a front laser X motor 5 arranged on the front laser X swing lens 9. The front laser Y galvanometer system includes a front laser Y swing lens 11 and a front laser Y motor 7 arranged on the front laser Y swing lens 11.

[0035] The rear laser X galvanometer system includes a rear laser X swing lens 10 and a rear laser X motor 6 arranged on the rear laser X swing lens 10. The rear laser Y galvanometer system includes a rear laser Y swing lens 12 and a rear laser Y motor 8 arranged on the rear laser Y swing lens 12.

[0036] The front laser X galvanometer system, the front laser Y galvanometer system, the rear laser X galvanometer system, and the rear laser Y galvanometer system are all a group of independent galvanometer systems. They can realize the swing of the front and rear lasers driven by the coded motor and complete the expected beam swing trajectory.

[0037] In practical applications, the dual-beam laser welding device further includes a front laser reflection lens 3 and a rear laser reflection lens 4. The front laser reflection lens 3 is arranged between the front laser and the front laser X galvanometer system. The rear laser reflection lens 4 is arranged between the rear laser and the rear laser X galvanometer system. The front laser reflection lens 3 and the rear laser reflection lens 4 are both used for correcting the beam propagation path.

[0038] In practical applications, the dual-beam laser welding device further includes a front-side laser focusing mirror 13 and a rear-side laser focusing mirror 14; the front-side laser focusing mirror 13 is disposed between the front-side laser Y galvanometer system and the substrate 15; the rear-side laser focusing mirror 14 is disposed between the rear-side laser Y galvanometer system and the substrate 15. The front-side laser focusing mirror 13 and the rear-side laser focusing mirror 14 are both focusing lenses for converging light beams.

[0039] In practical applications, the dual-beam laser welding device further includes a front-side laser protection gas pipe 16 and a rear-side laser protection gas pipe 17; the front-side laser protection gas pipe 16 is disposed at the contact position between the laser focused by the front-side laser focusing mirror 13 and the substrate 15; the rear-side laser protection gas pipe 17 is disposed at the contact position between the laser focused by the rear-side laser focusing mirror 14 and the substrate 15. The front-side laser protection gas pipe 16 and the rear-side laser protection gas pipe 17 are both for protecting the liquid molten pool from being polluted by external gases.

[0040] The present invention also provides a dual-beam laser welding method, which applies the above-mentioned dual-beam laser welding device, and the dual-beam laser welding method includes:

[0041] Obtain the gap and misalignment information at the starting position of the welded joint detected by the structured light sensor.

[0042] Determine the process parameters according to the gap and misalignment information by using the process matching model.

[0043] Control the front-side laser, the rear-side laser and the galvanometer system to perform fusion welding on the substrate respectively according to the welding parameters in the process parameters.

[0044] A laser welding method with the oscillation processes of two beams being co-controllable proposed by the present invention first formulates the welding process parameters of each beam according to key factors such as the physical properties of the welded metal material, the material size, and the welding joint alignment quality (gap and misalignment), including laser power, defocus amount, oscillation mode, oscillation direction, oscillation frequency, oscillation radius, and the distance between the two beams. The alignment quality before welding is automatically detected for the gap and misalignment information by the structured light sensor, and then the structured light sensor transmits the information to the process matching model for automatic adaptation and selection to achieve the autonomous matching of the welding process parameters. Through the autonomous co-control of the process parameters of the two beams, high-quality connection of complex structural parts that are difficult to weld by conventional lasers is achieved, and the comprehensive control objectives of simultaneously reducing the porosity of the weld seam, improving the working condition adaptability, and improving the weld forming quality are achieved.

[0045] The collaborative control refers to separately setting the position parameters and process parameters of two light beams to achieve the purpose of comprehensively regulating the welding quality of a weld seam. According to different welding quality requirements and actual working conditions, the collaborative control strategies include but are not limited to the following: ① In the case of poor fit-up quality of the test plate (generally, good fit-up quality means that the misalignment is between -0.3 and +0.3; the gap is between 0 and 0.2 mm), the process matching model will increase the swing amplitude of the front light beam to improve the adaptability to the gap and misalignment, and at the same time reduce the swing amplitude of the rear light beam to improve the penetration ability of the laser, so as to achieve high-quality laser welding of medium and thick plates in a harsh working condition environment; ② When the fit-up quality is good (poor fit-up quality means that the misalignment is < -0.3 mm, or > -0.3 mm; the gap > 0.2 mm), the process matching model will reduce the swing amplitude of the front light beam to improve the ability of the front light beam to melt materials, and use the front light beam to achieve single-sided welding with double-sided forming, while the rear light beam can increase the swing amplitude to improve the uniformity of the back formation of the weld seam; ③ By controlling the different laser swing directions of the front gun and the rear gun, it is possible to reversely change to make up for the asymmetric characteristics of the weld seam morphology caused by the difference in the molten pool flow direction, so as to improve the weld formation quality; ④ According to the optimal thermal cycle requirements of the welded joint and the welding process parameters, calculate the thermal cycle history at different positions of the weld seam and the heat affected zone under the different thermal cycles of the two light beams, and then determine the distance between the two light beams to achieve the regulation of the weld seam structure; ⑤ Through the implementation of the above measures, the combined regulation of the weld formation quality and the weld seam structure type is realized, so as to achieve the purpose of combined regulation of the shape / property of the welded joint.

[0046] The welding process parameters mainly refer to laser power, defocus amount, swing mode, swing direction, swing frequency, swing radius and the distance between the two light beams, etc. The swing mode of the laser beam includes but is not limited to circular swing, linear swing and "8"-shaped swing, etc., and also includes any swing method customized by an editable oscillation method. The swing frequency refers to the number of swings in each complete cycle per second; the swing radius refers to the distance from the center of the swing trajectory to the edge position of the swing trajectory.

[0047] A dual-beam laser welding method with collaborative control during the oscillation process, the execution process of which includes the following key steps:

[0048] Step 1: First, use a structured light sensor to obtain the gap and misalignment information at the starting position of the welded joint, judge the actual effect of the weld joint fit-up according to the gap and misalignment information of the weld joint fit-up, and transmit the weld joint fit-up effect to the process matching model.

[0049] Different groups of pairing effects correspond to different jointing qualities: better jointing quality (generally, better jointing quality means that the offset is between -0.3 and +0.3; the gap is between 0 and 0.2 mm); relatively poor jointing quality (relatively poor jointing quality means that the offset is < -0.3 mm or > -0.3 mm; the gap > 0.2 mm).

[0050] Input the physical properties and material dimensions of the metal material into the process matching model.

[0051] The physical properties of the material mainly refer to the viscosity of the liquid metal. The higher the viscosity of the liquid metal, the greater the resistance during flow; the material dimensions mainly refer to the thickness and width of the material. The thickness is the main factor affecting the laser power, and the width and thickness together determine the heat dissipation rate during the welding process of the material.

[0052] The process matching model automatically matches the optimal recommended process parameters according to the physical properties of the metal material, material dimensions, and weld jointing quality. The optimal recommended process parameters include the front-side laser power, oscillation mode, oscillation frequency, oscillation amplitude, oscillation direction, defocus amount, and welding speed. Before welding, input the material dimensions and material type into the expert database with a pre-judgment function first. The pre-mounted optical sensor will automatically detect the jointing quality (groove gap, offset) at different positions of the weld. Based on the above information, the expert database will adaptively match the process parameters. Among them, the process matching model is an expert database with a pre-judgment function. Based on the matched optimal recommended process parameters, according to the amount of offset and gap size, the model will adjust the three parameter values of the oscillation amplitude, oscillation frequency, and laser power in a linear interpolation manner between the sample data. In the database, the sample interval of the laser power is 100 W, the sample interval of the oscillation frequency is 5 HZ, and the sample interval of the oscillation amplitude is 0.2 mm.

[0053] Step 2: According to the optimal recommended process parameters, respectively set the defocus amounts f1 and f2 of the front-side laser and the rear-side laser in the controller, the oscillation frequencies F1 and F2, the oscillation amplitudes A1 and A2, the oscillation directions, and the corresponding laser powers P1 and P2, the welding speed V, and the distance L between the front-side laser and the rear-side laser. The distance L between the front-side laser and the rear-side laser has nothing to do with the weld forming quality, but only serves to regulate the heat input at different weld positions during the welding process. The gas flow rate is a basic welding parameter and will not be adjusted during the welding process after being fixed.

[0054] Step 3: According to the starting point position of the sample welding, respectively set the start-stop signals of the front-side laser and the rear-side laser as they change along with the welding trajectory.

[0055] The start signals of the front-side laser and the rear-side laser are at the same position, and the end signals are also triggered at the same position.

[0056] Step 4: Check whether the working states of the front laser and the rear laser of the device are normal.

[0057] Check whether the working state of the laser is normal. The working state is viewed through the self-alarm device of the laser. If there is no alarm signal, it is normal.

[0058] Check that the warning signal of the device control panel or the central control unit is normal. If the warning signal is normal, prepare for welding; if the signal is abnormal, after troubleshooting, prepare for welding.

[0059] Step 5: Start the device and start welding. The controller controls the traveling mechanism to weld according to the predetermined weld path. During the welding process, the butt joint data obtained by the structured light sensor will be transmitted to the process matching model in real time. The process matching model will adaptively select and match parameters according to the obtained data. During this process, according to the weld data during welding, the swing amplitude and laser power of the front laser and the rear laser are adjusted through their respective control systems, and other process parameters remain unchanged. The structured light sensor is located in front of the main welding torch in the welding direction. Detect the butt joint data of the welded joint, such as misalignment and gap. There is no connection between the front and rear lasers, and there is no connection between the swing amplitude and power of the same laser, which are all related to the actual welding situation and are adjusted according to the specific situation.

[0060] Step 6: After welding is completed, reset the signal and the welding torch returns to the starting position.

[0061] When welding reaches the end point, the opening signals of the front laser and the rear laser are reset, the welding equipment stops running, and the traveling mechanism brings the welding torch back to the starting position.

[0062] The present invention has the following remarkable technical advantages:

[0063] 1. To a great extent, it solves the technical problem that traditional single-laser welding has high requirements for misalignment and gap during butt joint and can only be limited to the welding of small precision parts, and further expands the application range of laser welding technology in engineering to the efficient and high-quality connection of large-size and complex components.

[0064] 2. Under the condition that the structured light sensor accurately obtains the butt information, based on the process matching model obtained from a large amount of test data, it can well identify and recommend the best welding process for each weld, completely achieving "tailor-made", and thus making the finished product rate of the welded product infinitely close to 100%.

[0065] 3. The front laser and the rear laser both have independent control systems. The gap and misalignment information automatically detected by the structured light sensor are calculated through the process matching model, and the parameters that need to be corrected are passed to the control systems of the two lasers respectively for adaptive adjustment of the welding parameters. The welding parameters of the two beams can be adjusted flexibly and autonomously. They can be adjusted separately under different welding conditions, such as large misalignment and large gap conditions. In terms of quality control of the entire weld, they can perform coordinated control on the basis of completing their respective tasks, realize joint control of the overall weld quality improvement, and meet flexible production needs.

[0066] 4. When the gap and misalignment are large, increase the swing amplitude of the front beam, reduce its melting depth, expand the melting volume of the shallow metal of the structural part to be welded, and minimize the influence of the misalignment and gap on the laser welding quality, providing a good foundation for full penetration welding under small swing amplitude of the rear laser. When the gap and misalignment are small and meet the laser welding requirements, the swing amplitude of the front laser can be reduced to achieve single-sided welding and double-sided forming. When the swing amplitude of the rear laser is increased, the weld formation quality of the front laser welding can be improved by controlling the swing direction, and the surface forming quality of the weld can be improved.

[0067] 5. Technological pores, which lack the ability to float in liquid metal and remain in the upper middle portion of the weld, are a major technical challenge that urgently needs to be addressed in laser welding. In this invention, a certain amount of pores remain in the weld after solidification by front-side laser welding. The secondary melting effect of the rear-side laser further releases these pores, achieving pore-free welding. This improves weld density, increases the weld's stress-bearing area, and further enhances the weld's overall serviceability.

[0068] 6. In terms of welding quality control, by reasonably setting different welding parameters of the front and rear beams, not only can the stirring effect of single laser oscillating welding on the molten pool be brought into play, the porosity can be reduced, and the homogeneity of the weld can be improved, but the coordinated oscillation control of the two beams can also compensate for the impact of the oscillation of a single beam on the directional flow of the high-temperature liquid molten pool, effectively improving the surface forming quality of the weld and solving the technical problem of asymmetric fusion line inside the weld.

[0069] 7. According to the optimal thermal cycle requirements of the material of the structural part to be welded and the heat transfer characteristics of the structural part, by adjusting the laser power and heat source spacing of the two beams, the thermal cycle process of different areas of the structural part welding joint can be controlled, achieving preheating-free welding, reducing welding processes, and playing a role in reducing costs and increasing efficiency in production. It can also improve the microstructure characteristics and enhance the comprehensive mechanical properties of the weld.

[0070] 8. Through the coordinated control of frequency, swing amplitude, heat source spacing and swing direction, the grains that have been nucleated in the mushy area close to the solidification temperature inside the molten pool can be broken, so as to achieve the effect of refining the grains and comprehensively improving the strength and toughness of the weld.

[0071] The present invention also provides two specific embodiments:

[0072] Embodiment 1:

[0073] Taking the butt joint component of high-strength steel Q960E for construction machinery as an example, the component has a thickness of 8 mm, a length of 12000 mm, and a width of 700 mm, and the weld has a type I groove. The specific implementation steps are as follows:

[0074] Step 1: After the workpiece is assembled, use a structured light sensor to obtain that the gap of the welded joint during assembly is between 0.3 - 2.2 mm, and the misalignment is between 0.5 - 1.8 mm. The process matching model automatically matches the optimal recommended process parameters according to the assembly information and material information.

[0075] Step 2: According to the optimally recommended process parameters, set the front laser defocus amount to +5 mm, the rear laser defocus amount to -2 mm, the front laser oscillation frequency F1 to 100 HZ, the rear laser oscillation frequency to 70 HZ, the front laser oscillation amplitude A1 to 5 mm, the rear laser oscillation amplitude A2 to 2 mm, the front laser oscillation direction to forward oscillation, the rear laser oscillation direction to reverse oscillation, the front laser power P1 to 5 kW, the rear laser power P2 to 7.5 kW, the welding speed V to 1.2 m / min, the distance L between the front laser and the rear laser to 80 mm, the front laser gas flow rate Q1 to 25 L / min, and the rear laser gas flow rate Q2 to 30 L / min.

[0076] Step 3: According to the characteristics of the welded sample, set the start and stop signals of the front laser and the rear laser when they change along with the welding trajectory respectively. The start signals of the front laser and the rear laser are at the same position, and the trigger of the end signal is also at the same position.

[0077] Step 4: Check whether the working state of the device laser is normal.

[0078] Step 5: Start the device and start welding.

[0079] Step 6: After welding is completed, reset the signal and the welding torch returns to the starting position.

[0080] When the butt joint gap reaches 2.0 mm and the misalignment reaches about 1.5 mm, the conventional laser welding method cannot meet the welding quality requirements. Moreover, the investment cost of the laser-arc hybrid welding equipment is relatively high, and the heat input is relatively higher than that of laser welding. The dual-beam laser welding method with synergistic autonomous control during the oscillation process effectively solves the technical problems of poor butt joint quality, difficult control of weld formation, high welding heat input, and large porosity inside the weld. When using this method for welding, the thermal cycle process is calculated in advance and measured on-site. Without additional preheating, crack-free welding is achieved, and most of the weld microstructure consists of acicular bainite, with excellent tissue properties. Compared with the conventional arc welding method, the welding efficiency of this method is increased by 280%, the tensile strength of the weld is increased by 5%, the impact energy of the weld is increased by 12%, and the wire consumption is reduced by 52%.

[0081] Implementation Case 2:

[0082] Taking 5A06 aluminum alloy as an example, the component is a long straight weld. The component has a thickness of 6 mm, a length of 3500 mm, and a width of 400 mm. The welding groove is machined and designed as a type I groove. The specific implementation steps are as follows:

[0083] Step 1: After the workpiece butt joint, use a structured light sensor to obtain the butt joint gap of the welding joint as 0 - 0.3 mm and the misalignment as 0 - 0.2 mm. The weld butt joint quality is relatively good. The process matching model automatically matches the optimal recommended process parameters according to the butt joint information and material information.

[0084] Step 2: According to the optimal recommended process parameters, set the front-side laser defocus amount to +3 mm, the rear-side laser defocus amount to +10 mm, the front-side laser oscillation frequency F1 to 100 HZ, the rear-side laser oscillation frequency to 80 HZ, the front-side laser oscillation amplitude A1 to 2.4 mm, the rear-side laser oscillation amplitude A2 to 8 mm, the front-side laser oscillation direction to forward oscillation, the rear-side laser oscillation direction to reverse oscillation, the front-side laser power P1 to 6.5 kW, the rear-side laser power P2 to 4.5 kW, the welding speed V to 0.8 m / min, the distance L between the front-side laser and the rear-side laser to 40 mm, the front-side laser gas flow rate Q1 to 35 L / min, and the rear-side laser gas flow rate Q2 to 40 L / min.

[0085] Step 3: According to the characteristics of the welding sample, set the start-stop signals of the front-side laser and the rear-side laser when they change along the welding trajectory. The start signals of the front-side laser and the rear-side laser are at the same position, and the trigger of the end signal is also at the same position.

[0086] Step 4: Check whether the laser equipment of the device is normal.

[0087] Step 5: Start the device and start welding.

[0088] Step 6: The welding is completed, the signal is reset, and the welding torch returns to the starting position.

[0089] The groove of the aluminum alloy structural part has good quality after machining and can directly meet the requirements of laser welding. Therefore, the swing amplitude of the laser on the front side is small, and single-sided welding with double-sided formation is achieved under a suitable laser power. The swing amplitude of the laser on the rear side is large, and the swing direction is opposite to that of the front side laser. Under a suitable laser power, the penetration depth is controlled at about 3.0 mm, which not only compensates for the problem that the formation of the laser weld on the front side is biased to one side, but also uses the large swing effect to well eliminate the pores that have not successfully overflowed in the upper and middle parts of the weld, achieving pore-free welding of the aluminum alloy welded joint.

[0090] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. For the same or similar parts between the various embodiments, reference can be made to each other.

[0091] Specific examples are used in this article to elaborate on the principles and implementation manners of the present invention. The descriptions of the above embodiments are only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, based on the idea of the present invention, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A dual-beam laser welding device, characterized in that, Including: A structured light sensor, a front laser control system, a rear laser control system, a front laser, a rear laser, and a galvanometer system; The structured light sensor is arranged at the starting position of the welded joint of the base body, and the structured light sensor is used to detect the gap and misalignment information at the starting position of the welded joint; the front laser control system is respectively connected to the structured light sensor and the front laser; the front laser control system is used to adjust the welding parameters of the front laser according to the gap and misalignment information detected by the structured light sensor; the rear laser control system is respectively connected to the structured light sensor and the rear laser; the rear laser control system is used to adjust the welding parameters of the rear laser according to the gap and misalignment information detected by the structured light sensor; The galvanometer system is arranged on the output light paths of the front laser and the rear laser, and the galvanometer system is used to adjust the swing of the output laser of the front laser and the rear laser; the rear laser and the front laser are arranged in sequence along the welding direction; both the front laser and the rear laser are used to melt the base body; According to the different welding quality requirements and actual working conditions, the cooperative control strategy includes: ① When the butt joint quality of the test plate does not meet the set requirements, increase the swing amplitude of the output laser beam of the front laser, and at the same time reduce the swing amplitude of the output laser beam of the rear laser; ② When the butt joint quality of the test plate meets the set requirements, reduce the swing amplitude of the output laser beam of the front laser and increase the swing amplitude of the output laser beam of the rear laser; ③ Control the swing directions of the output laser beams of the front laser and the rear laser to be different to change the directional flow of the high-temperature liquid molten pool; ④ Based on the thermal cycle requirements of the welded joint and the welding process parameters, obtain the distance between the output laser beams of the front laser and the rear laser to achieve the regulation of the weld microstructure.

2. The double-beam laser welding device according to claim 1, wherein The galvanometer system includes a front laser galvanometer system and a rear laser galvanometer system; the front laser galvanometer system includes a front laser X galvanometer system and a front laser Y galvanometer system; the front laser X galvanometer system and the front laser Y galvanometer system are arranged in sequence on the laser output light path of the front laser; the rear laser galvanometer system includes a rear laser X galvanometer system and a rear laser Y galvanometer system; the rear laser X galvanometer system and the rear laser Y galvanometer system are arranged in sequence on the laser output light path of the rear laser.

3. The double-beam laser welding device according to claim 2, wherein, The front laser X galvanometer system includes a front laser X swing lens and a front laser X motor arranged on the front laser X swing lens; the front laser Y galvanometer system includes a front laser Y swing lens and a front laser Y motor arranged on the front laser Y swing lens.

4. The double-beam laser welding device according to claim 2, wherein The rear laser X galvanometer system includes a rear laser X swing lens and a rear laser X motor arranged on the rear laser X swing lens; the rear laser Y galvanometer system includes a rear laser Y swing lens and a rear laser Y motor arranged on the rear laser Y swing lens.

5. The double-beam laser welding device according to claim 2, wherein It further includes a front laser reflection lens and a rear laser reflection lens; The front laser reflection lens is arranged between the front laser and the front laser X galvanometer system; the rear laser reflection lens is arranged between the rear laser and the rear laser X galvanometer system.

6. The double-beam laser welding device according to claim 2, characterized in that, It further includes a front laser focusing lens and a rear laser focusing lens; The front laser focusing lens is arranged between the front laser Y galvanometer system and the substrate; the rear laser focusing lens is arranged between the rear laser Y galvanometer system and the substrate.

7. The double-beam laser welding device according to claim 6, characterized in that, It further includes a front laser protection air pipe and a rear laser protection air pipe; The front laser protection air pipe is arranged at the contact position between the laser focused by the front laser focusing lens and the substrate; the rear laser protection air pipe is arranged at the contact position between the laser focused by the rear laser focusing lens and the substrate.

8. A dual-beam laser welding method, characterized in that, The dual-beam laser welding method uses the dual-beam laser welding device according to any one of claims 1-7, and the dual-beam laser welding method includes: Obtaining the gap and misalignment information at the starting position of the welded joint detected by the structured light sensor; Determining the process parameters according to the gap and misalignment information by using the process matching model; Controlling the front laser, the rear laser and the galvanometer system to perform fusion welding on the substrate respectively according to the welding parameters in the process parameters.

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