A heat source adjustable laser double-wire arc hybrid welding system and a variable gap thick plate component welding process

Abstract

The application discloses a heat source adjustable laser double-wire arc hybrid welding system and a variable-gap thick plate component welding process. The hybrid welding system comprises a laser, a double-wire arc welding system and a welding robot. The welding robot comprises a robot body, a robot end connecting piece and a welding assembly. The welding assembly is fixedly connected to the end of the welding robot through the robot end connecting piece. The welding assembly comprises a laser welding head and a double-wire welding gun. The laser welding head and the double-wire welding gun can form a heat source arrangement mode of laser guidance, double-wire and laser series connection or parallel connection. The application can adapt to self-adaptive welding of different welding seam assembly gaps. Laser is used in front guidance, double-wire is used in rear series connection or parallel connection with laser, the welding form can utilize the preheating effect of laser on the workpiece, effectively protect the arc welding electrode, improve the welding seam quality and reduce the workpiece welding deformation.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of welding technology, in particular to a laser double-wire composite welding system with adjustable heat source and a variable-gap thick plate component welding process. BACKGROUND

[0002] At present, the MIG / MAG multi-layer multi-pass welding arc welding process is generally used in heavy industry such as shipbuilding, and the production efficiency of the existing welding process has been increasingly unable to meet the needs of efficient welding production. Laser double-wire arc composite welding couples laser and double-wire arc two heat sources, which has the advantages of high energy density, strong penetration ability, low heat input, small welding deformation and no need to open the groove of laser welding, and the advantages of strong bridging ability of MIG / MAG welding joint, excellent weld forming and high weld metal deposition rate, and is particularly suitable for one-time welding forming of thick plate components.

[0003] Chinese patent CN 102069306A discloses a laser-double-wire pulse arc composite welding system, which comprises a first welding gun, a second welding gun, a laser source, a first welding machine, a second welding machine and a pulse coordination controller. The pulse coordination controller is used to coordinate and control the electrical signals output by the first welding machine and the second welding machine, so that the phase difference between the two is 70°-120°. The defects of this patent are mainly as follows: 1. The two arc welding guns can only be fixed at the two sides of the laser head with a relatively fixed posture and position, and the position matching between the double-wire arc heat source and the laser heat source during the welding process cannot be realized for different groove conditions, and the heat source arrangement mode cannot be adjusted; 2. The phase difference between the two arcs is 70-120°, the adjustment range is narrow, the weld quality and surface forming are poor, and the droplets are easy to splash.

[0004] Chinese patent CN 102225494A discloses a laser arc composite double-wire narrow groove welding method, which is realized by setting MSG arc and filler wire on the opposite sides of the laser beam, and then welding on the joint groove of the to-be-butted plate. The defects of this patent are mainly as follows: 1. The patent adds filler wire in front of the laser and MSG single arc in the rear of the laser, which is a simple composite of laser filler wire welding and single-wire arc welding, similar to common laser single-wire composite welding. Only the metal deposition rate is relatively improved, the gap bridging ability of single-pass welding is poor, and it cannot adapt to thick plate groove butt welding seam with large gap (maximum gap ≥15% of plate thickness); 2. There is one laser heat source and one arc heat source, and the relative position of the heat sources cannot be adjusted, and the gap tolerance for thick plate groove butt welding is poor.

[0005] Chinese patent CN 103753024A discloses a laser-double-wire indirect bypass electric arc composite welding method, which uses laser to bombard droplets to promote droplet transition, and also can heat the weld and adjust the heat input of the weld to control the weld forming. Two welding wires are sent by two wire feeders on both sides of the laser and above the workpiece, and the two welding wires are connected with two electrodes of an alternating current welding power source and an indirect electric arc is established. A reversing switch makes the main arc between the two welding wires and the workpiece alternately, and the reversing switch alternately reverses the current direction on the welding wire to realize the welding method of alternating bypass of the double-wire indirect electric arc, the welding method of laser and double-wire indirect electric arc composite, and the welding method of laser and double-wire indirect bypass electric arc composite. The main defects of the patent are: 1. The laser is mainly responsible for bombarding the droplets to promote the electric arc droplet transition, and secondly responsible for providing a small part of energy for the weld to heat the weld and improve the weld forming; the core is that the two welding wires are connected, the bypass electric arc between the two welding wires is alternately melted, the metal deposition efficiency is relatively low, and the relative position and combination form of the laser and the electric arc heat source cannot be adjusted.

[0006] In summary, the existing laser double-wire electric arc composite welding process has the following problems:

[0007] 1. The combined heat source is in a heat source series combination mode with the laser in the middle and the electric arc heat source on both sides, and the single-pass welding width is relatively narrow.

[0008] 2. The coupling mode of the two electric arc heat sources and the laser is fixed, and the position matching between the double-wire electric arc heat source and the laser heat source cannot be realized for different bevel conditions during the welding process, and the heat source arrangement mode cannot be adjusted.

[0009] 3. The phase difference between the two electric arcs is adjustable within a narrow range, the double-arc droplet transition interferes with each other, the droplet shedding timing between the two electric arcs cannot be accurately matched, and the welding process is unstable and has large spatter. SUMMARY

[0010] To solve the above technical problems, the present application provides a heat source adjustable laser double-wire electric arc composite welding system and a variable gap thick plate component welding process.

[0011] The technical solution adopted by the present application is:

[0012] A heat source adjustable laser double-wire electric arc composite welding system, comprising a laser, a double-wire electric arc welding system and a welding robot.

[0013] The welding robot comprises a robot body, a robot end connecting piece and a welding assembly; the welding assembly is fixedly connected to the end of the welding robot through the robot end connecting piece,

[0014] The welding assembly comprises a laser welding head, a rotating sleeve rotatably sleeved in the middle of the laser welding head, a first driving device for driving the rotating sleeve to rotate around a first axis, a double-wire welding gun synchronously connected with the rotating sleeve through a displacement table, and a second driving device fixedly installed on the displacement table and used for driving the double-wire welding gun to rotate around a second axis; the first axis is the axis of the laser welding head, and the first axis is parallel to the Z-axis of the robot base coordinate system; the second axis is the axis of the double-wire welding gun, and the angle between the second axis and the first axis is less than 90°; the displacement table is used for driving the double-wire welding gun to move up and down, left and right, and forward and backward on the back side of the laser welding head with the robot base coordinate system as the reference, so as to form a heat source arrangement mode in which the laser is guided, the double-wire is connected in series or in parallel with the laser.

[0015] The laser is used for providing a laser light source for the laser welding head; and the double-wire arc welding system is used for providing welding wires and a power source for the double-wire welding gun.

[0016] Further, a line laser vision system is further included, the line laser vision system comprising a vision sensor and a controller, the vision sensor being fixed on the robot end connecting piece, used for identifying and scanning the groove shape of the workpiece, and transmitting the scanning result to the controller, and the controller controlling the welding robot to perform adaptive welding.

[0017] Further, a water cooling machine is further included, the water cooling machine being used for cooling the laser and the laser welding head.

[0018] Further, the double-wire arc welding system comprises a first welding power source, a second welding power source, a first wire feeder, a second wire feeder, and a welding power source coupler, the first welding power source being connected with the first wire feeder through a cable, the second welding power source being connected with the second wire feeder through a cable, the first wire feeder and the second wire feeder being connected with the welding power source coupler through a cable, and the welding power source coupler being connected with the double-wire welding gun through a cable.

[0019] Further, the displacement table has three degrees of freedom along the first axis, the second axis and a third axis; and the third axis is parallel to the X-axis of the robot base coordinate system.

[0020] Further, the displacement table comprises a first screw rod transmission mechanism fixedly installed on the rotating sleeve along the direction of the first axis, a first connecting piece fixedly connected with a first nut of the first screw rod transmission mechanism, a second screw rod transmission mechanism fixedly installed on the first connecting piece along the direction of the third axis, a second connecting piece fixedly connected with a second nut of the second screw rod transmission mechanism, a third screw rod transmission mechanism fixedly installed on the second connecting piece along the direction of the second axis, and a third connecting piece fixedly connected with a third nut of the third screw rod transmission mechanism, the double-wire welding gun being rotatably installed on the third connecting piece through a bearing.

[0021] Further, the second driving device comprises a second servo motor fixedly installed on the third connecting piece along the second axis direction, a second gear fixedly sleeved on the double-wire welding gun, and a motor shaft gear meshedly connected with the second gear.

[0022] Further, the first driving device comprises a first servo motor fixedly installed on the robot end connecting assembly along the first axis direction, a first belt pulley fixedly sleeved on the rotating sleeve, a second belt pulley fixedly sleeved on the motor output shaft, and a synchronous belt connecting the first belt pulley and the second belt pulley.

[0023] A variable-gap thick plate member welding process using any one of the above heat source adjustable laser double-wire arc composite welding systems, specifically comprising the following steps:

[0024] (1) According to the plate thickness and the weld groove shape, the welding gun position, the defocusing amount, the heat source arrangement mode and the light wire spacing are determined, and the light wire spacing is the projection distance of the midpoint of the double-wire connection to the center of the laser spot on the workpiece surface;

[0025] (2) The workpiece to be welded is cleaned and fixed by spot welding before welding, the welding robot drives the welding assembly to the welding position, and the position relationship between the double-wire welding gun and the laser welding head is adjusted through the displacement table to achieve the set heat source arrangement mode and light wire spacing;

[0026] (3) According to the change amount of the weld gap, the welding process parameters are set in the controller of the line laser vision system, including: wire diameter, wire feed speed, welding voltage, welding current, welding speed of the welding gun, laser power, laser swing amplitude, laser swing frequency and heat source angle β1; The heat source angle β1 is the angle between the double-wire connection and the laser travel direction;

[0027] (4) Start the laser double-wire arc composite welding system for welding, during the welding process, the line laser vision system acquires the change amount of the weld gap of the workpiece in real time, and controls the welding robot to perform adaptive welding according to the set welding process parameters.

[0028] Further, when the double-wire and the laser are connected in series, the laser and the double-wire are in the same plane а1, the plane а1 is perpendicular to the workpiece, the double-wire welding gun is perpendicular to the workpiece, the laser is inclined to enter the workpiece, along the welding direction, the laser leads in front, the double-wire is arranged in front and behind the laser, and the heat source angle β1 is 0°;

[0029] When the double wires are in parallel with the laser, the laser is in plane a2, the double wires are in plane a3, the plane a3 is perpendicular to the workpiece, the angle between the plane a and the plane a3 is beta2, the double wire welding gun is perpendicular to the workpiece, the laser is obliquely shot into the workpiece, the intersection of the laser and the workpiece is C, the intersection of the double wires and the workpiece is A and B respectively, A point and B point are symmetrically distributed on the two sides of C point, along the welding direction, the laser is in front of the guide, the double wires are arranged left and right behind the laser, the angle of the heat sources is 0°<beta1<=90°.

[0030] The beneficial effects of the present application are:

[0031] (1) Compared with the current commonly used laser single wire arc composite welding system, the laser double wire arc composite welding of the present application has two welding arcs, which increases the heat input per unit time; secondly, multiple coupling exists between the arc and the arc, and between the arc and the laser, which increases the molten pool oscillation and improves the composition segregation of the molten pool metal; finally, the metal deposition rate of the double wire arc is greatly improved compared with the single arc, which makes the laser double wire arc composite weld more uniform and firm, and the weld quality is improved obviously.

[0032] (2) The present application adopts the welding form that the laser is in front of the guide, and the double wires are in series or parallel with the laser; first, the preheating effect of the laser on the workpiece can be utilized to effectively protect the arc welding electrode; second, the oxidation reaction in the welding process can be reduced, and the weld quality can be improved; third, the laser welding first forms a narrow and deep weld, and the arc fills the weld, the heat affected zone of the weld is narrow, and the workpiece welding deformation is small. Different heat source arrangement modes can adapt to different weld assembly gaps, the weld formed by the three heat sources in series mode is the narrowest, which is suitable for small gap welds, the weld formed by the three heat sources in parallel mode is wider, which is suitable for welds with larger gaps, and the angle between the double wires and the laser can be adjusted, the larger the angle, the wider the composite weld, when the angle is 90°, the composite weld is the widest, and the adaptability is wider.

[0033] (3) The double wire welding gun can be rotated around the shaft of the welding gun body and the laser welding head through the servo control of the two driving devices, and the position relationship between the double wire welding gun and the laser welding head can be controlled through the displacement table, which can improve the adjustment range of the double wire welding gun relative to the laser welding head, increase the matching and spatial arrangement mode of the heat sources, improve the coupling effect of the heat sources, and effectively improve the problems of weld undercut and sagging existing in laser single wire arc composite welding when welding thick plates with variable gaps.

[0034] (4) The laser double wire arc composite welding system provided by the present application matches the line laser vision system; has the function of adaptive welding of bevel; through the adaptive welding parameter library input in the online laser vision system, different plate thicknesses, blunt edges and gap sizes are input; during welding, the bevel size is scanned through the front line laser vision system, the driving device is automatically controlled to correct the deviation and real-time matching of the adaptive welding parameters, and the adaptive welding of the thick plate variable gap weld under the poor assembly condition can be realized. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the laser dual-wire arc hybrid welding system of the present invention.

[0036] Figure 2 This is a schematic diagram of the welding assembly structure of the present invention.

[0037] Figure 3 This is a schematic diagram of the robot end effector connector structure of the present invention.

[0038] Figure 4 This is a schematic diagram of the structure of the first driving device, the second driving device, and the displacement stage of the present invention.

[0039] Figure 5 This is a schematic diagram of the heat source arrangement of the present invention.

[0040] Figure 6 This is a schematic diagram of the adaptive welding process flow of Embodiment 2 of the present invention.

[0041] Figure 7 This is a front view of the weld in Example 1.

[0042] Figure 8 This is a reverse view of the weld in Example 1. Detailed Implementation

[0043] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0044] Example 1

[0045] See Figures 1-5 This embodiment provides a laser dual-wire electric arc hybrid welding system with adjustable heat source, including: fiber laser 1, water chiller 2, welding robot, dual-wire electric arc welding system 5 and line laser vision system 7.

[0046] The welding robot includes a robot body 4, a robot end effector 6, and a welding assembly 3. The welding assembly 3 includes a laser welding head 31, a rotating sleeve 32, a first drive device 33, a displacement stage 34, a twin-wire welding torch 36, and a second drive device 35. The twin-wire welding torch 36 is synchronously connected to the rotating sleeve 32 via the displacement stage 34. The twin-wire welding torch 36 and the rotating sleeve 32 are driven by the first drive device 33 to rotate around the axis of the laser welding head 31, i.e., the first axis. The twin-wire welding torch 36 is driven by the second drive device 35 to rotate around its own axis, i.e., the second axis, and is driven by the displacement stage 34 to move up and down, left and right, and forward and backward with the robot's coordinate system as a reference. The first axis is parallel to the Z-axis of the robot's coordinate system, and the angle between the second axis and the first axis is less than 90°.

[0047] In the embodiment, the robot end connecting piece 6 is composed of two parts of a robot connecting flange 61 and a welding assembly connecting seat; the robot connecting flange 61 is an aluminum alloy hollow cylinder structure, one end of which is fixedly connected to the six-axis end of the robot body 4, and the other end is fixedly connected to the welding assembly connecting seat through bolts. The welding assembly connecting seat adopts an aluminum alloy irregular frame structure, including a welding head mounting portion 62 and a line laser vision system mounting portion 63, and the line laser vision system mounting portion 63 is arranged below the welding head mounting portion 62.

[0048] The laser welding head 31 is fixedly installed on the welding head mounting portion 62 through screws, and the line laser vision system 7 is connected to the line laser vision system mounting portion 63 through a waist-shaped hole and bolts. During assembly, the bolts can freely slide in the waist-shaped hole, so as to finely adjust the relative positions of the laser vision system 7, the laser welding head 31 and the double-wire welding gun 36, so that the line laser vision system 7 has a suitable installation angle and a front distance. After the positions of the components are determined, the bolts are locked and fixed through nuts.

[0049] In the embodiment, as shown in Figure 2 The side surface of the laser welding head 31 is also fixedly connected to a welding head line groove 63 for placing a cooling water pipe and a compressed air pipe. The laser welding head 31 is a main execution mechanism of laser welding, and is preferably a swing welding head with a collimation focal length of 300 mm, a focusing focal length of 150 mm and a minimum spot diameter of output laser of 0.4 mm.

[0050] In the embodiment, the laser welding head 31 is sleeved with a rotating sleeve 32 outside the middle portion, and the rotating sleeve 32 is rotatably connected to the laser welding head 31 through a bearing. A first driving device 33 is fixedly installed on the welding head mounting portion 62, and is used to drive the rotating sleeve 32 to rotate around the axis of the laser welding head 31.

[0051] The first driving device 33 can adopt a belt driving mechanism or a gear driving mechanism, and in the embodiment, adopts a belt driving mechanism, including a first servo motor 331, a first belt pulley 333, a second belt pulley 332 and a synchronous belt 334. The first servo motor 331 is fixedly installed on the welding head mounting portion 62 along a first axis direction, the second belt pulley 332 is fixedly sleeved on the output shaft of the motor, and the first belt pulley 333 is fixedly sleeved on the lower end of the rotating sleeve. The first belt pulley 33 and the second belt pulley 332 are synchronously rotatably connected through the synchronous belt 334, and the first servo motor 331 drives the rotating sleeve 32 to rotate around the first axis through the belt.

[0052] The displacement table 34 has three degrees of freedom along the first axis, the second axis and the third axis; the third axis is parallel to the X axis of the robot base coordinate system. In the embodiment, the displacement table 34 comprises a fixing member, a first screw rod transmission mechanism 341, a first connecting member 342, a second screw rod transmission mechanism 343, a second connecting member 344, a third screw rod transmission mechanism 345 and a third connecting member 346; the first screw rod transmission mechanism 341, the second screw rod transmission mechanism 343 and the third screw rod transmission mechanism 345 each comprise a rotating hand wheel, a screw rod and a screw rod nut; the first connecting member 342, the second connecting member 344 and the third connecting member 346 each adopt a sliding block structure. The first screw rod transmission mechanism 341 is fixedly installed on the rotating sleeve 32 through the fixing member; the first screw rod is rotatably installed in the fixing member along the Z axis direction; the first screw rod nut is fixedly connected with the first connecting member 342; the second screw rod of the second screw rod transmission mechanism 343 is rotatably installed in the first connecting member 342 along the X axis direction; the second screw rod nut is fixedly connected with the second connecting member 344; the third screw rod of the third screw rod transmission mechanism 345 is fixedly installed on the second connecting member 344 along the second axis direction; the third screw rod nut is fixedly connected with the third connecting member 346; the double-wire welding torch 36 is rotatably installed on the third connecting member 346 through two bearings 361.

[0053] The second driving device 35 comprises a second servo motor 351, a second gear 352 and a motor shaft gear 353; the second servo motor 351 is fixedly installed on the third connecting member 346 along the second axis direction; the second gear 352 is fixedly sleeved on the double-wire welding torch 36 and is in meshing connection with the motor shaft gear 353.

[0054] The double-wire welding torch 36 can be driven to rotate around the first axis by the first servo motor 331; the rotation angle is preferably controlled within ±95°; when viewed from top to bottom, the welding torch rotates 95° clockwise, which is +95°, and rotates 95° counterclockwise, which is -95°. At the same time, the double-wire welding torch 36 can be driven to rotate around its own axis, i.e. the second axis, by the second servo motor 351; the rotation angle is preferably controlled within ±190°.

[0055] The relative position between the double-wire welding torch 36 and the laser welding head 31 can be adjusted through the first driving device 33, so that the double-wire welding torch always follows the laser spot on the weld.

[0056] The relative position between the double-wire welding torch 36 and the laser welding head 31 can be adjusted through the second driving device 35, so as to adjust the included angle between the double-wire connection line and the laser advancing direction, i.e. the heat source included angle β1, within the range of 0-90°, to realize series connection or parallel connection of the double-wire arc and the laser. Referring to Figure 5 , Figure 5 (a) for series connection of the double-wire arc and the laser, β1 is equal to 0°; Figure 5 (b) for parallel connection of the double-wire arc and the laser, β1 is equal to 30°; Figure 5(c) the double-arc is parallel to the laser, β1 is equal to 90°. Figure 5 In the figure, C is the intersection of the laser and the workpiece, A and B are the intersections of the front wire and the rear wire and the workpiece respectively, and D is the distance between the two wires.

[0057] The first screw rod transmission mechanism 341 is used to adjust the up-and-down movement of the double-wire welding gun 36 along the Z-axis direction, so as to adjust the distance between the welding wire and the workpiece plane.

[0058] The second screw rod transmission mechanism 343 is used to adjust the movement of the double-wire welding gun 36 along the X-axis direction, so as to adjust the relative position between the welding gun and the laser welding head 31, and make the laser spot be located on the perpendicular bisector of the double-wire line.

[0059] The third screw rod transmission mechanism 345 is used to adjust the left-and-right movement of the double-wire welding gun 36 along the Y-axis direction, so as to adjust the distance between the projection of the midpoint of the double-wire line on the workpiece surface and the center of the laser spot, i.e. the distance between the two wires.

[0060] In the embodiment, the robot body 4 is a six-axis robot. The welding assembly 3 is fixedly connected to the six-axis end of the welding robot 4 through the robot end connector 6. The fiber laser 1 is connected to the welding assembly 3 through an optical fiber, and is used to provide a laser light source for the laser welding head 31. The water chiller 2 is connected to the fiber laser 1 and the laser welding head 31 through pipelines, and is used to cool the laser 1 and the laser welding head 31.

[0061] The fiber laser 1 and the water chiller 2 are both prior art. In the embodiment, the fiber laser 1 is selected to have a rated laser output power of 12 kW, and has continuous and quasi-continuous laser output functions. The water chiller 2 is selected to have a rated refrigerating capacity of 25 kW. The water chiller 2 delivers cold water to the inside of the laser welding head, so as to cool the welding head and prevent overheating during long-time use.

[0062] The double-wire arc welding system 5 includes a first welding power source 51, a second welding power source 52, a first wire feeder 53, a second wire feeder 54, and a welding power source coupler 55. The first welding power source 51 is connected to the first wire feeder 53 through a cable, the second welding power source 52 is connected to the second wire feeder 54 through a cable, the first wire feeder 53 and the second wire feeder 54 are connected to the welding power source coupler 55 through a cable, and the welding power source coupler 55 is connected to the double-wire welding gun 36 through a cable. The double-wire welding gun 36 is a linear welding gun, and has two groups of electrically conductive nozzles at the end thereof, which are insulated from each other and are used to output two welding wires.

[0063] The welding power supply is prior art, which is responsible for providing energy required for welding, and can realize various welding functions such as direct current, pulse, variable polarity, etc.; the double-wire arc welding system connects two groups of welding power supplies through a welding power supply coupler, synchronously or asynchronously couples two arcs, coordinately controls the droplet transfer process of the two arcs, and makes the two arcs act on the same molten pool without mutual interference.

[0064] The line laser vision system 7 is prior art, which includes a vision sensor and a controller. The vision sensor is fixed on the robot end connector, used for identifying and scanning the groove shape of the workpiece, and transmitting the scanning result to the controller. The controller controls the welding robot to perform adaptive welding.

[0065] Preferably, the vision sensor adopts an infrared laser mode, the effective range of which is 88-182 mm, and the optimal range is 130 mm. The minimum weld gap that can be detected is 0.2 mm. The infrared laser mode can identify the weld feature points in offline mode, and can also identify the weld feature points, groove width, depth, gap, misalignment, cross-sectional area and other size information in online mode, match the groove parameter closed-loop control system, realize the autonomous calling and automatic adjustment of the welding process parameters under the condition of groove size change, and realize the laser scanning adaptive welding function. The controller is connected with the vision sensor, the first servo motor 331, the second servo motor 351, the fiber laser 1, the water cooler 2, the first welding power supply 51, the second welding power supply 52, the first wire feeder 53 and the second wire feeder 54.

[0066] Embodiment 2

[0067] Referring to Figure 6 , this embodiment provides a process method for adaptive welding of variable-gap thick plates by using the composite welding system of embodiment 1. Taking Q960 laser double-wire arc composite welding of Y-shaped groove butt weld with a plate thickness of 12 mm, a blunt edge of 8 mm, a single-side groove angle of 20°, a starting gap of 0 mm, a terminal gap of 3 mm and a linearly changing gap as an example, the specific steps are as follows:

[0068] For a plate thickness of 12 mm and a Y-shaped groove butt weld, the welding mode is determined as flat welding position, laser guidance and double-arc series arrangement. The welding wire diameter used for arc welding is 1.2 mm, and the welding protective gas is 82% Ar+18% CO2 mixed gas.

[0069] Step 1: Perform pre-welding cleaning and spot welding fixation on the components to be welded, and adjust the welding gun to the flat welding position.

[0070] Step 2: First, adjust the wire dry extension to 15 mm; second, adjust the displacement table to form a series arrangement of three heat sources with the laser in front and the two welding wires behind, and make the light-wire distance be 2-4 mm; finally, adjust the robot to make the laser head defocus amount be -2-0 mm.

[0071] Step 3: The position and angle of the line laser vision system 7 generally do not need to be adjusted, such as when the line laser vision system is interfered by a weld or a workpiece, the line laser needs to be calibrated again after adjusting the line laser vision system 7;

[0072] Step 4: According to the welding program, space points and weld trajectory points are taught. When teaching, two space safety points are needed before the arc starting point and after the arc ending point, and an additional space point is needed before the arc starting point for the line laser to dynamically search for the welding starting point, so as to ensure that the laser-arc composite head can effectively reach the welding arc starting position.

[0073] Step 5: Input the process parameters in Table 1 into the controller; do not turn on the arc and the laser, and test run the welding program; after confirming that the test run is correct, perform formal welding of the component. During the adaptive welding process, the controller automatically calls the welding parameters in Table 1 and adjusts in real time according to the weld gap detected by the vision sensor.

[0074] The appearance of the workpiece after welding is shown in Figure 7 and Figure 8 It can be seen from Figure 7 and Figure 8 that the front and back of the weld are well shaped, without undercut, incomplete penetration, and back hump defects, and the weld metal is well fused with the wood.

[0075] Table 1 Laser double-wire welding composite welding parameters of Example 2

[0076]

[0077] The above examples are typical embodiments of the present application, but the embodiments of the present application are not limited by the above examples. Any changes, substitutions, combinations, reconfigurations, simplifications made without departing from the spirit and principles of the present application shall be considered as equivalent replacement means and included in the protection scope of the present application.

Claims

1. A laser-coupled dual-wire electric arc hybrid welding system with adjustable heat source, characterized in that, Includes a laser (1), a dual-wire arc welding system (5), and a welding robot; The welding robot includes a robot body (4), a robot end connector (6), and a welding assembly (3); the welding assembly (3) is fixedly connected to the end of the robot body (4) via the robot end connector (6); The welding assembly (3) includes a laser welding head (31), a rotating sleeve (32) rotatably mounted in the middle of the laser welding head (31), a first drive device (33) for driving the rotating sleeve (32) to rotate around a first axis, a dual-wire welding torch (36) synchronously connected to the rotating sleeve (32) via a displacement stage (34), and a second drive device (35) fixedly mounted on the displacement stage (34) for driving the dual-wire welding torch (36) to rotate around a second axis; the first axis is the axis of the laser welding head (31), and the first axis is parallel to the Z-axis of the robot's base coordinate system; the second axis is the axis of the dual-wire welding torch (36), and the second axis is parallel to the Z-axis of the robot's base coordinate system. The included angle of the first axis is less than 90°; the displacement stage (34) is used to drive the twin-wire welding gun (36) to move up and down, left and right, and forward and backward on the back side of the laser welding head (31) with the robot base coordinate system as the reference, forming a heat source arrangement mode of laser guidance, twin wires and laser in series or parallel; when the twin wires and laser are in series, along the welding direction, the laser guides in front, and the twin wires are arranged back and forth behind the laser, and the included angle β1 of the heat source is 0°; when the twin wires and laser are in parallel, along the welding direction, the laser guides in front, and the twin wires are arranged left and right behind the laser, and the included angle of the heat source is 0°<β1≤90°; the included angle of the heat source β1 is the angle between the twin wire connection line and the laser travel direction; The laser (1) is used to provide a laser source for the laser welding head (31); the dual-wire arc welding system (5) is used to provide welding wire and power for the dual-wire welding gun (36).

2. The laser-coupled-wire hybrid welding system with adjustable heat source according to claim 1, characterized in that, It also includes a line laser vision system (7), which includes a vision sensor and a controller. The vision sensor is fixed on the robot end connector (6) and is used to identify and scan the bevel shape of the workpiece and transmit the scanning results to the controller. The controller controls the welding robot to perform adaptive welding.

3. A laser-coupled-wire hybrid welding system with adjustable heat source according to claim 1 or 2, characterized in that, It also includes a water chiller (2) used to cool the laser (1) and the laser welding head (31).

4. A laser-coupled-wire hybrid welding system with adjustable heat source according to claim 1 or 2, characterized in that, The dual-wire arc welding system (5) includes a first welding power source (51), a second welding power source (52), a first wire feeder (53), a second wire feeder (54), and a welding power coupler (55). The first welding power source (51) and the first wire feeder (53) are connected by a cable. The second welding power source (52) and the second wire feeder (54) are connected by a cable. The first wire feeder (53) and the second wire feeder (54) are connected to the welding power coupler (55) by a cable. The welding power coupler (55) is connected to the dual-wire welding torch (36) by a cable.

5. A laser-coupled-wire hybrid welding system with adjustable heat source according to claim 1 or 2, characterized in that, The displacement stage (34) has three degrees of freedom to move along the first axis, the second axis and the third axis; the third axis is parallel to the X-axis of the robot's base coordinate system.

6. The laser-coupled-wire hybrid welding system with adjustable heat source according to claim 5, characterized in that, The displacement stage (34) includes a first lead screw drive mechanism (341) fixedly mounted on the rotating sleeve (32) along the first axis direction, a first connecting member (342) fixedly connected to the first nut of the first lead screw drive mechanism, a second lead screw drive mechanism (343) fixedly mounted on the first connecting member along the third axis direction, a second connecting member (344) fixedly connected to the second nut of the second lead screw drive mechanism, a third lead screw drive mechanism (345) fixedly mounted on the second connecting member along the second axis direction, and a third connecting member (346) fixedly connected to the third nut of the third lead screw drive mechanism. The double wire welding gun (36) is rotatably mounted on the third connecting member (346) through a bearing (361).

7. The laser-coupled-wire hybrid welding system with adjustable heat source according to claim 6, characterized in that, The second drive unit (35) includes a second servo motor (351) fixedly mounted on a third connector (346) along the second axis, a second gear (352) fixedly mounted on a double wire welding gun (36), and a motor shaft gear (353) meshing with the second gear (352).

8. A laser-coupled-wire hybrid welding system with adjustable heat source according to claim 1 or 2, characterized in that, The first drive unit (33) includes a first servo motor (331) fixedly mounted on the robot end-connector assembly (6) along the first axis direction, a first pulley (333) fixedly mounted on the rotating sleeve (32), a second pulley (332) fixedly mounted on the motor output shaft, and a synchronous belt (334) connecting the first pulley (333) and the second pulley (332).

9. A welding process for a thick plate component with variable gap, characterized in that, The laser dual-wire electric arc hybrid welding system with adjustable heat source as described in claim 2 specifically includes the following steps: (1) Determine the welding torch position, defocusing amount, heat source arrangement and filament spacing according to the plate thickness and weld groove shape. The filament spacing is the projection distance from the midpoint of the double filament connection to the center of the laser spot on the workpiece surface. (2) Clean the components to be welded before welding and fix them with spot welding. The welding robot drives the welding assembly (3) to the welding position. The position relationship between the double wire welding gun (36) and the laser welding head (31) is adjusted by the displacement table (34) to achieve the set heat source arrangement and filament spacing. The filament spacing is the projection distance from the midpoint of the double wire connection line to the center of the laser spot on the workpiece surface. (3) Set welding process parameters in the controller of the online laser vision system (7) according to the change in weld gap, including: wire diameter, wire feed speed, welding voltage, welding current, welding speed of welding torch, laser power, laser oscillation amplitude, laser oscillation frequency and heat source angle β1; heat source angle β1 is the angle between the double wire connection line and the laser travel direction; (4) Start the laser dual-wire electric arc composite welding system to perform welding. During the welding process, the line laser vision system (7) acquires the change in the weld gap of the workpiece in real time and controls the welding robot to perform adaptive welding according to the set welding process parameters.

10. The welding process for variable gap thick plate components according to claim 9, characterized in that, When the twin wires and the laser are connected in series, the laser and the twin wires are in the same plane a1, the plane a1 is perpendicular to the workpiece, the twin wire welding gun is perpendicular to the workpiece, the laser is obliquely injected into the workpiece, along the welding direction, the laser guides in front, and the twin wires are arranged back and forth behind the laser, with the heat source angle β1 being 0°. When the twin wires and laser are connected in parallel, the laser is in plane a2, the twin wires are in plane a3, plane a3 is perpendicular to the workpiece, the angle between plane a2 and plane a3 is β2, the twin wire welding torch is perpendicular to the workpiece, the laser is obliquely injected into the workpiece, the intersection point of the laser and the workpiece is C, the intersection points of the twin wires and the workpiece are A and B respectively, points A and B are symmetrically distributed on both sides of point C. Along the welding direction, the laser guides in front, and the twin wires are arranged left and right behind the laser. The heat source angle is 0°<β1≤90°.

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