A laser welding device for heterogeneous metals

Abstract

The present invention relates to the field of laser welding technology, and specifically to a heterogeneous metal laser welding device, comprising a base, wherein the top of the base is set as a welding area. This heterogeneous metal laser welding device, through an intelligent airflow isolation system: adopts a spring-pressurized flexible baffle structure, which automatically adheres to the surface of the workpiece to form a dynamic seal during the welding process. A protective air curtain is established around the welding area, which allows cooling airflow to pass through the surrounding area to achieve overall cooling, and can effectively block airflow disturbances directly blowing toward the weld, through an adaptive weld tracking mechanism: when the welding gun performs a complex trajectory movement, the contact friction between the limit pad and the workpiece drives the entire protective frame to deflect synchronously. This mechanical tracking mechanism does not require additional sensors and control systems, and can adjust the baffle position in real time, so that the protection area always accurately covers the weld path. It is particularly suitable for irregular seams that are common in heterogeneous metal welding.

Description

Technical Field

[0001] The present invention relates to the technical field of laser welding, in particular to a heterogeneous metal laser welding device. Background Art

[0002] Laser welding of dissimilar metals is a key process for achieving complementary material performance advantages, with significant application value in aerospace, new energy vehicles, and other fields. The core contradiction faced by this technology stems from the significant differences in melting points, thermal conductivity, and thermal expansion coefficients of dissimilar materials. These differences can easily lead to metallurgical incompatibility and thermal stress concentration during welding, seriously affecting joint quality and service performance.

[0003] Regarding the currently common laser welding technology for heterogeneous metals, the following deficiencies still exist.

[0004] Insufficient dynamic protection: Traditional protection devices are difficult to adapt to complex weld trajectories, resulting in insufficient shielding gas coverage and the molten pool is susceptible to atmospheric contamination;

[0005] Real-time tracking lag: The existing tracking system has insufficient response speed, making it difficult to ensure accurate alignment of the laser focus and the weld during high-speed welding;

[0006] Thermal management imbalance: One-sided cooling exacerbates the thermal gradient at the interface of heterogeneous materials, inducing the formation of brittle phases and residual stress concentration.

[0007] In view of this, we propose a heterogeneous metal laser welding device. Summary of the Invention

[0008] The present invention aims to provide a heterogeneous metal laser welding device to address the issues of insufficient dynamic protection, delayed real-time tracking, and unbalanced thermal management raised in the aforementioned background art. To achieve the aforementioned objectives, the present invention provides the following technical solution: a heterogeneous metal laser welding device comprising a base, the top of the base being configured as a welding area, and the top of the base being fixedly provided with two first guide rails via columns, the first guide rail being provided with a second guide rail that moves laterally along the first guide rail, and the second guide rail being provided with a movable seat that moves longitudinally along the second guide rail;

[0009] A laser welding gun is provided on the movable seat for sliding in the up and down directions, and a rectangular structure frame is provided on the laser welding gun. Two sets of downward-blowing fans are symmetrically provided on the frame, and two baffles for blocking the airflow are symmetrically provided at the bottom of the frame. A spring is provided between the baffle and the frame, and the spring pushes the baffle down to the weldment.

[0010] Preferably, a ring seat is rotatably connected to the gun head of the laser welding gun, the frame is fixedly connected to the ring seat, and the ring seat is eccentrically connected along one end of the frame that deviates from the center position, a spring piece is fixedly provided at the bottom of the baffle, and the connection points of the spring piece and the ring seat are distributed oppositely, and a limit pad with friction resistance is fixedly provided at the contact end of the spring piece and the weldment.

[0011] Preferably, a through opening is provided on the surface of the baffle, and a flap is rotatably connected to the through opening through an axis rod, a through groove is provided on the surface of the flap for the laser to pass through, one end of the axis rod is fixedly connected to a lower cam that drives the flap to deflect, a micro motor is fixedly provided on the side of the baffle through a bracket, and an upper cam that intermittently pushes the lower cam is fixedly connected to the rotating shaft of the micro motor.

[0012] Preferably, a slot is provided on the ring seat, a buckle is fixedly provided on the frame, and the frame is fixed in the slot by means of a buckle and screws, and a notch is further provided on the ring seat for the buckle to be disengaged.

[0013] Preferably, the welding area is provided with a replaceable high-temperature resistant pad, and the surface of the pad is provided with a positioning groove that matches the contour of the heterogeneous metal weldment. The positioning groove on the surface of the pad matches the contour of the weldment to ensure that the heterogeneous metal weldment fits tightly, reducing welding misalignment. The pad can be quickly replaced to adapt to weldments of different shapes / sizes, thereby improving the versatility of the equipment. The high-temperature resistant pad isolates the high temperature of the molten pool, prevents thermal deformation of the base, and extends the life of the equipment. Replacing the pad can quickly clean the welding slag and reduce downtime.

[0014] Preferably, the movable seat is integrated with a laser positioning module, including a CCD camera and a cross laser pointer. The CCD camera captures the weld position in real time, and the cross laser pointer provides visual assistance to ensure that the laser focus is accurately aligned with the junction of heterogeneous metals. The welding path is corrected in real time through image feedback to reduce the scrap rate.

[0015] Preferably, the fan outlet is a tapered Venturi structure, and the baffle is embedded with a temperature sensor. The tapered Venturi structure accelerates the airflow and enhances the local cooling effect. The embedded temperature sensor monitors the temperature of the welding area in real time to avoid weld cracks due to uneven heat input (especially for heterogeneous metals with large differences in thermal sensitivity).

[0016] Preferably, a quick-detachable shielding gas nozzle is provided on the side of the frame. The nozzle angle can be adjusted by a universal joint. The universal joint adjusts the nozzle angle to ensure that the shielding gas accurately covers the molten pool and adapts to different welding directions. The quick-detach design facilitates cleaning of nozzle blockage or changing gas types (such as switching inert gas for aluminum / steel heterogeneous welding).

[0017] Preferably, an electromagnetic shielding layer is provided inside the base, and the shielding layer is made of Permalloy material. The Permalloy shielding layer blocks the high-frequency electromagnetic interference of the laser and ensures the signal stability of the control system (such as temperature sensor, positioning module).

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] This invention utilizes an intelligent airflow isolation system: a spring-loaded, flexible baffle structure that automatically conforms to the workpiece surface during welding, creating a dynamic seal. This system, through sophisticated airflow guidance, creates a protective air curtain around the weld area, allowing cooling air to flow through the surrounding area for overall cooling while effectively blocking air disturbances directly onto the weld.

[0020] This invention utilizes an adaptive seam tracking mechanism—an intelligent servo system based on friction transmission principles—to synchronize the deflection of the entire protective frame as the welding gun follows a complex trajectory, driven by the friction between the stop pad and the workpiece. This mechanical tracking mechanism, without the need for additional sensors or control systems, adjusts the baffle position in real time, ensuring that the protection zone always accurately covers the weld path. It is particularly well-suited for irregular seams commonly encountered in dissimilar metal welding.

[0021] This invention utilizes a dynamic alternating heat dissipation system: an innovative flap-type heat dissipation structure uses a cam mechanism to achieve periodic opening and closing, creatively dividing a single cooling area into two alternating heat dissipation channels. This design ensures continuous heat dissipation while avoiding the temperature gradient problems associated with traditional single-sided cooling. The system automatically adjusts the flap's frequency based on welding heat input, intelligently matching heat dissipation intensity with the welding process. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention;

[0023] Figure 2 For the present invention Figure 1 Enlarged view of point A in the middle;

[0024] Figure 3 Schematic diagram of the structure of the ring seat, frame and baffle of the present invention Figure 1 ;

[0025] Figure 4 Schematic diagram of the structure of the ring seat, frame and baffle of the present invention Figure 2 ;

[0026] Figure 5 For the present invention Figure 4 Enlarged view of point B in the middle;

[0027] Figure 6 An exploded view of the frame, baffle and flap of the present invention;

[0028] Figure 7 For the present invention Figure 6 Enlarged view of point C in the middle;

[0029] Figure 8 It is a structural schematic diagram of the flap in the deflected state of the present invention.

[0030] In the figure: 1. Base; 2. First guide rail; 3. Second guide rail; 4. Moving seat; 5. Laser welding gun; 6. Ring seat; 7. Frame; 8. Fan; 9. Baffle; 10. Spring; 11. Flip plate; 12. Through slot; 13. Limiting pad; 14. Slot; 15. Notch; 16. Buckle; 17. Micro motor; 18. Upper cam; 19. Lower cam. DETAILED DESCRIPTION

[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technical personnel in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0032] See also Figures 1 to 8 The present invention provides a technical solution: a heterogeneous metal laser welding device, including a base 1, the top of the base 1 is set as a welding area, and the top of the base 1 is fixed with two first guide rails 2 by a column, the first guide rail 2 is provided with a second guide rail 3, and the second guide rail 3 moves laterally along the first guide rail 2, and the second guide rail 3 is provided with a moving seat 4, and the moving seat 4 moves longitudinally along the second guide rail 3.

[0033] A laser welding gun 5 is provided on the movable seat 4 so as to slide in the up and down directions, and a rectangular frame 7 is provided on the laser welding gun 5. Two sets of downward-blowing fans 8 are symmetrically provided on the frame 7, and two baffles 9 for blocking the airflow are symmetrically provided at the bottom of the frame 7. A spring 10 is provided between the baffle 9 and the frame 7, and the spring 10 pushes the baffle 9 down to the weldment.

[0034] The laser welding gun 5 has a ring seat 6 rotatably connected to the gun head, and a slot 14 is provided on the ring seat 6. A buckle 16 is fixedly provided on the frame 7, and the frame 7 is fixed in the slot 14 by the buckle 16 and the screw. A notch 15 is also provided on the ring seat 6 for the buckle 16 to disengage.

[0035] The frame 7 is fixedly connected to the ring seat 6, and the ring seat 6 is eccentrically connected along one end of the frame 7 that deviates from the center position. A spring clip is fixedly provided at the bottom of the baffle 9, and the connection points between the spring clip and the ring seat 6 are distributed oppositely. A limit pad 13 with friction resistance is fixedly provided at the contact end of the spring clip and the weldment.

[0036] A through opening is provided on the surface of the baffle 9, and a flap 11 is rotatably connected to the through opening through a shaft. A through groove 12 is provided on the surface of the flap 11 for the laser to pass through. One end of the shaft is fixedly connected to a lower cam 19 that drives the flap 11 to deflect. A micro motor 17 is fixedly provided on the side of the baffle 9 through a bracket, and an upper cam 18 that intermittently pushes the lower cam 19 is fixedly connected to the rotating shaft of the micro motor 17.

[0037] Example 1: Welding device structure

[0038] The laser welding device comprises a cast iron base 1, the surface of which is provided with arrayed T-slots with a spacing of 50 mm.

[0039] The adjustable column is fixed vertically to the base 1 by a locking bolt, and the adjustment stroke is 200 mm and the accuracy is controlled within the range of ±0.5 mm.

[0040] The motion system uses a cross roller guide for X-axis movement with a travel of 300 mm. The Y-axis slide is connected to the X-axis guide rail via a linear slider, and the slide surface has an 8 mm diameter mounting hole.

[0041] The servo motor drives a 5mm lead ball screw with a repeatability of ±0.003mm.

[0042] The laser welding gun 5 is connected to the slide via a quick-change flange, and the flange locating pin is manufactured according to the G6 tolerance.

[0043] The floating buffer mechanism consists of two linear bearings with an inner diameter of 12 mm, a preload spring with an elastic coefficient of 8 Newton / mm ±5%, and a displacement sensor with a range of ±10 mm and a resolution of 0.01 mm.

[0044] Example 2: Dynamic Airflow Control System

[0045] The baffle 9 is made of a stainless steel plate with a thickness of 3 mm, and the working surface is polished to a surface roughness Ra of no more than 0.8 μm.

[0046] The bottom surface of the baffle 9 is vulcanized and bonded with a silicone rubber limiting pad 13 with a Shore hardness of 60HA and a thickness of 2 mm.

[0047] The flap 11 mechanism performs timing control: when the flap 9 is turned to an angle of 20 degrees in 0.8±0.1 seconds, it is kept for 1.2±0.2 seconds, and the closing action is completed in 2.0±0.1 seconds.

[0048] The centrifugal fan 8 has a power of 550 watts, and its air outlet is connected to a Venturi tube with a throat diameter of 25 mm. The rotation speed of the fan 8 is linearly related to the air flow velocity.

[0049] Example 3: Welding process

[0050] During operation, place the heterogeneous metal workpiece in the V-groove of the high-temperature resistant pad and apply a -0.08 MPa vacuum adsorption force to fix it. Call the preset parameters according to the material combination:

[0051] Copper-aluminum combination: laser power 2.8±0.2 kW, scanning speed 35±5 mm / s, defocus +1.5 mm.

[0052] Titanium-steel combination: laser power 3.6±0.3 kW, scanning speed 25±3 mm / s, defocus -0.8 mm.

[0053] During the dynamic control stage, when the temperature detected by the temperature sensor exceeds 350 degrees Celsius, the wind speed adjustment is increased by 0.05 meters per second for each degree Celsius deviation, and the maximum increase does not exceed 2.5 meters per second.

[0054] The use method and advantages of the present invention: When the heterogeneous metal laser welding device is in operation, the working process is as follows:

[0055] S1. The laser welding gun 5 is driven to move by the first guide rail 2 and the second guide rail 3 to process the dissimilar metal workpiece to be welded.

[0056] S2. During welding, the fan 8 blows down the workpiece to cool it down. During this process, the spring 10 pushes the baffle 9 to automatically press down and fit the workpiece surface, separating the welding point from the wind blowing area. In this way, while ensuring that the airflow cools the workpiece, it can also prevent the airflow from directly contacting the weld and affecting the welding effect.

[0057] S3. When the laser welding gun 5 switches between longitudinal and lateral movement, the friction resistance between the limit pad 13 and the workpiece pulls the baffle 9 and the frame 7 to deflect along the gun head, so that the direction of the weld is always between the two baffles 9, thereby preventing the baffle 9 from contacting the weld and affecting the welding effect.

[0058] S4. During welding, the micro motor 17 drives the upper cam 18 and intermittently pushes the lower cam 19 to periodically open and close the flap 11. The bottoms of the two baffles 9 fit the upper area of ​​the separated weld, and the weld is connected to the outside of the baffle 9. At this time, the airflow of the fan 8 cools the separated area along the inclined baffle 9. In this way, the deflection of the flap 11 is used to control the alternating connection between the weld and the two heat dissipation areas, thereby avoiding heat accumulation inside the baffle 9 and improving the heat dissipation efficiency of the weld area.

[0059] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely preferred examples of the present invention and are not intended to limit the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention, and such changes and modifications fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A heterogeneous metal laser welding device, characterized in that: include: A base (1) having a welding area on its top and two first guide rails (2) fixed thereto via uprights; The second guide rail (3) is slidably disposed on the first guide rail (2), and the movable seat (4) is slidably disposed on the second guide rail (3); The laser welding gun (5) is slidably mounted on the movable seat (4), and its gun head is rotatably connected to the ring seat (6); The frame (7) is eccentrically fixed to the ring seat (6), and is symmetrically provided with two sets of downward-blowing fans (8) and a bottom baffle (9), and the baffle (9) is press-connected to the weldment through a spring (10); The baffle (9) is provided with a flap (11) controlled by a cam mechanism on its surface, and a through slot (12) is provided on its working surface for the laser beam to pass through; A limiting pad (13) with friction resistance is provided at the bottom of the baffle (9); The ring seat (6) is provided with a slot (14) and a notch (15), and the frame (7) is detachably fixed by a buckle (16); The deflection angle of the flap (11) is 0°-20°; The cam mechanism comprises an upper cam (18) driven by a micro motor (17) and a lower cam (19) connected to a shaft of the flap (11).

2. The heterogeneous metal laser welding device according to claim 1, characterized in that: The welding area is provided with a replaceable high-temperature resistant backing plate, and the surface of the backing plate is provided with a positioning groove that matches the contour of the heterogeneous metal weldment.

3. The heterogeneous metal laser welding device according to claim 1, characterized in that: The moving seat (4) is integrated with a laser positioning module, comprising a CCD camera and a cross laser indicator.

4. The heterogeneous metal laser welding device according to claim 1, characterized in that: The air outlet of the fan (8) is a tapered Venturi structure, and the baffle (9) is embedded with a temperature sensor.

5. The heterogeneous metal laser welding device according to claim 1, characterized in that: A quick-detachable protective gas nozzle is provided on the side of the frame (7), and the angle of the nozzle can be adjusted by a universal joint.

6. The heterogeneous metal laser welding device according to claim 1, characterized in that: An electromagnetic shielding layer is provided inside the base (1).

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