Laser welding equipment compatible with multi-size square-shell battery cells

Abstract

The utility model discloses laser welding equipment compatible with multi-size square shell battery cells, and belongs to the field of new energy automobile power battery manufacturing. The equipment comprises a gantry type three-axis servo system, a laser ranging system, a robot and galvanometer control system, a visual positioning system and a copper nozzle pressing mechanism. The gantry three-axis servo system drives the copper nozzle to realize X, Y and Z three-dimensional movement; the laser ranging system detects the surface height of a battery cell pole and feeds back deviation, and automatic calibration of a welding focus is achieved in cooperation with the robot; the robot is used for coarse positioning of a welding head, and the galvanometer control system is used for achieving high-speed fine scanning of light beams. The visual positioning system consists of a CCD (Charge Coupled Device) camera and an AI (Artificial Intelligence) image processing module, and is used for identifying the position of a battery cell pole and correcting welding deviation; the copper nozzle pressing mechanism is driven by an air cylinder to achieve flexible pressing. The equipment can be adapted to square shell battery cells of different sizes, automatic positioning, distance measurement and welding integrated operation is achieved, and the welding precision and the production efficiency are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of laser welding technology, and in particular to a laser welding equipment and method suitable for manufacturing power batteries for new energy vehicles, compatible with multi-size prismatic cells, which can achieve high-precision and high-efficiency automated welding of aluminum bars and cell terminals. Background Technology

[0002] Currently, in the production of power battery modules for new energy vehicles, the welding of aluminum bars and terminals of prismatic cells generally adopts a combination of traditional tooling positioning and laser welding. Existing technology suffers from the following problems: poor compatibility, requiring frequent tooling changes when cell sizes vary, leading to low equipment utilization and increased costs; insufficient positioning accuracy, as manual or mechanical positioning is easily affected by deviations in the cell terminal position, resulting in welding misalignment and decreased yield; and low automation, requiring multiple steps of manual intervention during the clamping, positioning, and welding processes, resulting in low efficiency. Summary of the Invention

[0003] The purpose of this invention is to provide a laser welding equipment compatible with multiple sizes of square-shell battery cells, achieving a fully automated process and high welding precision.

[0004] The copper nozzle clamping mechanism includes a pressure plate, a copper nozzle, and a drive cylinder. The pressure plate is connected to the cylinder via a floating joint, and a spring at the bottom enables adaptive clamping. The copper nozzle is threaded to the end of the pressure plate. The cylinder stroke is adjustable to accommodate clamping requirements of aluminum bars of different thicknesses.

[0005] The laser ranging system is used to detect the height of the battery cell electrode surface in real time and feed the deviation value back to the robot control system in real time. The robot automatically compensates for the height difference to complete the welding focus calibration and ensures that the laser focusing position is consistent with the welding surface.

[0006] The visual positioning system includes a CCD camera and an AI image processing module. The AI ​​module is connected to the control system via Ethernet. The AI ​​module uses a deep learning algorithm based on convolutional neural networks to extract features and calculate offsets from the polar image, and outputs correction parameters to the welding path planning system. The welding path planning system adjusts the motion trajectory of the robot and the galvanometer in real time based on the compensation data to ensure that the weld center is aligned with the target point.

[0007] The air knife system includes an angle adjustment mechanism, which consists of an adjusting screw and a fixing screw. The adjusting screw is installed at one end of the air knife support rod, and its rotation allows the air knife outlet angle to be continuously adjusted within the range of 0° to 45°. The fixing screw is used to lock the angle position after adjustment to adapt to the dust exhaust direction requirements of different welding areas.

[0008] The gantry-type three-axis servo system includes linear modules arranged along the X, Y, and Z directions. Each module consists of a servo motor, a lead screw, and a slider guide rail. The main controller coordinates the spatial positioning and trajectory movement of the copper nozzle. The X and Y axes of the gantry-type three-axis servo system can adjust the horizontal dimension of the worktable, and the Z axis can adjust the height of the worktable via a servo to adapt to the welding requirements of square-shell battery cells within the range of 50mm to 200mm.

[0009] According to a preferred embodiment, five sets of mounting holes are provided on the upper part of the robot flange fixing plate (1), and the mounting holes are rigidly connected to the flange of the robot (23) by a set of high-strength bolts; a guide boss is provided at the bottom of the flange fixing plate, and the guide boss slides in cooperation with the guide groove of the galvanometer fixing plate (2) to achieve precise positioning.

[0010] According to a preferred embodiment, the side of the fixing plate is provided with a locking bolt, which is connected to the galvanometer locking block (17).

[0011] According to a preferred embodiment, one end of the fiber fixing rod (3) is fixed to the side wall of the galvanometer fixing plate (2) by a locking nut, and the other end is connected to the fiber fixing block (4) by a floating connector; the floating connector allows the fiber axial displacement of ±0.1mm to avoid mechanical stress causing optical path deviation.

[0012] According to a preferred embodiment, the outlet end of the air knife (7) is sealed to the air knife air pipe connector (8) through a threaded interface, and the threaded interface is sealed with an O-ring to ensure airtightness.

[0013] According to a preferred embodiment, the air knife flow meter (9) is installed in series at the rear end of the air knife air pipe connector (8), and the flow meter housing is equipped with a digital display to display the airflow parameters in real time.

[0014] According to a preferred embodiment, a camera light source (13) is distributed in a ring around the lens of the camera (12), and the light source is connected to the camera housing by a bolt structure, which supports quick replacement and angle adjustment.

[0015] According to a preferred embodiment, the laser rangefinder (15) probe is fixed in the groove of the rangefinder fixing block (14) through a threaded interface, supporting adjustment along the axial position of the welding head.

[0016] According to a preferred embodiment, the galvanometer (16) is embedded in the slot of the galvanometer locking block (17) and locked by a wing bolt.

[0017] According to a preferred embodiment, the reinforcing rib (31) is welded to the column of the gantry bracket (19) to reinforce the structure and improve the load-bearing stability of the gantry bracket; the column of the gantry bracket is bolted to the crossbeam (30) through a flange; the top crossbeam is connected to the gantry frame (28) through a high-strength bolt group.

[0018] According to a preferred embodiment, the robot (23) is bolted to the robot base (25) via a flange, and the end flange is connected to the robot flange fixing plate (1) via a damping gasket.

[0019] According to a preferred embodiment, one end of the drag chain (26) is fixed to the side wall of the linear module (27), and the other end is connected to the control cabinet through a bracket. The internal wiring channel accommodates air pipes and cables.

[0020] According to a preferred embodiment, the servo motor (29) is directly connected to the lead screw of the linear module (27) via a coupling, and the motor base is fixed to the gantry frame (28) by vibration damping pads.

[0021] According to a preferred embodiment, the pressure plate (34) is driven by a cylinder and linked with the connecting plate (33), and the bottom is adaptively pressed by a spring, which adapts to the undulations of the cell electrode surface.

[0022] According to a preferred embodiment, the copper nozzle (35) is installed at the end of the pressure plate (34) via a threaded interface, and has a dust suction duct inside.

[0023] According to a preferred embodiment, the mounting plate (32) is connected to the upper linear module guide rail via a slider mechanism, and the surface is provided with an array of threaded holes to support the rapid installation of extended functional modules. Detailed Implementation

[0024] To better understand and implement this invention, the technical solutions in the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Taking the welding of a 150mm square-shell battery cell as an example:

[0025] Initial position: Adjust the positioning of the Pack tray (20) and lower the Z-axis of the linear module to the position that is compatible with the 150mm battery cell.

[0026] Visual positioning: The robot (23) moves the CCD camera (12) above the cell to capture the electrode image and calculate the offset in the X / Y direction.

[0027] Pressing and ranging: Based on the offset calculated by vision, the linear module (27) moves the XY axis to the top of the cell electrode post, the linear module drives the copper nozzle (35) to press down the aluminum bar, and the laser rangefinder (15) measures the height of the electrode post surface and feeds back the Z-axis compensation value to the robot.

[0028] Welding execution: The galvanometer (16) adjusts the laser path according to the offset data and completes the weld seam welding at a scanning speed of 300 mm / s. The air knife (7) blows away the fumes at a flow rate of 15 L / min.

[0029] Cyclic operation: The linear module (27) drives the welding copper nozzle (35) to move to the next station and repeat the above process.

[0030] Beneficial effects

[0031] The technical solutions of the embodiments of the present invention have at least the following advantages and beneficial effects:

[0032] 1. High compatibility: Adaptable to prismatic battery cells ranging from 50mm to 200mm through adjustable positioning mechanism and multi-axis coordinated control;

[0033] 2. Improved accuracy: Dual calibration of visual positioning and laser ranging ensures welding position deviation ≤0.1mm;

[0034] 3. Efficiency optimization: The entire process is automated, reducing the welding cycle time to 2 seconds per piece, and achieving a yield rate of over 99.5%;

[0035] 4. Process stability: The air knife system can effectively blow away the fumes and dust in the welding area, control the range of the heat-affected zone of welding, and avoid damage to the battery cells due to high temperature. Attached Figure Description

[0036] Figure 1 Schematic diagram of the overall structure of the equipment;

[0037] Figure 2 Schematic diagram of visual positioning system module and laser rangefinder;

[0038] Figure 3 Schematic diagram of air knife and protective cover;

[0039] Figure 4 : A magnified view of a portion of the galvanometer welding head;

[0040] Figure 5 Schematic diagram of welding workbench and positioning mechanism.

[0041] Icons: 1. Robot flange mounting plate; 2. Galvanometer mounting plate; 3. Fiber optic mounting rod; 4. Fiber optic mounting block; 5. Air knife mounting block; 6. Air knife support rod; 7. Air knife; 8. Air knife air pipe connector; 9. Air knife flow meter; 10. Mounting base plate; 11. Camera mounting plate; 12. Camera; 13. Camera light source; 14. Rangefinder mounting block; 15. Laser rangefinder; 16. Galvanometer; 17. Galvanometer locking block; 18. Water-cooled field mirror barrel; 19. Gantry bracket; 20. Pack tray; 21. Connecting flange; 22. Manifold; 23. Robot; 24. Pipeline column; 25. Robot base; 26. Cable chain; 27. Linear module; 28. Gantry frame; 29. ​​Servo motor; 30. Crossbeam; 31. Reinforcing rib; 32. 33. Mounting plate; 34. Connecting plate; 35. Pressure plate; 36. Copper nozzle.

Claims

1. A laser welding apparatus compatible with multiple size prismatic cells, characterized by, The system includes a gantry-type three-axis servo system, a laser ranging system, a CCD camera and AI image processing module, and an air knife system. The gantry-type three-axis servo system integrates a copper nozzle clamping mechanism, and its height can be adjusted via the Z-axis, while the horizontal dimensions of the worktable can be adjusted via the X and Y axes to accommodate the welding positioning requirements of various sizes of prismatic battery cells. The laser ranging system is used to detect the surface height of the battery cell electrode in real time. The CCD camera and AI image processing module work together to achieve visual positioning of the battery cell electrode. The air knife system is used for fume removal in the welding area.

2. The apparatus of claim 1, wherein, The copper nozzle clamping mechanism includes a pressure plate and a copper nozzle. The pressure plate is driven by a cylinder to achieve flexible clamping between the aluminum bar and the battery cell electrode.

3. The apparatus of claim 1, wherein, The laser ranging system feeds back the height deviation of the detection pole to the robot control system in real time. The robot automatically compensates for the height difference to complete the welding focus calibration, ensuring that the laser focusing position is consistent with the welding surface.

4. The apparatus of claim 1, wherein, The CCD camera of the visual positioning system is communicatively connected to the AI ​​image processing module. The AI ​​image processing module corrects the positioning deviation of the battery cell electrode in real time through deep learning algorithms and synchronizes the compensation data to the welding path planning system.

5. The apparatus of claim 1, wherein, The air knife system further includes an angle adjustment mechanism, which is composed of an adjusting screw and a fixing screw. The angle adjustment mechanism can adjust the air knife outlet direction according to the welding position to ensure maximum dust removal efficiency.

6. The apparatus of claim 1, wherein, The gantry-type three-axis servo system adopts a three-axis linkage adjustment method of X, Y, and Z. Its horizontal dimension adjustment stroke of the X and Y axes and the height adjustment stroke of the Z axis are adapted to the welding requirements of square battery cells in the range of 50mm~200mm.

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