Laser flyover welding of a waterproof nut

Abstract

The application provides a laser flying welding waterproof nut device and relates to the field of laser welding. The laser flying welding waterproof nut device comprises a placing table, the placing table is provided with a moving unit which is freely movable in three mutually perpendicular directions in space, a last free end of the moving unit is provided with a laser welding unit, the laser welding unit adopts a galvanometer scanning system, the placing table is provided with a positioning unit which is positioned from top to bottom in at least two directions and establishes a coordinate system which is uniform with the moving unit. The laser flying welding waterproof nut device, the moving unit is responsible for "going to the position", and the galvanometer is responsible for "completing the welding". The slide rail remains stationary during the welding process, thereby ensuring the welding stability; and the galvanometer is high-speed scanned in the macro range, thereby ensuring the welding speed.

Description

Technical Field

[0001] This invention relates to the field of laser welding, specifically to a laser flying welder for waterproof nuts. Background Technology

[0002] Welding waterproof nuts is a common process used in industries such as automotive, communication equipment, and hardware to achieve threaded connections and seals. Traditional welding methods include: Resistance spot welding: Welding is performed by applying pressure and electricity to electrodes. Disadvantages include the need for electrodes to contact the workpiece, high electrode wear, spot-like weld points, limited sealing, and low efficiency.

[0003] Argon arc welding (TIG): High heat input, resulting in severe welding deformation.

[0004] If manual laser welding is used, the laser welding gun is operated manually to weld point by point. The disadvantages are that it depends on the operator's skill level, the weld consistency is poor, and the speed is slow. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a laser flying welder for waterproof nuts, which solves the problems mentioned in the background section.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a laser flying welder for waterproof nuts, comprising a placement platform, wherein the placement platform is provided with three moving units that can move freely in mutually perpendicular directions within a space, and a laser welding unit is provided at the final free end of each moving unit. The laser welding unit employs a galvanometer scanning system. The placement platform is provided with positioning units that form a positioning from top to bottom in at least two directions and establishes a coordinate system unified with the moving units. The workpiece and the waterproof nut are located in this coordinate system. The positioning units, moving units, and laser welding units are jointly controlled by a control system.

[0007] Preferably, the air knife includes an air outlet biased to one side, and the air knife includes cleaning the welding surface with air before welding and cleaning the passing surface with air during movement.

[0008] Preferably, it includes an image recognition unit for identifying welding characteristics and welding defects.

[0009] Preferably, a welding database is established based on the material and diameter of the waterproof nut. The database includes at least the welding heat transfer range and cooling time.

[0010] Preferably, the laser welding unit moves synchronously with the air knife, welding multiple weld points on the workpiece in sequence, selecting the position of the subsequent weld point to be welded so that the heat transfer range generated by the welding of the previous weld point is staggered. When the air knife moves with the welding device as the air blowing and slag removal device moves, the air knife stops blowing when the moving path of the air blowing and slag removal device reaches the heat transfer range corresponding to the weld point and within the cooling time.

[0011] Preferably, the image recognition unit moves synchronously with the laser welding unit, and during the movement, it identifies defects in the weld that has been completed and cooled.

[0012] Preferably, the path of the laser welding unit is to establish a molten pool along the welding plane, and during the forward movement, it turns back and moves back at most half the distance of the forward movement, repeating the action until the laser welding unit trajectory fills the circumference of the waterproof nut.

[0013] Preferably, the path of the laser welding unit is to establish a molten pool along the welding plane, melt the nut obliquely upward in the direction of establishment, and then break the line to the molten pool plane, repeating the action until the laser welding unit trajectory fills the circumference of the nut.

[0014] Preferably, the workpiece mounting position is provided with a through hole equal to the inner diameter of the waterproof nut, the workpiece surface is provided with a recess with a diameter larger than the flange of the waterproof nut, the waterproof nut is provided with a fixing pin inside to limit the extrusion deformation of the waterproof nut and the workpiece, the fixing pin includes a circumferentially arranged elastic element, the elastic element is provided with a protrusion inside, the middle of the elastic element is slidably connected to an extrusion part, the extrusion part moves upward to extrude the elastic element and cause the elastic element to bulge outward, the top end of the extrusion part extends to the top of the elastic element and is provided with a snap-fit ​​groove, the top end of the elastic element is provided with an elastic snap-fit ​​part snapping into the snap-fit ​​groove.

[0015] Preferably, at least two placement platforms are provided, and the movement range of the moving unit covers both placement platforms.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. This laser flying-shaped welding equipment for waterproof nuts uses a moving unit responsible for "moving to position" and a galvanometer responsible for "scanning and completing the weld." The slide rail remains stationary during the welding process, ensuring welding stability; the galvanometer scans at high speed within a micro-range, ensuring welding speed.

[0017] 2. The laser flying-shaped welding equipment for waterproof nuts includes a fixing pin comprising a circumferentially arranged elastic element. The elastic element has a protrusion inside, and a pressing part is slidably connected to the middle of the elastic element. The pressing part moves upward to press the elastic element, causing the elastic element to bulge outward. The top of the pressing part extends above the elastic element and is provided with a snap-fit ​​groove. The top of the elastic element is provided with an elastic snap-fit ​​part that snaps into the snap-fit ​​groove. Through this technical solution, the elastic deformation of the elastic element can be used to quickly position the waterproof nut and the workpiece, avoiding the displacement of the waterproof nut during the welding process and causing misalignment.

[0018] 3. This laser-guided welding equipment for waterproof nuts uses a laser welding unit that establishes a molten pool along the welding plane. During its forward movement, it reverses direction and travels at least half the distance of its initial advance, repeating this motion until the laser welding unit's trajectory fills the circumference of the waterproof nut. The moving unit is responsible for vertical movement, and the change in the plane of the galvanometer scanning system creates a three-dimensional welding path. This three-dimensional approach increases the area of ​​the waterproof nut that is melted and participates in the welding process. Simultaneously, the top-to-bottom movement agitates the weld pool, accelerating gas expulsion. The repeated forward and backward movement increases the time for the weld pool to melt, facilitating gas expulsion and ensuring the weld's seal.

[0019] 4. In this laser flying-shaped welding waterproof nut equipment, the laser welding unit moves synchronously with the air knife, welding multiple weld points on the workpiece in sequence. The position of the subsequent weld point is selected so that the heat transfer range generated by the welding of the previous weld point is staggered. Although the heat generated by laser welding is relatively small, continuous heating will cause thermal deformation of the workpiece. Therefore, the welding sequence is adjusted. The larger the welding diameter, the larger the heat radiation area and the greater the adaptability of the cooling time.

[0020] 5. In this laser flying welder for waterproof nuts, the air knife stops blowing as the air-blowing and slag-removing device moves with the welding device. Once the air-blowing and slag-removing device reaches the heat transfer range corresponding to the weld point and within the cooling time, the air knife stops blowing. During its movement, the air knife removes welding slag with high-speed airflow, carrying away heat in the process. Rapid cooling of the weld point without natural cooling leads to stress concentration, making it prone to cracking later, resulting in seal failure and water leakage. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the placement platform of the present invention; Figure 3 This is a schematic diagram of the moving unit of the present invention; Figure 4 This is a schematic diagram of the laser welding unit connection of the present invention; Figure 5 This is a schematic diagram of the structure of the present invention; Figure 6 This is a schematic diagram of a welding path according to the present invention; Figure 7 This is a partial schematic diagram of another welding path according to the present invention.

[0022] In the diagram: 1. Placement platform; 2. Moving unit; 4. Laser welding unit; 5. Positioning unit; 6. Image recognition unit; 7. Fixing pin; 701. Elastic element; 702. Protrusion; 703. Extrusion part; 704. Snap-fit ​​groove; 705. Elastic snap-fit ​​part; 8. Air knife. Detailed Implementation

[0023] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0024] It should be noted that all directional indications in the embodiments of this application are only used to explain the relative positional relationship and movement of each component in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0025] In this application, unless otherwise expressly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0026] Furthermore, the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. If the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed in this application.

[0027] like Figure 1-7As shown, a laser flying-shaped welding device for waterproof nuts includes a placement platform 1, which is equipped with three moving units 2 that can move freely in three mutually perpendicular directions within a space, and an XYZ three-axis slide rail structure, specifically including: X-axis slide rail: horizontally arranged on the equipment frame, providing the welding head with a travel range in the X direction. The range is designed according to the workpiece size, with a typical value of 500-1500mm. Y-axis slide rail: horizontally arranged, orthogonal to the X-axis, providing travel in the Y direction; Z-axis slide rail: Vertically arranged and installed at the actuator end of the Y-axis slide rail, providing the welding head with lifting stroke in the Z-direction height direction.

[0028] Each of the three-axis slide rails is driven by a servo motor, and through linear motor transmission, high-precision position control is achieved, with a positioning accuracy of ±0.02mm. The laser flying welding head is fixedly installed at the lower end of the actuator of the Z-axis slide rail and moves in three-dimensional space in conjunction with the three axes.

[0029] The three-axis slide rail can be replaced with: gantry-type three-axis worktable, cantilever three-axis worktable or column-type three-axis worktable; The linear motor drive can be replaced by: servo motor + ball screw drive, linear motor drive, synchronous belt drive or gear and rack drive, or cylinder drive. The arrangement order of the X-axis, Y-axis, and Z-axis can be adjusted according to the available space.

[0030] The final free end of the moving unit 2 is equipped with a laser welding unit 4. The laser welding unit 4 adopts a galvanometer scanning system, and the welding head includes a PFO programmable focusing optical head, which internally contains: X-axis scanning mirror galvanometer: used for high-speed deflection of the laser beam in the X direction; Y-axis scanning mirror galvanometer: used for high-speed deflection of the laser beam in the Y direction; Telecentric focusing lens: focuses the deflected laser beam onto the surface of the workpiece to form a uniform spot within a certain focal length range.

[0031] The laser beam emitted by the laser is transmitted to the PFO optical head through optical fiber. The control system controls the deflection angle of the galvanometer to achieve high-speed scanning and positioning of the laser beam on the workpiece surface.

[0032] During welding, the control system performs the following coordinated actions according to the preset welding program: Large stroke positioning: Three-axis slide rail linkage, the welding head is moved to the predetermined working distance directly above the nut to be welded, which is usually 200-500mm; Micro-scanning welding: The slide rail remains stationary at this position, and the galvanometer drives the laser beam to scan at high speed along the annular / spiral path to complete the welding; Workstation switching: After one nut is welded, the slide rail moves to the position of the next nut and repeats the above action.

[0033] In short, the slide rail is responsible for "moving into position," and the galvanometer is responsible for "scanning and completing the weld." The slide rail remains stationary during the welding process, ensuring welding stability; the galvanometer scans at high speed within a micro-range, ensuring welding speed.

[0034] The placement platform 1 is equipped with positioning units 5 that form a positioning from top to bottom in at least two directions and establishes a coordinate system that is consistent with the moving unit 2. The workpiece and the waterproof nut are located in this coordinate system. The positioning unit 5, the moving unit 2 and the laser welding unit 4 are jointly controlled by the control system 3.

[0035] The system includes an air knife 8 with its air outlet angled to one side. The air knife 8 is used to clean the welding surface with air before welding and to clean the surface as it moves. The air knife device blows air onto the weld joint, causing weld slag to be blown away and preventing it from obstructing laser induction welding.

[0036] Includes an image recognition unit 6 for identifying welding characteristics and welding defects.

[0037] Based on the material and diameter of the waterproof nut, a welding database is established. The database includes at least the welding heat transfer range and cooling time. The laser welding gun moves back and forth along the X-axis, Y-axis, and Z-axis slide rails according to the product welding parameters set on the operating system touch screen and the actions of the buttons on the PLC control panel. It stops sliding and moves when it reaches the specified coordinate.

[0038] The laser welding unit 4 moves synchronously with the air knife 8 to weld multiple weld points on the workpiece in sequence. The position of the subsequent weld point is selected so that the heat transfer range generated by the welding of the previous weld point is staggered. Although the heat generated by laser welding is relatively small, continuous heating will cause thermal deformation of the workpiece. Therefore, the welding sequence is adjusted. The larger the welding diameter, the larger the heat radiation area and the greater the adaptability of the cooling time.

[0039] During the movement of the air-blowing and slag-removing device along with the welding device, the air knife 8 stops blowing when its movement path reaches the heat transfer range corresponding to the weld point and within the cooling time. As the air knife 8 moves, it blows away welding slag with high-speed airflow, simultaneously carrying away heat. Rapid cooling of the weld point without natural cooling can lead to stress concentration, making it prone to cracking later, resulting in seal failure and water leakage.

[0040] The image recognition unit 6 moves synchronously with the laser welding unit 4. During the movement, it identifies defects in the weld that has been completed and cooled. The image recognition unit 6 can also be suspended above the device to fix and identify the weld points.

[0041] The path of laser welding unit 4 is to establish a molten pool along the welding plane. During the forward movement, it turns back and moves at most half the distance forward. The action is repeated until the trajectory of laser welding unit 4 fills the circumference of the waterproof nut.

[0042] This technical solution is an improvement on the laser welding path. The traditional laser welding path is a planar spiral, which has a fast welding efficiency but carries the risk of gas entrapment. Therefore, the moving unit 2 in this application is responsible for vertical movement, and the change in the plane of the galvanometer scanning system makes the welding path three-dimensional. The advantage of the three-dimensional structure is that it can increase the area of ​​the waterproof nut that participates in the welding process. At the same time, the movement from top to bottom can stir the weld pool and accelerate the gas discharge. The repeated movement path formed by moving forward and backward increases the time for the weld pool to melt, thereby facilitating gas discharge and ensuring the sealing of the weld.

[0043] The path of laser welding unit 4 is to establish a molten pool along the welding plane, melt the nut obliquely upward in the direction of establishment, and then break the line to the molten pool plane. The action is repeated until the trajectory of laser welding unit 4 fills the circumference of the waterproof nut. As an improvement on the previous technical solution, the main improvement of this technical solution is that it increases the welding area of ​​the waterproof nut, thereby improving the sealing effect.

[0044] The workpiece mounting position is provided with a through hole equal to the inner diameter of the waterproof nut. The workpiece surface is provided with a recess with a diameter larger than that of the flange of the waterproof nut. The waterproof nut is provided with a fixing pin 7 inside to limit the deformation of the waterproof nut and the workpiece. The fixing pin 7 includes a circumferentially arranged elastic element 701. The elastic element 701 is provided with a protrusion 702 inside. The middle part of the elastic element 701 is slidably connected to a pressing part 703. The pressing part 703 moves upward to press the elastic element 701 and make the elastic element 701 bulge outward. The top end of the pressing part 703 extends above the elastic element 701 and is provided with a snap-fit ​​groove 704. The top end of the elastic element 701 is provided with an elastic snap-fit ​​part 705 that snaps into the snap-fit ​​groove 704. Through this technical solution, the waterproof nut and the workpiece can be quickly positioned by using the elastically deformable elastic element 701, avoiding the displacement of the waterproof nut during the welding process and causing misalignment.

[0045] At least two placement platforms 1 are provided. The movement range of the moving unit 2 covers both placement platforms 1. With two placement platforms 1, they can work alternately, reducing the waiting time for loading and unloading.

[0046] The welding process flow of the laser flying welding waterproof nut equipment based on a 3D master control worktable is as follows: Step 1: Loading and Positioning of Workpieces: The operator loads the workpieces and places them on the positioning fixture of the worktable, aligning the nut mounting holes on the workpieces with the positioning mandrel of the fixture.

[0047] Step 2: Nut Placement: The operator or automatic feeding mechanism places the waterproof nut at the workpiece welding position, with the nut flange facing down and attached to the workpiece surface.

[0048] Step 3: Locating pin clamping and fixing: The drive mechanism pushes the locating pin downwards, and the pin body engages with the locating structure on the workpiece housing. The end face of the pin directly presses against the preset clamping surface of the workpiece housing, fixing the workpiece on the worktable. If the pressure sensor provides feedback on the clamping force, it will send it to the control system to confirm that the preset value has been reached. The locating pin is positioned to avoid the welding areas of each nut, so as not to interfere with the movement of subsequent welding heads.

[0049] Step 4: Slide rail positioning and movement: The control system calls the preset welding parameters such as laser power, welding speed, and scanning path. The three-axis slide rails work together to move the laser flying welding head to the predetermined working distance directly above the first nut. The slide rails then stop and remain stationary.

[0050] Step 5: Flying Welding Scanning Welding: The galvanometer system is activated, and the laser beam moves at high speed along a preset spiral or circular scanning path, forming a circular sealing weld on the contact surface between the nut flange and the workpiece. During the welding process, the slide rail remains stationary.

[0051] Step Six: Station Switching and Cycling: After the nut is welded, the three-axis slide rail moves to the position of the next nut, and steps four and five are repeated until all nuts are welded.

[0052] Step 7: Material Preparation and Quality Inspection: After all welding is completed, the clamping mechanism is released, and the workpiece with the welded nuts is removed. The welding quality can be determined by coaxial vision or manual visual inspection.

[0053] Order restrictions that require special explanation: Step three, "clamping and pressing," must be completed before step five, "welding." Step four, “slide rail positioning”, must be completed before step five, “galvanometer scanning welding”, and the slide rail must remain stationary during the welding process and must not move simultaneously with the galvanometer scanning to avoid laser focus shift. If a multi-station fixture is used, each station is welded in sequence according to a preset order.

[0054] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0055] Furthermore, the technical solutions of the various embodiments can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0056] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A laser flying-shaped welding device for waterproof nuts, comprising a placement platform (1), characterized in that: The placement platform (1) is provided with three moving units (2) that can move freely in three mutually perpendicular directions in space. The final free end of the moving unit (2) is provided with a laser welding unit (4). The laser welding unit (4) adopts a galvanometer scanning system. The placement platform (1) is set in at least two directions to form a positioning unit (5) from top to bottom and establishes a coordinate system that is consistent with the moving unit (2). The workpiece and the waterproof nut are located in this coordinate system. The positioning unit (5), the moving unit (2), and the laser welding unit (4) are all controlled by the control system (3).

2. The laser flying-shaped welding waterproof nut equipment according to claim 1, characterized in that: The air knife (8) includes an air outlet that is biased to one side. The air knife (8) includes cleaning the welding plane with air before welding and cleaning the plane through it during movement.

3. A laser-welded waterproof nut device according to claim 1 or 2, characterized in that: Includes an image recognition unit (6) for identifying welding characteristics and welding defects.

4. The laser flying-shaped welding waterproof nut equipment according to claim 3, characterized in that: Establish a welding database based on the material and diameter of the waterproof nut. The database should include at least the welding heat transfer range and cooling time.

5. The laser flying-shaped welding waterproof nut equipment according to claim 4, characterized in that: The laser welding unit (4) moves synchronously with the air knife (8) to weld multiple weld points on the workpiece in sequence. The position of the subsequent weld point is selected so that the heat transfer range generated by the welding of the previous weld point is staggered. When the air knife (8) moves with the welding device, the air knife (8) stops blowing when the moving path of the air blowing and slag removal device reaches the heat transfer range corresponding to the weld point and within the cooling time.

6. The laser flying-shaped welding waterproof nut equipment according to claim 5, characterized in that: The image recognition unit (6) moves synchronously with the laser welding unit (4). During the movement, it identifies defects in the weld that has been completed and cooled.

7. The laser flying-shaped welding waterproof nut equipment according to claim 1, characterized in that: The path of the laser welding unit (4) is to establish a molten pool along the welding plane. During the forward movement, it turns back and moves forward at most half the distance. The action is repeated until the trajectory of the laser welding unit (4) fills the circumference of the waterproof nut.

8. The laser flying-shaped welding waterproof nut equipment according to claim 7, characterized in that: The path of the laser welding unit (4) is to establish a molten pool along the welding plane, melt the nut obliquely upward in the direction of establishment, and break the line to the molten pool plane, repeating the action until the laser welding unit (4) fills the circumference of the waterproof nut.

9. The laser flying-shaped welding waterproof nut equipment according to claim 1, characterized in that: The workpiece mounting position is provided with a through hole equal to the inner diameter of the waterproof nut, the workpiece surface is provided with a recess with a diameter greater than that of the waterproof nut flange, and the waterproof nut is provided with a fixing pin (7) to limit the extrusion deformation of the waterproof nut and the workpiece. The fixing pin (7) includes a circumferentially arranged elastic element (701), the inside of the elastic element (701) is provided with a protrusion (702), the middle part of the elastic element (701) is slidably connected with a pressing part (703), the pressing part (703) moves upward to press the elastic element (701) and make the elastic element (701) protrude outward, the top end of the pressing part (703) extends to the top of the elastic element (701) and is provided with a snap-fit ​​groove (704), the top end of the elastic element (701) is provided with an elastic snap-fit ​​part (705) snapped into the snap-fit ​​groove (704).

10. The laser flying-shaped welding waterproof nut equipment according to claim 1, characterized in that: At least two placement platforms (1) are provided, and the movement range of the moving unit (2) covers both placement platforms (1).

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