Multi-source laser welding droplet transfer control device and method in severe environment

Abstract

The invention discloses a multi-source laser welding droplet transition control device and method in a severe environment. The multi-source laser welding droplet transition control device comprises a wire feeding assembly, the wire feeding assembly comprises a wire feeder and a wire storage box, an elastic welding wire is arranged in the wire storage box, the wire feeder is provided with a contact tube, and the elastic welding wire extends into the wire feeder and extends out of the contact tube; the optical fiber-semiconductor composite laser welding assembly comprises an optical fiber laser and a semiconductor laser, the optical fiber laser emits optical fiber laser, the semiconductor laser emits semiconductor laser, and a laser head passes through the optical fiber laser and the semiconductor laser; the walking mechanism is provided with a support, and the wire feeder and the dichroscope are installed on the support. The invention discloses underwater local dry-method small drainage equipment. A welding part is placed in the test water tank, and the welding part is located below the waterproof shell. According to the method, the welding efficiency can be effectively improved, the welding quality is improved, and the design of the local dry cavity combines the advantages of underwater wet welding and underwater dry welding.

Description

Technical Field

[0001] The invention relates to the technical field of underwater welding, and in particular to a multi-source laser welding droplet transition control device and method under harsh environments. Background Art

[0002] Laser welding is a connection method that uses laser as a heat source. When a traditional single-mode Gaussian laser is used as a heat source, it has a small core diameter, high energy density, and strong penetration ability. However, it often leads to uneven energy distribution during the welding process. The focus of the laser beam may be too concentrated, resulting in local overheating, or when welding larger joints, the heat input is too small, making it difficult to completely melt the material, affecting the welding quality. In addition, due to the different sensitivities of different materials to heat input, a single heat source mode is difficult to accurately adjust the heat input according to the characteristics of different materials. Especially for materials with high reflectivity such as aluminum alloys and copper alloys, in the traditional laser welding process, the laser energy is often difficult to effectively absorb, resulting in low welding efficiency.

[0003] In recent years, with the increase in human demand for energy, marine resources have been continuously developed. With the deepening of marine resource development and the advancement of marine engineering technology, underwater welding technology has also been continuously developing to adapt to the challenges of deeper waters and more complex environments. Underwater welding technology can be divided into three categories: underwater wet welding, underwater dry welding, and underwater local dry welding. Underwater dry welding requires the design and manufacture of complex pressure chambers, and its equipment is expensive and has poor adaptability; while underwater wet welding, although the equipment is simple, the applicability is strong, and the cost is low, the workpiece is completely exposed to the water during wet welding, which greatly increases the hydrogen content of the weld. This reduces the quality of the weld, which limits the application of wet underwater welding in the repair of key parts. Summary of the invention

[0004] The purpose of the present invention is to provide a multi-source laser welding droplet transfer control device and method under harsh environment to solve the problems existing in the above-mentioned prior art.

[0005] To achieve the above object, the present invention provides the following solution: The present invention provides a multi-source laser welding droplet transfer control device in a harsh environment, comprising:

[0006] A wire feeding assembly, the wire feeding assembly comprising a wire feeding machine and a wire storage box, the wire feeding machine and the wire storage box are connected by a wire, the wire storage box contains an elastic welding wire, the wire feeding machine has a conductive nozzle, the elastic welding wire extends into the wire feeding machine and extends from the conductive nozzle;

[0007] An optical fiber-semiconductor composite laser welding assembly, the optical fiber-semiconductor composite laser welding assembly comprises an optical fiber laser and a semiconductor laser, the optical fiber laser emits an optical fiber laser, the semiconductor laser emits a semiconductor laser, the optical fiber laser and the semiconductor laser are connected to a laser head, the laser head contains a dichroic mirror; a walking mechanism, the walking mechanism has a bracket, the wire feeder and the laser head are mounted on the bracket;

[0008] An underwater local dry small-scale drainage device, comprising a waterproof shell, the waterproof shell is mounted on the laser head, the waterproof shell has a waterproof inner wall, an air supply port is provided on the waterproof shell, the air supply port is connected to a conduit, the conduit is connected to a gas cylinder, and a visual detection and feedback mechanism is installed on the waterproof inner wall;

[0009] A test water tank, wherein a welding part is placed in the test water tank, and the welding part is located below the waterproof shell.

[0010] Preferably, the visual detection and feedback mechanism includes a lens, an image sensor and a control system, the lens and the image sensor are both fixedly connected to the inner water wall, and the lens and the image sensor are connected to the control system via a data cable.

[0011] Preferably, an adjustable opening is provided on the waterproof shell, and the interior of the waterproof shell is a local dry cavity.

[0012] Preferably, the laser head includes a laser emitting device, an optical fiber, a focusing lens, a dichroic mirror, and a focusing system. The laser emitting device contains two coaxially distributed laser beams, the large spot is a semiconductor laser beam λ2, and the smaller spot is a fiber laser beam λ1.

[0013] Preferably, the vertical distance between the laser head and the welding part is between 250 mm and 450 mm.

[0014] Preferably, the vertical distance between the bottom end of the elastic welding wire and the welding part is between 35 mm and 55 mm.

[0015] Preferably, the welding parameters of the optical fiber-semiconductor composite laser welding assembly are: laser power 2000W / 2000W, inner and outer core diameter combination 20 / 400 μm, and processing speed 150 mm / s.

[0016] A multi-source composite laser droplet transfer control method for harsh underwater environments includes the following steps:

[0017] Step 1: Install the elastic welding wire in the wire storage box and adjust the extension length of the elastic welding wire; then install the wire feeding assembly and the optical fiber-semiconductor multi-source composite laser welding assembly at both ends of the walking mechanism via the bracket;

[0018] Step 2: Debug the equipment to ensure that the laser can be generated normally, the elastic welding wire can be fed normally, and the walking mechanism and visual detection and feedback mechanism can operate stably;

[0019] Step 3: Install the weldment, set the welding path, and adjust the height of the laser head after focusing so that the vertical distance between it and the weldment is between 250mm-450mm and ensure the alignment of the light wire;

[0020] Step 4: Open the valve of the gas cylinder and introduce protective gas into the local dry cavity until the water in the local dry cavity is drained;

[0021] Step 5: Input laser power, welding speed and wire feeding speed according to welding requirements;

[0022] Step 6: Start the fiber laser and semiconductor laser to generate laser beams. The lasers are transmitted through the optical fiber. The two laser beams are integrated into a laser head through a dichroic mirror and coaxially distributed. Underwater local dry welding is achieved with the assistance of underwater local dry small drainage equipment.

[0023] Step 7: After welding is completed, turn off the travel mechanism, fiber laser and semiconductor laser, wire feeding assembly and gas cylinder.

[0024] Preferably, the method for obtaining the elastic welding wire is: first, select a welding wire material with better shaping, and obtain the target diameter according to the conventional wire drawing process; secondly, add a twister during the wire drawing process so that the welding wire is twisted during longitudinal stretching to form a spiral shape; finally, use mechanical forming to wrap multiple strands of spiral welding wire together to complete the processing.

[0025] The present invention discloses the following technical effects: during the welding process, the spirally wound elastic welding wire will generate elastic potential energy after being released, and the molten droplets formed by heat melting will be subjected to a downward force, which acts on the molten droplets simultaneously with gravity to promote the droplet to fall off. In addition, the visual sensor is used to instantly observe the molten droplet transition, and the welding wire extension length is adjusted to ensure the alignment of the light wire. In the process of the molten droplet transitioning from short-circuit transition to jet transition, the welding efficiency can be effectively improved, the welding quality can be improved, and the design of the local dry cavity combines the advantages of underwater wet welding and underwater dry welding, further expanding the development prospects of underwater welding. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0027] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0028] Figure 2 A schematic diagram of the spiral welding wire of the present invention;

[0029] Figure 3 This is a schematic diagram of the laser shaping principle of the dichroic mirror of the present invention;

[0030] Figure 4 It is a schematic diagram of the force of the molten droplet of the present invention;

[0031] Among them, 1. Wire storage box; 2. Fiber laser; 3. Semiconductor laser; 4. Gas cylinder; 5. Bracket; 6. Wire feeder; 7. Elastic welding wire; 8. Waterproof outer shell; 9. Waterproof inner wall; 10. Adjustable opening; 11. Local dry cavity; 12. Air supply port; 13. Lens; 14. Image sensor; 15. Laser head; 16. Catheter; 17. Welding parts; 18. Test water tank; 19. Control system; 20. Conductive nozzle. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] Reference Figure 1-4 The present invention provides a multi-source laser welding droplet transfer control device under harsh environment, comprising:

[0035] The wire feeding assembly includes a wire feeding machine 6 and a wire storage box 1. The wire feeding machine 6 and the wire storage box 1 are connected by a wire. The wire storage box 1 contains an elastic welding wire 7. The wire feeding machine 6 has a conductive nozzle 20. The elastic welding wire 7 extends into the wire feeding machine 6 and extends from the conductive nozzle 20.

[0036] The optical fiber-semiconductor composite laser welding assembly includes an optical fiber laser 2 and a semiconductor laser 3. The optical fiber laser 2 emits optical fiber laser, and the semiconductor laser 3 emits semiconductor laser. The optical fiber laser 2 and the semiconductor laser 3 are connected to a laser head 15, and a dichroic mirror is installed inside the laser head 15.

[0037] A traveling mechanism, the traveling mechanism comprises a bracket 5, a wire feeder 6 and a laser head are mounted on the bracket 5;

[0038] The underwater local dry small-scale drainage equipment comprises a waterproof shell 8, which is mounted on a laser head 15, and has a waterproof inner wall 9. The waterproof shell 8 is provided with an air supply port 12, and the air supply port 12 is connected with a conduit 16, and the conduit 16 is connected with a gas cylinder 4. A visual detection and feedback mechanism is installed on the waterproof inner wall 9;

[0039] A test water tank 18 , in which a welding piece 17 is placed, and the welding piece 17 is located below the waterproof housing 8 .

[0040] The elastic welding wire 7 in the device is a spiral welding wire formed by a wire drawing process, so that the welding wire itself stores elastic potential energy. The end of the welding wire is fixed. During underwater welding, the transition of the molten droplet is observed by visual detection and feedback mechanism to achieve light wire alignment, and the adjustment of the wire feeding speed and laser power is coordinated. After the welding wire is melted, it will rotate at a high speed, inducing the release of internal elastic potential energy, affecting the distribution of the force field around it, and thus promoting the transition of the molten droplet. The fiber laser 2 and the semiconductor laser 3 are connected to the laser head 15 through optical fibers.

[0041] The fiber-semiconductor laser head contains a fiber laser and a semiconductor laser. The two laser beams are beam shaped. The fiber laser beam is incident from the transmission surface of the dichroic mirror, and the semiconductor laser beam is incident from the reflection surface, thereby synthesizing into a coaxial beam. Finally, the synthesized beam is passed through a focusing lens or a scanning galvanometer and acts on the weld 17.

[0042] The laser head 15 is connected to the fiber laser 2 and the semiconductor laser 3 respectively through optical fibers.

[0043] According to a further optimized solution, the visual detection and feedback mechanism includes a lens 13, an image sensor 14 and a control system 19. The lens 13 and the image sensor 14 are both fixedly connected to the inner wall of the water. The lens 13 and the image sensor 14 are connected to the control system 19 via a data cable.

[0044] According to a further optimized solution, an adjustable opening 10 is provided on the waterproof housing 8 , and a local dry cavity 11 is provided inside the waterproof housing 8 .

[0045] According to a further optimization scheme, the laser head 15 includes a laser emitting device, an optical fiber, a focusing lens, and a focusing system. The laser emitting device contains two coaxially distributed laser beams, the large spot is a semiconductor laser beam λ2, and the smaller spot is a fiber laser beam λ1.

[0046] Optical fibers can transmit laser energy;

[0047] The focusing system can adjust the focal planes of the two laser beams.

[0048] According to a further optimization scheme, the vertical distance between the laser head 15 and the welding part 17 is between 250 mm and 450 mm.

[0049] According to a further optimized solution, the vertical distance between the bottom end of the elastic welding wire 7 and the welding piece 17 is between 35 mm and 155 mm.

[0050] To further optimize the solution, the welding parameters of the optical fiber-semiconductor composite laser welding assembly are laser power 2000W / 2000W, inner and outer core diameter combination 20 / 400μm, and processing speed 150mm / s.

[0051] In this embodiment, Figure 3 This is the principle diagram of laser shaping by the dichroic mirror of the present invention. Figure 4 Schematic diagram of the force on the molten droplet of the present invention, in which λ1 is the fiber laser beam; λ2 is the semiconductor laser beam; G is gravity; F1 is the electromagnetic force; F2 is the plasma flow force; F3 is the elastic force; and F is the resistance.

[0052] A multi-source composite laser droplet transfer control method for harsh underwater environments includes the following steps:

[0053] Step 1: Install the elastic welding wire 7 on the wire storage box 1, and adjust the extension length of the elastic welding wire 7; then install the wire feeding assembly and the optical fiber-semiconductor multi-source composite laser welding assembly on both ends of the walking mechanism via the bracket 5;

[0054] Step 2: Debug the equipment to ensure that the laser can be normally generated, the elastic welding wire 7 can be normally fed, and the walking mechanism and the visual detection and feedback mechanism can operate stably;

[0055] Step 3: Install the welding part 17, set the welding path, and adjust the height of the laser head 15 after focusing so that the vertical distance between it and the welding part 17 is between 250mm and 450mm and ensure the alignment of the light wire;

[0056] Step 4: Open the valve of the gas cylinder 4 and introduce the protective gas into the local dry chamber 11 until the water in the local dry chamber 11 is drained;

[0057] Step 5: Input laser power, welding speed and wire feeding speed according to welding requirements;

[0058] Step 6: Start the fiber laser 2 and the semiconductor laser 3 to generate laser beams, the laser beams are transmitted through the optical fiber, the two laser beams are integrated into a laser head 15 through a dichroic mirror and coaxially distributed, and underwater local dry welding is achieved with the assistance of underwater local dry small drainage equipment;

[0059] Step 7: After welding is completed, turn off the travel mechanism, fiber laser 2 and semiconductor laser 3, wire feeding assembly and gas cylinder 4.

[0060] According to a further optimization scheme, the method for obtaining the elastic welding wire 7 is as follows: first, a welding wire material with better shaping is selected, and a target diameter is obtained according to a conventional wire drawing process; secondly, a twister is added during the wire drawing process so that the welding wire is twisted during longitudinal stretching to form a spiral shape; finally, multiple spiral welding wires are wound together using mechanical forming to complete the processing.

[0061] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0062] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A multi-source laser welding droplet transfer control device under harsh environment, characterized in that: include: A wire feeding assembly, the wire feeding assembly comprising a wire feeding machine (6) and a wire storage box (1), the wire feeding machine (6) and the wire storage box (1) being connected via a wire, the wire storage box (1) containing an elastic welding wire (7), the wire feeding machine (6) having a conductive nozzle (20), the elastic welding wire (7) extending into the wire feeding machine (6) and extending from the conductive nozzle (20); An optical fiber-semiconductor composite laser welding assembly, the optical fiber-semiconductor composite laser welding assembly comprising an optical fiber laser (2) and a semiconductor laser (3), the optical fiber laser (2) emitting optical fiber laser, the semiconductor laser (3) emitting semiconductor laser, the optical fiber laser (2) and the semiconductor laser (3) being connected to a laser head (15), the laser head (15) containing a dichroic mirror; A walking mechanism, the walking mechanism having a bracket (5), and the wire feeder (6) is mounted on the bracket (5); An underwater local dry small-scale drainage device, the underwater local dry small-scale drainage device comprising a waterproof shell (8), the waterproof shell (8) being mounted on the laser head (15), the waterproof shell (8) having a waterproof inner wall (9), an air supply port (12) being provided on the waterproof shell (8), the air supply port (12) being connected to a conduit (16), the conduit (16) being connected to a gas cylinder (4), and a visual detection and feedback mechanism being mounted on the waterproof inner wall (9); A test water box (18), wherein a welding piece (17) is placed in the test water box (18), and the welding piece (17) is located below the waterproof shell (8).

2. The multi-source laser welding droplet transfer control device in a harsh environment according to claim 1, characterized in that: The visual detection and feedback mechanism comprises a lens (13), an image sensor (14) and a control system (19); the lens (13) and the image sensor (14) are both fixedly connected to the inner wall of the water; and the lens (13) and the image sensor (14) are connected to the control system (19) via a data line.

3. The multi-source laser welding droplet transfer control device under harsh environment according to claim 1, characterized in that: An adjustable opening (10) is provided on the waterproof shell (8), and a local dry cavity (11) is formed inside the waterproof shell (8).

4. The multi-source laser welding droplet transfer control device in a harsh environment according to claim 1, characterized in that: The laser head (15) comprises a laser emitting device, an optical fiber, a focusing lens, a dichroic mirror, and a focusing system. The laser emitting device contains two coaxially distributed laser beams, the large light spot is a semiconductor laser beam λ2, and the smaller light spot is a fiber laser beam λ1.

5. The multi-source laser welding droplet transfer control device in a harsh environment according to claim 1, characterized in that: The vertical distance between the laser head (15) and the welding piece (17) is between 250 mm and 450 mm.

6. The multi-source laser welding droplet transfer control device in a harsh environment according to claim 1, characterized in that: The vertical distance between the bottom end of the elastic welding wire (7) and the welding piece (17) is between 35 mm and 155 mm.

7. The multi-source laser welding droplet transfer control device in a harsh environment according to claim 1, characterized in that: The welding parameters of the optical fiber-semiconductor composite laser welding assembly are: laser power 2000W / 2000W, inner and outer core diameter combination 20 / 400μm, and processing speed 150mm / s.

8. A multi-source composite laser droplet transfer control method for harsh underwater environments, applied to the multi-source composite laser welding droplet transfer control device as claimed in any one of claims 1 to 7, characterized in that: The steps include: Step 1: Install the elastic welding wire (7) on the wire storage box (1), and adjust the extension length of the elastic welding wire (7); then install the wire feeding assembly and the optical fiber-semiconductor multi-source composite laser welding assembly on both ends of the walking mechanism via the bracket (5); Step 2: Debug the equipment to ensure that the laser can be normally generated, the elastic welding wire (7) can be normally fed, and the walking mechanism and the visual detection and feedback mechanism can operate stably; Step 3: Install the welding part (17), set the welding path, and adjust the height of the laser head (15) after focusing so that the vertical distance between the laser head (15) and the welding part (17) is between 250 mm and 450 mm and ensure the alignment of the light wire; Step 4: Open the valve of the gas cylinder (4) and introduce protective gas into the local dry chamber (11) until the water in the local dry chamber (11) is drained; Step 5: Input laser power, welding speed and wire feeding speed according to welding requirements; Step 6: Start the fiber laser (2) and the semiconductor laser (3) to generate laser beams, the laser beams are transmitted through the optical fiber, the two laser beams are integrated into a laser head (15) through a dichroic mirror and are coaxially distributed, and underwater local dry welding is achieved with the assistance of underwater local dry small drainage equipment; Step 7: After welding is completed, turn off the travel mechanism, the fiber laser (2), the semiconductor laser (3), the wire feeding assembly and the gas cylinder (4).

9. The multi-source composite laser droplet transfer control method for harsh underwater environments according to claim 8 is characterized in that: The method for obtaining the elastic welding wire (7) is as follows: firstly, a welding wire material with good shaping properties is selected, and a target diameter is obtained according to a conventional wire drawing process; secondly, a twister is added during the wire drawing process so that the welding wire is twisted during longitudinal stretching to form a spiral shape; and finally, multiple spiral welding wires are wound together using mechanical forming to complete the processing.

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